Simulation of a spherical punch hitting the shell
OBJECTIVE:
-The main objective of this Assignment 4 is to apply material properties to the component and to interpolate the results in respect to their behaviour. The important step is to prefer the best fit for further analysis of all the 7cases.
-The 7cases assked in the assignment were
1. To run the basic rad file, save it as Law2_epsmax_failure
2. In Failure Johnson card, Change Ifail_sh=1, Dadv=1,IxFem=1, run and save it as Law2_epsmax_crack
3. Delete Failure Johnson card, run and save it as Law2_epsmax_nofail
4. Delete Eps_P_max in material property and save it as Law2
5.Convert the material2 into material1(elastic) with basic material properties and run the simulation as Law1.
6.Create the material property of Law36 by adding and applying the parameters of Material36 and save it as Law36.
7.Run the rad file, create material27 property, interpolate results and save the file as Law27.
CASE SETUP AND EXECUTION:
- Run the Rad file which is named as Failure_Johnson_RAD
1.Law2_epsmax_failure
-The Rad file should be opened in solver deck for starting the simulation.
-In the shell element properties, the recommended properties of Ishell=24,Ismstr=2,Iah3n=2,N=5,ithick=1,Iplas=1 were applied to the P1_shell element.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Von Mises vs Time Step
Time vs IE KE TE and Resultant Normal and Tangent Force
Result:
-After changing the element properties, the punch breaks the shell element where the maximum deformation is obtained at 287.6J and the minimum deformation is found at3.82 J.
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. This is the region where the material breaks(maximum deformation is noticed).
-Hourglass energy as well as contact energy is obtained near the zero deformation on the nodes.
-In Johnson-Cook Material, the material is represented and it behaved as an isentropic elasto-plastic material. Material damage is very high.
2.Law2_epsmax_crack
-The Rad file should be opened in solver deck for starting the simulation.
-In FAILURE JOHNSON card, the values of Ifail_sh=1;Dadv=1;Ixfem=1 are needed to change.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Von Mises vs Time step
Time vs IE KE TE Total Resultant force
Result:
- The simulation is run after changing the recommended parameters in Failure_Johnson_card.
- The spherical punch breaks the shell at a maximum displacement of 294.7Joules where the energy required is 7joules more than the 1st case. Minimum deformation is occured at 3.27Joules.
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. This is the region where the material breaks(maximum deformation is noticed).
-Contact energy obtained is same as the hourglass energy.
-The change obtained is because of the change in Dadv which is responsible for the
crack advancement criteria.
3. Law2_epsmax_nofail
-The Rad file should be opened in solver deck for starting the simulation.
-Delete the FAILURE JOHNSON Card
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Von Mises vs Time step
Time vs IE KE TE Resultant Normal and Tangent Force
Result:
-Once the failure Johnson card is removed, the punch breaks the shell material into pieces.
-The spherical punch breaks the shell at a maximum displacement of 270.5 Joules where the energy is less required because of no failure card assigned to it. Minimum deformation is occured at 3.01Joules.
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. This is the region where the material breaks(maximum deformation is noticed).
-Contact energy obtained is same as the hourglass energy.
-As there was no failure card assigned to the component, the breakage was very high when compared with two other cases.
4. Delete Eps_P_Max
-Delete the value of Eps_P_max in the material property of the component.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Time vs Von_Mises
Time vs IE KE Resultant Normal_Tangent force
Result:
-The plastic strain rate at failure was removed in order to perform this case.
-The spherical punch didnt break the shell in pieces but the maximum displacement is obtained at 424.7J which is the highest maximum displacement in all the cases. Minimum displacement is obtained at 4.7J
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. There is no much change in Kinetic energy.
-Contact energy obtained is same as the hourglass energy.
-As the plastic strain rate at failure was removed, it is quite understood that the material is not going to behave in plastic, so there was no breakages but the punch abruptly breaks shell in small quantities(very low).
5.Law 1
-Run the Rad file in new session.
-Create Material1 (i.e) elastic property of the material and apply the same material card to run the simulation.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Time vs Von Mises
Time vs IE KE Resultant Forces
Result:
- The simulation is run inorder to check how the material behaves when changed from Plast_Johnson to perfectly elastic.
-The spherical punch didnt break the shell in pieces but the maximum displacement is obtained at 1086J which is the highest maximum displacement in all the cases. Minimum displacement is obtained at 120.6J. There is no breakage in this simulation.
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. There is no much change in Kinetic energy.
-Contact energy obtained is same as the hourglass energy.
-The elastic material behaved perfectly well where the elasticity of the material is so high that the component didnt break at the estimated time of simulation.
6.LAW 36
- Run the Rad file in the solver deck.
-Change the material card into Material36 where the behaviour will be elastic_plastic_tabulated which is only applicable for shell elements.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Time vs Von_Mises
Time vs IE KE Resultant forces
Result:
-The material property has been changed from elastic to elastic_plastic to check the behaviour of the material.
-The spherical punch didnt break the shell but the energy is felt in all area of the shell. Maximum displacement is obtained at 1186J which is the highest maximum displacement in all the cases. Minimum displacement is obtained at 120.6J. There is no breakage in this simulation.
-The internal energy increases as the time increases where the kinetic energy is constant and a little change in deformation occurs. There is no much change in Kinetic energy.
-Contact energy obtained is same as the hourglass energy.
-A little breakage in elements has been observed but the elastic_plastic property of the material resulted in creating a hole like structure in the shell at the end of the simulation.
7. Law27
-Run the rad file in the sover deck.
-Apply material card 27, so that the material can behave elastic_plastic_brittle.
-The file is now sent for analysis in Radioss wherein the Engine input file,Output file,animation file, time step file, Results were obtained.
-The energy checks and mass error checks were approved as the values generated in output file were in acceptable proportions.
-To perform Von Mises Stress plot, the animation file(.h3d) file is ran in Hyperview and with the help of Timesteps(T01) file, various graphs are plotted using Hypergraph.
Time vs Von-Mises
Time vs IE KE Resultant_forces
Result:
-The material property has been changed into Material 27 to check the behaviour in Plastic_elastic brittle model.
-The spherical punch breaks the shell at a maximum displacement of 277.2 Joules where the minimum deformation is noted at 3.08Joules.
-The internal energy increases as the time increases where the kinetic energy is constant till 4milliseconds and a little change in deformation occurs. This is the region where the material breaks(maximum deformation is noticed).
-Contact energy obtained is same as the hourglass energy.
-The punch broke the shell as the element behaved in a quite stiff manner apart from all the cases. Breakage is high in this material property.
\"The missed snapshots were attached in the google drive\".
The folders are created and kept in a following google drive link
https://drive.google.com/drive/folders/1loLoFSatnmzwhAFRvMzYd4KtAvLsbbJ0?usp=sharing
CONCLUSION:
The simulation of all the 7 cases were simulated according to the required parameters and the simulation where run wherein the results and material behaviour of all the cases were interpolated.
* No material breakage is observed in Material 1 (i.e) Law1 and Delete_Eps_max which will be highly influential in reducing costs to the company and so on.
Change in the values of Dadv and Ixfem in Law2_Epsmax_crack resulted in more crack advancements.
The removal of failure card in Plast_Johnson resulted in breaking of the material in Law2_epsmax and the removal of plastic strain rate resulted in material failure in Law2.
So by running all the simulation, cases like Law1 and Delete_Eps_max will be the most preferred material properties to run a simulation where there is no breakage and the energy observed is considerable.