I have this simulation with SOL209 and obtained results. But after all is set and done I have more questions than answers. Hopefully some of the experts can help me out.
My model is a 3d flat plate shell elements (composite), simply supported at the 4 edges, each edge constraint with an RBE2, a lumped mass (2lbs) drop off from 2ft. The most intriging about the results is that by changing the gap element compression stiffness it behaves differently. Also I can't make sense of the constrait results. I plotted the constraint force vs time and the constraint force oscillates off the zero load, meaning that the response reaches steady state not at zero load, but about 30 lbs. It appears as if it had a weight on the plate already giving me those reactions before impact. What would cause this?, an explanation of this would be appreaciated.
I would have thought that the weight of the plate is where steady state would reach, the weight of the laminate composite is only 8lbs.