Project

Element-Property simulation check

The task was to compare the simulation results of the base setup and improved shell element properties for crash tube analysis

Simulation of crash tube before changing the shell element property

Intially simulation was done with the base setup without editing any element properties
The setup was made with basic setup to run the file without any error
Proof of the run output file

As per the results obtained from the simulation we should understand that max energy error that occurs is -11%
But enery error acceptable level is -15%
In this hourglass is not countable in this energy balance, so that a negative
energy generally occurs.
The energy error is negative is due to energy is dissipating.
Simulation result is visualized using hyperview and hypergraph

First image represents the vonmisses stress average method, The maximum stress occurs at node 708 with the magnitude of 349Mpa and min node occurs at node 716 as 0
Second image represents the Energy vs Time plot
As we can see kinetic energy initially is at very high because tube initially targeted at the wall with high velocity.whereas internal energy started opposing and started to increase from 0, hour glass energy not accounted in energy errors and it explains negative energy
Third image represents the Force vs time, Resultant force is always similar to resultant normal force. The frictional force slightly goes on high with time as the crash tube opposes the collision so frictional force increases.

Simulation of crash tube after changing the shell element property

After applying the property cards, again ran the model and checked the simulation, output file representing errors screenshot

As we see max energy error is only 0.1% and the mass error is similar to previous one. In case of using QEPH shell formulation, the energy error can be slightly positive since no hourglass energy and the computation is much more acurate.

First image represents the vonmisses stress average method, The maximum stress occurs at node 168 with the magnitude of 346.15Mpa and min node occurs at node 716 as 0
Second image represents the Energy vs Time plot
As we can see kinetic energy initially is at very high because tube initially targeted at the wall with high velocity.whereas internal energy started opposing and started to increase from 0, hour glass energy not accounted in energy errors and it explains negative energy

Conclusion

Finally applying the property card to the elements will omit the hourglass energy.These elements increses the number of integration points and so the element gets more stiffer thus resulting in less deformation.
And applying the correct element property is also most important thing to maintain the result as expected.

Ship work like this
in your own course.