Interface study on crash tube

Objective :

• To mesh the given bumper assembly using hypermesh under recommended mesh size
• To run the simulation for the given crash tube model under several different interface cases and by changing the parameters & shape of the model
• To analyze the changes with different cases applied
  
  

Procedure - Meshing :

1. Import the given model in hyperworks
   
   
   
   
2. To mesh the surfaces , Go to 2D panel and select
3. Mention required element size and mesh type
   
   
4. Select surfaces option and select the surfaces individually in the model and click mesh
   
   
   
5. Similarly mesh all the surfaces in the model
   
   
   
   
   
   
6. Meshing is complete for the given model
   
   

Procedure - CASE 1 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
   
   
2. From the browser tab , select groups and then select self-contact(interface)
   
   
3. The parameters for interface setting appears
   
   
4. As per case 1 , there are no changes made in parameters and interface type
   
   
   
   
5. Then RUN the simulation using analysis panel and select RADIOSS
   
   
6. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
   
   
   
   
7. After simulation run , a dialog box shows the total number of cycles and simulation time
   
   
   
8. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
   
   
9. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
   At ideal conditions -15%
   
   
10. Using page window layout , split the window for convenienece
    
    
11. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
12. Click Apply
    
13. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
    
    
14. Similarly analyse using contour
    
    
15. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
16. Click Apply
    
    
    
    
17. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
18. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
    
    
    
19. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
20. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
21. Thus the given model file with input of interface with no change in parameters has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour
    
    

Procedure - CASE 2 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
2. From the browser tab , select groups and then select self-contact(interface)
   
   
3. The parameters for interface setting appears
   
   
4. As per case 2 , there are changes made in parameters and no changes in interface type
   Change inacti = 6
   
   
   
   
5. Then RUN the simulation using analysis panel and select RADIOSS
   
   
6. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
   
7. After simulation run , a dialog box shows the total number of cycles and simulation time
   
   
   
   
8. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
   
   
9. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
   At ideal conditions -15%
   
   
10. Using page window layout , split the window for convenienece
    
    
11. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
12. Click Apply
    
    
13. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
14. Similarly analyse using contour
    
    
15. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
16. Click Apply
    
    
17. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
18. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
19. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
20. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
21. Thus the given model file with input of interface with change in parameter ( inacti = 6 ) has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour

Procedure - CASE 3 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
2. From the browser tab , select groups and then select self-contact(interface)
   
   
3. The parameters for interface setting appears
   
   
4. As per case 3 , there are changes made in interface type
   Interface type = 11
   
   
5. In the interface parameters , select the slave and master
   
   
   
   
   
   
6. Then RUN the simulation using analysis panel and select RADIOSS
   
   
7. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
   
   
8. After simulation run , a dialog box shows the total number of cycles and simulation time
   
   
   
   
9. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
   
   
10. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
    At ideal conditions -15%
    
    
11. Using page window layout , split the window for convenienece
    
    
12. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
13. Click Apply
    
    
14. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
15. Similarly analyse using contour
    
    
16. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
17. Click Apply
    
    
    
18. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
19. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
20. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
21. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
22. Thus the given model file with input of interface with change in interface type ( Type = 11 ) has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour

Procedure - CASE 4 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
2. As per case 4 , there are changes made in surface of the model ( Removing notch ) and removing the boundary conditions ( all same parameters as case 3 )
   
3. Using align nodes from the geometry panel the notch of the crsuh tube could be removed
   
   
4. All the notches through the crush tube are removed following similar method
   
   
   
   
5. As per requirement remove the boundary conditions by deleting the BCS card in the load collector
   
   
   
   
6. All changes made as per case 4
   
   
7. From the browser tab , select groups and then select self-contact(interface)
   
   
8. The parameters for interface setting appears
   
   
   
   
9. Then RUN the simulation using analysis panel and select RADIOSS
   
   
10. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
    
    
11. After simulation run , a dialog box shows the total number of cycles and simulation time
    
    
    
12. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
    
    
13. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
    At ideal conditions -15%
    
    
14. Using page window layout , split the window for convenienece
    
    
15. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
16. Click Apply
    
    
17. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
18. Similarly analyse using contour
    
    
19. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
20. Click Apply
    
    
    
21. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
22. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
23. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
24. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
25. Thus the given model file with input of interface with change in model shape and boundary condition (removed) has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour

Procedure - CASE 5 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
2. As per case 5 , there are changes made in surface of the model ( New notch in middle , all same parameters as case 4 )
   
   
3. Using distance option from the geometry panel the new notch in middle of the crush tube could be created
   Use two nodes in distance and manually set distance between two nodes according to axis and make the nodes move and create a notch manually
   
   
   
   
4. All changes made as per case 5
   
   
5. From the browser tab , select groups and then select self-contact(interface)
   
   
6. The parameters for interface setting appears
   
   
7. Then RUN the simulation using analysis panel and select RADIOSS
   
   
8. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
   
   
9. After simulation run , a dialog box shows the total number of cycles and simulation time
   
   
10. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
    
    
11. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
    At ideal conditions -15%
    
    
12. Using page window layout , split the window for convenienece
    
    
13. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
14. Click Apply
    
    
15. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
16. Similarly analyse using contour
    
    
17. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
18. Click Apply
    
    
    
    
19. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
20. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
    
