Assignment 4-RADIOSS Material Laws Challenge

OBJECTIVE:

1. To set up 7 different type of cases and run the simulations in the hyperwoks Radioss Solver.

2. To compare the Total number of cycles,EnergyError,mass error and Simulation time of all the 7 cases in the tabulated format.

3. Notice the animation of all 5 and describe the the animations in brief on the basis whether the elements are being deleted or cracked.

4. Plot the energies and notice any difference.

5. Based On the results, Conclude which case Suits the Real life scenario.

CASE SETUP AND EXECUTION :

CASE1:

The material card is choosen to be M2_PLAS_JOHN_ZERIL and the failure card is chosen to be FAILURE_JOHNSON_1. All the values in the Input card and the Failure card are kept as default and the model is RUN with the name Law2_epsmax_failure.Following are the images of the Material input cards and the Failure cards:

FIG1: INPUT MATERIAL CARD VALUES_CASE1

FIG2 : FAILURE CARD INPUTS_CASE1

CASE2:

The material card is choosen to be M2_PLAS_JOHN_ZERIL and the failure card is chosen to be FAILURE_JOHNSON_1. All the values in the Input card are kept as default where as in the Failure card the input values for Ifail_sh, Dadv and Ixfem are changed to 1 and the model is RUN with the name Law2_epsmax_Crack.Following are the images of the Material input cards and the Failure cards:

FIG3 : MATERIAL CARD INPUT VALUES_CASE2

FIG4 : INPUTS TO THE FAILURE CARD_CASE2

CASE3:

The material card is choosen to be M2_PLAS_JOHN_ZERIL and the failure card FAILURE_JOHNSON_1 is deleted. All the values in the Input card are kept as default and the model is RUN with the name Law2_epsmax_nofail.

FIG5 : DELETING THE FAILURWE CARD_CASE3

CASE4:

The material card is choosen to be M2_PLAS_JOHN_ZERIL . The value of Eps_P_max is deleted and the model is RUN with the name Law2.Following is the image of the Material input card:

FIG6 :MATERIAL CARD INPUT_CASE4

CASE5:

The material card is changed to Law1_elastic with the values of the aluminium material i.e,

Density `rho`= 0.0028 g/mm3, Modulus of Elasticity E = 71000 MPa and Poisson's ratio `nu`=0.33 and the model is RUN with the name Law1.Following is the image of the Material input card:

FIG6 : MATERIAL INPUT CARD_CASE5

CASE6:

The material card is changed to Law36_elastoplastic with the values of the aluminium material i.e,

Density `rho`= 0.0028 g/mm3, Modulus of Elasticity E = 71000 MPa and Poisson's ratio `nu`=0.33 . The Ohter values with the creation of the curve according to the image given below are inserted.

FIG7 : CASE 6_CARD_INPUTS

The created curve is assigned to the material card and the model is run with the name Law36. The following are the images of the Function curve being created and assigning the curve to the material card.

FIG8 : CREATING THE FUNCTION CURVE_CASE6

FIG9 : ASSIGNING THE CURVE TO THE MATERIAL_CASE6

FIG10 : MATERIAL INPUT CARD_CASE6

CASE7:

The given RAD file LAW27_0000 is imported and the material card is /MAT/PLAS_BRIT/1 which is mainly for the brittle materials. The shell properties are changed to the recommended values . The Eps_values for the johnson failure cards are observed to be different from the previous set up. The model is run with file name Law27. Following is the image of the material card.

FIG11 : MATERIAL INPUT CARD FOR CASE7

RESULTS :

1. Tabulation of the No of Cycles, Mass Error, Energy Error & Simulation Time

Case No	No of Cycles	Mass Error	Energy Error	Simulation Time(Sec)
1	49380	0	0.8%	43.96
2	49217	0	4.1%	103.80
3	49408	0	0.8%	148.61
4	48737	0	3.0%	152.70
5	47969	0	1.3%	119.86
6	52193	0	-1.9%	163.45
7	49508	0	0.8%	41.15

2. Animation of all the cases

Case 1 :(Law2_epsmax_failure)

Observation : The Elements are failing as well as they are getting deleted without any crack propogation since the value of the Epsmax have been given with no values for Ixfem in the failure johnson card. The Maximum amount of Stress induced is 275.2 GPa. Also due to the Pressence of the Failure Johnson card the nature of the failure is Isotropic.

Case 2 :(Law2_epsmax_Crack)

Observation : The Elements are failing as well as they are getting deleted with the crack propogation since the value of the Epsmax have been given with values for Ixfem in the failure johnson card. The Maximum amount of Stress induced is 295.1 GPa.

Case 3 :(Law2_epsmax_nofail)

Observation : The Elements are failing as well as they are getting deleted without any crack propogation since the value of the Epsmax have been given and No failure card. The Maximum amount of Stress induced is 270.7 GPa.

Case 4 : (Law2)

Observation : Due to the absence of the value to the Epsmax i.e, Epsmax=0(by default Epsmax= 1E+30), there is no failing of the elements and hence the elements are not getting deleted. The Maximum amount of Stress induced is 424.7 GPa.

Case 5 :(Law1_elastic)

Observation : Since the M1_Elastic material card is been used, the Plate is undergoing only elastic deformation and not undergoing any plastic deformation and no criterion for failure of the Plate/material exists. Hence,no elements are getting deleted. The maximum amount of stress induced is 108.9 GPa.

Case 6 :(Law36_elastoplastic)

Observation : In this the deformation is uniform since the material card that is being used is for the Isotropic material. The Elements are failing as well as they aregetting deleted since all the values are Such as the Epsmax has been given. The Maximum induced stress is 590.1 GPa.

Case 7 : (Law27)

Observation : The Elements are getting deleted only on three sides leaving the elements on one side . This is due to the Material card which is M27_PLAST_BRIT which is meant for the orthotropic materials which arebrittle in nature. The Maximum Stress induced is 287.5Gpa.

2. COMPARISON OF THE INTERNAL ENERGIES

FIG12 : INTERNAL ENRGIES COMPARISON

Observations :

1. The highest amount of internal energy was generated for the case 5 i.e, 8.575E+05 J. This was observed since the material law 1 for the elastic material was used and also no failure card was being used. This caused the material to absorb more and more energy and hence increase in the internal energy as compared to the other cases.

2.For all the cases except case 4 and case 5 the increase in the internal energy is linear upto certain point and then becomes constant where as for the case 4 and case 5 , the internal energy increases exponentially.

3. COMPARISON OF THE KINETIC ENERGIES

FIG13 : KINETIC ENERGIES COMPARISON

Observations :

1. The highest amount of Kinetic energy was generated for the case 5 i.e, 3250 J. This was observed since the material law 1 for the elastic material was used and also no failure card was being used.

2. It can be observed that in all the cases the Kinetic energies are stagnant upto certain points and there is a sudden increase in the Kinetic energy value for a brief period of time and then towards the end the it starts to decrease.

4. COMPARISON OF THE TOTAL ENERGIES

FIG14 : TOTAL ENERGIES COMPARISON

Observations :

1. The highest amount of Total energy was generated for the case 5 i.e, 8.575E+05 J. This was observed since the material law 1 for the elastic material was used and also no failure card was being used. This caused the material to absorb more and more energy and hence increase in the internal energy as compared to the other cases.

2.For all the cases except case 4 and case 5 the increase in the internal energy is linear upto certain point and then becomes constant where as for the case 4 and case 5 , the internal energy increases exponentially.

CONCLUSION: Based on the Results, the most likely Case to represnt the Real Life Scenario is Case-6 (Law36_elastoplastic).