engdyn 2014.1 manual

RD.14/185701.1

Ricardo Software Engine Dynamics

Simulation

ENGDYN

DOCUMENTATION/USER MANUAL VERSION 2014.1

May 2014

Contents

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Contents

WHATS NEW IN ENGDYN 2014.1? .............................................................................................. V

A. KNOWLEDGE CENTRE ........................................................................................................... 1

1 WHAT IS ENGDYN? ................................................................................................................... 1 2 TUTORIALS .................................................................................................................................. 3

2.1 Tutorial 1: An Introduction to ENGDYN Concept Crankshaft Analysis .......................... 3 2.2 Tutorial 2: Crankshaft Dynamic Analysis ........................................................................ 43 2.3 Tutorial 3: NVH Analysis ................................................................................................. 79 2.4 Tutorial 4: Block Stress Analysis ................................................................................... 125 2.5 Tutorial 5: Crankshaft Stress Analysis .......................................................................... 149 2.6 Tutorial 6: EHL Big End Bearing Analysis ..................................................................... 183

B. HELP ..................................................................................................................................... 213

1 USING ENGDYN .................................................................................................................... 213 1.1 Overview ....................................................................................................................... 213 1.2 Getting Started .............................................................................................................. 213 1.3 Description of the Main Panel ....................................................................................... 214

2 ENGDYN MODELS ................................................................................................................. 223 2.1 Overview ....................................................................................................................... 223 2.2 ENGDYN Co-ordinate System ...................................................................................... 223 2.3 Finite Element Model Data ............................................................................................ 224 2.4 Crank Train Model ......................................................................................................... 225 2.5 Cylinder Block Model .................................................................................................... 231 2.6 Journal Bearing Oil Film Model ..................................................................................... 232 2.7 In-Cylinder Model .......................................................................................................... 235 2.8 Gas Cylinder Pressure .................................................................................................. 236

3 MODEL GENERATION ............................................................................................................... 237 3.1 General .......................................................................................................................... 237 3.2 Configure Engine .......................................................................................................... 237 3.3 Define Models ............................................................................................................... 246 3.4 Editing the Crank Train Model ....................................................................................... 253 3.5 Editing the Cylinder Block Model .................................................................................. 324

4 SOLUTION ............................................................................................................................... 353 4.1 General .......................................................................................................................... 353 4.2 Lubrication ..................................................................................................................... 354 4.3 Loading .......................................................................................................................... 359 4.4 Evaluate Solution .......................................................................................................... 374

5 POST-PROCESSING ................................................................................................................. 391 5.1 General .......................................................................................................................... 391 5.2 Selecting Loadcases ..................................................................................................... 391 5.3 Selecting Crank Train Modes ........................................................................................ 392 5.4 Plotting EHL Results ..................................................................................................... 393 5.5 Plotting Results ............................................................................................................. 402 5.6 Exporting Results .......................................................................................................... 407 5.7 Backsubstitution ............................................................................................................ 413 5.8 Animate Results ............................................................................................................ 413

6 CRANK SHAFT STRESS ANALYSIS ............................................................................................. 419 6.1 Overview ....................................................................................................................... 419 6.2 Using the Graphical User Interface ............................................................................... 434

7 CYLINDER BLOCK ANALYSIS ..................................................................................................... 463 7.1 Overview ....................................................................................................................... 463

KNOWLEDGE CENTRE What is ENGDYN?

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7.2 Frequency Response and Acoustic Analysis ............................................................... 463 7.3 Quasi-Static Analysis .................................................................................................... 468 7.4 Using the Graphical User Interface .............................................................................. 476

8 ADDITIONAL POST-PROCESSING .............................................................................................. 499 8.1 Overview ....................................................................................................................... 499 8.2 Quasi-Static Analysis of a Piston .................................................................................. 499 8.3 Applying Loads to a Finite Element Model of a Connecting Rod ................................. 500

C. COMMAND FILES ............................................................................................................... 505

1 PRE-PROCESSOR COMMANDS ................................................................................................. 506 1.1 AXES ............................................................................................................................ 507 1.2 BEARING ...................................................................................................................... 508 1.3 BLOCK .......................................................................................................................... 515 1.4 CHILD ........................................................................................................................... 519 1.5 CONROD ...................................................................................................................... 521 1.6 CRANK ......................................................................................................................... 525 1.7 CYLINDER .................................................................................................................... 530 1.8 DAMPER ...................................................................................................................... 534 1.9 DIRECTION .................................................................................................................. 539 1.10 DRIVE ........................................................................................................................... 540 1.11 ELEMENT ..................................................................................................................... 541 1.12 ENGINE ........................................................................................................................ 548 1.13 IN_CYLINDER .............................................................................................................. 549 1.14 LINK .............................................................................................................................. 550 1.15 LOADING ...................................................................................................................... 552 1.16 LUBRICANT ................................................................................................................. 557 1.17 MASS ............................................................................................................................ 559 1.18 MATERIAL .................................................................................................................... 564 1.19 MOUNT ......................................................................................................................... 565 1.20 NODE............................................................................................................................ 567 1.21 OPEN ............................................................................................................................ 568 1.22 PROFILE ...................................................................................................................... 569 1.23 TITLE ............................................................................................................................ 572

2 SOLVER COMMANDS ............................................................................................................... 573 2.1 BEARING ...................................................................................................................... 574 2.2 BLOCK .......................................................................................................................... 575 2.3 COUPLING ................................................................................................................... 576 2.4 DAMPING ..................................................................................................................... 578 2.5 LUBRICANT ................................................................................................................. 580 2.6 OPEN ............................................................................................................................ 581 2.7 SOLUTION ................................................................................................................... 582

3 POST-PROCESSOR COMMANDS ............................................................................................... 592 3.1 CRANK_ANALYSIS ...................................................................................................... 592 3.2 BLOCK_ANALYSIS ...................................................................................................... 606

D. THEORY ............................................................................................................................... 616

1 INTRODUCTION ........................................................................................................................ 616 2 STATIC SOLUTIONS ................................................................................................................. 617

2.1 Determinate Solution .................................................................................................... 617 2.2 Indeterminate Solution .................................................................................................. 617

3 DYNAMIC SOLUTIONS .............................................................................................................. 618 4 BEARING MODEL ..................................................................................................................... 619

4.1 Mobility Method ............................................................................................................. 621 4.2 Solution of Reynolds Equation on a Computational Mesh ........................................... 629

Contents

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4.3 Oil Viscosity ................................................................................................................... 641 4.4 Boundary Lubrication Model ......................................................................................... 643 4.5 Integration of Bearing Forces and Moments ................................................................. 645 4.6 Bearing Thermal Balance Solution ............................................................................... 645 4.7 Compliant Model for EHD Bearing ................................................................................ 650 4.8 Nomenclature ................................................................................................................ 653 4.9 References .................................................................................................................... 655

E. APPENDICES ....................................................................................................................... 657

