Reply To: Questions about the Static/Quasi-Static/Dynamic

[Daming Wang]

Hi Peter, I decided to solve this problem by turning to a new direction. I think it is not a good idea to solve the gap contact problem in a unstable system using "contact Stablization Damping Factor". As we know, the cylinder is un-restrained relative to the wall. 

 

 

 

This time I combined the 2 contact pairs (one pair for the contact between the cylinder bottom and the base face, the other is the side of the cylinder and the side of the wall) into only one contact pair, see the figure below. The contact type is frictional with frictional coefficient of 0.2. The load applied on the cylinder is unchanged. The initial distance between the cylinder and the wall is 0.6m. The stablization damping factor is 0. 

The run was finished successfully. I can see clearly the cylinder moves towards the wall and stopped there. This time, when the cylinder hits the wall, there is a extremely large stress spike, which is 7.9Mpa, which is reasonable. It can be seen from the figure below that the cylinder hits the wall at 2.057s. 

Since the load is still applied, I thought the Von Mises stress should drop and reached the same value as the case previously mentioned with zero initial distance between the cylinder and the wall (0.16Mpa). However, from the figure above, we can see the maximum Von Mises stress after the hit remains at 0.287Mpa until the end of the simulaton (t=3s), which is much higher than 0.16Mpa. 

 

 

 

Do you know what caused the differnece?