I want to analyze a steel ball with initial velocity impact the floor.In order to create a nodal point at the center of the sphere, I combine the ball with 8 one eighth ball parts. It's very stranger that the results (Dz of the ball center nodal point) are quite different with different contact conditions or element types setting.
Initial velocity= -500mm/s
impact plane= -10mm (Z direction)
standard gravity force ( -Z direction)
*design scenario 1 (contact tolerance for impact plane 0.01mm):
The bounces are tending down, but sometimes the decrease is not obvious between two sequential bounces.
*design scenario 2 (contact tolerance for impact plane 0.01mm; each element is with midside nodes):
The ball seems to bounce at the same level after the 2nd jump
*design scenario 3 (contact tolerance for impact plane 0.254mm - default setting of the program):
The ball will bounce higher and higher.
Q1: How to explain the differences which are described above?
Q2: How to make sure which analysis is correct without experiments? This is a simple model, we can ascertain the numerical result more easily. For a complex model?
Q3: How to define a nodal point with specific coordinate position inner a brick part? (e.g. Import a whole sphere and Autodesk simulation will create a nodal point at the center of the sphere exactly.)
Thanks! Ccz90
There are a few parameters which can influence the solution of drop test via impact planes. Some of them have dependence on the others;
-Shoubing