Assignment 4-RADIOSS Material Laws Challenge
Aim: Using The Radioss engine starter files need to make changes in material card and simulate the model for below mentioned cases as per the challenge. Observe the all cases find recommended material to use.
Case-1: Run the file as it is and name it as Law2_Epsmax_failure
Case-2: In the failure johnson card(In/FAIL/Johnson) change the follwing Ifail_sh=1, Dadv=1 and Ixfem =1. Run the model as Law2_Epsmax_Crack.
Case-3: Delete/FAIL/JOHNSONCARD. Delete the johnson failure card from the model tree and run the model as Law2_Epsmax_no fail.
Case-4: Delete the value of the EPS_p_max and run the model name LAW2
Case-5: Convert this material model to LAW1 ELASTIC with same same density(row),Youngs Modulus(Y),Poissions ratio.(E=71000,Row=0.0028, NU=0.33)
Case-6: Convert the card to LAW36 elasto plastic
Case-7: Open Law27_000.rad
i) Change the shell properties to recommended shell properties.
ii) Notice the material card. johnson cook parameters but different values for EPS based failure.
iii)Run the model with name LAW27.
Case -1: LAW2_EPSmax_failure:
Here from the import option >import the solver deck >select the file (JOHNSON_0000) > Import. once the model in GUI from the model tree check the properties and from the material card the card image as M2_PLAS_JOHNS_ZERIL as shown below.
one this cards checked select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_1)_0001. out file and open ,as shown below.
Here the energy error is about 0.8% and mass error is about 0 and The Elapsed time =60.99. Total number of cycles =49380.
If we look at the dispalcement contour and the vonmises contour as below
Dispalcement contour
vonmises contour
using hyper graph Kinetic energy,internal energy,hourglass energy,total energy(KE+PE) as shown below.
Case-2: LAW2_EPSMAX_Crack:
To observe the cracking of the elements .In the failure card we need to give values mentioned below.
Ifail_sh=1, Dadv=1 and Ixfem =1.
one this cards checked select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_2)_0001. out file and open ,as shown below.
energy error is about 4.1% and mass error is 0 this accptable range we can proceed to go further.
Elapsed time=69.07 and the total number of cycles =49217
displacement and vonmises contours mentioned below.
vonmises contour
Displacement contour
Case-3: Law2_Epsmax_no fail:
In this import the johnson_0000.rad file and from the model tree delete the failure johnson card. run the simulation 
one this cards checked select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_3)_0001. out file and open ,as shown below.
Energy error is 0.8% and mass error is =0 and Elapsed time =62.97 and the total number of cycles =49408.
Displacement and vonmises countours as shown below.
Displacement contour
Vonmises counter
Case-4: LAW2
In this case From the material card Remove the Elastic plastic strain max value and run the simulation.
once EPS_p_max value is removed select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_3)_0001. out file and open ,as shown below.
Here the energy error is 3.0% and mass error is 0 .Elapsed time =61.94,Total number of cycles =48737 and in the card image :M2 Plas_JOHNS_ZERIL.
Displacement contour
Vonmises contour
Case-5: LAW 1 elastic:
In this Import the JOHNSON_0000.rad file and from the material card change the card image to LAW 1 ELASTIC. as shown below.
once card image and given (Row,E,NU) enter after that select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_5)_0001. out file and open ,as shown below.
Here the Energy error value is 1.3% and mass error is =0.Elapsed time =62.16 and total number of the cycles =47969 and card image =LAW1 ELASTIC.
Displacement and Vonmises contours shown below
Displacement contour
Vonmises contour
Case-6: LAW36
Here import > geoemtry solver deck >select the Law27_0000.rad file and in the material card change the card image to LAW36_PLAS_TAB and change the property as well. here i wondered that when i did not change the property card in this case my result was beyond the recommendation after editing the property card then my results were proper.
The importence of the card is if we have the Engineering stress and true stress values are different then we can use this material card. most of the industies use this for the better results. From the lectures samples values given for the engineering stress values in both X and Y diresction . Here below respective of this shown below.
