using adams/durability - md adams 2010

Download Using Adams/Durability - MD Adams 2010

Post on 18-Nov-2014




6 download

Embed Size (px)


1 Welcome to Adams/DurabilityWelcome to Adams/DurabilityAdams/DurabilityIntroduction to Adams/Durability2Introduction to Adams/DurabilityAdams/Durability, part of the MD Adams 2010 suite of software, extends the traditional test-based durability design process into the virtual world. With Adams/Durability, you can simulate a durability duty cycle and write out component load histories in or formats and drive a durability test rig using output data in RPC III Format or DAC Format. You can visualize stress or detect hot spots in flexible or rigid components, and you can improve component design by interfacing with fatigue life prediction programs.Some of the features of Adams/Durability are available as a demand-loaded library (DLL), while the rest are available as a plugin to the various Adams interface or vertical products, such as Adams/View, Adams/PostProcessor, and Adams/Car.How You Benefit from Using Adams/DurabilityAdams/Durability enables you to work faster and smarter, letting you easily interface with durability test machines using the RPC III Format, and with fatigue life calculation programs using DAC Format, or with an FEA program for stress recovery.You benefit from using Adams/Durability in the following ways: Shortens your development cycle, reducing costly durability testing. Reduces disk space requirements and improves performance by providing direct file input and output in RPC III and DAC formats. For example, when you perform a 25-second Adams simulation with 300 channels of data, sampled at a rate of 409.6 points per second, to capture a durability event, the Adams Request files are approximately 48 MB, whereas the RPC III file is only 6 MB. Provides access to the system-level simulation capabilities of Adams/View, or vertical products, such as Adams/Car. Provides access to dynamic stress recovery methods using NASTRAN or ANSYS. Performs modal stress recovery of flexible bodies. Provides access to component life prediction using MSC.Fatigue or FE-Fatigue. Using Adams/Durability On DemandThe Adams/Durability installation includes a library that is compatible with most of the Adams products, including Adams/View, Adams/PostProcessor, Adams/Solver, and the vertical product solvers such as Adams/Car Solver. This library provides the DAC and RPC III file capabilities of Adams/Durability. It is demand-loaded automatically by the various products when you use a feature of Adams/Durability that requires this library; therefore, you do not need to know how to access this library. With the Adams/Durability demand-loaded library, you can simulate a durability duty cycle in Adams and write out component load histories in RPC III and DAC formats. For example, you can simulate a virtual test rig where actuator inputs like spindle loads are taken from field measurements and stored in 3 Welcome to Adams/DurabilityIntroduction to Adams/Durabilitythe RPC III format. Then, you can write out component load histories in DAC format for subsequent component durability testing or fatigue life prediction. You can perform the following with DAC or RPC III files: Browse the files for header information, such as number of time steps, sample rate, number of channels, channel names, channel maximums, and channel minimums. Plot the time history data. Filter, integrate, or transform the sampled data. Drive or excite Adams models with the data. Interpolate the channel data by cubic splines. Loading the Adams/Durability PluginThe Adams/Durability plugin gives you access to the various stress recovery techniques in Adams, and interfaces to NASTRAN, ANSYS, FE-Fatigue, and MSC.Fatigue. This plugin is available in most of the Adams interface or vertical products, such as Adams/View, Adams/PostProcessor, Adams/Car, and Adams/Driveline.To load the Adams/Durability plugin:1. Start one of the Adams interface or vertical products.2. From the Tools menu, select Plugin Manager.3. Select the Load checkbox next to Adams/Durability.4. Select OK. This creates the Durability menu, adds various stress and strain Plot Type menu options for the Contours tab in Adams/PostProcessor, and adds several functions to the Misc. Functions category in the Adams/View Function Builder, such as LIFE, MAX_STRESS, HOT_SPOTS, and TOP_SPOTS.To unload the Adams/Durability plugin:1. From the Tools menu, select Plugin Manager.2. Clear the Load checkbox next to Adams/Durability.3. Select OK.Adams/DurabilityIntroduction to Adams/Durability41 Performing Stress RecoveryPerforming Stress RecoveryAdams/DurabilityStress Recovery in Adams/Durability2Stress Recovery in Adams/DurabilityWith Adams/Durability you can recover stresses on flexible or rigid bodies. Recovering stresses on flexible bodies is called Modal Stress Recovery (MSR). You can perform MSR inside Adams or, in the case of NASTRAN, outside of Adams.Recovering stresses on rigid bodies is based on the loading time history of the