ansys workbench optimization

Part and Assembly Modelingwith ANSYS DesignModeler 14

Huei-Huang Lee

Contents 1

ContentsPreface 2

Section A. Sketching 5

Exercise 1. Arm 6 Exercise 1a. Structural Analysis of the Arm 21

Exercise 2. Ratchet Stop 28

Exercise 3. Ratchet Wheel 35

Exercise 4. Cover Plate 44

Section B. Part Modeling 54

Exercise 5. Crank 55 Exercise 6. Geneva Gear Index 64

Exercise 7. Yoke 72

Exercise 8. Support 79

Exercise 8a. Structural Analysis of the Support 88

Exercise 9. Wheel 94

Exercise 10. Pipe 98

Exercise 11. C-Bar Dynamometer 106

Exercise 11a. Deformation of the C-Bar 111

Exercise 12. Threaded Shaft 119

Exercise 13. Lifting Fork 124

Exercise 14. Caster Frame 130

Section C. Assembly Modeling 144

Exercise 15. Threaded Shaft Assembly 145 Exercise 16. Universal Joint 152

Exercise 16a. Dynamic Simulation of the Universal Joint 165

Exercise 17. Clamping Mechanism 176

Exercise 17a. Simulation of the Clamping Mechanism 197

Section D. Concept Modeling 215

Exercise 18. 2D Solid Modeling (Arm) 216 Exercise 18a. Structural Analysis of the Arm Using 2D Model 219

Exercise 19. Surface Modeling (Support) 225

Exercise 19a. Structural Analysis of the Support Using Surface Model 230

Exercise 20. Line Modeling (Space Truss) 234

Exercise 20a. Structural Analysis of the Space Truss 240

2 Preface

Preface

Use of the BookThis book is designed for those who want to learn how to create parts and assembly models using ANSYS

DesignModeler. The author assumes no previous CAD/CAE experiences to begin with the book.

This book is mainly designed as an auxiliary tutorial in a course using ANSYS as a CAE platform. In particular,

this book can serve as a preparation to the author's another book Finite Element Simulations with ANSYS Workbench 14,

which emphasizes on finite element simulations rather than geometry modeling such that the exercises on geometry

modeling (especially assembly modeling) may not be adequate.

ANSYS DesignModelerANSYS DesignModeler is a CAD program running under ANSYS Workbench environment. The DesignModeler can

create geometries as sophisticated as any other CAD programs. Yet, many engineers choose to create geometry

models using other CAD programs (e.g., Pro/Engineer, SolidWorks) and then import them into an ANSYS simulation

module (such as Mechanical) for simulations. One of the reasons may be that, other than the training materials

provided by the ANSYS Inc., there exist no tutorials in the bookstore. That is the main reason that I created this book.

The DesignModeler is designed specifically for creating models which can be seamlessly imported into an ANSYS

simulation modules (such as Mechanical). Therefore, if a geometry model is solely used for ANSYS simulations, I

strongly suggest that we create the model from scratch using DesignModeler, rather than other CAD programs, to

avoid any unnecessary incompatibilities.

Structure of the BookThere are 20 exercises and 8 appendices in the book; each of them is designed in a step-by-step tutorial style. The 20

exercises involve creating parts and assemblies models, while the 8 appendices show how to perform simulations using

some of the models. If you are not currently interested in simulations, you may freely skip the 8 appendices without

affecting the learning of the 20 exercises.

An assembly consists of two or more parts. Each part can be viewed as boolean operations (union, subtraction,

etc.) of simpler 3D bodies. Each of the 3D bodies usually can be created by a two-step operation: drawing a 2D sketch

on a 2D plane and then generate the 3D body by extrusion, revolution, sweeping, or skin/lofting.

The book is divided into 4 sections. Section A lets students familiarize with sketching techniques. Section B

contains exercises of part modeling. Section C consists of exercises of assembly modeling. The last section introduces

the creations of concept models, including 2D models, surface models, and line models. A concept model is a

simplification of a 3D models, and is usually easier to create and more efficient to be simulated.

Preface 3

Companion WebpageA webpage dedicated to this book is maintained by the author:

http://myweb.ncku.edu.tw/~hhlee/Myweb_at_NCKU/ADM14.html

The webpage contains links to finished project files of each exercise and appendix. If everything works smoothly, you

do not need them at all. Every model can be built from scratch according to the steps described in the book. The

author provides these project files just in some cases you need them. For examples, if you have troubles to follow the

geometry details in the textbook, you may need to look up the geometry details from the project files.

Huei-Huang Lee

Associate Professor

Department of Engineering Science

National Cheng Kung University

Tainan, Taiwan

[email protected]

myweb.ncku.edu.tw/~hhlee

Section A. Sketching 5

Section ASketching

An assembly is a combination of parts. From manufacture point of view, a part is a basic unit for manufacturing process. Many parts can be created by a two-step operation: drawing a 2D sketch on a plane and then generate a 3D body by extrusion, revolution, sweeping, or skin/lofting. The exercises in Section A are designed to introduce the 2D sketching techniques provided by the DesignModeler. Each part created in Section A involves drawing a sketch and then extrude to generate a 3D solid body representing the part. Although it can be used as a general purpose CAD software, the DesignModeler is particularly designed for creating geometric models to be analyzed (simulated) under the ANSYS environment. To let the readers understand what it means by analysis (simulation) as early as possible, an exercise (Exercise 1a) is appended right after Exercise 1 to perform a structural analysis for the part created in Exercise 1. However, the reader has option to skip Exercise 1a without affect the subsequent learning of geometric modeling.

6 Exercise 1. Arm

X

Y

1.375

2.2

5

Unit: in.

Thickness: 0.125 in.

R0.5

3D0.25

R0.313

R0.25

R0.313

[2] Details of the arm.

[3] The global coordinate

system.

[1] The arm is a part of a clamping mechanism.

Exercise 1Arm

In this exercise, we will create a 3D solid model for an arm, which is a part of a clamping mechanism [1]. The clamping mechanism will be introduced in Exercise 17 and simulated in Exercise 17a. The arm model consists of a single solid body, which can be generated by extruding a sketch by a thickness of 0.125 inches [2]. Before creating a geometry model, we must set up a global coordinate system. For this exercise, we arbitrarily choose the global coordinate system as shown [3]. Note that the origin is on the back surface of the part.

1-1 Introduction

Exercise 1. Arm 7

[2] The (graphical user interface) shows up.

[3] Click the plus sign (+) to expand . The plus sign becomes minus sign.

[4] Double-click to create a system.

[7] Double-click to start up the DesignModeler.

[6] You may click here to show the messages from ANSYS Inc. To hide the message, click it again.

[1] Launch ANSYS Workbench.

1-2 Start Up DesignModeler

[5] A system is created in the area.

8 Exercise 1. Arm

[10] Click . Note that, after clicking and

entering DesignModeler, the length unit cannot be

changed anymore.

[9] Select as length unit.

[8] shows up.

Speech Bubbles1. In this book, each exercise is divided into subsections (e.g., 1-1, 1-2). In each subsection, speech bubbles are ordered with numbers, which are enclosed by pairs of square brackets (e.g., [1], [2]). When you read, please follow the order of speech bubble; the order is significant.2. The square-bracket numbers also serve as reference numbers when referred in other text. When in the same subsection, we simply refer to a speech bubble by its number (e.g., [1], [2]). When in the other subsections, we refer to a speech bubble by its subsection identifier and its bubble number (e.g., 1-2[1]).3. When a circle is used with a speech bubble, it is to indicate that mouse or keyboard ACTIONS are needed in that step [1, 3, 4, 7, 9, 10]. A circle may be filled with white color [1, 4, 7] or unfilled [3, 9, 10]. A speech bubble without a circle [2, 8] or with a rectangle [6] is used for commentary only, i.e., no mouse or keyboard actions are needed.

Workbench KeywordsA pair of angle brackets is used to highlight an Workbench keyword (e.g., in [3]). Sometimes, if the angle brackets do not add any clarity, they may be dropped (e.g., DesignModeler).

Clicking and SelectingWhen we say "click" or "select," we mean left-click the mouse button.

Exercise 1. Arm 9

1-3 Prepare to Draw a Sketch on

[1] By default, is the current sketching

plane (active plane).

[2] Click to switch to . Note that there are 5

toolboxes available: Draw, Modify, Dimension, Constraints, and Settings.

is the default toolbox.

[3] Click to rotate the view angle so

that you look at the current sketching

plane.

[4] By default, the ruler is on. In the next step, we will turn off the ruler to make

more sketching space.

[5] Select to turn it off. For the rest of this

book, we always leave the ruler off.

[6] This is the global coordinate system.