1 CALCULATION OF CRANKSHAFT STIFFNESS USING THE FINITE ELEMENT METHOD ....................... 657 1.1 Overview ....................................................................................................................... 657 1.2 Calculation of Crankshaft Web Stiffnesses ................................................................... 657 1.3 Calculation of Crankshaft Element Stiffnesses ............................................................. 660

2 A METHOD OF EVALUATING THE MASS AND STIFFNESS PROPERTIES OF A FLYWHEEL ................. 663 2.1 Overview ....................................................................................................................... 663 2.2 Modelling Approach ...................................................................................................... 663 2.3 Calculation of Mass and Stiffness Properties ............................................................... 663

3 CALCULATION OF MATERIAL STRENGTH PROPERTIES FOR CRANKSHAFT STRESS ANALYSIS ....... 669 3.1 Overview ....................................................................................................................... 669 3.2 Base Strengths .............................................................................................................. 669 3.3 Elevated Strengths ........................................................................................................ 669

4 CALCULATION OF STRESS CONCENTRATION FACTORS FOR CRANKSHAFT STRESS ANALYSIS ...... 671 4.1 Overview ....................................................................................................................... 671 4.2 Nomenclature ................................................................................................................ 671 4.3 Journal Fillets ................................................................................................................ 671 4.4 Oil Hole Breakouts ........................................................................................................ 673

5 TREATMENT OF NOTCH SENSITIVITY IN CRANKSHAFT STRESS ANALYSIS .................................... 677 5.1 Overview ....................................................................................................................... 677 5.2 Treatment in Finite Element Analysis ........................................................................... 678

6 USING OUTPUT FROM THE RICARDO PROGRAM VALDYN AND TVFORCED IN CRANKSHAFT STRESS CALCULATIONS ................................................................................................................... 681

6.1 Using VALDYN for Crankshaft Stress Calculations ...................................................... 681 6.2 Using TVFORCED for Crankshaft Stress Calculations ................................................ 684

7 SAFETY FACTOR CALCULATIONS .............................................................................................. 687 7.1 The Goodman Diagram ................................................................................................. 687 7.2 Goodman Diagram Construction................................................................................... 688 7.3 Equivalent Stress Options ............................................................................................. 689 7.4 Multi-axial Fatigue Safety Factor................................................................................... 691 7.5 Dang Van Fatigue Safety Factor ................................................................................... 692 7.6 LinearSWT Safety Factor .............................................................................................. 695 7.7 Cycles to Failure Calculation ......................................................................................... 696

8 RADIATED NOISE CALCULATIONS ............................................................................................. 699 8.1 Overview ....................................................................................................................... 699 8.2 Acoustic Equations and the Rayleigh Integral .............................................................. 699 8.3 Radiation Efficiency ....................................................................................................... 703 8.4 Multiple Face Sets ......................................................................................................... 703

9 MODAL FREQUENCY RESPONSE CALCULATIONS ....................................................................... 705 9.1 Overview ....................................................................................................................... 705 9.2 Calculation of Modal Contributions and Vibration Response ........................................ 705

10 APPLYING LOADS PREDICTED BY VALDYN TO THE CYLINDER BLOCK AND CRANKSHAFT MODELS 707

10.1 Overview ....................................................................................................................... 707 10.2 Writing Force Profile Data From VALDYN .................................................................... 707 10.3 Applying Force Profile Data to the ENGDYN Model ..................................................... 710


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10.4 Applying Force Profile Data to the Cylinder Block Model ............................................. 710 11 ASCII DATA FILE FORMAT READ BY SDF_READ_ASCII() ........................................................ 715

11.1 Introduction ................................................................................................................... 715 11.2 Format........................................................................................................................... 715

12 MATUTIL .......................................................................................................................... 720 12.1 Overview ....................................................................................................................... 720 12.2 Using matutil ................................................................................................................. 720 12.3 Theory ........................................................................................................................... 727

Whats New in ENGDYN 2014.1?

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Whats New in ENGDYN 2014.1? Enhancements Feature Documentation

Updated NVH Analysis Tutorial Knowledge Centre Tutorial 3

Updated Block Stress Analysis Tutorial Knowledge Centre Tutorial 4

Various bug fixes Release Notes


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A. KNOWLEDGE CENTRE

1 What is ENGDYN? ENGDYN is a computer program for analysing the dynamics of the engine and in particular the dynamics of the crank train and its interaction with the cylinder block. ENGDYN provides a number of different solution techniques for predicting engine dynamics using models of varying degrees of sophistication. The crank train and cylinder block models can either be defined as rigid, compliant and dynamic. In its simplest form ENGDYN can be used to perform a statically-determinate solution, whilst in its most sophisticated form it can be used to predict the time-domain response of the 3-dimensional vibration of the coupled crank train and cylinder block system with non-linear oil films at each of the main journal bearings. This flexibility enables the user to generate an engine model and to perform a solution to meet his particular needs. ENGDYN provides a Graphical User Interface (GUI) to enable the user to perform the model generation, solution and results presentation phases within an easy to use graphical environment. The GUI contains a built-in units converter and automatically converts parameters from their defined units to SI units. Alternatively, for the more experienced user and to provide compatibility with models that were generated before the development of the GUI, ENGDYN also provides a non-graphical environment that uses command data files for model generation, solution and results presentation. ENGDYN uses a Ricardo binary standard data file to store both the model and the results of the solution. When saving, ENGDYN stores the model at the current position and as the model is built the file is appended to. Similarly, once a simulation has been executed, the results are appended to the file. Crank train simulation using ENGDYN consists of three stages. Firstly, the engine model must be generated and consists of the crank train and cylinder block. The GUI is designed such that the user builds the model in a sequential order by using a series of forms. Once the key engine parameters have been defined ENGDYN draws the reduced model of the crank train that the user can pick to edit particular items. Finite element models of the crank train and cylinder block can be viewed with the reduced models. ENGDYN performs its own finite element solution, to evaluate for example crankshaft web stiffness. Once the model has been generated, the GUI can be used to generate the input command file for performing a solution. This file contains the engine conditions to be simulated, the type of solution to be performed, the models to be included in the solution and the solution parameters for controlling the solution. The solver performs the simulation and appends the results to the binary standard data file. An ASCII file is also written summarising the results of the solution for each load case. Finally, once the simulation has finished running, the user is able within the GUI to select load cases for post-processing. The interface lists all the load cases within the file and for each load case gives the solution parameters defined for that case. The interface currently allows simulation results to be plotted, animated and exported to an ASCII file.


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The interface has a built in library of pre-defined plots that enables the user to rapidly view the results. The plots can either be printed or saved to file. The user is also able to export results to an ASCII file to allow further data manipulation by the user not currently supported by ENGDYN. In addition, for solutions in which the displacement or vibratory motion of the engine is predicted, the results can be animated interactively in both the time and frequency domains. In addition, the loads calculated by ENGDYN can be used to evaluate the stresses and fatigue safety factors at the critical locations of the crankshaft and can also be applied to the cylinder block either in the frequency domain to perform modal frequency response and acoustic analyses or in the time domain to perform quasi-static analyses. The user can then perform further analyses if required. A new solution can be executed and on completion the results are appended to the binary standard data file.

