Assignment 4-RADIOSS Material Laws Challenge

Aim:

To apply different materials and simulate the components and compare the material behaviour.

Objective:

Perform the simulation as per the cases given below.

Case 1

• Import the FAILURE_JOHNSON_0000.rad file and run the model as it is. Give the title name as Law2_epsmax_failure.

Case 2

• Import the case 1 rad file, named “Law2_epsmax_failure” and perform the simulation with failure plastic strain (EPS_p_max) and fail_Johson card enabled.
• Changes to be made in /FAIL/JOHNSON card:

• ifail_sh= 1
• Dadv= 1
• Ixfem= 1

• Use the recommended values for the property card.
• Give the title name as Law2_epsmax_crack.

Case 3

• Import the case 2 rad file, named “Law2_epsmax_crack” and perform the simulation by removing the fail_Johnson failure card. Give the title name as Law2_epsmax_nofail.

Case 4

• Import the case 3 rad file, named “Law2_epsmax_nofail” and perform the simulation by removing both the failure plastic strain (EPS_p_max) and the fail_Jhonson failure card.

Case 5

• Import the case 4 rad file and perform the simulation by changing the material card to Law 1. Keep the same value for rho, E, and nu values.

Case 6

• Import the case 1 rad file, named “Law2_epsmax_failure” and perform the simulation with the law 36 material card. Refer to the video titled "Materials 7" for further information.

Case 7

• Open the Law27_0000.rad file and perform the simulation with the law 27 material card. Use the recommended shell properties.

Procedure:

Case 1:

Import the FAILURE_JOHNSON_0000.rad file and run the model as it is. Give the title name as Law2_epsmax_failure.

¬ Import the FAILURE_JOHNSON_0000.rad file in hypermesh.

Material:

Properties:

Failure Card:

¬All these values kept in default no need to change.

¬run the file as it default.

¬Then go to analysis - radioss.

¬ Save the file name as ''Law2_epsmax_failure''

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

energy error = o.8%

Mass error = 0

¬Then plot graph for enegy

¬ GO to drop down button of hypermesh and select hypergraph 2D

¬Above the grapg shows kinetic, hourglass, contact, internal and Total Energy.

¬NO Hourglass Energy formed.

¬Internal energy close to Total Energy.

¬Next plot contour go to drop dwon button of hypermesh and select hyper view

¬This material properties failed.

¬Due to plastic strain failure Eps_max =15%.

¬Integration point reaches the 15%, so the material failed.

¬ Max Von mises stress formed 275.2 Mpa.

Case 2:

• Import the case 1 rad file, named “Law2_epsmax_failure” and perform the simulation with failure plastic strain (EPS_p_max) and fail_Johson card enabled.
• Changes to be made in /FAIL/JOHNSON card:

• ifail_sh= 1
• Dadv= 1
• Ixfem= 1

• Use the recommended values for the property card.
• Give the title name as Law2_epsmax_crack.

¬Import the case 1 rad file, named “Law2_epsmax_failure” in Hypermesh.

¬ Use the recommended values for the property card.

Material card:

Falilure Card:

¬Change the value in material card below.

• ifail_sh= 1
• Dadv= 1
• Ixfem= 1

¬ ifail_sh = 1 = which helps to determine the failure to be deleted or cracked.

¬ Dadv= 1 = Criterion for the crack advancement (Only active if with Ixfem =1), how much element crack into small pieces.

¬ Ixfem= 1 = which means element to be cracked not deleted.

Then go to analysis - radioss.

¬ Save the file name as '' Law2_epsmax_crack''

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

¬ Energy error = 4.1%

¬ Mass Error = 0

¬Then plot graph for enegy

¬ GO to drop down button of hypermesh and select hypergraph 2D.

¬ Above the grapg shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬Internal Energy increase close to the Total Energy.

¬Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are cracked.

¬Max Von mises stress formed 295.1mpa higher than previous case.

Case 3

• Import the case 2 rad file, named “Law2_epsmax_crack” and perform the simulation by removing the fail_Johnson failure card. Give the title name as Law2_epsmax_nofail.

¬ Import the case 2 rad file, named “Law2_epsmax_crack”

¬ This case remove the Failure card.

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬ Save the file name as '' Law2_epsmax_nofail ''

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

¬ Energy Error = 0.8%

¬ Mass error = 0

¬Then plot graph for enegy

¬ Above the grapg shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬ Internal Energy and Total energy are close to each other sightly deviate.

Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are cracked.

¬Max Von mises stress formed 270.7 Mpa.

¬Element break occurs it hasve elasto-plastic material card.

Case 4:

• Import the case 3 rad file, named “Law2_epsmax_nofail” and perform the simulation by removing both the failure plastic strain (EPS_p_max) and the fail_Jhonson failure card.

¬ Import the case 3 rad file, named “Law2_epsmax_nofail” .

¬ Remove failure plastic strain(EPS_max) and failure card.

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬ Save the file name as '' fail_Jhonson failure card ''

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

Energy error = 3%

Mass error = 0

Then plot graph for enegy

¬ Above the grapg shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬ Internal Energy and Total energy are close each other.

Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are safe.

¬ vonmises stress formed 424.7 Mpa .

¬Due to EPS_max value is zero

Case 5:

• Import the case 4 rad file and perform the simulation by changing the material card to Law 1. Keep the same value for rho, E, and nu values.

¬ Import the case 4 rad file

¬ Change the material card to Law1 (Elastic)

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬ Save the file name as '' Elastic ''

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

Energy error = 1.3%

Mass error = 0

Then plot graph for enegy

¬ Above the grapg shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬ Internal Energy and Total energy are close each other.

Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are safe.

¬ vonmises stress formed 10890 Mpa .

¬Used the Elastic Material card.

Case 6:

• Import the case 1 rad file, named “Law2_epsmax_failure” and perform the simulation with the law 36 material card.

¬ Import the case 1 rad file, named “Law2_epsmax_failure” .

¬Change the '' material card to Law 36 ''.

EPS_t = beginning of tensile damage

EPS_m = End of tensile damage

EPS_f = tensile failure strain element deleted

Fsmooth = smooth the curve

¬Create the function curve .

¬create new cruve with x and y value

¬Assign the curve in material card.

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬ Save the file name as '' plast_tab ''

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

energy error = -1.8%

Mass error = 0

Then plot graph for enegy

¬ Above the graph shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬ Internal Energy and Total energy are close and slightly deviate .

Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are deleted.

¬ vonmises stress formed 597.8 Mpa .

¬Used the Plast-tab law 36 card.

Case 7:

• Open the Law27_0000.rad file and perform the simulation with the law 27 material card. Use the recommended shell properties.

¬ Import the '' Law27_0000.rad file ''.

¬use Law 27 material card.

¬use recomended shell properties.

Material Card:

¬ EPS_t1 = Tensile failure strain at which stress starts to reduce in the principal strain direction 1

¬ EPS_m1 = Maximum tensile failure strain in principal strain direction 1

¬ EPS_f1 = Maximum tensile strain for element deletion in principal strain direction 1

¬ EPS_t2, EPS_m2, EPS_f2, are direction 2.

Properties:

¬Then give -nt 4 in the box run the simulation fast.

¬Finally click radioss to run the suimulation.

¬ Save the file name as '' Law 27 brittle ''

¬After simulation completed, check the result.

¬open the 0.0001out file in text format

Energy error = 0.8 %

mass error = 0

Then plot graph for enegy

¬ Above the graph shows kinetic, hourglass, contact, internal and Total Energy.

¬ Hourglass energy zero due to QEPH element formulation.

¬ Internal Energy and Total energy are close and slightly deviate after 4ms .

Next plot contour go to drop dwon button of hypermesh and select hyper view.

¬ Above the contour plot are deleted.

¬ vonmises stress formed 287.5 Mpa .

¬Used the brittle law 27 card.

Compare all the 7 cases:

Case & material

case & material law	Simulation Name	Energy Error (%)	Simulation Time (s)	No of Cycles	von mises stress max value (Mpa)	Element Behaviour
Law 2	epsmax_failure	0.8	49.36	49380	275.5	Deleted
Law 2	epsmax_crack	4.1	209.54	49217	295.1	crack and deleted
Law 2	epsmax_nofail	0.8	209.54	49408	270.7	deleted
Law 2	fail_Jhonson failure card	3	204.76	48737	424.7	safe
Law 1	Law 1	1.3	210.98	47969	10890	safe
Law 36	Law 36	1.8	268.82	53143	597.8	deleted
law 27	Law 27	0.8	220.26	49508	287.5	deleted

Conclusion:

¬Compare all the & cases of different materials and failure cards applyingthem in simulatuion.

¬Learn Element formulation.

¬learn the material definition and failure