Assignment 3-2D Element Formulation Challenge

Aim- 2D element formulation.

Objective-

Comparison of results with base simulation and improved shell element properties

1.Using the crash beam file from the previous assignment, change the run time to 55 ms.

2. Change the number of animation steps during simulation to a minimum of 25 and maximum of 60.

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

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

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

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

7. Follow steps 5 and 6.

8. Create a brief report comparing all the results from steps 5 and 6 for both simulations.9. Comment whether there is any change in the results and why there is any change in the result.

Improved parameters-

Ishell =24		QEPH 4 nodes shells are best combination of cost and accuracy.
Ismstr=2		Full geometric nonlinearities (default)with possible small strain formulation activation in RADIOSS Engine.
Ish3n=2		Standard 3 noded shell (C0)with modification for large rotation(default)
N=5		Number of integration points set to 5 for accuracy bending.
Ithick=1		Thickness change is taken into account for accuracy.
Iplas=1		Iterative plasticity for good accuracy.

Procedure-

#Case 1-

Import the file – After opening the hypermesh select the radioss and select the solver deck the select the file and hit import.

2.Set run time-Go to card select ENG RUN >T STOP 55

Set time freq -ENG_ANIM_ DT>T FREQ=1

Analysis- Radioss>Radioss

Below screen shows the output file

After hitting the result shows the hyper view window

Click the contour option then select von mises it will show below screen-

For graph click the hyper graph 2d option -

Internal and kinetic energy -

Rigid wall total resultant force-

Hourglass energy-

Energy error-

#Case-2

Putting the property parameters-

result-

von-mises stress-

Graphs-

Internal energy and kinetic energy-

Rigid wall forces-

hourglass energy-

Result-

Comparison- Case-1 Case-2

Maximum kinetic energy- 0.3652E+08 0.3967E+08

Maximum internal energy- 0.1942E+08 0.1929E+08

Maximum energy error- -8.7% -3.8%

Hourglass energy- Variable Constant

Outcomes-

Learned about energies plotting graph and analysis.