Assignment 3-2D Element Formulation Challenge

1 ] Changing of the Run Time to 55 ms for crash beam file can be seen below .

• Initially the Run Time was 60 ms which is changed to 55 ms

Before : After :

2 ] For changing the Animation step during the similation wee need to calculate the Tfrequency by the formula as ,

Tfrequency = Siulation Time / Number of Animation steps

Tfreq. = 55 / 40 ( here I have taken the Animation step = 40 , which is between the minimum 25 to maximum 60 )

hence , Tfreq. = 1.375

this value is then kept in the Anim/DT card as ,

• Now after making the change in the Tfrequency , using the Radioss Solver Analysis is done and simulation is carried out in Hyperview .
• In the Time History File we can clearly see that the Energy error is in between the 0 to -11 % .
• The range of Energy error allowed is about -15 to +5 % .
• And also the Mass error is very less as compair to total mass of the .
• The Mass error should be less than the + 2% of total mass system .
• Hence Our model simulation's results are acceptable .
• Now we can see the Plots of the various parameters which are plotted using the HyperGraph 2D.

• Now By changing the Shell Elemental Properties provided , analysis is done and the Simulation is performed in Hyperview .
• Provided improved shell elemental properties are ,

• The Results are also plotted using the HyperGraph 2D .

Comparison Between Base simulation results and improved shell elements properties :

• Above graph shows the Rigid Wall Force - Total Resultant Force of base simulation and after the Improved shell elements properties respectively .
• We can clearly see that the Rigid wall Force _ Total resistance Force against the Time is much more stabalized .

• Above graphs are of the Internal Energy , Where can see that the Internal Energy is Increase Initially at the start of impact but reduces over the total peroid of time .

• Above graph shows the Hourglass energy of the base simulation result and the Improved shell elements result .
• We can clearly see that the , Usage of improved Shell elements properties can make the huge difference .
• Usage of the Improved Shell elements property using the Ishell = 24 , which is QEPH 4 nodes Shells are best combination of the Cost and accuracy and the Ishe3n standard 3 noded shell ( CO ) with modification for large rotation .
• This improved Elemental properties reduces the hourgalss energy to almost Zero .

• In the above Graph , we can see that the Contact energy is increases in case of the Improved Shell elements properties than the base simulation results .

• But For the Internal Energy in case of the improved Shell elements properties ,becomes difficult to control internal energy .
• we can see that the Total Energy more Vibrant .
• In case base simulation result Total energy reduces linearly .

Conclusion :

From Both results we can see that the Hourglass energy is reduced to almost Zero % , becuase the use of the Ishell = 24 ,which is modied 2D shell formulation used to Controll the Hourglass Energy .

Rigid wall forces are stabalized much more in the improved Shell elements properties result than the base simulation results , as the Hourglass energy is reduced ,then contact between the rail and the Wall are improved hence proper stabalization in the Rigid wall forces .