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(OP)
Hello!

I am assigned an academic task of simulating a 2D disc (plane strain assumption) falling from a height of 0.2m to the ground (analytical rigid surface) and allowed to bounce until it rests. The disc is modelled in two parts (namely DiscPart-1 and DiscPart-2). The parts of the disc and its assembly are shown in the attachment.

I used contact pairs in the simulation with master surface as ground surface and slave surface as the bottom surface of DiscPart-2 and the discretization technique used is surface-to-surface discretization. Tie constraints were used to couple the parts. In edit section I checked with a tick mark in the option "the plane stress/strain thickness =1". The elements used are CPE4R.

I am currently doing  a mesh convergence study on this task. I did this by keeping the element size constant for DiscPart-1 and reducing the initial element size of DiscPart-2  by a factor of 2 for every following simualtion  (because DiscPart-2 comes into contact with the ground).

I carried out the simulations in the following manner:

Simulation-1: DiscPart-1 (seed size = 0.3), DiscPart-2 (seed size = 0.02).

Simulation-2: DiscPart-1 (seed size = 0.3), DiscPart-2 (seed size = 0.01).

Simulation-3: DiscPart-1 (seed size = 0.3), DiscPart-2 (seed size = 0.005) and likewise.

The simulation results are shown in the attachment.

Question : It is evident from the results of simulation-1 and simulation-2 that they are  different in a sense that the peaks don't match. But when I carried out simulation-3, the result is somewhat like the result of simulation-1 and the result of simulation-4 is kind of similar to the result of simulation-2 and the cycle repeats for the following simulations. Eventually, none of the results converge.

I want to get the convergence. So, it would be better if someone can help me in pointing out the problem and provide possible solution to get convergence.

Thank you.

Regards,

Pravin


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