We have to mention above parameter values in M36_PLAS_TAB card but Row as=0.0027,E=71000,NU=0.33 we have to take from sample card because this values being used to calculate the stress vs strain curve and same will be reflected in material card.As shown below .
Here in material card N_function enter the value 1(N=1) then only we can add this engineering curve to material card.
Enter the above mentioned edings after that select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_6)_0001. out file and open ,as shown below.
Here the Energy error value is -1.6% and the mass error is about 0. Elapsed time=66.69 and total number of cycles=53144 and card image=LAW36.(M36 PLAS_TAB).
Displacement Contour
Vonmises contour
Case-7: LAW27:
Import > Geometry solver deck >select the LAW27_0000 ,edit the below mentioned parameter as given in slides.
Enter the above mentioned edings after that select the analysis >Radioss > In the options set to -nt 4 and set the folder where do we want to save the file > click the radioss button it will start the simulation. once the simulation is done open the folder we have selected ,suppose in this i case i had PC >document> and save all the respective files stored in this document folder. radioss generate the number of files while simulating out this select JOHNSON(case_7)_0001. out file and open ,as shown below.
Energy error is =0.8% and mass error is =0 . Elapsed time =62.85 and Total number of the cycles=49508 and cardimage is:M27_PLAS_BRIT.
Displacement and vonmises contours shown below
Dispalcement contour
Vonmises contour
Observations:
1.As per the values mentioned in in the case 1 and case 2 in the case 1 we have used the default values that Ixfem and Dadv is zero this is crack on the element and crack advancement .if use default values in the card there will not be any crack on the element and elements deleted and in the case 2 the elements getting cracked after using (Ixfem=1,Dadv=1) and stress experience during simulation for the default values in case is high in vonmises contour and in case 2 stress is bit less in vonmises contour .
2.In the case 2 the crack was proper in regular manner.
3.In case 3 the failure card is deleted and then the elements experience more strain and deleted and if we observe the vonmises contour the stress value is more compare to case 2.
4.In case 4 the the deletion of the elements almost negligible the EPsmax is zero and the elements elongated enough and cracks on elements the values of the Ixfem and Dadv is present.
5.In case 5 material card is changed to LAW1 eleastic because of this elastic the deformation is linear and when we remove the load it come back to its original position and in the contour the displacement is more and stress is less.
6. In the Case 6 the displacement and stresses are the more in this case and rupture(break) in the plots the hourglass energy is zero. In the result at the end of the curve the internal energy is fluctuating as the ball hitting the flat surface and the elements absorbing energy as long as it absorbing energy it experience stress thats what shown in contour and plot.
7.In the case 7 the breaks and deletion ,if the elements presents it absorb energy and experience stress and same will be reflected in the contour . in the dispalcement and vonmises contour it experience less displacement and stress shown.
8. In the all cases(1 to 7) the Hourglass energy is zero because used the proper shell element properties. and in every graph the total energy is shown(Kinetic energy(1/2mv^2) +potential energy(mgh) shown difference.
9. Out of all cases LAW36 material is preferred to use and recommended .
Result:
Using The Radioss engine starter files changes in material card card and simulation has been done for below mentioned cases as per the challenge. LAW36 material card is recommended to use.
Case-1: Run the file as it is and name it as Law2_Epsmax_failure
Case-2: In the failure johnson card(In/FAIL/Johnson) change the follwing Ifail_sh=1, Dadv=1 and Ixfem =1. Run the model as Law2_Epsmax_Crack.
Case-3: Delete/FAIL/JOHNSONCARD. Delete the johnson failure card from the model tree and run the model as Law2_Epsmax_no fail.
Case-4: Delete the value of the EPS_p_max and run the model name LAW2
Case-5: Convert this material model to LAW1 ELASTIC with same same density(row),Youngs Modulus(Y),Poissions ratio.(E=71000,Row=0.0028, NU=0.33)
Case-6: Convert the card to LAW36 elasto plastic
Case-7: Open Law27_000.rad
i) Change the shell properties to recommended shell properties.
ii) Notice the material card. johnson cook parameters but different values for EPS based failure.
iii)Run the model with name LAW27.