Assignment 3-2D Element Formulation Challenge

OBJECTIVE

1.Run the base simulation without any modification to element properties.

2. At the end of the simulation, do the energy error and mass error checks and determine whether results would be acceptable.

3. If acceptable, Plot rigid wall forces, internal energy, hourglass energy, contact energy, total energy of the simulations.

4. Change all the shell elements properties to recommended properties, save this as separate, rad files and run the simulation.

5. Follow steps 3 and 4.

Recommended properties:

PROCDEDURE

CASE 1: No CHANGE IN PROPERTIES

• Open Hyperworks. Select the solver as radioss.
• Go to Import- Solver Deck- Browse the file which is in .0000.rad format.

• Go to analysis- radioss- run the simulation.
• After analysis check the energy and mass error and nd determine whether results would be acceptable.
• Divide the display panel into two sections. Change the second section to hyperview.
• Open the file which is in .h3d format.Check how material got fail.

• Again divide the panel into another section.Change to Hypergraph 2D.
• Open the file which is in .T01 format.
• Plot rigid wall forces, internal energy, hourglass energy, contact energy, total energy of the simulations.

CASE 2: WITH PROPERTIES CHANGE

• Again import the model and save as in another location and select radioss as solver.
• Go to model-properties-hat section.
• Change Ishell value to 24.
• Change Imstr = 2 and Imsh3n = 2.
• Run the simulation and do the above procedure

RESULT

Run the simulation with and without change in values mentioned in objective has performed

CONCLUSIONS

Energy error of -15% to 2% and mass error upto 2% are acceptable. Here in both cases it is within the limits.

Change in Ishell:

QEPH is an improved under-integrated 4 node element with one integration point on the surface.So by chanaging the value Ishell = 24 it reduces the hourglass energy.

When Ishell =0 maximum hourglass energy = 6866264 Kg*mm^2/ms^2

When Ishell = 24 maximum hourglass energy= 2584660 Kg*mm^2/ms^2

Change in Imstr:

It is Shell small strain formulation flag.When change to 2 it causes large strain with full geometric nonlinearities.

Because of that internal energy increases.

Case 1: Maximum internal energy= 20671958 Kg*mm^2/ms^2

Cae 2: Maximum internal energy= 21928150 Kg*mm^2/ms^2

Change in Imsh3n:

It is standard triangle with modification for large rotation. Because of possibility large rotation.When Imsh3n= 2 kinetic energy at the end of simulation gets reduced.

Case 1: Minimum Kinetic energy= 38696048 Kg*mm^2/ms^2

Case 2:Minimum Kinetic energy= 32496366 Kg*mm^2/ms^2