KNOWLEDGE CENTRE Tutorials

Tutorial 1: An Introduction to ENGDYN Concept Crankshaft Analysis

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2 Tutorials

2.1 Tutorial 1: An Introduction to ENGDYN Concept Crankshaft Analysis

2.1.1 Introduction

Objective:

Gain a general understanding of how to use ENGDYN GUI and carry out the simplest analysis using user defined (non-FE) data. The user will perform statically determinate analysis to calculate loads for

both a Mobility and Hydrodynamic (HD) bearing analysis User will also gain experience in using plotting and animation features.

Items covered:

Building the engine model

Bearing analysis using the Mobility Method

Bearing analysis using the Hydrodynamic Method (Finite Volume Solver)

Plotting and Animation Estimated duration:

KNOWLEDGE CENTRE Tutorials Tutorial 1: An Introduction to ENGDYN Concept Crankshaft Analysis

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The data for this tutorial was obtained from a benchmark study of this engine

by Ricardo. Required Files:

..\Ricardo\2014.1\Products\ENGDYN\Tutorials\v6\cp700.PRES ..\Ricardo\2014.1\Products\ENGDYN\Tutorials\v6\cp1000.PRES ..\Ricardo\2014.1\Products\ENGDYN\Tutorials\v6\cp2000.PRES ..\Ricardo\2014.1\Products\ENGDYN\Tutorials\v6\cp4000.PRES

2.1.2 Getting Started

Copy the necessary files from the example directory to a working directory and ensure that you have write permissions for all the files.

Start engdyn

On Unix or Linux platforms simply type engdyn On windows click on the shortcut, otherwise go to Start>Programs>Ricardo

Software>2014.1>Mechanical Suite>ENGDYN>ENGDYN

2.1.3 Building engine model

2.1.3.1 Configure Engine

Select Configure Engine from the buttons on the left side of the Main Panel

Complete the Engine Configuration Panel as shown



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Note that warning messages will pop up as long as all the needed data is not properly entered. If you close the Engine Configuration Window while warning messages still appear, all the data will be lost. Therefore, please make sure all the data is properly entered before closing this window.


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To enter the main bearings non-uniform information, the user must use the mouse to click on the red dimensions in the diagram in the panel.

On completion select Apply which will display

Press OK button. The crankshaft model will appear in the Main Panel as shown

Use CTRL + middle mouse in order to zoom in and zoom out Use SHIFT + middle mouse in order to rotate

2.1.3.2 Define Models

Select Define Models from the buttons on the left side of the GUI.


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Complete the model definitions for the crankshaft, cylinder block, in-cylinder and connecting rod as shown

2.1.3.3 Edit Cranktrain

Select Edit Cranktrain from the buttons on the left side of Main Panel.

Items are edited by selecting from the list on the left of the panel Many items shown in the panel below need not be defined due to the type of

model being edited.

Highlight Crank Web as shown This will then display each of the web elements in green

Click on Select All



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Each of the web elements will then turn red

Click on Edit Selected to display the Web Panel

Complete the Web panel as shown below

The web thickness and journal lengths are taken from the data entered in the

configure engine section The Web panel allows counterweight data to be entered for the crank webs The counterweight geometry is defined only for balancing the crankshaft at a

later stage, NOT for defining the mass properties. As we shall be defining the mass properties explicitly in this example (rather than using an FE model), we do not require any counterweight data to be added

Select OK

Highlight Big End Bearing This will then display each of the pin journal nodes in green

Click on Select All Each of the main journal nodes will then turn red


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Click on Edit Selected to display the Pin Bearing Panel

Complete the Bearing panel as shown below

The oil hole angular position can be defined either using the Height column (as in this case) or using the Position column. The value not supplied is calculated from the journal diameter.

The remaining tabs (Mesh, Material, Profile) need not and cannot be edited because the model type is Mobility. These tabs are only required with Hydrodynamic or Elastohydrodynamic models

Select OK

Highlight Main Bearing

Click on Select All to highlight all main bearing nodes

Click on Edit Selected to display the Main Bearing Panel

Complete the Main Bearing Panel as shown



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The Oilholes tab cannot be edited because the bearing is fed by a groove. The remaining tabs (Mesh, Material, Profile, Stiffness) need not and cannot

be edited because the model type is Mobility. These tabs are only required with Hydrodynamic or Elastohydrodynamic models

Select OK

Highlight Connecting Rod

Click on Select All to select all pin journal nodes

Click on Edit Selected

Complete the Conrod panel as shown.

Select OK

Highlight Piston


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Complete the Piston panel as shown.

Highlight Cranknose Assembly In this instance since there is only one cranknose there is no need to use

Select All or to pick using the mouse. The program automatically selects the cranknose and displays it in red

Select Edit Selected to display the Cranknose Assembly Panel

Complete the Cranknose Assembly Panel as shown

The Element Length field does not have to be entered accurately because the crankshaft is not modelled using an FE model. This data will only be used for showing a representative model on the screen.

Select OK

Highlight Flywheel Assembly



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Again there is no need to use Select All or to pick using the mouse. The program automatically selects the cranknose and displays it in red

Select Edit Selected to select the Flywheel Assembly Panel

Complete the Flywheel Assembly panel as shown

Select on OK

Highlight Lumped Masses


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The nodes are numbered from the front of the crankshaft, number one representing the damper hub

For a rigid or compliant crankshaft model it is not necessary to define masses at all the nodes

Select node 3 using the left mouse button. This is the web node of the first web on the crankshaft axis. Alternatively nodes can be picked by dragging the mouse with the left button

held down To make multiple selections, hold the SHIFT key down whilst selecting nodes

Select Edit Selected to display the Lumped Mass Panel as shown

Complete the panel as shown

Data can either be defined with known properties or using a geometric shape

and can be with respective to a Cartesian or Polar coordinate system.

Select the Add or Update button to add the data Multiple masses can be added to each node

Select OK The mass will be shown in white



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Repeat this process defining the masses as listed in the table below.

Node Description Mass

x y z

[kg] [mm] [mm] [mm]

3 Web 1 counterweight 2.610 0.470 -23.220 10.270

5 Pin 1 mass 0.408 -0.875 0.000 0.000

8 Pin 2 mass 0.408 0.875 0.000 0.000

10 Web 2 counterweight 1.500 -0.075 -20.460 7.247

12 Web 3 counterweight 1.760 0.300 13.090 12.280

14 Pin 3 mass 0.408 -0.875 0.000 0.000

17 Pin 4 mass 0.408 0.875 0.000 0.000

19 Web 4 counterweight 1.760 -0.050 12.280 13.100

21 Web 5 counterweight 1.500 0.297 7.215 -20.510

23 Pin 5 mass 0.408 -0.875 0.000 0.000

26 Pin 6 mass 0.408 0.875 0.000 0.000

28 Web 6 counterweight 2.630 -0.051 10.140 -22.720

Offset

When all lumped masses have been entered the model should appear as shown

Click on Define Material to display the Crankshaft Material Properties Panel


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Complete the Crankshaft Material Properties Panel as shown

Select on OK

Click on Calculate Masses The message Calculation of mass properties completed successfully,

Balance Not Set should appear in the message box at the bottom of the Main Panel.

