Comparing and Analyzing the 7 cases of Rupture Plates

OBJECTIVE:-

• To compare and analyze the 7 cases of Rupture Plate by applying different materials and properties.

QUESTIONS:-

7 different cases will be provided to us which has to be taken into account and then compared. Following are the list of points which needs to be followed i this report:

Slides:-

CASE 1:-

FAILURE_JOHNSON_0000.rad file was imported into the hypermesh and the following properties were noticed. The model was basically of aluminium material property which was assigned with the material card LAW2(/MAT/PLAS_JOHNS/) and a fail card (/FAIL/JOHNSON).

(/MAT/PLAS_JOHNS/) - It is a law which represents an isotropic elastoplastic material using Johnson Cook material model.

(/FAIL/JOHNSON) - This card is basically used as a criteria card for failure mode for Johnson Cook method, and id basically used for brittle material failure.

The name of the model was changed to Law2_epsmax_failure as the question asked to.

Simulation was ran after checking the properties and making it sure to change it into recommended if needed to be.

After the simulation ends, we get the following termination result which results in a normal termination with no errors.

After the end of the simulation, we opened the Law2_epsmax_failure_0001.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49445-49479 is around 0.2%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3598 = 2.758E+01.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 2.803E+01 at Node 3598.

Minimum velocity = 0.000E+00 at Node 3635.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 7.392E+00 at Shell 150.

Minimum % thickness reduction = -1.177E+01 at Shell 413.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 1.510E-01 at Shell 253.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 3.282E+02 at Shell 262.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

From the Internal Energy\'s graph we can conclude that by increasing the strain energy, the elements starts getting destroyed.

If we observe the graph of Kinetic Energy carefully, then at the time step at 4 ms the elements in the material got deleted or destroyed. Just as the strain rate reached upto 15%, the elements starts getting destroyed.

CASE 2:-

FAILURE_JOHNSON_0000.rad file was imported into the hypermesh and under failure cards the value of Ifail_sh, Dadv and Ixfem were changed as follows:

The name of the model was changed to Law2_epsmax_crack as the question asked to. Similar to CASE 1 the simulation was ran in Radioss, and after the end of the simulation, we opened the Law2_epsmax_crack_0001.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49390-49396 is around 4%, so the results would be not be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3984 = 1.327E+01.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 2.311E+01 at Node 3983.

Minimum velocity = 0.000E+00 at Node 3635.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 9.908E+00 at Shell 773.

Minimum % thickness reduction = -1.325E+01 at Shell 440.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 1.489E-01 at Shell 159.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 2.947E+02 at Shell 219.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

Internal Energy increases with increase in Strain rate.

In Kinetic Energy Graph, crack is seen to occur at around 0.3 ms mark, and it keeps happening until the failure occurs and the graph falls.

CASE 3:-

In this case, we were supposed to delete the Failure Card and run the simulation. So we imported the FAILURE_JOHNSON_0000.rad file, deleted the Failure Card and then ran the simulation. The name of the model was changed to Law2_epsmax_nofail as the question asked to. Similar to CASE 1 the simulation was ran in Radioss, and after the end of the simulation, we opened the Law2_epsmax_nofail_0001.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49390-49404 is around 0.8%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3844 = 1.858E+01.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 2.792E+01 at Node 3592.

Minimum velocity = 0.000E+00 at Node 3635.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 7.410E+00 at Shell 152.

Minimum % thickness reduction = -1.179E+01 at Shell 297.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 1.500E-01 at Shell 164.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 3.114E+02 at Shell 246.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

CASE 4:-

In this case, we were supposed to delete the EPS_p_max value and run the simulation. So we imported the FAILURE_JOHNSON_0000.rad file, deleted the EPS_p_max value and then ran the simulation. The name of the model was changed to Law2 as the question asked to. Similar to CASE 1 the simulation was ran in Radioss, and after the end of the simulation, we opened the Law2.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49280-49303 is around 1.1%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3999 = 5.629E+00.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 3.031E+00 at Node 3688.

Minimum velocity = 0.000E+00 at Node 3677.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 7.530E+01 at Shell 192.