[7] This is the plane (local) coordinate

system.

10 Exercise 1. Arm

1-4 Draw a Circle with Dimension

[1] Select tool.

[2] In case you don't see the tool, scroll down to reveal

the tool.

[3] It gives you hints for using the tool.

[4] Move the mouse around the origin until a (Point) appears

and then click the mouse to locate the center of the circle.

The ability to "snap" a point is a feature of the DesignModeler, called .

[5] Move the mouse away from the center and then click the mouse to

create a circle with arbitrary radius.

[7] Select

toolbox.

[8] Select tool.

[9] Select the circle, move the mouse

outward, and then click to create a dimension.

Note that the circle turns blue, meaning the circle

has fully constrained (fixed in the space).

[10] In the , type 0.25 for

the diameter.

[11] It is possible that the circle becomes too small. Select tool to fit the sketch into the graphics window. Now, we may need to adjust (move) the position of the

dimension.

[6] As soon as you begin to draw, a name

is assigned to the sketch and it becomes

the active sketch.

Exercise 1. Arm 11

[12] Select tool. Remember to scroll

down to reveal a tool if you don't see the tool.

[13] Select the dimension, move to a suitable position, and

then click again.

[14] Whenever necessary, select tool to fit the

sketch into the graphics window.

[15] Select tool. You may need to scroll down to reveal

the tool if you don't see the tool.

[16] Click to turn the dimension name off. Note that

automatically turns on.

[17] Instead of displaying dimension name, now the dimension value is

displayed. For the rest of the book, we always display dimension values

instead of name.

12 Exercise 1. Arm

1-5 Draw Two More Circles

[1] Click anywhere in the graphics window and then scroll the mouse wheel down to zoom out the sketch roughly like this.

[2] Select toolbox.

[4] Move the mouse around the horizontal

axis until a (Coincident) appears

and then click the mouse to locate the center of the circle.

This center is snapped on the horizontal axis.

[5] Move the mouse until an (Radius) appears and then click the

mouse. The radius dimension is constrained to be the same as the first circle. Note that the circle is

greenish-blue, meaning it is not fully fixed in the space yet. A

horizontal location is needed to fully defined the circle.

[6] Create another circle in a similar way. Make sure a and an appear before clicking. A vertical location is needed to fully

defined the circle.

[3] Select tool.

Exercise 1. Arm 13

[7] Select toolbox

and then select tool.

[8] Select the vertical axis. Note that the shape

of the mouse cursor changes when your mouse

is on the axis.

[9] Select the center of the circle. Note that the

shape of the mouse cursor changes when your

mouse is on the point.

[10] Move the mouse upward roughly here and click to locate a horizontal

dimension. Note that the circle turns blue (fully constrained).

[11] In the , type 1.375 for

the horizontal dimension.

[12] Remember that you always can use and scroll the mouse wheel [1] to zoom in/out the view. Also, to "pan" the view, simply move the mouse while holding the

control-middle-button.

[13] Select tool.

[14] Select horizontal axis, select the center of the lower

circle, move the mouse leftward roughly here, and click to locate a vertical dimension.

The circle turns blue.[15] In the , type 2.25 for

the vertical dimension.

[16] Before going further, make sure you familiarize the two most frequently used view

operations: scrolling the mouse wheel to zoom in/out the view and moving mouse with control-middle-button to pan the view.

14 Exercise 1. Arm

1-6 Draw Three Concentric Circles

[1] Select the tool, and draw a

concentric circle. Make sure a appears before defining the center.

[2] Select the tool, and create a radius dimension for the circle. In the , type 0.313 for the radius.

[3] Select the tool, and draw a concentric circle with the

same radius as the previous circle. Make sure a appears before defining the center and an

appears before defining the radius.

[4] With the tool still selected, draw a

concentric circle. Make sure a appears before defining

the center.

[5] Select the tool, and create a radius dimension for the circle. In the , type 0.5 for the

radius.

Exercise 1. Arm 15

1-7 Draw Tangent Lines

[1] Select the tool, and

then select the two circles to be tangent to. A tangent

line is created.

[2] Create additional three tangent lines in a

similar way.

16 Exercise 1. Arm

1-8 Draw a Fillet

[1] Select the tool, and type 0.25

for .

[2] Select these two lines. A fillet is created. Note that the fillet is not blue-

colored. We need to specify the radius. The

radius typed in [1] is not necessarily the final

dimension; it just serves as a default dimension.

[3] Select the tool, and create a radius dimension for the fillet. You don't need to type in the , since the default value

[1] is automatically used. Note that the color turns blue now.

Exercise 1. Arm 17

1-9 Trim Away Unwanted Segments

[1] Select the tool, and turn on , meaning

that the axes will not serve as trimming tools.

[2] Click the circle roughly here to trim away the arc. Note that when you select an edge (a line or a

curve), the remaining edges will serve as

trimming tools.

[3] Click to trim away two other

arcs.

[4] The sketch after trimming.

18 Exercise 1. Arm

1-10 Extrude the Sketch to Create the Arm

[1] Select tool.

[2] It automatically switches to

, in which a is displayed, which will be explained later.

[3] Click the little cyan sphere

to rotate the view into an

isometric view.

[4] Type 0.125 for the .

[6] Click to produce a 3D solid

body.

[7] Click to turn off the

display of XYPlane (and the sketches it contains).

1-11 Save the Project and Exit Workbench

[1] Select . The

disappears.

[2] In the , save the project

as "Arm."

[3] Select to quit

from the Workbench.

[5] The active sketch is automatically taken as

.

Exercise 1. Arm 19

Global Coordinate SystemBefore creating a geometry model, you must set up a global coordinate system (1-1[3], 1-3[6]).

Workbench GUIIn the (1-2[2]), you can create a system (1-2[4]) and start up DesignModeler (1-2[7]). Other capabilities will be introduced later.

Project SchematicCreated systems appear on the , an area in the .

DesignModeler GUIGeometries are created entirely within the (1-2[8]).

Length UnitBefore creating a model in the DesignModeler, you must choose a length unit (1-2[9, 10]). The length unit cannot be changed thereafter.

Mouse OperationsClick -- Left-click the mouse button.Select -- Left-click the mouse button.Double-Click -- Left-click the mouse button twice.Zoom In/Out -- Scroll the mouse wheelPan -- Move the mouse while holding control-left-button.Other mouse operations will be introduced later.

Current Sketching PlaneEach sketch is stored in the current sketching plane (1-3[1]). Manipulating (switching, creating, etc.) sketching planes will be introduced later.

Sketching Mode v.s. Modeling ModeTools for sketching are provided in the mode (1-3[2]), while tools for creating and manipulating bodies are provided in the mode (1-10[2]). There are 5 toolboxes available: Draw, Modify, Dimension, Constraints, and Settings. Tools in mode includes (1-10[1]). Some tools are available in both modes, e.g., (1-4[11]).

Look At Face/Plane/SketchClicking this tool to rotate the view angle so that you look at the current sketching plane (1-3[3]).

RulerThe ruler (1-3[4, 5]) is to help you obtain a better feeling of the drawing scale. In this book, we always leave the ruler off to make more sketching space.

Plane Coordinate SystemEvery plane has its own coordinate system (1-3[7]); it is also called a local coordinate system. The plane coordinate system will be explained further later.

1-12 Review

20 Exercise 1. Arm

ScrollingIn case you don't see a tool in a toolbox, scroll down/up to reveal the tool (1-4[2]). There is also a scrolling controller for the .

Tools in ToolboxCircle -- Draw a circle, giving the center and the radius (1-4[1, 3-5]).Line by 2 Tangent -- Draw a line tangent to two curves (including circles and arcs) (1-7[1, 2]).

Tools in ToolboxRadius -- Specify a radius dimension by selecting a circle (1-4[6, 8-10]) or an arc (1-8[2]).Move -- Move (relocate) a dimension name/value by dragging the name/value (1-4[12, 13]).Display -- This tool is to toggle the display of dimension name and the dimension value (1-4[15-17]). In this book, we always turn off the dimension name and turn on the dimension value.Horizontal -- Specify a horizontal dimension by first selecting a or a point (or a vertical line) and then a second point (or a vertical line) (1-5[7-10]).Vertical -- Specify a vertical dimension by first selecting a or a point (or a horizontal line) and then a second point (or a horizontal line) (1-5[13, 14]).

Tools in ToolboxFillet -- Create a fillet by selecting two lines or curves (1-8[1-3]).Trim -- Trim away unwanted segments (1-9[1-4]).