    
21. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
22. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
23. Thus the given model file with input of interface with change in model shape ( new notch in middle created ) , has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour

Procedure - CASE 6 :

1. Open hyperworks, select RADIOSS as interface and import 0000.rad file given
   
   
2. As per case 6 , there are changes made in surface of the model ( New notch in opposite faces , all same parameters as case 5 )
   
   
3. Using distance option from the geometry panel the new notch in twofaces of the crush tube could be created
   Use two nodes in distance and manually set distance between two nodes according to axis and make the nodes move and create a notch manually
   
   
   
   
4. All changes made as per case 6
   
   
5. From the browser tab , select groups and then select self-contact(interface)
   
   
6. The parameters for interface setting appears
   
   
7. Then RUN the simulation using analysis panel and select RADIOSS
   
   
8. Select input file location for saving generated files of simulation and also check for other default options like export , run , run number and then click RADIOSS
   
   
9. After simulation run , a dialog box shows the total number of cycles and simulation time
   
   
10. After which open the 0001.out file that was generated during simulation run and check the energy error & mass error
    
    
11. Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
    At ideal conditions -15%
    
    
12. Using page window layout , split the window for convenienece
    
    
13. Select Hyperview option in toolbar and click load model to upload .h3d file from the generated files during simulation run
    
    
14. Click Apply
    
    
15. Click the play button in the toolbar to run the simulation and analyse the deformation in the animation for crash tube , for a period of 3 seconds
    Here the animation between cases are compared for the frames 4 and 14 for comparison purpose
    
    
    
    
    
    
16. Similarly analyse using contour
    
    
17. Select result type as Displacement or Vonmises , averaging method as simple
    Also use maximum and minimum measurement plotiing using measures icon in the toolbar
    
    
18. Click Apply
    
    
    
    
19. Next open Hypergraph , import T01 file using data file option to plot graphs
    
    
20. Plot ,
    Y Type - Global variables
    Y request - Hourglass energy , Total Translational energy , Internal energy , Kinetic energy
    Y component - MAG
    
    
    
    
21. Then select -
    Rigid wall/R-wall in Y type
    4 Rigid wall 1 in Y request
    Resultant NF , Resultant TF , total resultant force in Y component
    
    
    
    
22. Then select -
    Rigid body / TH RBODY in Y type
    1970 rbody 1 in Y request
    TF Resultant force in Y component
    
    
    
    
23. Thus the given model file with input of interface with change in model shape ( new notch in two opposite faces created ) , has been run and analysed using several tools like hyperview , hypergraph to analyse its behaviour

Comparison and Observation :

By running the siimulation for various cases by changing the parameters and shape of the crush tube , changes on the output could be analysed on the energies, forces and stress

Energy error and Mass error ( observation ) :

Mass error is almost NIL in all the cases

Energy error varies a little in each case

Energy error to very maximum level of +5% is acceptable model , -5% represents a good model and better to be close to 0%
At ideal conditions -15%

Case 1 : Error starts at -0.0% and gradually decreases to -4.6% and then slowly increases to -3.8% for a period of 3 seconds

Case 2 : Error starts at -0.0% and gradually decreases to -4.6% and then slowly increases to -3.8% for a period of 3 seconds

Case 3 : Error starts at -0.0% and gradually decreases to -8.8% and then slowly increases to -8.1% for a period of 3 seconds

Case 4 : Error starts at -0.0% and gradually decreases to -10.9% and then slowly increases to -10.1% for a period of 3 seconds

Case 5 : Error starts at -0.0% and gradually decreases to -11.7% and then slowly increases to -10.3% for a period of 3 seconds --> ( Better of all cases since the error is maintained very low )

Case 6 : Error starts at -0.0% and gradually decreases to -9.5% and then slowly increases to -8.5% for a period of 3 seconds

Animation ( observation ) : --> ( All the cases are compared at Frame 4 )

• In all the cases during deformation , the strain is observed to be formed initially at a greater rate in and around the Notch area
  
  
• This deformation varies with the location of the notch in the crush tube
  
  
• In CASE 4 , there are no notches present , in which during deformation , the strain is observed to be greater at the point of contact with the rigid surface
• Thus by observation , the strain during deformation through animation could be studies for different cases

Energy plot ( observation ) :

• Hourglass energy : Almost zero (0) in all the cases
  
  
• Total Translation Energy : Maintains at maximum level throughout the period of observation ( Almost of all cases same )
• Kinetic energy : For all the cases the kinectic energy decreases with time and at a certain limit it stays constant
  
  ( Initially the energy produced with mass and velocity , gets transferred into the crush tube as internal energy and thus kinetic energy gradually decreases with time and stops at a point where there is no more energy to transmit )
• Internal energy : This energy increases with time and at a certain limit it stays constant where kinetic energy maintains at constant level ( vice versa with kinectic and internal energies )
  
  ( Initially during deformation starts , the kinectic energy gets transferred into the crush tube as internal energy and this internal enrgy spreads inside the tube during the entire deformation and stops once there is no more energy )
  
  In each case , the time at which the energy stays to become constant differ due to shape of the crush tube and the parameters
  
  

Result and conclusion :

• Given model is meshed with given requirement ( In this case mesh size )
  
  
• Hence with the given input model file , various interface cases where examined , different shapes were created and differences in thier simulation runs were observed