WS14-1

WORKSHOP 14

KNOWLEDGEWARE

CAT509, Workshop 14, March 2002

WS14-2CAT509, Workshop 14, March 2002

WS14-3CAT509, Workshop 14, March 2002

Problem Description The preliminary design of the ATV Foot Peg must be completed as

soon as possible and must meet the given structural requirements. The design must not exceed the material yield strength under loading and it must not deform in a manner causing interference with other parts of the vehicle.

An initial static analysis of the Foot Peg has been completed (Workshop 2). To assist in our design iterations, we need to activate CATIA Knowledgeware capabilities to provide immediate feedback on the critical analysis parameters.

WORKSHOP 14

WS14-4CAT509, Workshop 14, March 2002

Suggested Exercise Steps

1. Open the existing document for the Foot Peg static analysis.

2. Create analysis sensors for maximum displacement and maximum

stress.

3. Create a knowledge rule for maximum displacement.

4. Create a knowledge check for maximum stress.

5. Modify the Foot Peg design to meet requirements.

6. Compute the analysis for the modified design.

7. View results.

WORKSHOP 14

WS14-5CAT509, Workshop 14, March 2002

Open the Foot Peg

static analysis

document from the

training directory.

Steps:

1. Select File and

Open from the top pull-down menu.

2. Access the class

workshop directory

using the typical

Windows interface.

3. Open the

ws14footpegstatic.CA

TAnalysis document

by double-clicking.

The document is

opened in the GSA

workbench.

Step 1. Open the analysis document

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2

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WS14-6CAT509, Workshop 14, March 2002

Analysis sensors must

be created to provide

results information to

the Knowledgeware

application. Create a

sensor for maximum

displacement and for

maximum stress.

Steps:

1. Right mouse click

on Sensors.1 in the

specification tree.

2. Click on Create

Sensor in the menu.

3. Highlight dispmax

(max. displacement) in

the sensor creation

window.

4. Click OK.

5. Repeat steps 1-4 to

create the misesmax

sensor (max. Von

Mises stress).

Step 2. Create analysis sensors

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WS14-7CAT509, Workshop 14, March 2002

The sensors branch in

the specification tree

must be expanded to

view the newly created

sensors.

Steps:

1. Click the plus (+)

symbol on the branch

node to expand the

sensors branch.

2. Expanded branch

shows all sensors.

The Energy sensor is

automatically created

with every analysis

document. It measures

global strain energy of

the structure.

Step 2. Create analysis sensors

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2

dispmax sensor

misesmax sensor

Default Energy sensor

WS14-8CAT509, Workshop 14, March 2002

Step 3. Create knowledge rule

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4

Update the analysis

solution if needed.

Steps:

1. Check for update needed symbol on the Static Case Solution.1

2. Compute to update

the analysis results

(see Section 3).

Activate the ability to

view knowledge rules

and checks in the

analysis specification

tree.

Steps:

1. Select Options from

the Tools menu.

2. Select Analysis &

Simulation branch.

3. Select General tab.

4. Activate both boxes

to show parameters

and relations.

1

Symbols shows

update needed

WS14-9CAT509, Workshop 14, March 2002

Now create a rule that

will monitor maximum

displacement of the

Foot Peg and provide

pop-up messaging on

the screen. Rules are

created using the

CATIA Knowledge

Advisor.

Steps:

1. Select Start from

the top pull-down

menu.

2. Drag the cursor and

click the Knowledge

Advisor workbench

under Infrastructure.

Step 3. Create knowledge rule

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2

WS14-10CAT509, Workshop 14, March 2002

The Knowledge

Advisor workbench

should now

be active .

Steps:

1. Click the Rule icon

from the Knowledge

Advisor

workbench.

2. Key Displacement Max as the name of the rule.

3. Key in a description

for the rule or accept

the default.

4. The rule will be

saved under the

Relations category do not modify.

5. Click OK.

6. Rule Editor window

displays the active rule

(Displacement Max).

Step 3. Create knowledge rule

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2

3

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Rule definition

entered here

Dictionary

categories to

assist in

defining rules

WS14-11CAT509, Workshop 14, March 2002

Define the rule.

Steps:

1. Click to place the

cursor at the end of

the 1st line and then hit

the Enter key to start a

new line.

2. Select Keywords in

the Dictionary window.

3. Double-click on if to begin the line.

4. Single-click the Max

Displacement sensor

in the tree to list its

parameters in the

Members of All area.

5. Double-click on

Maximum displacement Value to add it to the definition.

6. The parameter for

the max. displacement

value is added.

7. The current value is

shown (.011 in).

Step 3. Create knowledge rule

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3

4

5

2

7

6

1st line: Rule

description

WS14-12CAT509, Workshop 14, March 2002

Define the rule (cont.).