Auto ConstraintsP -- The mouse cursor snaps to a point (or the origin) (1-4[4]).R -- The radius is the same as another circle (or arc) (1-4[5]).C -- The mouse cursor is coincident to a line (or an axis) (1-5[4, 6]).Other auto constraint features will be introduced later.

Color CodesGreenish-blue -- Under-constrained (1-8[2])Blue -- Fully constrained (fixed in the space) (1-4[9], 1-5[10,14]).Red -- Over-constrained

Zoom To FitClick this tool to fit the entire sketch (in the mode) or entire model (in the mode) into the graphics window (1-4[14]).

ExtrudeThis tool extrude a sketch by a specified depth to create a 3D body (1-10[1-5]). More exercises will be given later.

Isometric ViewClick the little cyan sphere of the triad will rotate the view into an isometric view (1-10[3]). Other view controls will be introduced later.

Display PlaneThis tool is to toggle the display of current sketching plane and the sketches it contains (1-10[6]).

Exercise 1a. Structural Analysis of the Arm 21

[2] This is the deformed structure under the design loads. The wireframe is the underformed configuration. Note that, for visual effects, the deformation has been

exaggerated.

Appendix:

Exercise 1aStructural Analysis of the Arm

Although it can be used as a general purpose CAD software, the DesignModeler is particularly designed for creating geometric models to be analyzed (simulated) under the ANSYS environment. The purpose of this exercise is to let the readers understand what it means by analysis (simulation). However, the reader has option to skip this exercise without affect the subsequent learning of geometric modeling. In this exercise, we will perform a static structural analysis for the arm created in Exercise 1. The objective is to find the deformation and stresses under the working loads. The clamping mechanism is entirely made of steel and is designed to withstand a clamping force of 450 lbf [1]. After a structural analysis of the entire mechanism [2] (also see Exercise 17a), the results show shows that, to withstand a clamping force of 450 lbf, the arm is subject to external forces as shown [3] (also see 17a-13). Note that the external forces are in a state of static equilibrium. The analysis for the entire clamping mechanism will be perform in Exercise 17a. In this exercise, we will only perform a analysis on the arm. The purpose is to make sure the stresses are within the allowable stress of the steel, which is 30,000 psi. The analysis task cannot not be performed in DesignModeler. Rather, it is carried out with , another Workbench application program.

1a-1 Introduction

[1] The clamping mechanism is

designed to withstand a clamping force of

450 lbf.

281 lbf 126 lbf

264 lbf 187 lbf

407 lbf

77 lbf

[3] The external forces on the arm. These forces are

calculated according to

17a-13.

22 Exercise 1a. Structural Analysis of the Arm

[2] Open the project "Arm," which was saved in Exercise 1.


1a-2 Start Up

[3] Double-click to create a

analysis system.

[4] Drag ...

[5] And drop here. A link is created, indicating that both share

the same data.

[6] Double-click to start up the

.


[7] This is the GUI. Note that the model is automatically brought into . By default, the body

is assumed to be made of steel.

[8] Make sure the length unit is . If not,

select the right unit from the pull-down menu (see [9]).

[9] If the length unit is not , select . Unlike DesignModeler, the units can be changed any time as you like in

.


1a-3 Specify Loads

[1] Click to highlight .

[2] Select .

[3] A object is inserted under the branch.[4] Select this

cylindrical face.

[5] Click .

[6] Select .

[7] Type -187 (lbf) for , and 126 (lbf)

for .

[8] Select again.

[9] A object is inserted.

[10] Select this cylindrical face.

[11] Click .

[12] Select .

[13] Type 264 (lbf) for , and 281 (lbf)

for .


[1] Select .

[2] A is inserted.

[4] Click .


1a-4 Specify Supports

1a-5 Insert Result Objects


[3] A solution object is inserted under the branch.

[2] Select .


1a-6 Solve the Model[1] Click .

[7] Click to close the window.

[8] Click to animate the deformation.

[9] Click to stop the animation.

[2] Click the Z-axis to rotate the view so that you look into the

.

[3] The maximum stress is 29,690 psi, slightly below

the allowable stress (30,000 psi). Note that the

maximum stress can be reduced by increasing the

radius of the fillet.

[6] For visual effect, the

deformation is automatically

enlarged 49 times. [5] Undeformed shape.

[4] Select .


1a-7 Save the Project and Exit Workbench

[1] Select . The

disappears.

[2] In the , save the project as

"Arm-a".

[3] Select to quit from the Workbench.

28 Exercise 2. Ratchet Stop

Exercise 2Ratchet Stop

The ratchet stop is used to control a ratchet wheel so that the ratchet wheel rotates in a certain direction only [1, 2]. The ratchet wheel will be created in Exercise 3. In this exercise, we'll create a 3D solid model for the ratchet stop. The details of the ratchet stop are shown in the figure below [3]. Note that the coordinate system is also shown in the figure.

2-1 Introduction [2] The ratchet stop is used to control the rotational direction of

the ratchet wheel.

[1] The ratchet wheel.

Y

X

0.57

0.1

25

Unit: in.


R0.56

R0.188

R0.34

0.16

Slop:

40

[3] Details of the

ratchet stop.


[2] Double-click cell to start

up the DesignModeler. Select as the length

unit (1-2[9, 10]).

[1] Launch ANSYS Workbench and create a

system (1-2[1-5]).


2-3 Draw a Circle on XYPlane

[1] Switch to (1-3[2]).

[2] Rotate to XYPlane view

(1-3[3])

[3] Draw a circle centered at the plane origin

(1-4[1-5]).

[4] Select tool and specify a radius of 0.188 (in.) for the circle.

Remember to turn on the display of dimension value (1-4[15-17]). Also remember to use

to move the dimension to a suitable position (1-4[12, 13]).


2-4 Draw a Line

[1] Select tool and

draw a line roughly like this.

[2] Select tool and create a length

dimension by simply selecting the line segment and move the

mouse upward. Specify a dimension value of 0.16 (in.).

[3] Select tool and specify a horizontal

dimension of 0.57 (in.) (1-5[7-11]).

[4] Select tool and specify a vertical dimension of 0.125 (in.) (1-5[13-15]).

[5] The line is not blue-colored, meaning it isn't fully defined in the space yet. We

now specify an angle dimension for the line.

2-5 Specify an Angle Dimension

[1] To specify an angle dimension, you need to select two lines (or axes). When you select a line (or axis), the end near where you click become the "arrow end" of the line. The angle is then measured from the first

line to the second line in a counter-clockwise fashion.

[2] Select tool and then click the X-axis on the

positive side.[3] Click the line here near the

upper-right end.

[4] Click here to create an angle dimension.

Type 40 (degrees) in the . Note

that the angle is measured counter-

clockwise from the first line to the second. Also

note that the line is blue-colored now.

[5] If you made mistakes (click on wrong ends or in a wrong order) and the angle is not what you meant, right-click anywhere in the graphics window to

bring up a and choose . Repeat this before you click to locate the angle dimension until the correct angle appears.


2-6 Draw Arcs

[1] Select tool and then click roughly here to

define the center.

[3] Click to define another end roughly here on the circle.

[2] Click the upper-right end of the line to define an end of

the arc.

[4] An arc is created.

[5] Select tool and specify a radius

dimension of 0.56 in. [6] Select tool and then select

the arc and the circle. A constraint is

imposed between the arc and the circle. Note that the arc

turns blue.

[7] Also note that the center of the arc moves to a new location to accommodate the constraint.


[8] Select tool again and

define the center roughly here.

[9] Click the lower-left end of the line to define an end of the

arc.

[10] Click to define another end roughly here on the circle.

[11] Select tool and specify

a radius dimension of 0.34 in.

[12] Select tool and impose a

constraint between the newly created

arc and the circle.



[1] Select tool and make sure is turned on (1-9[1]). Click here to trim away the arc segment.

[2] The finished sketch.

2-8 Extrude the Sketch to Create the Ratchet Stop

[1] Extrude the sketch 0.125 in. to create the

ratchet stop (1-10[1-6]).

Wrap UpClose DesignModeler, save the project as "Stop," and exit the Workbench (1-11[1-3]).


Context MenuWhen you right-click the mouse, a menu pops up. The contents of the menu depends on when and where you right-click the mouse. The menu is thus called the (2-5[5]). Try to right-click anywhere in the graphics area, , or (1-10[2]), to see the contents of the .

ToolThis tool can be used for any type of dimension. For a line, the default is to create a dimension (2-4[2]). For a circle or arc, the default is to create a diameter dimension. If the default is not what you want, right-click anywhere in the graphics window to bring up the [1] and choose a dimension type.