Click on Set Balance to display the Primary Balance Panel as shown

No additional balancing is required because the Lumped Masses include the effect of balancing the crankshaft.

Click on Assemble Model The message Model assembly completed successfully, Block not

assembled should appear in the message box at the bottom of the Main Panel

Click on OK

Click on the Dismiss button of the Edit Cranktrain panel



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The message Ready to Perform Solution should appear in the message box at the bottom of the Engdyn screen

Save the model

2.1.4 Bearing analysis using the Mobility Solution

2.1.4.1 Define Lubricant Properties

Click on Lubrication button from the buttons on the left hand side of the Main Panel

Use the Browse button to select the lubricant SAE5W30 from the database By default the program should initially select the database directory at

..\Ricardo\2014.1\Common\Materials\Lubricants This database contains the most common lubricants

Use either Add or Update to add the lubricant

Click on OK

2.1.4.2 Define Loading Conditions

The cylinder pressure diagram and any additional loadings (e.g., loads from Valdyn and gravity forces) are entered in this step.


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Click on the Loading button on the Main Panel

This will display the Loading Definition Panel as shown

A number of different loading maps can be defined, Full Load, Part Load and No Load.

The solver will interpolate at speeds between those defined using this panel

Type in a speed of 750 rev/min

Position the mouse over the File Name column and use the right button to display the pop-up menu. Use Select Pressure file to select the file cp700.PRES from your working directory. The panel will appear as shown.

You may wish to remove the pathname in front of the file.



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The pressure file can contain just pressures (at equal intervals) or as in this case pressures and angles.

You may wish to inspect and understand the file using an appropriate editor

Define the Ambient and Crankcase Pressure as 1.0 bar The crankcase pressure is only currently used for Hydrodynamic and

Elastohydrodynamic bearing models to define the boundary condition at the edge of the bearing

Add an extra line to the table by positioning the mouse over the left column (line number) and using the right button to display a pop-up. Select Insert Row After


The remaining tabs, Force Profile, Force Equation and Distortion need not be completed for this tutorial.

When a model has a piston pin offset or crank offset, the cylinder pressure diagram is often redefined by ENGDYN internally to have the interval angle reduced to 0.25 degrees (sometimes lower) by a process of interpolation. This is because the offsets cause the TDC angle to change slightly and it is important to have an accurate cylinder pressure definition at TDC to achieve good results.

Use the Plot button to display the applied loads and to plot for example the Indicated Torque as shown


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This diagram is not particular smooth. If the indicated torque curve is known then you can factor each diagram using the Factor column.

Enter 400[N.m]/T at 3000 rev/min and see the graph change. Set back to 1.0 before proceeding

Click on OK

Save the model using the File menu from the top of the Main Panel

2.1.4.3 Evaluate Solution

We now have sufficient data to proceed with an analysis.

Click on the Evaluate Solution button on the Main Panel



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The panel will appear as shown. No changes are required We can only perform a Determinate solution because we have only built a

rigid model

Select the Cases tab

Click on Select button to add an arithmetic speed sweep series of engine speeds to the loadcases


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Select the Bearing Model tab


The remaining tabs do not need to be completed for a solution with a rigid block and crankshaft.

Select Solve Directly.

The analysis should take a few seconds to run. On completion of the analysis the summary file .EDSUM will be

written. This file contains summary data for the solution. Open this file with an

appropriate editor to view the results.

Now that the analysis had been completed, the results can be plotted. The next two steps show how to plot the results of the completed analysis.

2.1.4.4 Select Loadcases



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Click on the Select Loadcases button on the Main Panel

Select the loadcases as shown

This table displays the solution parameters defined for each loadcase Loadcases are grouped by Solution Type and by Loading

2.1.4.5 Plot Results

Click on the Plot results button on the Main Panel

Select Journal Bearing from the Model list and highlight the Subset, Plot and Results.


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Move the panel so that the crankshaft can be seen on the screen as shown

As with editing the cranktrain each of the main journal nodes are displayed in green

Select main bearings 1 and 2 by dragging the mouse whilst keeping the left button held down Each of the main journal nodes will then turn red Alternatively select the nodes by using the Select All button or by selecting

each node individually and using the SHIFT key

Click on the Apply button to display the Graph Panel.

Use the Page Up and Page Down buttons to view the following graphs



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2.1.4.6 Exporting the data

In addition to the pre defined plots ENGDYN also has the option of exporting formatted data into ASCII files

Click on the Export Results button on the left hand side of the software and the following panel appears

As an example, we are going to export the journal bearing load at the main bearing 1.

Select JOURNAL_BEARING_LOADS in the dataset and Main bearings on the subset

Select the bearing 1 in the 3D viewport

Name the ASCII file with something suitable, such as bearing_load

Change format to block and select only Y & Z directions

Click Apply



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Two new .EDRES files, for loadcase 1 & 4, were written to your directory. Their content can be reviewed through an appropriate text editor.

2.1.5 Bearing analysis using the Hydrodynamic Solution

Main bearing number 1 will be modified to solve using the Hydrodynamic model

2.1.5.1 Copy the ENGDYN Model to a new filename

Use the File menu on the Main Panel to Copy Design This will copy all model and loading data

2.1.5.2 Set up Main Bearing 1 as a Hydrodynamic Model

Click on the Edit Cranktrain button on the Main Panel to display the Edit Cranktrain Panel

Highlight Main Bearing as shown


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This will then display each of the main journal nodes in green

Select main bearings 1 by dragging the mouse whilst keeping the left button held down or by picking the node. The main journal nodes will turn red

Select Edit Selected to display the Main Bearing Panel

Change the Model Type to Hydrodynamic as shown



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For a Hydrodynamic Model Type it is necessary to use the Mesh and Material tabs to define additional data for this model.

In this tutorial we will assume the bearing and journal are circular, and therefore it is not necessary to define a profile using the Profile tab.

Select the Mesh tab, and define a mesh 11 x 73

Select the Material tab

This material is used for the boundary lubrication model It is necessary to define the journal material and the material of the bearing

lining

Click on Define adjacent to Bearing Material, to display the Material Properties Panel.


These data values are typical for a bearing surface. These data are only used by the boundary lubrication model.


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Asperity RMS Height h, Density and Asperity radius can be calculated

from measured data using the Ricardo MATUTIL program supplied with the Ricardo Software installation which is described in Appendix 12.

The Select button is used to select materials that have previously been defined or that are in the SFE file of finite element model defining the bearing.

Select OK

Click on Define adjacent to Journal Material, to display the Material Properties Panel as shown.

The journal material defaults to the crankshaft material STEEL which was defined in Section 2.1.3.3

Complete the panel as shown The asperity data can be calculated from surface profile measurements using

the MATUTIL program supplied with the Ricardo Software installation which is described in Appendix 12.

Select OK and enter the wear and friction coefficients for the bearing surface as shown



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Select OK

Click on Define Material to display the Crankshaft Material Properties Panel

Select OK No edits are required since we have defined the material previously.

