Tài liệu STRESS ANALYSIS Using Pro/MECHANICA pptx

• Analyses/Studies menu to define the type of analysis – in this case static analysis, and Convergence Method.. • Results menu to review design study results.. From Properties pull down

ME-430 INTRODUCTION TO COMPUTER AIDED DESIGNSTRESS ANALYSIS Using Pro/MECHANICA

Pro/ENGINEER Wildfire 2.0

Dr Herli Surjanhata The bicycle wrench shown in the figure below is made of stainless steel The wrench

is 5 mm thick A total load of 264 Newtons is uniformly distributed over the top surface located on the horizontal plane in the right of the wrench The inside surfaces

of the left hexagon are fixed to simulate the bolt tightening

Determine the von Mises stresses, and maximum deflection under the given

distributed load and boundary conditions

Check the convergence of your analysis

Step 2:

Transfer the model to Integrated Mode of Pro/MECHANICA

Three algorithms that can be chosen:

1 Quick Check (No convergence):

Pro/MECHANICA performs a single pass analysis with uniform p = 3 This method is used to verify if your analysis has been set up

correctly

2 Single-Pass Adaptive:

Pro/MECHANICA runs a first pass at p = 3 and determines a local estimate of stress error Using this error estimate, Pro/MECHANICA determines a new p-order distribution and performs a final pass

3 Multi-Pass Adaptive:

When you run a design study, the Structure engine performs calculations and increases the polynomial order (p-order) for each element edge until the convergence criteria is satisfied An analysis converges when the difference in the results of the results of the current and previous passes are within the percentage you specify under Convergence

From Applications pull-down menu, select

Mechanica

The Unit Info window appears

Click Continue button if the system

of units is correct and consistent

From Model Type dialog box, select

Structure

Click OK

In MEC STRUCT menu, you will use,

• Model menu to assign material properties of bike wrench, and also to define

loads and constraints

• Analyses/Studies menu to define the type of analysis – in this case static

analysis, and Convergence Method Then run a design study

• Results menu to review design study results

Step 3:

Define the material of bike wrench

From Properties pull down menu, select

Materials

Or click on Define Materials icon

on the right toolbar

From the

Materials in Library list,

select SS

Click the Assign button, then Part - Pick the

From Insert pull-down menu, select

Displacement Constraint, or click on

located on the right toolbar,

and the Constraint window appears

Enter the name of the constraint

as “fixed” Click the arrow button under the

Surfaces Pick all surfaces of hexagon on the left – see Figure below Make sure

to press and hold Ctrl key while selecting the next surfaces

OK, then click OK button in the Constraint window

Done/Return

Note that FIXED constraint should be applied on these surfaces

Step 5:

Apply the load on the flat-top surface of the right part of the wrench – see Figure below

From Insert pull-down menu, select

Force/Moment Load, or click on

located on the right toolbar,

and the Force/Moment window appears

Enter the name of the load as

OK, then click OK button in the Constraint window

Done/Return.

Step 6:

Define the STATIC analysis by:

From Analysis pull-down menu, select Mechanica

Analyses/Studies, or click on

icon on the top toolbar

Analyses and Design Studies

dialog box opens

From File pull down menu, select

New Static

Enter the name of analysis

as “bike_wrench” Select Multi-Pass Adaptive method

Maximum Polynomial Order = 9

Percent Convergence = 5

Convergence on Local

Displacement, Local Strain Energy and Global RMS Stress

Click the OK button

Step 7:

Run the design study by

selecting

Click the Yes button

Click the Display study status button to review the progress of the analysis

Make sure you have “Run

Completed” message

Click Close in the Run Status dialog box

Step 8:

Review design study results

Click on to review the results of design study The Result Window

Definition dialog box

opens

Enter Window Name

as “von_Mises” for Von Mises stress Enter the Title of Von Mises Stress

Distribution Plot

By default

bike_wrench Design

Study and Analysis

have been selected

Select the Display

Options tab

Make sure you fill in the following form (window) as shown on the left

Click the OK and

From Info pull down menu, select View Max Repeat the procedure and select Model Max

Click the Copy button

Enter the name as

“displ”

Enter the Title of

Displacement Fringe Plot

Click the Quantity tab, and change the type to

We are also interested in the Max Von Mises Stress, Max Displacement Magnitude and Strain Energy convergence

Click the Copy button - in the Result Window, and name it as convm

Set the following:

Set the Display

type to Graph

Set the Quantity

to Measure

Click icon to select the Max

Von Mises Stress

Click OK button

Click OK

Repeat the same procedure to create another window called conse and set the following – choose strain_energy as measure quantity:

Click icon

In the Display Result Window, make sure to highlight convm, condef, and conse ONLY, and click the OK button

Notice that the max_stress_vm does NOT converge This is due to the sharp corners in the wrench – see the Von Mises Stress fringe plot

Save the results windows as bike_wrench

Click

Enter the file name

bike_wrench.rwd

Click OK

Close the Analyses and design Studies

To eliminate this problem, transfer the model back to

Pro/ENGINEER, create the fillets or rounds at the location of sharp corner, and run the analysis again until the max von

Mises stress converges

The following results show the convergence

Save the results windows as bike_wrench_new