ToolTo specify an angle dimension, you need to select two lines (or axes). When you select a line (or axis), the end near where you click become the "arrow end" of the line. The angle is then measured from the first line to the second line in a counter-clockwise fashion (2-5[1-4]). If you made mistakes (click on wrong ends or in a wrong order) and the angle is not what you meant, right-click anywhere in the graphics window to bring up the [2] and choose . Repeat this until the correct angle appears before you click to locate the angle dimension (2-5[5]).

ToolThis tool draws a line by defining two end points (2-4[1])).

ToolThis tool draws an arc by defining its center and two end points (2-6[1-4]).

ToolThis tool impose a constraint between two curves or between a line and a curve (2-6[6, 12]).

2-9 Review

[1] This is the when is

activated.

[1] This is the after you select two lines (or axes) and

before you click to create an angle dimension.

Exercise 3. Ratchet 35

Exercise 3Ratchet Wheel

In this exercise, we'll create a 3D solid model for the ratchet wheel mentioned in Exercise 2 [1]. The details of the ratchet wheel are shown in the figure below [2].

3-1 Introduction

[1] The ratchet wheel.

Y

X

Unit: in.

Thickness: 0.25 in.

D0.25

1.00

15 60

[2] Details of the ratchet

wheel.

36 Exercise 3. Ratchet



unit.


system.


3-3 Draw Two Concentric Circles

[1] On XYPlane, draw two concentric circles with

diameters of 0.25 in. and 1.00 in. respectively.


3-4 Draw Lines with Angle Dimensions

[1] Draw a line passing the origin like this.

[2] Specify an angle dimension of 15 degrees. Remember to select the line first and then

the axis. Clicking positions are also important (2-5[1-5]).

[3] Draw another line like

this.

[4] Specify an angle dimension of 60

degrees.



[1] Draw a circle which passes through an end point of the line.

When you define the radius, remember to snap (with a

constraint) the end point of the line. The circle serves as a construction

(temporary) circle.

[2] Trim away unwanted segments.

Remember to turn on (1-9[1]).

[3] After trimming, a single tooth remains.


3-6 Duplicate Teeth

[1] Select .

[2] Select these two lines. To select multiple entities, hold Control key while click the

entities sequentially. You also can "sweep select" multiple entities, i.e., holding left mouse button

while sweep through the entities. After the selection, the entities

are highlighted with yellow color.

[3] Right-click anywhere in the

graphics window to bring up the

, and select . Now the tooth has been copied to a

"clipboard."

[4] The tool is automatically activated. Type 15

(degrees) for the , meaning that the rotating

angle is 15 degrees.


[5] Bring up the ,

and select . Note that a negative angle

is to rotate clockwise. [6] Bring up the

again, and select .

[7] The tooth is rotated 15 degree clockwise (using plane origin as

center of rotation) and

pasted.

[8] Repeat steps [5, 6] four more times. Press to end the tool or choose from the .


[9] Select again, and

select all the teeth, using "sweep

select" [2]. From the , select [3].

[10] Type 90 (degrees) for the rotating angle.

[11] Repeat steps [5, 6].

[12] Repeat steps [5, 6] two more times. Press to

end the tool or choose from the .


3-7 Extrude the Sketch to Create the Ratchet Wheel

Wrap UpClose DesignModeler, save the project as "Ratchet," and exit the Workbench.

[1] Extrude the sketch 0.25 in. to create the ratchet

wheel.


Selection of Multiple EntitiesThere are several ways to select multiple entities. Two of them are and . Control-Select -- Click the entities sequentially while holding the Control key. Sweep Select -- Hold the left mouse button and sweep through the entities. Box Select -- Select [1], and use mouse to define a box. All entities inside the box are selected.

3-8 Review

and Tools copies the selected entities to a "clipboard." A must be specified using one of the methods in the (3-6[3]). After completing the tool, the tool is automatically activated. pastes the entities in the "clipboard" to the graphics window. The pasting location corresponds to the specified in the tool. To define the pasting location, you either click on the graphics window or choose from the (3-6[6]). Many options also can be chosen from the (3-6[5]), where the rotating angle and the scaling factor can be specified with the tool (3-6[4]). A positive rotating angle is to rotate counter-clockwise.

Tool is equivalent to a followed by a .

Ending a ToolYou can press to end a tool (3-6[8, 12]). Besides, the often provides an option to end a tool (3-6[5, 6]).

[1] One way to select multiple entities is to

turn on .

44 Exercise 4. Cover Plate

Exercise 4Cover Plate

In this exercise, we'll create a 3D solid model for a cover plate, of which the details are shown in the figure below [2].

4-1 Introduction

Y

X

Unit: in.


8 R0.15

2.0

0

[1] Details of the cover plate.

0.376 1.

25

0.7

5

0.2

5 0

.25

0.562

1.50

6 R0.06

0.312 0.312

2 R0.188 2 D0.201




unit.


system.


4-3 Draw Circles

[1] On XYPlane, draw a circle centered at the

origin and with a diameter of 0.201 in.

[2] Draw another circle with the same diameter.

Make sure an appears when you define the radius

(1-5[5]).

[3] Use to specify a dimension of 0.376 in.

[4] Use to specify a

dimension of 2 in.


[5] Draw a concentric circle with a radius of

0.188 in.

[6] Draw a concentric circle with the same radius. Make sure an appears when you define the radius.

4-4 Draw Rectangles and Lines

[1] Select and draw a

rectangle with dimensions a shown.


[2] Select and draw three segments like this. Select from the after you

define the fourth point. Note that the three segments are either horizontal or vertical,

therefore make sure an or a appears before clicking.

Specify the dimensions as shown.

[3] Select again and draw a line like this. Note that the two end points coincide with

the Y-axis.

[4] Trim away this extra segment.

[5] Trim away this extra segment.


[6] Use again to draw a vertical

line and specify a horizontal dimension as

shown.

[7] Trim away this segment.




4-5 Draw Fillets

[1] Select

and type 0.06 (in.) for the .

[2] Create 6 fillets with the same radius

(1-8 [2]).

[3] Create a radius dimension for

anyone of the fillets (1-8[3]).

[4] Select

again and type 0.15 (in.) for the .

[5] Create 4 fillets with the same

radius.


[6] With tool still activated, create this fillet by clicking the horizontal line and the circle. Note that the

horizontal line is automatically trimmed.

[7] Repeat the last step to create this fillet.

[8] Use to re-create the

trimmed segment.

[9] Repeat the last step to re-create this line.



[10] Use to create this fillet (with the same radius as before) by

clicking the horizontal line and the circle.

[11] Repeat the last step to create this fillet.

[1] Select and turn on , then

trim away this segment.

[2] And this segment.

[12] Create a radius dimension for anyone

of the 8 fillets.


4-7 Extrude the Sketch to Create the Cover Plate

Wrap UpClose DesignModeler, save the project as "Cover," and exit the Workbench.

[3] The final sketch.

[1] Extrude the sketch 0.046 in. to create the

cover plate.


Draws a rectangle by defining two diagonally opposite points. The edges of the rectangle are either horizontal or vertical. To draw a rectangle at an arbitrary orientation, please use .

This tool allows you to draw a series of connected lines, called a polyline. The polyline can be closed or open. After defining the last point, choose or from the .

Auto ConstraintsH -- HorizontalV -- Vertical

4-8 Review

Note:For a comprehensive description of sketching tools, please refer to the following ANSYS on-line reference:ANSYS Help System//DesignModeler User Guide//2D Sketching

54 Section B. Part Modeling

Section BPart Modeling

As mentioned in the opening of Section A, many parts can be created by a two-step operation: drawing a 2D sketch on a plane and then generate a 3D body by extrusion, revolution, sweeping, or skin/lofting. A more complicated part often can be viewed as a series of the two-step operations; each two-step operation either add material to the existing body or cut material from the existing body. The exercises in Section B are designed to introduce the 3D modeling techniques for more complicated parts.

Exercise 5. Crank 55

Exercise 5Crank

In this exercise, we'll create a 3D solid model for a crank, of which the details are shown in the figure below. Note that a global coordinate system is set up and shown in the figure. The crank model can be viewed as a series of three two-step operations; each involves drawing a sketch on XYPlane and then extrude the sketch to generate a material. The materials are either add to the existing body or cut from the existing body.

5-1 Introduction

Y

X

Unit: mm.

75

65

Y

Z

20 8

R22

D30

D20

R10

2 R10 2 D10

56 Exercise 5. Crank


up DesignModeler.


system.


5-3 Draw a Sketch on XYPlane

[1] On XYPlane, draw 5 circles and 4 tangent lines (using ) like this. Specify the dimensions.

[3] Select as the

length unit.


[2] Use to draw a fillet

with a radius of 10 mm.

[3] Trim away these three arc segments.