Steps:

8. Key in the

remainder of the rule

definition as shown.

Dictionary selection

can be used for

Keywords, Operators,

Messages, etc.

9. Click OK when

finished.

10. If successful, the

rule message will be

displayed.

Note: The current

max. displacement

value exceeds our

defined rule value of

.009 in. The message

suggests a design

modification is

required.

11. Click OK to

dismiss the message.

Step 3. Create knowledge rule

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9Rule created

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WS14-13CAT509, Workshop 14, March 2002

Step 4. Create knowledge check

Create a check that

will monitor maximum

Von Mises stress on

the Foot Peg so that

our design does not

exceed the material

yield strength.

Steps:

1. Click the Check icon

from the Knowledge

Advisor

workbench.

2. Key Von Mises Max as the name of the check.

3. Key in a description

for the check or accept

the default.

4. The check will be

saved under the

Relations category do not modify.

5. Click OK.

6. Check Editor

window is displayed.

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WS14-14CAT509, Workshop 14, March 2002

Define the check.

Steps:

1. Select Warning as

the check type.

2. Key warning

message as shown.

3. Place the cursor at

the end of the 1st line

and then hit the Enter

key to start a new line.

4. Single-click the Max

Von Mises sensor in

the tree to list its

associated

parameters.

5. Double-click on

Maximum Von Mises Value to add it to the definition.

6. The parameter for

the max. Von Mises

value is added and the

current value is shown

(3484.577 psi).

7. Enter the less than

symbol (

WS14-15CAT509, Workshop 14, March 2002

Define check (cont.).

Steps:

8. Expand the tree to

view the Foot Peg.

9. Single-click the Foot

Peg to list associated

parameters.

10. Scroll to locate

Pressure in Members

of Parameters area.

11. Click Pressure to

display parameters

including material yield

strength.

12. Double-click on

AluminumYield Strength to add to the definition.

13. Click OK when

finished.

Note: The check is

showing green which

means the max. Von

Mises stress is below

the material yield

strength for Aluminum.

Step 4. Create knowledge check

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119 12

Check created and

shows green light

(check not violated)

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WS14-16CAT509, Workshop 14, March 2002

The knowledgeware

results indicate the

maximum Von Mises

stress is acceptable,

however the maximum

displacement of the

Foot Peg is too large.

Lets modify the Foot Peg design as

suggested by the

knowledge rule to

reduce maximum

displacement.

Steps:

1. Double-click the

PartBody in the tree to

switch to the Part

Design workbench.

2. Part Design is now

the active workbench.

3. Expand the

PartBody branch to

show solid features.

Step 5. Modify Foot Peg design

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WS14-17CAT509, Workshop 14, March 2002

Now in Part Design,

reduce the length of

the Foot Peg by

modifying the

corresponding solid

feature.

Steps:

1. Double-click Pad.1

in the tree to modify.

Pad Definition window

is displayed.

2. Double-click the

parameter Offset.19 to

modify its value.

3. Change the value to

7 inches as shown in

the Constraint

Definition window.

4. Click OK.

5. Click OK in the Pad

Definition window.

The length of the Foot

Peg is reduced to 7

inches.

Step 5. Modify Foot Peg design

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WS14-18CAT509, Workshop 14, March 2002

After making the

change, it is apparent

that the outer edge is

too thin. Modify the

spacing between the

top face cutouts.

Steps:

1. Double-click the

feature pattern

(RectPattern.1) in the

tree to modify.

2. Select the First

Direction tab.

3. Key in a new

spacing for the First

Direction of 2.5 inches.

4. Click the Preview

button to view change.

5. Click OK to accept.

The cutouts are now

positioned closer

together.

Step 5. Modify Foot Peg design

1 3

2

45

Preview of

modified spacing

Arrow shows

1st direction

WS14-19CAT509, Workshop 14, March 2002

Now that the Foot Peg

design has changed,

our analysis conditions

have changed as well.

The analysis must be

computed again.

Steps:

1. Return to the GSA

workbench by double-

clicking the Finite

Element Model branch

in the tree.

2. Select the Compute

icon.

3. Specify that All

parameters should be

used in the calculation.

4. Click OK.

Step 6. Compute analysis

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Symbol showing

analysis case

not updated

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43

WS14-20CAT509, Workshop 14, March 2002

Immediately after

computing the analysis

solution we can verify

our rule and check. In

this case our design

modifications are

successful.

Steps:

1. A message

generated from the

knowledge rule pops

onto the screen after

the computation is

complete.

2. The check for max.

Von Mises stress is

green indicating the

value is less than the

material yield strength.

3. The value of each

sensor can be seen by

double-clicking on the

sensor in the tree.

Step 7. View results

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2

3 Max. displacement

is now acceptable