Click on Calculate Masses The message Calculation of mass properties completed successfully,

Balance Not Set should appear in the message box at the bottom of the Main Panel.

Click on Set Balance No additional balancing is required because the Lumped Masses include the

effect of balancing the crankshaft.

Click on Assemble Model The message Model assembly completed successfully, Block not

assembled should appear in the message box at the bottom of the Main Panel

Click on OK

Click on the Dismiss button of the Edit Cranktrain panel The message Ready to Perform Solution should appear in the message box

at the bottom of the Engdyn screen The model should appear as shown.


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2.1.5.3 Evaluate Solution

We now have sufficient data to proceed with an analysis.


The Evaluate Solution Panel will appear.



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Set the End Angle to 1440 deg This is equivalent to two and a half cycles and should be sufficient to obtain a

converged solution of the main bearing HD solution

Select the Cases tab and define a single speed of 3000 rev/min as shown

Select the Bearing Model tab and complete the panel as shown


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The remaining tabs do not need to be completed for this solution since the other parameters are related to indeterminate or dynamic analyses.

Select Define Oil Temps to display the Bearing Oil Temperatures Panel

We will assume that the temperature of the oil in the bearing is at the inlet

temperature.

Select OK

Select Solve Directly on the Evaluate Solution Panel.



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On completion of the analysis the summary file .EDSUM will be written.

This file contains summary data for the solution. Open this file with an appropriate editor to view the results.

The solution time for this solution on a Pentium M 1.4 GHz Laptop with 512 Mbytes RAM is approximately 9 minutes.

Solution time will be dependent on how heavily loaded the bearing is and whether there is any boundary lubrication occurring.

This model at this engine condition has some asperity contact which can be viewed by selecting Contact Pressure when animating (See 2.1.5.5)

The memory usage is 67 Mbytes.

2.1.5.4 Select Loadcases

Click on the Select Loadcases button on the Main Panel

Highlight the only speed selectable (3000 revs/min) and then select OK

2.1.5.5 Animate Results

Click on the Animate Results button on the Main Panel

Complete the Animation Results panel as shown


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Zoom onto main bearing 1 Hold down both the Ctrl button on the keyboard and the middle mouse

button whilst dragging the mouse.

Change the angle of the view Hold down both the Shift button on the keyboard and the middle mouse

button whilst dragging the mouse.

Click on the Play button of the animation control toolbar to animate the results as shown.



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Experiment with looking at different results by selecting various parameters from the Animation Results Panel

Close the animation panels and exit the program.


Tutorial 2: Crankshaft Dynamic Analysis

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2.2 Tutorial 2: Crankshaft Dynamic Analysis

2.2.1 Introduction

Objective:

To build an ENGDYN model suitable for performing a dynamic analysis of a crankshaft. Introducing FE models of the crankshaft The results of this tutorial are used as input to the NVH and Crankshaft

Stress tutorials Items Covered:

Building the engine model

Introducing an FE model of the crankshaft Matrix Reduction

Dynamic solution

Estimated duration:

0.5 day (model preparation)

1 day (overall including performing solutions)

Engine:

Inline 4 gasoline engine

75.0 x 44.75 mm

1.6 litre

Required Files:

..\Ricardo\2014.1\Products\ENGDYN\Tutorials\il4\il4_crank.inp

..\Ricardo\2014.1\Products\ENGDYN\Tutorials\il4\il4_2000.PRES






Finite element model requirements:

KNOWLEDGE CENTRE Tutorials Tutorial 2: Crankshaft Dynamic Analysis

44

The crankshaft FE model should be modelled as described in the Geometry of the Finite Element Model Section (Section B.2.4.5.2 in the Help part of the manual)


Copy the necessary files from the example directory to a working directory and ensure that you have write permissions for all the files.

Start engdyn


Software>2014.1>Mechanical Suite>ENGDYN>ENGDYN

2.2.3 Building the Model

2.2.3.1 Configure Engine

In order to build an ENGDYN model it is first necessary to define the major dimensions and features of the engine. This is done using the Engine Configuration Panel.

Select Configure Engine from the buttons on the left side of the Main Panel.

Complete the Engine Configuration Panel as shown.



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The Firing Order can be selected using the Options button or supplied as a hyphen separated list as shown

Journal lengths are the lengths of the journals including the journal fillets NOT the bearing lengths which are defined later

All data in this example are uniform. In cases where data are non-uniform is selected. This will display in red on the 2D graphic those items that can be edited by selecting with the mouse. Items that are not shown are edited using the Edit button.

On completion select Apply which will display

Select OK. The crankshaft model will appear in the Main Panel as shown


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Note that the dimensions of the cranknose and flywheel assemblies on screen are only representations as no data has yet been entered for these. These are defined in 2.2.3.3.


An ENGDYN model consists of a number of sub-models which are defined using the Model Definitions Panel.

Select Define Models from the buttons on the left side of the Main Panel.

Complete the model definition for the Crankshaft



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Use default values for Model, Data and Matrix Formulation The crankshaft in this example is already in the same co-ordinate system and

orientation as defined in the 2.2.3.1. No transformation is therefore necessary

Click on Browse button to display the Model Translation Panel as shown

This panel is used to translate FE models to Ricardo SFE format Models can alternatively be translated outside the graphical interface using

the appropriate FEARCE translator. If the user does this then Origin is left as Ricardo-SFE.

The crankshaft in this example is already in the same co-ordinate system and orientation as defined in the 2.2.3.1. No transformation is therefore necessary

>


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Set origin to ABAQUS and Units to mm Units is the units of the ABAQUS model During the translation the model will be translated so that the SFE file is in SI

units.

Use the Browse button to select the file il4_crank.inp from the working directory

The program will automatically set the output name to il4_crank.SFE

although this can be changed Click Translate to translate the model from the ABAQUS format into SFE

format

Select OK to close the panel. On completion the message Translation successful will appear at the bottom

of the Main Panel. Then there will be a SFE file named il4_crank.SFE in the current directory.

Go to the current directory, find the file il4_crank.SFE

Double-click on this file and the RICARDO FE viewing and interface tool (R-DESK) will launch showing our crankshaft FE model

Note that on UNIX/LINUX systems, type rdesk into the shell at the working directory.



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The R-Desk viewport can be controlled in a similar way to ENGDYNs. To move the model in the panel,

Middle mouse and move = translation + middle mouse and move = rotation middle mouse scroll wheel = zoom in/out

Select the Cylinder Block tab and define the Model as Rigid with User Defined data as shown.

Click on OK. This will display the model as shown.

By default only the edges of the FE model of the crankshaft will be displayed as shown. To change the appearance of the model select the Model Appearance Panel from the View Menu.

Note that the webs and journals align with the reduced model (green), but that the cranknose and flywheel assemblies are not yet correctly defined. This will be addressed in the next step


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2.2.3.3 Editing the Cranktrain

The next step is to define the data related to the cranktrain.