5-4 Extrude to Create a Solid Body

[3] Click .

[4] It automatically switches to

.

[1] The active plane.

[2] The active sketch.

[6] Click . The active sketch is automatically taken for .

[7] Type 8 (mm) for .

[9] Click .

[8] Click the small cyan

sphere to rotate the view into an isometric view.

[10] Click to turn off the plane display.

[12] Click all the plus signs to expand the model

tree.

[11] The displays a

tree structure for the geometry model,

called .

[13] Under the XYPlane, we've created a sketch

(Sketch1)

[14] The uses as the base geometry.

[5] An object is inserted in

the model tree.

[15] This is the body we've

created so far.


5-5 Create a New Sketch on XYPlane

[3] Click to switch to .

[2] A new sketch (Sketch2) is created. Note that, for the first sketch of a plane, you don't need to explicitly click . However, for additional sketches on the same plane, you need to click . Remember that the

drawing entities always belong to the active sketch.[4] Click .

[5] Click to turn off

the solid model display.

[6] Draw a circle with a diameter of 30 mm. This is the only entity in . Note that both

Sketch1 and Sketch2 are on the same plane (XYPlane).

[1] Click .


5-6 Add Material to the Existing Body

[1] Click .

[2] Click .

[3] Type 20 (mm).[5] Click

.

[6] The newly created material is simply a

cylinder; it adds to the existing body to form a

single body.

[4] The default is .

[8] Click the plus sign to

expand .

[9] uses as

the base geometry. The is

simply a cylinder.

[10] The body after adding

material.

[7] is added under

XYPlane.


5-7 Create Another New Sketch on XYPlane


[2] A new sketch (Sketch3) is created. [4] Click .

[5] Click to turn off

the solid model display.

[6] Draw a circle with a diameter of 20 mm. This is the only entity in . Note that all three sketches are on

the same plane (XYPlane).

[1] Click .


5-8 Extrude to Create a Third Simple Body

Wrap UpClose DesignModeler, save the project as "Crank," and exit the Workbench.

[1] Click .

[2] Click .

[4] Select .

[5] Click .

[6] The newly created material is simply a

cylinder; The material is cut from the existing body.

[3] Select .

[10] The body after cutting

material.

[7] is added under

XYPlane.

[9] uses as

the base geometry. The is

simply a cylinder.

[8] Click the plus sign to

expand .


and A sketch must be created on a plane; each plane, however, may contain multiple sketches. In the beginning of a DesignModeler session, three planes are automatically created: XYPlane, YZPlane, and ZXPlane. You can create new planes and new sketches as many as needed.

and The currently active plane and active sketch are shown in the toolbar (5-4[1, 2]). New sketches are created on the active plane, and new drawing entities are created on the active sketch. You may change the active plane or active sketch by selection from the pull-down list, or simply clicking the names on the model tree.

Modeling ModeIn the modeling mode (5-4[4]), several modeling tools become available, including Extrude, Revolve, Sweep, Skin/Loft, Thin/Surface, Blend, Chamfer, Point, etc. In addition, a is displayed.

Model Tree (5-4[11]) contains an outline of the model tree, the data structure of the geometric model. Each branch of the tree is called an object, which may contain one or more objects. At the bottom of the model tree is a part branch, which is the only object that will be exported to . By right-clicking an object and selecting a tool from the context menu, you can operate on the object, such as delete, rename, duplicate, etc. The order of the objects is relevant. renders the geometry according to the order of objects in the model tree. New objects are normally added one after another. If you want to insert a new object BEFORE an existing object, right-click the existing object and select from the context menu. After insertion, will re-render the geometry.

and With operation mode, the created material adds to the existing active body (i.e., they form a union). With operation mode, the material is cut from the existing active body. An active body is one that is not frozen (to be defined later).

5-9 Review

64 Exercise 6. Geneva Gear Index

Exercise 6Geneva Gear Index

In this exercise, we'll create a 3D solid model for a Geneva gear index, of which the details are shown in the figure below. Note that a global coordinate system is set up and shown in the figure.

6-1 Introduction

Y

X

Unit: in.

Y

Z

0.25

D0.5

0.44

D0.25

D1.25

D2.47

5 0.2 5 R0.63

1.529

Exercise 6. Geneva Gear Index 65

[2] Double-click cell to start up the

DesignModeler. Select as the length unit.


system.


6-3 Draw a Sketch on XYPlane

[1] On XYPlane, use to draw an arc centered at

the origin and with a radius of 1.235 (in.) like this.

[2] draw two lines, each connects the origin to an

end point of the arc.

[3] Specify an angle dimension of 72 (degrees) for the

sector.

[4] Use to draw another arc with a radius of 0.625

(in.) like this.

[5] draw two circles centered at end points

of the new arc and with the same radius

of 0.1 (in.).


[8] Apply a on the lower circle and

the horizontal line.

[7] Draw a line connecting the upper circle to the outer arc like this. The line is parallel to the adjacent line,

therefore make sure a (indicating parallel auto constraint)

appears before clicking.

[9] Apply a on the upper

circle and the parallel line.

[6] Draw a line connecting the lower circle to the outer arc like this. The

line is horizontal, therefore make sure an appears before clicking.


[10] Draw a line starting from the origin like this. Then, make the outer arc symmetric about the newly created line. To do

this, select , and then

subsequently click the line and the two end points of the arc.

[11] Use to specify a length dimension of

1.529 (in.).

[12] Use to draw an arc

centered at one end of the new line. Specify the radius

dimension of 0.63 (in.).


6-4 Extrude to Generate 1/5 of the Gear Index

[1] Extrude the sketch 0.25 in.

[13] Trim away unwanted segments. This is the sketch after trimming. Note that,

although the the sketch is no more blue-colored, all the

dimensions are not changed.


6-5 Duplicate the Body Circularly

[1] Select from the pull-down menu.

[2] In the , select

for .

[3] Click the yellow area to bring up buttons.

[4] Select the body.

[5] And click .

[6] Click the yellow area to bring up buttons.

[7] Select this edge.

[8] And click .

[9] Type 4 for .

[10] Click .


6-6 Create the Hub

[1] Select from

the pull-down menu.

[4] Click .

[2] Type 0.44 (in.) for the .


[5] Select again.



[6] Select for .

[9] Click .

Wrap UpClose DesignModeler, save the project as "Geneva," and exit the Workbench.


Auto Constraints: It is applicable to a line, indicating that the line is parallel to another line in the same plane (6-3[7]).

Sketching Tools: It can be applied on two edges (lines or curves), one of them must be a curve, to make them tangent to each other (6-3[8, 9]).

This tool allows you to create copies bodies in three types of pattern: Linear, Circular, and Rectangular (6-5).

This tool creates a cylinder by specifying its origin, axis, and radius (6-6). The origin and axis are defined by referring to the active plane coordinate system (1-12).

6-7 Review

72 Exercise 7. Yoke

Exercise 7Yoke

The yoke is a part of a universal joint [1]. In this exercise, we'll create a 3D solid model for the yoke, of which the details are shown in the multiview drawings below. Note that a global coordinate system is also shown in the figure.

7-1 Introduction

Y

X

Unit: in.

Y

Z

R1.00

X

Z

D0.75

D1.20

2 0.75

R1.00

1.50

3.5

5[1] The yoke is a part of a universal joint.

Exercise 7. Yoke 73




system.


7-3 Create a U-Shape Body

[1] On XYPlane, use tool to draw two concentric arcs. Specify

the radius dimensions (1.00 in. and 1.75 in. respectively).[2] Use tool to draw a 3-segment polyline,

starting from this point.

[5] Click the last point and then select from the . If the last segment is not vertical,

use to make it vertical.

[3] Click the second point. Make sure the first segment is vertical.

[4] Click the third point. Make sure the

second segment is horizontal.

[6] Use to

specify a length of 2.50 (in.).

74 Exercise 7. Yoke

[7] Draw two vertical lines.


[9] Click .

[12] Click .

[10] Select .

[11] Type 1 (in.) for . Note that, the sketch is extruded

by 1.0 in. for both sides of XYPlane,

therefore the total depth is 2.0 in.

Exercise 7. Yoke 75

7-4 Create Rounds

7-5 Create Holes

[1] Select

from the toolbar.[2] Control-

select these 4 edges.

[3] Click .

[4] Type 1 (in.) for . [5] Click

.

[1] Select from

the pull-down menu.

[3] Click .

[2] Click to bring up buttons, then select

from the model tree and click . Now the

global Y-axis becomes local X-axis, and the global Z-axis becomes local Y-axis.

The origin and the axis are defined using the local

(plane) coordinate system.

