jacksonfem
Structural
- Dec 8, 2010
- 52
Hi everybody!
I 'm trying to perform a contact analysis. As you can see in pics 1 and 2, I 'm trying to pass the ball through the 2 plates. I do the followings:
1) Plates and ball from shell elements
2) Displacement assigned on ball, not force.
3) SOL 601 Non-linear static, not transient
4) ATS method, line search on, iterations 30.
5) Plates are not rigid targets
6) Default contact parameters
7) Large displacements, strains and angles enable
8) Elastic materials (ball E= 10MPa)
At a first analysis, I separated the displacement to 100 steps, with step size 0.01sec (total time 100*0.01= 1sec). The analysis failed to converge at step 34 (time 0.335sec). I thought that may I needed smaller time steps around step 34. Pictures 3 and 4 shows the position of the ball at the final step and picture 5 the nonlinear steps procedure. No strange stresses or strains or displacements.
So, at a second analysis I separated the displacement with very many steps from step 32 and after. 32*0.01+100*0.001+58*0.01= 1sec. Again failed to converge at the same time (0.03348sec).
But, in the second analysis, I saw very strange convergence ratios path near the end of the analysis, as you can see in picture 6.
Could somebody give me an advice of what is happening and a way to proceed?
I 'm trying to perform a contact analysis. As you can see in pics 1 and 2, I 'm trying to pass the ball through the 2 plates. I do the followings:
1) Plates and ball from shell elements
2) Displacement assigned on ball, not force.
3) SOL 601 Non-linear static, not transient
4) ATS method, line search on, iterations 30.
5) Plates are not rigid targets
6) Default contact parameters
7) Large displacements, strains and angles enable
8) Elastic materials (ball E= 10MPa)
At a first analysis, I separated the displacement to 100 steps, with step size 0.01sec (total time 100*0.01= 1sec). The analysis failed to converge at step 34 (time 0.335sec). I thought that may I needed smaller time steps around step 34. Pictures 3 and 4 shows the position of the ball at the final step and picture 5 the nonlinear steps procedure. No strange stresses or strains or displacements.
So, at a second analysis I separated the displacement with very many steps from step 32 and after. 32*0.01+100*0.001+58*0.01= 1sec. Again failed to converge at the same time (0.03348sec).
But, in the second analysis, I saw very strange convergence ratios path near the end of the analysis, as you can see in picture 6.
Could somebody give me an advice of what is happening and a way to proceed?