Select Edit Cranktrain from the buttons on the left side of the Main Panel to display the Cranktrain Tool Panel

Given we defined the crankshaft as Dynamic (See 2.2.3.2) it will be necessary to define everything listed on the left hand side of the panel except Lumped Mass and Mechanical Links

Lumped Mass is used to define any additional masses that are not included in the FE model or defined using Flywheel Assembly or Cranknose Assembly.

Mechanical Links is used to define links for co-simulation. Highlight Crank Web as shown

This will then display each of the crank web numbers and elements in green.

Select webs 1, 2, 7 and 8 by dragging the mouse with the left mouse button held down. Each of the selected webs will then turn red as shown



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Select Edit Selected to display the Web Panel

Set Counterweight to Present and complete the counterweight data as shown


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The counterweight geometry is defined only for the purposes of balancing the crankshaft in 2.2.3.4 NOT for defining its mass properties.

The angles are with respect to the Engdyn coordinate system not with respect to the web.

The journal and thickness data has been calculated from the data supplied in 2.2.3.1.

The stiffness data is calculated in 2.2.3.5

Select OK

Select webs 3, 4, 5 and 6 by dragging the mouse with the left mouse button held down.

Select Edit Selected to display the Web Panel

Set Counterweight to Present and complete the counterweight data as shown



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Select OK

Highlight Pin Journal Element This will then display each of the pin journal elements in green

Select Select All Each of the pin journal elements will then turn red

Select Edit Selected to display the Element Panel as shown


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This panel allows the internal diameter of a hollow journal to be defined. The pin journals of this crankshaft are solid.

The Outside Diameter was defined during 2.2.3.1.

Select OK

Highlight Main Journal Element This will then display each of the main journal elements in green

Select Select All Each of the main journal elements will then turn red

Select Edit Selected to display the Element Panel as shown

As with the pin journals this panel allows the internal diameter of a hollow journal to be defined. The main journals of this crankshaft are solid.

The Outside Diameter was defined during 2.2.3.1.

Select OK

Highlight Big End Bearing This will then display each of the cylinder numbers and pin journals in green.

Select Select All Each of the pin journals will then turn red

Select Edit Selected to display the Bearing Panel

Complete the Bearing Panel as shown



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Given the Model Type is Mobility and the bearings are plain it is not

necessary to enter any other data than shown. These bearing are feed from the journal via a feed from the adjacent main

bearings. The oil hole angular position can be defined either using the Position column

(as in this case) or using the Height column. The height is calculated from the angle and vice-versa.

The remaining tabs (Mesh, Material, Profile) need not and cannot be edited because the model type is Mobility. These tabs are only required with Hydrodynamic or Elastohydrodynamic models

Select OK

Highlight Main Bearing This will then display each of the bearing numbers and main journals in

green.

Select Select All Each of the main journals will then turn red

Select Edit Selected to display the Main Bearing Panel

Complete the Main Bearing Panel as shown


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Given the Model Type is Mobility and the bearings are partial grooved it is not necessary to enter any other data than shown.

Any journal oil holes of a grooved bearing are not currently considered. The remaining tabs (Mesh, Material, Profile) need not and cannot be edited

because the model type is Mobility. These tabs are only required with Hydrodynamic or Elastohydrodynamic models

Select OK

Highlight Thrust Bearing This will then display the single main journal node in red corresponding to the

thrust bearing defined in 2.2.3.1. There is therefore no need to Select All

Select Edit Selected to display the Thrust Bearing Panel




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Supply geometric extent of the axial thrust face and the bearing clearance ENGDYN will calculate appropriate stiffness/damping based upon the system

material properties

Select OK

Highlight Cylinder



Complete the Cylinder panel as shown.

The height Head Height is used to derive a node for the cylinder block model

in 2.2.3.6.

Select OK

Highlight Connecting Rod



Complete the Conrod panel as shown.


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Note the units for the connecting rod inertia!

Select OK

Highlight Piston



Complete the Piston panel as shown.

The skirt and top ring data has been set to 0 since this data are only required

for block stress analysis and is therefore not required for this tutorial.

Select OK

Highlight Cranknose Assembly This will then display the cranknose assembly in red. Therefore there is no

need to Select All

Select Edit Selected to display the Cranknose Assembly Panel




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The Element Length effectively positions the first node of the reduced model of the crankshaft. The position of this node must correspond to a plane of nodes in the FE model.

The natural frequency of the vibration damper is 123.3 Hz. The seismic mass of the damper defined here must not be included in the FE

model of the crankshaft

The hub of the vibration damper may be included in the FE model or as in this case defined using this panel.

Any other additional masses, for example gears, sprockets and pulleys, not included in the FE model can be defined by selecting Lumped Mass on the Edit Cranktrain Panel. For the purposes of this exercise we will assume there is no additional masses.

Select Edit button adjacent to Hub Data to display the Lumped Mass Panel

Complete the Panel as shown.


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This defines the mass and inertia of the hub. Given X offset is 0 this lumped mass is assumed to be at the node (defined

by the element length on the Cranknose Assembly Panel)

Click on OK

Click on OK on the Cranknose Assembly Panel

Highlight Flywheel Assembly This will then display the flywheel assembly in red. Therefore there is no

need to Select All

Select Edit Selected to display the Flywheel Assembly Panel




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The distance X1 effectively positions the last node of the reduced model of the crankshaft. The position of this node must correspond to a plane of nodes in the FE model.

In this example, by setting Type to Conventional, we are assuming the flywheel to be rigid.

The Offset is with respect to the node defined by X1. The inertia data is with respect to its centroid.

Click on the Clutch tab and enter the mass and inertia data for the clutch.

The other tabs to not apply to a conventional flywheel assembly

Select OK There are no additional lumped masses to be defined or mechanical links to be defined.

Select Define Material to display the Crankshaft Material Properties Panel as shown


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The material data will be read from il4_crank.SFE.

Use select to list the materials in the SFE file and select the material STEEL from the list as shown.

This table lists all the material in the SFE file. The selected material is the material of the web overlap section. Materials used by ENGDYN and those stored in the .SFE are identified by a

single unique name.

Select OK and the material is added to the panel as shown

These data may be edited if required

Select OK These data are now stored by ENGDYN and also written to the .SFE file. Previous data will be overwritten. The message Mass Not Calculated will be written to the Main Panel.



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2.2.3.4 Calculating the Mass Properties and Balancing the Crankshaft

Click on Calculate Masses to calculate lumped mass properties at each reduced node The progress bar as shown will be displayed

The program derives an element set (as described 2.4.5.3 of the manual) for each reduced node. These sets can be viewed using FEVIEWER. The mass and inertia of each set is then assigned to the appropriate node.

On completion the message Balance Not Set will be written to the Main Panel.

Click on Set Balance to display the Primary Balance Panel as shown


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This panel shows the primary imbalance of the model as given by As modelled. This is the imbalance of the FE model and any additional lumped masses.

The imbalance will invariably be dependent on the accuracy of the finite element model.

For an in-line 4 engine we would expect the crankshaft to have primary balance.

This panel allows the user to simulate balancing the crankshaft by drilling the counterweights.