76 Exercise 7. Yoke

7-6 Create Shaft[1] Click to create a new plane.

[2] A new plane (Plane4) is inserted into

the model tree.

[3] Click to bring up buttons, then select from the model tree and click . Now the

global Z-axis becomes local X-axis, and the global X-axis becomes local Y-axis.

[4] Select for . Note that it refers to the local Z-axis.

[5] Type 3.55 (in.) for .

[6] Click .

[7] The new plane become active plane.

[8] The global coordinate system.

Note that the Workbench uses RGB

colors to represent XYZ axes respectively.

[9] The local coordinate system of the new plane.

Note that, in a local coordinate system, the Workbench also uses

RGB colors to represent XYZ axes respectively.

Exercise 7. Yoke 77

[1] Click to switch to the .

[2] Click to look at .

[3] Click to turn off model display.

[4] Draw a circle with a diameter of

1.2 (in.).

[5] Click .

[8] Click .

[6] Select for

. Now, the extrusion

direction is the -Z direction.

[7] Select . Now the

sketch will be extruded up to the

next face.

Wrap UpClose DesignModeler, save the project as "Yoke," and exit the Workbench.

78 Exercise 7. Yoke

Extrude DirectionThere are four options you can choose for the extrusion direction: , , , and . In case, the extrusion direction is the Z-direction of the sketching plane. When is selected, the extrusion direction reverses to the -Z-direction (7-6[6]). For , the extrusion is along both +Z and -Z directions with the same depth (defined by ) (7-3[10]). For , the extrusion is along both +Z and -Z directions with the different depths (defined by and ).

This tool can be used to place rounds or fillets on a body (7-4). The fillets are specified on edges, while the rounds can be specified on edges or faces. When faces are specified for rounds, the rounds are placed on the enclosing edges.

Create New Planes from Existing PlanesThere are many ways to create a new plane [1]. Creating new plane from an existing plane (7-6[1-9]) involves selecting the existing plane and then transforming the existing plane to a new position and orientation.

7-7 Review

[1] There are many ways to create a plane.


0.375

[1] The support is a part of a clamping

mechanism.

Exercise 8Support

The support is a part of the clamping mechanism mentioned in Exercise 1 [1]. In this exercise, we'll create a 3D solid model for the support, of which the details are shown in the multiview drawings below. Note that a global coordinate system is also shown in the figure.

8-1 Introduction

Y

X

Unit: in.

Y

Z

X

Z

6 D0.25

2.500

R0.313

0.8

75

1.250

2 R0.100

1.25

0 0

.750

R0.100

0.6

25 0.125

0.375

0.125

0.250 0.219

1.250 0.375

0.250

0.375

Slope: 45 R0.156

1.000

80 Exercise 8. Support




system.


8-3 Create Vertical Plate

[1] On XYPlane, draw three circles of the same

radius. Specify their locations (two horizontal dimension of 1.25 and one vertical dimension of 1.25)

[2] Specify a diameter of 0.25 in. for any one of

the circles.

[3] Use to draw a

polyline starting from roughly here.

[4] Click the second point, making sure the last segment is

vertical.

[5] Click the third point, making sure the last segment is

horizontal.

[6] Click the fourth point, making sure the last segment is vertical. Then select from the .

[7] Specify all dimensions so that all entities become blue-colored: length dimensions of 2.50 and 0.625; a horizontal dimension of

0.375, a vertical dimension of 0.875, and an angle dimension of 45 degrees.


[8] Draw two more circles, specify their radii (0.156 and

0.313) and locations (horizontal dimensions of 0.219 and 0.250; vertical

dimensions of 0.25 and 0.75)

[9] Trim away unwanted segments.


[10] Draw two fillets with the same radius of

0.1 in.

[13] Click .

[11] Click .

[12] Type 0.125 (in.) for .


8-4 Create Horizontal Plate

[1] Click .

[4] Click the yellow area to

bring up buttons.

[2] Select .

[6] Click .

[7] Click ; a is created.

[5] Click this face at a location near this circle. A plane coordinate system shows up like this (the X axis points to global -X

axis). Note that the location you click

determines the origin and the axes of the plane

coordinate system. If the coordinate system is not like this, simply re-click again until it is correct.



[10] Click to turn of the model

display.

[11] This is ; it is called an since it includes an outline. The outline is not part of a sketch

but can be used as references.

[12] Draw a rectangle like this. Note that three sides of the rectangle coincide with plane's outline. Specify a length dimension of 0.125 in.

so that the rectangle become blue-colored.

[3] The default is

.

X Y

Z


[15] Click .

[13] Click .

[14] Type 1 (in.) for .

[1] Click .

8-5 Create Holes on the Horizontal Plate

[6] Click ; a is created.


bring up buttons.[2] Select

.

[5] Click .

[4] Click this face at a location near this corner so that the plane coordinate system is like this (the

X axis points to global X axis). Remember, if the coordinate

system is not like this, simply re-click again until it is correct.

X

Y

Z




[9] Click to turn of the model

display.

[10] This is ; it includes an

outline.

[11] Draw three circles of the same diameter (0.25 in.) and specify their positions (horizontal dimensions of

0375, 0.375, and 1.25; vertical dimensions of 0.375, 0.375, and 0.125)

[16] Click .

[12] Click .

[13] Select .

[15] Select .

[14] The automatically

becomes .


8-6 Create the Round

[1] Select

from the toolbar.

[5] Click .

[2] Click this edge.

[3] Click .

[4] Type 0.1 (in.) for .

Wrap UpClose DesignModeler, save the project as "Support," and exit the Workbench.


Create New Planes From FacesYou can create a new plane from an existing face (8-4[1-7]). There are subtypes to choose: and . The only difference is that a doesn't include the outline of the face. In either subtype, the plane coordinate system is determined according to how you click the face. The origin is usually located at the closest corner point or the center of a circle (or an arc); The Z-axis always points out of the face; The X-axis is usually parallel to the closest edge. An outline plane include the outline of the face (8-4[11]). The outline is not part of a sketch but can be used as references (datum). Without the outline, the only references are two exes (X-axis and Y-axis of the plane). However, you can copy the outline (or part of the outline) into a sketch, using the sketching tool .

8-7 Review

88 Exercise 8a. Structural Analysis of the Support

[2] This is the deformed structure under the design loads. The wireframe is the underformed configuration.

Appendix:

Exercise 8aStructural Analysis of the Support

In this exercise, we will perform a static structural analysis for the support created in Exercise 8. The objective is to find the deformation and the stresses under the working loads, and make sure the stresses are within the allowable level (30,000 psi). As mentioned in Exercise 1a, the clamping mechanism is entirely made of steel and is designed to withstand a clamping force of 450 lbf [1]. After a structural analysis of the entire mechanism [2] (which is performed in Exercise 17a), the results show shows that, to withstand a clamping force of 450 lbf, the support is subject to external forces as shown [3] (also see 17a-4). Note that the holes on the horizontal plates are fixed to the ground [4]. The analysis task will be carried out with .

8a-1 Introduction

[1] The clamping mechanism is designed to withstand a clamping force of 450 lbf.

62 lbf

163 lbf

380 lbf

[3] The external force on the arm.

See 17a-14.

380 lbf

[4] The horizontal plates are fixed to

the ground.


[2] Open the project "Support," which was saved in

Exercise 8.


8a-2 Start Up

[3] Double-click to create a

analysis system.

[4] Drag ...

[5] And drop here. A link is created, indicating that both share

the same data.

[6] Double-click to start up the

.


[7] Make sure the length unit is (1a-2[8, 9]).

8a-3 Specify Loads


[2] Select .


[4] Click .

[5] Select .

[6] Type -380 (lbf) for , and 62 (lbf)

for .


[7] Select again.


[9] Click .

[10] Select .

[11] Type 380 (lbf) for , and 163 (lbf)

for .

[1] Select .

[2] Control-select the three cylindrical

faces on the horizontal plate.

8a-4 Specify Supports

[3] And control-select

this face.




[3] A solution object is inserted under the branch.

[2] Select .

[4] Click . Totally 5 faces are set to .

[5] Select


8a-6 Solve the Model[1] Click .



[3] The maximum stress is 20,608 psi,

well below the allowable stress

(30,000 psi).

[2] Select .

Wrap UpClose , save the project as "Support-a," and exit the Workbench.

94 Exercise 9. Wheel

Exercise 9Wheel

The main purpose of this exercise is to introduce another modeling tool (than ): , which takes a sketch as the profile and revolves about an axis to create a 3D solid body. We'll create a 3D solid model for a wheel, of which the details are shown in the multiview drawings below. A global coordinate system is also shown in the figure. Note that the wheel is axisymmetric. An axisymmetric body can be created by drawing a profile then revolting about its axis to generate the 3D solid body.

