Hello,
I am interested in studying energy dissipation under impact loading. To start, I created an axisymmetric model similar to the example problem pl3d_erode_ale (where a rigid projectile impacts a plate, deforms it, and then bounces back) and gave the plate LINEAR ELASTIC properties.
When I look at all the different energy quantities, I see that ALLVD (energy dissipated by viscous effects) is very large. It starts from zero and as the plate starts to go back to its original shape (after the projectile has already bounced off) it gets larger and almost reaches ETOTAL. This was without using *Bulk Viscosity, so then I entered zero for both linear and quadratic parameters under *Bulk Viscosity thinking that it would decrease viscous dissipation, but it increased ALLVD to magnitudes higher than the total energy! It also increased the work done by contact penalties which was rather small in the first scenario. So next, in addition to this, I also zeroed contact damping by adding the following, since I assumed that because there was only a slight change in ALLVD between these two cases, the large ALLVD was due to another factor:
*Surface Interaction, name=IntProp-1
*CONTACT DAMPING, DEFINITION=DAMPING COEFFICIENT
0
This didn't change anything either.
Are there other form of viscous damping I am missing? Any help would be appreciated! This is really perplexing!
Thanks
Kacy
I am interested in studying energy dissipation under impact loading. To start, I created an axisymmetric model similar to the example problem pl3d_erode_ale (where a rigid projectile impacts a plate, deforms it, and then bounces back) and gave the plate LINEAR ELASTIC properties.
When I look at all the different energy quantities, I see that ALLVD (energy dissipated by viscous effects) is very large. It starts from zero and as the plate starts to go back to its original shape (after the projectile has already bounced off) it gets larger and almost reaches ETOTAL. This was without using *Bulk Viscosity, so then I entered zero for both linear and quadratic parameters under *Bulk Viscosity thinking that it would decrease viscous dissipation, but it increased ALLVD to magnitudes higher than the total energy! It also increased the work done by contact penalties which was rather small in the first scenario. So next, in addition to this, I also zeroed contact damping by adding the following, since I assumed that because there was only a slight change in ALLVD between these two cases, the large ALLVD was due to another factor:
*Surface Interaction, name=IntProp-1
*CONTACT DAMPING, DEFINITION=DAMPING COEFFICIENT
0
This didn't change anything either.
Are there other form of viscous damping I am missing? Any help would be appreciated! This is really perplexing!
Thanks
Kacy