Set Calculation to Using Web data

Use select adjacent to Web Numbers to display the Select Web Panel as shown

This displays all webs that have counterweights as defined in 2.2.3.3

Select webs 3, 4, 5, and 6 as shown

Select OK

Use Define adjacent to Material Name to display the Counterweight Material Properties as shown



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This by default will display the crankshaft material properties as defined in 2.2.3.3.

Select can be used to select a different material for the counterweight material.

Click on OK. The Primary Balance Panel will appear as shown.

For an in-line 4 engine the Required balance is 0

Click on Apply to balance the crankshaft The message Balance calculation completed successfully will be written to

the Main Panel.

Click on OK The message Balance Set, Stiffness Not Calculated will be written to the

Main Panel.


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Scroll up on the messages on the Main Panel to see the output related to the balance drillings.

2.2.3.5 Matrix Reduction

Click on Calculate Stiffnesses to calculate the crank web and element stiffness using the finite element method. 2 solvers are available. The default Vectorized Sparse Solver (VSS) or the

Symmetric Conjugent Gradient

Click on No to select the VSS solver

The program splits the FE model of the crankshaft into a number of sub-models. FE calculations are performed on each model.

These calculations take circa 5 minutes on am Intel I7-2620M 2.70 GHz Laptop with 4 GB RAM.

On completion of the finite element solutions the reduced mass and stiffness matrices of the crankshaft are derived and an eigenvalue solution performed.

The message Stiffness Calculated, Model Not Assembled will be written to the Main Panel on completion.

Inspect the contents of your working directory to see the files generated.

Click on Calculate Stiffnesses again This time a query panel will be displayed as shown

The program checks whether finite element solutions for each web and element already exist.

Click on No No finite element solutions will be performed The reduced mass and stiffness matrices of the crankshaft are derived and

an eigenvalue solution performed. Click on Assemble Model

This verifies the validity of the data The message Model Assembly completed successfully. Block not

assembled will be written to the Main Panel if assembly was successful.

Click on Dismiss on the Cranktrain Tool Panel. The main panel will now appear as shown



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2.2.3.6 Assembling the Cylinder Block Model

The next step is to assembly the cylinder block model.

Select Edit Block from the buttons on the left side of the Main Panel to display the Cylinder Block Tool Panel The Main Panel will appear as shown


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The program creates nodes at each main bearing and at the reversal positions of the small end of the connecting rod (Thrust and Anti-Thrust) and at the centre of the cylinder head for each cylinder. These nodal positions are derived from data defined in 2.2.3.1 and 2.2.3.3.

Simply click on Assemble Model.

Click on OK The model is now completed and should appear as shown



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Save the model using the File menu from the top of Main Panel

2.2.4 Solution

2.2.4.1 Define Lubricant Properties

Click on Lubrication button from the buttons on the left hand side of the Main Panel

Use the Browse button to select the lubricant SAE5W30 from the database By default the program will initially select the database directory at

..\Ricardo\2014.1\Common\Materials\LubricantsThis database contains the most common lubricants

Use either Add or Update to add the lubricant

Click on OK

2.2.4.2 Define Loading Conditions

The cylinder pressure diagram and any additional loadings (for example loads from Valdyn and gravity forces) are entered in this step.

Click on the Loading button on the Main Panel


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This will display the Loading Definition Panel as shown

A number of different loading maps can be defined, Full Load, Part Load and No Load.

The solver will interpolate at speeds between those defined using this panel.

Type in a speed of 2000 rev/min

Position the mouse over the File Name column and use the right button to display the pop-up menu. Use Select Pressure file to select the file il4_2000.PRES from your working directory. The panel will appear as shown.

You may wish to remove the pathname in front of the file. You may wish to inspect and understand the selected file using an

appropriate editor

Define the Ambient and Crankcase Pressure as 1.0 bar



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The crankcase pressure is only currently used for Hydrodynamic and Elastohydrodynamic bearing models to define the boundary condition at the edge of the bearing

Position the mouse over the column number and with the right button depressed display the Row Operations pop-up. Select Insert After. The Panel will appear as shown

Define the pressure diagram at 3000 rev/min as shown

Complete the panel as shown.


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The remaining tabs, Force Profile, Force Equation and Distortion need not be completed for this tutorial.

Use the Plot button to display the applied pressure loading as shown


We now have sufficient data to proceed with an analysis

2.2.4.3 Evaluate Dynamic Solution




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The Evaluate Solution Panel will appear.

Set the solution Type to Dynamic and edit the solution tolerances as shown

Select the Cases tab and click on Select to define a speed sweep at full load between 2000 and 6000 rev/min in steps of 250 rev/min as shown


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Click on OK to populate the table on the Evaluate Solution Panel as shown

Select the Model Options tab and change the Cylinder Damping to 500 N.s/m and Frequency to 50 Hz as shown.



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The cylinder damping parameter is used to tune the torsional response of the crankshaft

The coupling is a torsional spring and damper to prevent rigid motion of the crankshaft about its axis. This is analogous to the stiffness and damping of a dynamometer connected to the crankshaft.

The damping value of the coupling can be used to tune the torsional response of the crankshaft.

The natural frequency of the coupling must be significantly lower than the first flexible torsion mode of the crankshaft.

Select the Bearing Model tab and complete the panel as shown


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Select Define to display the Bearing Oil Temperatures Panel

We will assume that the temperature of the oil in the bearing is at the inlet

temperature

Select OK

Select Solve Directly on the Evaluate Solution Panel.



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On completion of the analysis the summary file .EDSUM will be written.

This file contains summary data for the solution. Open this file with an appropriate editor to view the results


Tutorial 3: NVH Analysis

79

2.3 Tutorial 3: NVH Analysis

2.3.1 Overview

Objective:

To use ENGDYN to perform vibration and acoustic analysis on a powertrain The analysis uses finite element (FE) models of both the powertrain

assembly and the crankshaft The tutorial requires the ENGDYN model from the Crankshaft Dynamic

Crankshaft Tutorial Items Covered:

Dynamic cylinder block model Engine mount modelling Component Mode Synthesis (CMS) matrix reduction

Vibration Analysis

Acoustic Analysis Rayleigh Integral Method Indirect Boundary Element Method (BEM)

Estimated duration:

0.5 day (model preparation)

1 day (overall including performing solutions)

Engine:

1.6 litre Inline 4 gasoline engine

75.0 x 44.75 mm Required Files:

..\Ricardo\2014.1\Products\ENGDYN/Tutorials\il4\IL4_BLOCK.SFE

..\Ricardo\2014.1\Products\ENGDYN/Tutorials\il4\il4_block_noise.VPT

..\Ricardo\2014.1\Products\ENGDYN/Tutorials\il4\il4_block_vibration.VPT

..\Ricardo\2014.1\Products\ENGDYN/Tutorials\il4\IL4_BLOCK_BoundaryElementModel.SFE

The .EDSF file from Crankshaft Dynamic Analysis Tutorial, so all the files used in

tutorial 2 are needed here.

