Assignment 4

OBJECTIVES :

To compare 7 cases and discuss the energies and animation.

• CASES

1. Run the model as it is. Name it as Law2_epsmax_failiure.

2. In /FAIL/JOHNSON, change ifail sh =1, Dadv =1, and Ixfem=1. Run the model as Law2_epsmax_crack.

3. Delete /FAIL/JOHNSON card. Run the model as Law2_epsmax_nofail.

4. Delete the value of eps_p_max and run the model with name Law2.

5. Convert this material into LAW1 elastic with same density, E and nu and check results.

6. Open LAW27_000.rad

• Change the shell properties to recommended.
• Notice the material card, Johnson cook paramaterial but different values for EPS based failiures.
• Run the model with Law27.

7. Run the model with Law36 and change material properties as shown.

Compare 7 cases as discussed in last 3 slides, in a tabulated format on the basis of:

1. Total number of cycles, Energy error, mass error and simulation time.
2. Notice the animation of all 5 and describe the animations in brief on the
basis of whether the elements are being deleted or cracked.
3. Plot energies and notice any difference.
4. Based on all the results, which case would represent the on-field
scenario.
5. Prepare a ppt/docx and list down case by case result and your conclusion
as to why the failure happened.

PROCEDURE :

1. CASE 1

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. Notice the properties , change if needed to recommended.

3. Go to Analysis > Radioss select a folder to save as Law2_epsmax_failiure , options : -nt 4.

4. Open Law2_epsmax_failiure\FAILURE_JOHNSON.h3d in Hyperview to play the animation.

5. Open Hypergraph in splitted window with Law2_epsmax_failiure\FAILURE_JOHNSONT01. Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

B. CASE 2

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. In /FAIL/JOHNSON, change ifail sh =1, Dadv =1, and Ixfem=1.

3. Analysis > Radioss , save as Law2_epsmax_crack and run.

4. Open Hyperview ,Law2_epsmax_crack\FAILURE_JOHNSON.h3d.

5. Open Hypergraph Law2_epsmax_crack\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

C. CASE 3

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. Delete /FAIL/JOHNSON card.

3. Analysis > Radioss, save as Law2_epsmax_nofail and run the file.

4. Open Hyperview ,Law2_epsmax_nofail\FAILURE_JOHNSON.h3d.

5. Open Hypergraph > Law2_epsmax_crack\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

D. CASE 4

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. Delete the value of eps_p_max and

3. Analysis > Radioss run the model with name Law2.

4. Open Hyperview ,Law2\FAILURE_JOHNSON.h3d.

5. Open Hypergraph > Law2\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

E. CASE 5

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. Convert this material into LAW1 elastic with same density, E and nu.

3. Analysis > Radioss run the model with name Law1.

4. Open Hyperview ,Law1\FAILURE_JOHNSON.h3d.

5. Open Hypergraph > Law1\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

F. CASE 6

1. Open LAW27_000.rad in Hypermesh Radioss.

2. Change the shell properties to recommended.

• Notice the material card, Johnson cook paramaterial but different values for EPS based failiures.

3. Analysis > Radioss run the model with name Law2.

4. Open Hyperview ,Law27\FAILURE_JOHNSON.h3d.

5. Open Hypergraph > Law27\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

G. CASE 7

1. Import the FAILIURE_JOHNSON_0000.rad file to Hypermesh Radioss.

2. Change the material properties in LAW36 as specified.

3. Create a stress -strain curve and apply it to the property.

4. Go to Analysis > Radioss , save as Law36 and run.

5. After Radioss job is done, Open Hyperview, open Law36\FAILURE_JOHNSON.h3d.

6. Open Hypergraph > Law36\FAILURE_JOHNSONT01, Plot for Total Energy, Internal energy, Contact energy, Hourglass energy, Rigid wall forces.

COMPARISON

1. .out file data

CASE	TOTAL NO OF CYCLES	ENERGY ERROR	MASS ERROR	SIMULATION TIME
CASE 1	49480	+1.0 %	0.000	130.04 s
CASE 2	49397	+4.1 %	0.000	128.19 s
CASE 3	49405	+1.2 %	0.000	135.45 s
CASE 4	49304	+1.2 %	0.000	124.76 s
CASE 5	47969	+4.0 %	0.000	122.81 s
CASE 6	49356	+1.2 %	0.000	126.51 s
CASE 7	53181	-1.2 %	0.000	127.08 s

2. Animation

CASE 1 - where the simulation is run using saved settings, the elements in animation gets cracked when sphere hits plate and few sections are chipped away.

CASE 2 - when the simulation is run , most elements in animation gets deleted when sphere hits the plate.

CASE 3 - when the simulation is run after deleting failiure card, the elements in animation are ruptured and chipped away.

CASE 4 - when the simulation is run after deleting eps_p_max value, the elements of plate ruptured and few contact error are observed.

CASE 5 - when the simulation is run after changing Law1 and respective properties, the elements of plate is elastic and no rupture happens when sphere hits it but contacts are observed.

CASE 6 - when the simulation is run using Law27, the elements get deleted after some elastic behaviour and rupture happens.

CASE 7 - when the simulation is run using LAW36, the elements makes some plastic behaviour and ruptures while few elements getting chipped away.

3. Graph

• Total energy is identical for first 5 cases following a uniform increase in energy , but for case 6, the energy lowers a bit after starting and increases abruptly.
• The rigid wall forces are identical for all cases except Case 6 which follows the similar curve as its Total energy.
• For Case 7, the Total energy is uniform at elastic state and when plate ruptures , the energy deflects.

4. The on-field scenario represents CASE-7 , because of the -1.2% energy error which is more acceptable when compared to other simulation cases.

• The animation is more practical than other cases when spherical ball hits the plate at 1 m/s.
• No mass error, acceptable energy error .
• No hourglass error and negligible contact error.

LINK FOR ASSIGNMENT 4 : https://drive.google.com/drive/folders/1HH-EwlUSei4lvDAJXlY7WdQxRrDQQ4IH?usp=sharing

CONCLUSION :

1. The simulation for 7 cases are run as specified.

2. The .out files are compared.

3. The Graphs are plotted for energies.

4. The appropriate on-field scenario would be Case7 because all the remaining cases did not meet expected .out values or simulation results.