9-1 Introduction

X

Unit: in.

Y

Z

D4.00

Y

0.25

0.50

0.75

45

D3.50

D1.50

D1.00





system.


9-3 Create the Profile

[2] and ending here. Select from the context menu. Specify all

dimensions as shown.

[1] On XYPlane, use to

draw a polyline starting from here.

96 Exercise 9. Wheel

[3] Use to "mirror copy" everything about the Y-axis. The procedure is as follows:

(a) select all segments;(b) select from the context menu;(c) select from

the context menu;(d) select

from the context menu;(e) finally select from the context menu (or press ).


9-4 Revolve the Sketch about X-Axis

[4] On the graphics window, select the X-axis

and click .

[1] Click in the toolbar.

[2] Rotate to an isometric view.

[5] Click .

[6] Click to turn off the plane

display.

Wrap UpClose DesignModeler, save the project as "Wheel," and exit the Workbench.

[3] Click . The active sketch is automatically taken

as the profile.

9-5 Review

Modeling Tool It takes a sketch as the profile and revolves about an axis to create a 3D solid body (9-4[1-5]). The angle of revolution can be specified.

98 Exercise 10. Transition Pipe

Exercise 10Transition Pipe

10-1 Introduction

Y

Z

Y

Unit: in.

8 D0.25

2 D2.50

2 D3.50

2 0.25 R2.50

X

D1.00

R3.50

The transition pipe is used to connect two pipe segments. In this exercise, we'll create a 3D solid model for the transition pipe, of which the details are shown in the multiview drawings below. A global coordinate system is also shown in the figure. The main purpose of this exercise is to introduce another modeling tool: , which takes a sketch as the path and another sketch as the profile; the profile then "sweeps" along the path to create a 3D solid body. Note that it is possible to create the curved pipe by using of tool (Exercise 9), however, as an exercise, we decide to create the curved pipe by using .

R1/8"

R1/16"

Exercise 10. Transition Pipe 99




system.


10-3 Create a Sketch for the Path

[1] On the XYPlane, draw an arc like this . This sketch will be used as the sweeping path

of the curved pipe.

10-4 Create a Sketch for the Profile

[1] On the ZXPlane, draw two concentric circles like this. This

sketch will be used as the profile of the curved pipe.

[1] Select (or click ZXPlane in the model tree).


10-5 Create a Body Using

[1] Click on the

.

[3] Click .

[2] Select (from the model tree) for the and

select (from the model tree) for the

.

10-6 Create a Plane on One End of the Pipe

[1] Click .

[2] Select .

[4] Click this face. Note that the local Z-axis (blue) points out of the face, and the local

X-axis (red) points to the global -Z direction.

[3] Click the yellow color area to bring up

buttons. [6] Click .

[5] Click


10-7 Create an End Plate

[1] On the new plane (Plane4), create a sketch like

this (see next two steps). Remember to impose two constraints to make the four small circles

symmetric about X-axis and about Y-axis.

[2] The sketch includes a circle

that overlaps with the inner circle of the plane outline.

[3] The sketch doesn't include this circle, which is

the outer circle of the plane outline.

[6] Click .

[4] Click .

[5] Select . This generates a

separate body.


10-8 Create Another End Plate by Duplication

[1] Click .

[2] Select .

[3] Click the yellow color to bring up

buttons.

[4] Click this face. Note that the local Z-axis (blue) points

out of the face.

[6] Click . is

created.[5] Click .

[7] Select .

[12] Click .

[9] Select the existing end plate.

[10] Select from the model tree.

[11] Select from the model tree.

[8] Select .


10-9 Unite All Bodies into One Body

[1] Select .

[3] Control-select all three bodies.

[4] Click .

[2] is the default .

10-10 Create Fillets

[1] Select .

[3] Click .

[2] Control-select these two

edges.

[4] Click .


10-11 Create Rounds

[1] Select .

[3] Click .

[2] Control-select these two

edges.

[4] Click .

10-12 Turn Off Edges

[1] Select to turn off

the edges display.

Wrap UpClose DesignModeler, save the project as "Pipe," and exit the Workbench.


10-13 Review

Modeling Tool The can be thought of a generalization of the . takes a sketch as the path and another sketch as the profile; the profile then "sweeps" along the path to create a 3D solid body (10-5). The also can be used to create spiral shapes, which will be demonstrated in Exercise 12.

Add FrozonA body is either in a state of active or frozen. The default state is active. Two overlapped active bodies would automatically join together to form a single body. If either of them is frozen, they wouldn't join together. Therefore, the only way to avoid overlapped bodies joining together is to make at least one of them frozen. In 10-7, we create the end plate as frozen body (separating it from the curved pipe), so that, in 10-8, we can copy the end plate alone without the curved pipe.

This tool moves a body (or a group of bodies) to another position and orientation in the same way that the source plane is move to coincide with the destination plane (10-8). If the option is , it essentially copies the bodies. This tool is useful for "assembling" parts together to form an assembly.

Using boolean operations, bodies can be united, intersected, and subtracted.

106 Exercise 11. C-Bar

40

40

70

D10

120

30

20

20

R10

R50

100

Exercise 11C-Bar

11-1 Introduction

Y

Z

Y

Unit: mm.

The C-shaped steel bar is used as a dynamometer, a device to measure the magnitude of a force P [1]. A strain gauge is bonded to the surface of a location as shown [2]. The measured strain is then used to calculate the force P. The details are shown below; a coordinate system is also included in the figure. In this exercise, we will create a 3D solid model for the C-bar. Due to the symmetry, we will create the upper half of the model and then complete the model by using a "mirror" (copy) operation.

P

P

[1] The C-bar is used to

measure a force P.

[2] A strain gauge is bonded to the surface here. The measured strain is used to calculate

the force P.

X

[3] The body has a thickness of 5 mm.

everywhere.

[4] All fillets have radii of 3 mm.

Exercise 11. C-Bar 107




system.


11-3 Create a Sketch for the Path

11-4 Create a Sketch for the Profile

[1] On the XYPlane, draw a sketch like this.

[2] On the YZPlane, draw a sketch like this.

The sketch is symmetric about the

horizontal axis.

[1] Select (or click YZPlane in the model tree).


11-5 Create a Body Using

[1] Click on the .

[3] Click .

[2] Select and (from the model tree) as the and

respectively.

11-6 Create an Ear

[1] Select

[4] Draw a sketch for the like this. Note that

is hidden now.

[2] Click .

is created on the .

[3] Right-click and select from the context menu.

Exercise 11. C-Bar 109

[7] Click .

[5] Click .

[6] Extrude 2.5 mm both sides.

11-7 Create Fillets

[1] Select .

[4] Click .

[3] Click .

[2] Control-select these two edges.


11-8 "Mirror" Copy the Body

[1] Select .

[4] Select from the

model tree.

[5] Click .

[6] Select to turn off

the edges display.

[3] Select the body and click .

[2] is the default

operation type.

Wrap UpClose DesignModeler, save the project as "CBar," and exit the Workbench.


Appendix:

Exercise 11aDeformation of the C-Bar

11a-1 Introduction

P

P

[1] Applied force P.

[2] Strain gauge.

As described in Exercise 11, the C-shaped steel bar is used to measure the magnitude of a force P [1]. A strain gauge is bonded to the surface of the location as shown [2]. The location is chosen because the strain is relatively large and distributed quite uniformly, so that the measured strain is not sensitive to the variation of the location of the strain gauge. The measured strain is then used to calculate the force P. The idea also relies on the fact that the strain is linearly proportional to the force P, which is true when the deformation is small enough. In other words, if the measured strain is doubled, then the force must be doubled. In this section, we will assume a force of P = 2,000 N, and perform a simulation to establish a relation between the force P and the strain .

11a-2 Start Up

[1] Launch Workbench

[2] Open the project "CBar," which was saved in Exercise 11.

[3] Drag and drop to cell of the system.

[4] A

system is created.

[5] The two systems share the same

. You can edit up-stream cell but not the down-

stream cell.[6] Double-click

to start up application.

112 Exercise 11a. Deformation of the C-Bar

[10] Pull-down-select .

Unlike DesignModeler, the units in can be

changed any time.

[8] Whenever necessary, pull-down-select and select tab to bring back

the "standard" layout.

[7] shows up. If your GUI layout is not like

this, pull-down-select and

select tab., see [8].

[9] If the unit system is not like this, see [10].


11a-3 Generate Mesh

[1] Highlight .

[3] In the , select for

and type "75" for .

[4] Select .