Finite element model requirements:

For dynamic and acoustic analysis of the powertrain it is necessary to have a fully dressed finite element model with engine mount brackets to support the engine

KNOWLEDGE CENTRE Tutorials Tutorial 3: NVH Analysis

80

mounts. The model used in this tutorial is not representative but is sufficient for demonstrating the analysis steps.


Go to the working directory in which you completed the Crankshaft Dynamic Analysis Tutorial. Copy the file IL4_BLOCK.SFE from the Tutorials directory in the installation to this working directory and ensure that you have write permissions for this file.

Start engdyn


Software>2014.1>Mechanical Suite>ENGDYN>ENGDYN In the Crankshaft Dynamic Analysis Tutorial the cylinder block (or powertrain) was modelled as rigid. Obviously for analysing the vibration and acoustic behaviour of the powertrain it is necessary to model the powertrain as dynamic. This section describes the steps in updating the model derived in the previous tutorial.

Open the .EDSF file used for the Crankshaft Dynamic Analysis Tutorial using the File menu at the top of the Main Panel

From the same menu Copy Design to a new file

2.3.3 Updating the Model


In this step we need to redefine the cylinder block model as dynamic rather than rigid.

Select Define Models from the buttons on the left side of the Main Panel to display the Model Definitions Panel.

Select the Cylinder Block tab and define the model as Dynamic as shown.



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Click on Browse button to display the Model Translation Panel as shown

Use the Browse button to select the file IL4_BLOCK.SFE from the working directory.

The program will automatically set the output name to IL4_BLOCK.SFE although this can be changed

Click on the Transformation tab to define the translation vector as shown to transform the finite element model of the cylinder block.


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Click on OK to dismiss the panel In this case no translation is performed since the model has already been

translated into SFE format using the appropriate translator.

Click on OK Note how the previously defined reduced model of the cylinder block has

disappeared. By default the finite element model of the cylinder block is not displayed. The

model may be displayed using the Model Appearance Panel from the View Menu at the top of the Main Panel.

2.3.3.2 Reassembling the Crankshaft Model

The program forces you to reassemble the crankshaft model because the cylinder block model has changed.

Select Edit Cranktrain from the buttons on the left side of the Main Panel to display the Cranktrain Tool Panel



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We do not need to redefine any data. However the program will force us to re-edit the main and thrust bearing data.

Click on Assemble Model An error message will be displayed in the pop-up as shown.

Dismiss the error message

Highlight Main Bearing, click on Select All followed by Edit Selected to display the Main Bearing Panel.

Simply select OK since we do not want to re-edit the data.

Click on Assemble Model again An error message will be displayed in the pop-up as shown.

Dismiss the error message

Highlight Thrust Bearing and click on Edit Selected to display the Thrust Bearing Panel

Simply select OK since we have no data to edit. This is an error in the current release of the program since it should not force

you to edit the thrust bearing since the stiffness is later calculated from the cylinder block model.

Click on Define Material and OK the panel.

Follow Step 4 and Step 5 of the Crankshaft Dynamic Analysis Tutorial On completion the message Stiffness Calculated, Block Not Assembled

should be displayed in the message area of the Main Panel.

2.3.3.3 Edit Cylinder Block - Model Definition


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It is necessary to define a reduced model of the cylinder block. The reduced model is a number of nodes and degrees of freedom that are a subset of the complete model. We need to define a number of sets.

A constrained node set for each main bearing. For this set the bearing is defined by a single node with 6 degrees of freedom whose movement is the average of the nodes on the bearing surface.

Four node sets for each cylinder to define the upper and lower reversal points of the small end of the connecting rod on the thrust and anti-thrust sides of the cylinder bore. Each node set will contain a single structural node.

A constrained node set for the head gas face of each cylinder. For this set the gas face is defined by a single node with 3 translational degrees of freedom whose movement is the average of the nodes on the gas face.

A constrained node set that defines the attachment point of each engine mount. For this set the mount is defined by a single node with 3 translational degrees of freedom whose movement is the average of the nodes on the bracket.

Select Edit Block from the buttons on the left side of the Main Panel to display the Cylinder Block Tool Panel

The following Query Panels will be displayed in succession.

These are displayed because we have already defined a cylinder block model and in doing so have defined a number of sets

Click on Yes in each case

In most cases you want to answer No to the question. You only want to answer Yes if either the block model type has changed (as in this case) or the main bearing or cylinder geometry has changed.

Messages will appear in the bottom of the Main Panel and the Cylinder Block Tool Panel will appear as shown



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In this action the program has transformed the finite element model of the

cylinder block, calculated its mass properties and attempted to automatically define the sets of the reduced model using the data supplied previously

The reduced model is shown in orange. The sets defining each main bearing are incomplete and nothing has been

defined for the cylinders. This is because the nodes are outside the geometric tolerance.

It is necessary to define these sets using the Define Model Panel.

Click on Define Model to display the Define Model Panel as shown

Consider firstly the constrained node sets defining each main bearing

Change Type to Constrained Node and Name to Main Bearing


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The Cyl and Val fields will now be ghosted and the ID field will be editable.

Click on Select adjacent to the ID field and select 1 from the list so that the panel appears as shown

ID 1 denotes main bearing 1 Alternatively you can simply type 1 in the field

Select the Definition tab

Select each tab and understand the default values Each set is clipped based on geometric shape Each shape is defined by a Centre, Axis, Extent and Diameter

Select the Tolerance tab



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The default linear tolerance is set to half the minimum distance between any two adjacent finite element nodes.

Each set has its own tolerance values

Change the Linear Tolerance to 0.5 mm and press Clip Set.

The clipped mesh is shown in pink The program only clips the external surfaces of the model.

This set is OK so click on Add Set to add the set to the reduced model as shown


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Repeat this procedure for each of the remaining main bearing by changing the ID on the Name tab and the linear tolerance on the Tolerance tab.

On completion the panel should appear as shown.

Secondly consider the node sets defining the thrust and anti-thrust nodes for each cylinder.



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Select the Name tab

Change Type to Node and Name to cylinder as shown

Click on Select adjacent to the Cyl field and select all the cylinders

Click on Select adjacent to the ID field and select lowerAntiThrust so that the panel appears as shown

Select the Definition tab and again understand the default data The data for cylinder, valve seat and valve spring are with respect to a

cylinder local coordinate system with the origin at the top of the cylinder. This enables sets to be defined for multiple cylinders in a single action.

The shape is set to Sphere in this case to find the nearest relative to the specified centre.

Select the Tolerance tab and again change the linear tolerance to 0.5 mm and click on Clip Set


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The node numbers are displayed The coordinates of each node are displayed in the message area with

respect to the cylinder and the global system.

Select Add Set to add the nodes to the reduced model.

Repeat this procedure for each of the remaining cylinder nodes lowerThrust, upperAntiThrust and upperThrust by changing the ID on the Name tab and the linear tolerance on the Tolerance tab.

On completion the panel should appear as shown.



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Finally add sets defining the attachment points of the engine mounts. Again these sets will be from the SFE file.

In this example there are no engi

engdyn 2014.1 manual

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