Week 12 - Flex Bodies

Aim

Procedure

• Creation of flex body

1. First import the flex body FE file by using flex tool -> flex prep
2. Locate the FE file
3. Specify the nodes 4887+4888+4890
4. Additional steps -> stress and strain options should be activated
5. Create RBE2 spiders
   
   
   
6. Select user profile as obistruct
7. Click on left tab -> utility -> user -> super spider -> click on node
   U will get RBE2 spider
   
8. Go to card edit -> elements -> select mount ->edit
9. 1D check box - > config edit -> new config -> rigid link -> return
10. Save and close
    Save as FEM format
    Ur flex body is created
11. U will return to main menu, click on ok
    To load model click on load / apply
12. Use different modes and modal animation to observe the
    Disp
    Stress
    Strain
    In the left arm
    
13. Again use flex prep
    Check mirror existing body
    Select left arm
    Rename new file name to right arm
    Mirror about XZ

• Setting Up Vehicle simulation

1. New file
2. Model -> assembly wizard
   
3. Front end only
4. No drive line
5. Suspension system to -> front LCA
6. Keep all values to default
7. Ur front suspension system will load in
8. Analysis tab -> task wizard -> static ride analysis
   
   This option will select the type of simulation on suspension system

• Replacing control arm

1. Expand front SLA suspension -> bodies ->lower control arm
2. Uncheck symetrical properties -> retain values -> flex body option ->yes
3. Select the file -> open -> nodes ->select search for interface nodes -> align all
4. Click on yes
5. Left arm is now imported
   Repeat same for right arm using right arm tab

Click on run
Quasi static analysis
Step size to 0.01
Time 4 sec

Run

Obtain various plots for stress strain in standard condition and also at the 5 varying parameters

Results

Stress strain in normal Case

Strain

MAX 1.404E-2

MIN 3.3E-17

Stress

MAX 5.18E+3
MIN 8.26E-12

Stress Strain @ 10% increase in Various Parameters

• Vehicle CG

Strain

MAX 1.45E-2

MIN 3.434E-17
Stress

MAX 5.35E+03

MIN 8.63E-12

• Vehicle Weight
  Strain
  
  MAX 2.41E-03
  MIN 5.12E-18
  Stress
  MAX 8.3E+02
  MIN 1.4E-12
  

• Front Breaking Ratio
  
  Strain
  MAX 1.40E-02
  MIN 3.3E-17
  
  Stress
  MAX 5.18E+3
  MIN 8.36E-12

• Wheel Base
  

Strain
MAX 1.4E-02
MIN 3.308E-17
Stress
MAX 5.18E+03
MIN 5.36E-12

• Axle Ratio
  Strain
  
  MAX 1.404E-02
  MIN 3.308E-17
  
  Stress
  MAX 5.18E+03
  MIN 8.36E-12

Conclusion

Upon observation it can be seen that the highest change by altering parameter was seen most in Vehicle Weight
And then followed by Vehicle CG height