[6] Number of nodes and elements are shown in the Details view. Your

numbers may not be the same as here. Also note that in an academic teaching

version of ANSYS Workbench, the number of nodes or the number of

elements is limited to 30,000.

[5] Click "+" to expand

.

[2] Click "+" to expand

.


11a-4 Set Up Environment Conditions

MeshingThe process of dividing a body into small bodies is call meshing. The small bodies are called elements, or finite elements. The simulation method is thus called finite element simulation. The basic idea of finite element methods is to divide a body of rather complicated geometry into smaller elements of simple geometry, and the elements are assumed to be connected to each other through nodes. The element's geometry is so simple that a set of equations may be established easily for each element. All equations are then solve simultaneously for the displacements. Strains are then calculated from the displacements. And stresses are in turn calculated from the strains. In general, the finer the mesh, the more accurate the solution (and more computing time). In this exercise, we control the mesh size by simply adjusting and . Also, note that the Workbench will automatically generate a mesh right before it solves the problem if a mesh doesn't exist.

Limitation of Mesh CountIn this book, we will restrict the number of nodes or elements to be no more than 30,000, which is a limitation imposed by the version.

[1] Highlight .

[2] Select .

[3] Select this inner cylindrical surface.

[4] Click .


[10] We've added these two environment

conditions.

[5] Select . [6] Select this inner

cylindrical surface.

[7] Click .

[8] Select for and type

-2,000 (N) for .



[1] Highlight .

[2] Select to insert a result object.

[3] Select for

.

[4] Right-click the result object as shown and

select from the

context menu.

[5] The object is renamed for better readability.


11a-6 Solve the Model and View the Results

[1] Click .



[4] Click .

[5] Move the mouse around the model to display the strain value.

[6] Move the mouse to the location of the strain gauge and

click to put a label on the location. The strain is about 0.000296.


11a-7 Conclusion

The simulation results show that a force of P = 2,000 N produces a strain = 0.000296. We may establish a relation between the force P and the strain as follows:

P = 2000

0.000296

For example, if the measured strain in the strain gauge is

1 = 0.0001, then the force

P1 is

P1= 2000

0.0002960.0001= 676 N

Wrap UpClose , save the project ("CBar"), and exit the Workbench.


[1] The threaded shaft is a part of a

clamping mechanism.

D0.625

Exercise 12Threaded Shaft

12-1 Introduction

X

Y

Unit: in.

The threaded shaft is a part of the clamping mechanism mentioned in Exercise 1 [1]. In this exercise, we will create a 3D solid model for the threaded shaft, of which the details are shown below.

.375-16UNC

[4] Thread form: Unified

national coarse

[2] Major diameterd = .375 in.

[3] Pitchp = 1/16 in.

H = ( 3 2)p = 0.0541266 in

p H8= 0.0557342 in

H4= 0.0135316 in

D0.250

0.438 3.750

D0.266

0.875 M

ajor

dia

met

er d

Pitch p

p H 8

H 4 H=

(3

2)p

H 8

Slope: 60

Slo

pe: 6

0

120 Exercise 12. Threaded Shaft




system.


12-3 Create the Shaft

[1] On the XYPlane, use to draw a sketch like this. Specify the dimensions.

[3] In the graphics window, select the X-axis for .

[2] Click .

[4] Click .


12-4 Create a Hole [1] Select from

the pull-down menu.

[3] Click .

12-5 Create Threads[1] Click to create a new

sketch (Sketch2) on XYPlane.

[2] Right-click and select

.

[3] Click to make it active.

[2] The length is arbitrary as long as it is not less than

0.625 in.

122 Exercise 12. Threaded Shaft

[4] Draw a sketch like this.

Specify the dimensions. This sketch will be

used as the sweeping profile.

[5] This is the horizontal

dimension measured from the Y-axis.

[6] This is the vertical dimension measured from the

X-axis.

[7] Click to create a new sketch (Sketch3) on

XYPlane.

[8] Hide and make

active.

[9] Draw a sketch like this. The sketch is simply a horizontal line. The length of the line is arbitrary as long as it is not less than the total

length of the threads (3.75 in.). This sketch will be used as the sweeping

profile.


[11] Select (from the model tree) as the

.

[15] Click .

[12] Select (from the model tree) as the

.

[13] Select for .

[14] Type 0.0625 (in.) for .

[10] Click .

Wrap UpClose DesignModeler, save the project as "Shaft," and exit the Workbench.

124 Exercise 13. Lift Fork

[1] At the root, the cross section is 160x40 (mm.).

Exercise 13Lift Fork

13-1 Introduction

X

Y

Unit: mm.

The lifting fork is used in an LCD (liquid crystal display) manufacturing factory to handle glass panels. In this section, we will create a 3D solid model for the lift fork, of which the details are shown below. The cross sections of the prongs (fingers) are not uniform along the length [1-3]. The tools or cannot be used to created the prongs. This exercise introduces a modeling tool, , which takes a series of profiles from different planes and creates a 3D solid that fits through these profiles

1600

Z

200

2400

[3] At the midway, the cross section is

130x20 (mm.).

[2] At the tip, the cross section is 100x10 (mm.).

Exercise 13. Lift Fork 125




system.


[2] Extrude 200 mm. For details, see [3].

[3] Details view of the extrusion.

Remember to click .

13-3 Create the Transversal Beam

[1] Draw a rectangle on . The rectangle is symmetric about Y-

axis. Note that the top edge coincides with X-axis.


13-4 Create Three Planes Based on a Face of the Beam

Skin/LoftNow we want to create a single prong, or finger. The prong is then duplicated to create other prongs. The prong's cross section is not uniform. You cannot create the prong using or . A more general way to create a solid or surface of different cross sections along its path is using . takes a series of profiles from different planes and creates a solid that fits through these profiles. You may view as a generalization of , and as a generalization of .

[2] Create , see

[3].

[4] Create , see [5].

[6] Create , see [7].

[3] Details of .[5] Details of

.[7] Details of .

[1] All three planes will be created based on this face. When you select the face, make sure the coordinate system is attached at the

bottom-right corner and the directions of the axes are the

same as global axes.


13-5 Create a Sketch on Each Plane

[1] Create this sketch on . This

becomes .

[2] Create this sketch on . This becomes

.

[3] Create this sketch on . This becomes

.

[1] Click on

the toolbar.

[2] Control-select , , and (the order is important) in the model tree, and click . Note that a grey lofting guide

line appears. If your guide line is not correct, it can be resolved by right-clicking anywhere and selecting

to redefine the lofting guide line.

[3] Select .

[4] Click .

[5] The prong is created as a frozen body, because we

don't want the prong to join the transversal

beam for now.


13-7 Duplicate the Prong Using

[1] Select .

[2] Select the prong body.

[3] Click .


bring up .

[5] Select this edge.

[8] Click .

[6] If the direction is not like this...

[7] Click an arrow to switch the

direction.

[9] Type 480 (mm) for and 3

for .

[10] Click .


13-8 Combine the Bodies Using

[1] Select .

[4] Click .

[3] Control-select all five bodies and

click .

[2] The default operation is

.

Wrap UpClose DesignModeler, save the project as "Fork," and exit the Workbench.

130 Exercise 14. Caster Frame

Exercise 14Caster Frame

In this exercise, we'll create a 3D solid model for a caster frame, of which the details are shown in the multiview drawings below. A coordinate system is also shown in the figure.

14-1 Introduction

X

Unit: mm.

Fillets and rounds: R3

Z

Y

D21.5

Y

X

Z

D32

92

28

50

D17.5 D25

D35

64

126

76

13 10

10

10

10

R10 R15 10





system.


14-3 Create A Quarter of Main Body

[1] Click to make it active.


[3] Draw a rectangle of 50x32 (mm.). In this

exercise, we'll sketch in 3D view (rather than

plane view).

[4] Click .


[5] Select in the model tree.

[6] And click

.

[7] Click .

[8] Click .

[11] Click .

[9] Select .

[10] Click the yellow area to bring up buttons and select the face with the coordinate system as

shown.


[12] Switch to and use to draw a sketch like this on the newly

created plane (Plane4).

[14] Click .

[13] Click .


[17] Click .

[16] Select the face with the coordinate

system as shown.

[15] Click .

[18] Switch to and draw a sketch

like this on the newly created plane (Plane5).


[20] Click .

[19] Click .

[21] Click .

[23] Click .

[22] Select the face and the coordinate system as shown.


[24] Switch to and draw a sketch

like this on the newly created plane (Plane6).

[26] Click .

[25] Click .

Exercise 14

ansys workbench optimization

Documents

ansys simulations

geometry modeling

concept modeling

ansys simulation modules

surface modeling support

assembly models

structural analysis

geometry models