Assignment 3-2D Element Formulation Challenge

OBEJECTIVE: To Run the analysis of the given model with the default property and recomended property parametres, and plot graphs and compare the result bor both the cases.

PROCEDURE:

Step1: Importing the give file to the GUI

• File>Import> Selecting the file type 0000.rad>Export.

• Turning on the shaded Geometry for better view.

Step2: To Change the Run time to 55ms.

• Cards>ENG_RUN>Tstop=55ms

Step3: Selecting the animation steps for the simulations.

• Animation=60

Formula for Tfreq= Tstop/ no of Animation.

= 55/60

= 0.9167ms

• Cards>ENG_AnimDT>Tfreq=0.9167ms

Case1;

Step3: Runing the Simulation with the default property parametres.

• Choosing the destination to save the simulation files.
• -nt 4 it is the command which will use all the 4 cores to run the simulation.
• Analysis>Radios>saving the file>Radioss.

• From the above result the energy error varies from -0.00% to -10.3% which is in the acceptable range
• The mass energy did not vary and remained constant throughout.
• The mass error percentage obtained is 0.001% which less than 2% which is acceptable range

Step4: Since all the Errors are falling under acceptable range now ploting Plot rigid wall forces, internal energy, hourglass energy, contact energy, total energy of the simulations.

• Now to plot the graph, Hypergraph 2D.

• Now selecting T01 file obtained from the analysis folder
• Global variable> selecting internal energy, hourglass energy, contact energy, total energy and kinetic energy to be ploted >Mag>Apply.

• From the above graph we observe following result
• Internal Energy: This energy is developed in the tube when it is crashed into the rigid wall and deforms this causes the internal energy to increases
• Kinetic Energy:This energy is developed when the tube is in motion,The kinetic energy decrease as the tube hits the wall decelerates.
• Contact Energy: This energy is the interface energy developed between the tube and the rigid wall.

• Energy is 0 before the contact and energy increase as the tube comes in contact with wall an reduces when tube deforms as the area of the contact reduces.
• Hourglass Energy: Energy is developed to resist hour glass mode, The energy is slightly increasing.
• Total energy: Is sum of internal energy, kinetic energy, contact energy, hourglass energy..etc in the model, the total energy is reduce slightly.
• Rigid wall forces: Are the forces that is developed when the tube is in contact with the Rigid wall.

Step 5: To Run the Animation or stimulation.

• Hyper view> selecting the h3d file to run the animation from the analysis file>apply.

To plot Von mises and displacement stress using contour Plot .

Contour option>selcting the result type>apply.

Case2:

Step6:

Now Changing the property with the given parameter.

Parameters		Comment
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.

• Changing the Property Card.

Step7: Runing the Simulation with the Given property parametres. flowing the same procedure.

• From the above result the energy error varies from -0.00% to -0.1% which is in the acceptable range
• The mass energy did not vary and remained constant throughout.
• The mass error percentage obtained is 0.001% which less than 2% which is acceptable range

Step8: Since all the Errors are falling under acceptable range now ploting Plot rigid wall forces, internal energy, hourglass energy, contact energy, total energy of the simulations.

• Now to plot the graph, Hypergraph 2D.

• From the above graph total energy is constant.
• The kinetic energy is decreasing.
• The internal energy is increasing

• From the above graph Hour glass energy is zero
• The contact energy is fluctuating.

• From the above graph Rigid wall forces is decreasing.

Step9: To Run the Animation or stimulation.

To plot Von mises and displacement stress using contour Plot .

Now comparing the results Of case1 and case2;

Results to be compared	Case 1: With default Property Paramater	Case 2: With Given property Paramater
Energy error	-0.0% to 10.3%	-0.0% to -0.1%
Kinetic energy	0.6131E+08mj	0.6129E+08mj
Internal energy	0.3512E+05mj	0.2845+05mj
Hour Glass energy	6.30E+06	0
Von mises stress	3.500E02MPA	3.500MPA
Displacement	7.596E+02	7.794E+02

• From the above table we can see that energy error has been reduced when the given parameter is added.
• There kinetic and internal energy has reduced when the given parameter is added
• Hour Glass energy is reduced to zero when the given parameter is added.
• The displacement is also increased.
• The result are accurate in case 2 when the parameter is added.
• When we campare the simalation in case2 the difornation looks natural.

Steps to avoid Hourglass:

• To choose Full or Reduced integration Method
• To refine the mesh
• To add stiffness to the node.