component and its geometry and mass. If a finite-element mesh is available for the rigid component, the forces from an Adams simulation can be exported and applied to the components mesh. A finite element program like NASTRAN can then be employed to recover the static stress resulting from the foce application at each Adams output step. This method of stress recovery is sometimes referred to as quasi-static stress recovery.Note that user functions are available for modal stress recovery to determine hot spot regions and maximum stress. Learn more about User Functions.3 Performing Stress RecoveryModal Stress RecoveryModal Stress Recovery The benefit of this process is being able to recover any type of output that is available in MSC.Nastran (also MD Nastran) such as element stresses or strains, nodal forces, and so on. Due to limitations of the MNF, only grid point stresses or strains can be post-processed in Adams. Also, MSC.Nastran does not allow grid point stress or strain on composite shell elements or beams, so it is not possible to post-process strain or stress for these type of elements in Adams. In addition, plates or shells have more than one layer, but the MNF allows only one layer of stress or strain to be stored in the file. These limitations are avoided by exporting data for MSC.Nastran.MSC.Nastran has the function to recover stresses and strains in the version 2006 (MDR1) and later, and a special DMAP is not required. For modal stress recovery, a restart run is used thus MSC.Nastran database (.MASTER and .DBALL) have to be kept in the primary run to build the flexible body for Adams, and to do that the command option "scratch=no" should be applied. Modal transient response analysis (SOL 112) and modal frequency response analysis (SOL 111) should be applied for time dependent data and frequency dependent data respectively with ADMPOST parameter.Learn Exporting Data for NASTRAN.Restarting NASTRANA restart MSC.Nastran for modal stress recovery needs to be specified at the top of the MSC.Nastran input deck in the file management section:ASSIGN =''RESTART LOGICAL=where is the logical name of the database to be assigned and is MASTER file name of the primary run. Note that the logical name is arbitrary characters within 8 letters and first one should be alphabet.Reading Modal Deformations File (MDF)Modal deformations to be read have to be in binary (OUTPUT2) format, and the following statement needs to be specified near the top of the MSC.Nastran input deck in the file management section:ASSIGN INPUTT2='' UNIT= [FORM=]where is the name of the modal deformations file from Adams. For directions on how to create this file, see the FEMDATA or OUTPUT Adams/Solver statement. And indicates an ID number of DLOAD statements in the case control section. The option FORM may be requested when the binary format of MDF is not applicable to the platform of MSC.Nastran (see the MSC.Nastran quick reference guide for more information).Note: AUTOQSET cannot be used for the primary run due to the limitation of MSC.Nastran restart capabilityAdams/DurabilityModal Stress Recovery4Results PostprocessingDynamic stress/strain output can be either in F06, PUNCH OUT, XDB or OUTPUT2 according to standard MSC.Nastran functionality, and the output files can be postprocessed in Patran or SimXpert Structures.If displacements, stresses, and/or strains are to be available for postprocessing, one or more of the following statements must appear in the case control section of the MSC.Nastran input file:DLOAD = DISP(PLOT) = STRAIN(FIBER,PLOT) = STRESS(PLOT) = where is a ID number indicated by ASSIGN statement in the executive control section, and is a ID number defined in SET statement.PARAM, ADMPOSTRequest modal stress recovery (see the MSC.Nastran quick reference guide for more information): 0: Modal stress recovery is not activated (default) 1: Request modal stress recovery without rigid body motion 2: Request modal stress recovery with rigid body motionThis parameter is used to activate modal stress recovery and control the addition of rigid body motion with modal deformations. Rigid body motions from an Adams simulation are included in the modal deformations file (MDF), but they are not applied unless this parameter is set to 2. Including rigid body motion affects the display or animation of the flexible component, but it has no effect on dynamic stresses.PARAM, POSTRequest stress/strain/displacement output for postprocessing (see the MSC.Nastran quick reference guide for more information): 0: No Example of Input FileAn example MSC.Nastran input file for modal stress recovery run compared to a typical input file for building flex body is shown below. These examples are located in the following installation files: /durability/NASTRAN/plate.dat /durability/NASTRAN/plate_msr.dat /durability/NASTRAN/plate.cmd5 Performing Stress RecoveryModal Stress RecoveryNote that "plate.cmd" is the command file to create the example model with the flex body (MNF) by "plate.dat" and run the dynamic simulatio


View more >