Minimum % thickness reduction = -2.301E+01 at Shell 389.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 3.216E-01 at Shell 192.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 3.280E+02 at Shell 262.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

The energy error occurs because of the creation of internal energy and computational time decreases because it does not have plastic strain value to calculate failure strain.

CASE 5:-

In this case, we were supposed to change the material to M1_ELAST and then feed the value of Rho_Initial, E and nu and then run the simulation. So we imported the FAILURE_JOHNSON_0000.rad file, changed the material property and then ran the simulation. The name of the model was changed to Law1 as the question asked to. Similar to CASE 1 the simulation was ran in Radioss, and after the end of the simulation, we opened the Law1.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 47960-47968 is around 0.3%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3688 = 4.999E+00.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 9.881E+01 at Node 3902.

Minimum velocity = 0.000E+00 at Node 3677.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 4.544E+01 at Shell 151.

Minimum % thickness reduction = -1.360E+01 at Shell 414.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 0.000E+00 at Shell 153.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 1.099E+04 at Shell 192.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

Increase in strain rate makes the Internal Energy increase as well.

Due to the Elastic behaviour there is not any breaking of the material, so the Kinetic Energy keeps on increasing.

CASE 6:- LAW27 PLAS_BRIT MATERIAL

This law combines an isotropic elasto-plastic material with orthotropic brittle failure model. Such failure can only be seen when the model in under tensile force.

LAW27_0000.rad file was imported into the hypermesh and the following properties were noticed.

Simulation was ran after checking the properties and making it sure to change it into recommended if needed to be.

After the end of the simulation, we opened the Law27_0001.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49335-49355 is around 1.1%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3990 = 6.013E+00.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 6.906E+01 at Node 3990.

Minimum velocity = 0.000E+00 at Node 3635.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 6.669E+00 at Shell 172.

Minimum % thickness reduction = -1.419E+01 at Shell 321.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 2.038E-01 at Shell 145.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 3.294E+02 at Shell 436.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

The energy error occurs beacuse of the absorption of energy. The computational time is less because the material is brittle and it has plastic strain value.

CASE 7:-

In this method of simulation, the LAW36 material is the most commonly used material property in the industrial analysis.

In this case, we at first imported the FAILURE_JOHNSON_0000.rad file and created a material card and filled in the values of Rho_Initial, E, Nu, EPS_p_max, EPS_t, EPS_m, N_funct, fct_ID, Fscale, EPS_dot and Fsmooth.

The curve \"Test_curve\" which was added was:

Simulation was ran after checking the properties and making it sure to change it into recommended if needed to be. After the end of the simulation, we opened the Law36_0001.out file in order to study the results on the basis of cycles, energy error, mass error and simulation time.

Since the energy error in the end of the cycle from 49445-49479 is around 0.2%, so the results would be acceptable as the acceptable error should be around positive 1% or 2%.

And the mass error at the end of the cycle is 0.000.

Comparing the animation and the results of all the 5 factors below:

1. Displacement:

Maximum displacement occurs at node 3688 = 5.000E+00.

Minimum displacement occurs at node 3697 = 0.000E+00.

2. Velocity:

Maximum velocity = 1.173E+00 at Node 3873.

Minimum velocity = 0.000E+00 at Node 3677.

3. % Thickness Reduction (calculated):

Maximum % thickness reduction = 4.863E+01 at Shell 153.

Minimum % thickness reduction = -1.117E+01 at Shell 365.

4. Plastic Strain along the thickness:

Maximum plastic strain along the thickness = 5.671E-01 at Shell 153.

Minimum plastic strain along the thickness = 0.000E+00 at Shell 153.

5. Von Mises

Maximum Von Mises stress = 3.204E+02 at Shell 153.

Minimum Von Mises stress = 0.000E+00 at Shell 153.

HyperGraph 2D was then opened to compare the graphs of the energies released.

Graph 1:- Internal Energy, Hourglass Energy, Kinetic Energy, Contact Energy and Total Energy.

CONCLUSIONS:-

• Case 1, Case 6 and with proper stress-strain curve inputs in Case 7, the resulted outcome will be much more realistic.
• Law 27 proved to be much better than Law 2 materials.