May 29, 2021 at 4:24 pm

peteroznewman

Subscriber

Hello Qing
Dynamics solvers are used when inertial forces are a significant portion of the internal forces caused by deformation. Rolling is a low speed process so the inertial forces are insignificant. That means you could solve this problem using the Static Structural solver.

The Static Structural solver permits you to apply rotations to rollers and move a sheet through the roller system. Though time is used in Static Structural, it is only used to keep track of load increments and so is arbitrary and by default, each step is 1 second in a multistep solution.

The most important feature to include in your simulation is Plasticity in the Material model. The simplest plasticity material model is Bilinear Kinematic Hardening.

The benefit of Explicit Dynamics over implicit solvers such as Static or Transient Structural is that the contact algorithm is very robust. However, this sheet rolling problem is not too difficult and can be made to work in Static Structural.

The problem with Explicit Dynamics is the very tiny time steps it is required to take. The time step is dictated by the materials and the smallest element in the whole model. The way to reduce your wait time is to move things faster than in real life, but not so fast that the inertia forces start to become significant.

I recommend you start with Static Structural. Make the roller bodies have a Stiffness Behavior of Rigid. Put 8 linear elements through the thickness of the sheet. Try a 2D plane strain model as that will solve very fast if you can get the boundary conditions the way you need them. For a 2D model, you need surfaces in the XY plane.

The Static Structural solver permits you to apply rotations to rollers and move a sheet through the roller system. Though time is used in Static Structural, it is only used to keep track of load increments and so is arbitrary and by default, each step is 1 second in a multistep solution.

The most important feature to include in your simulation is Plasticity in the Material model. The simplest plasticity material model is Bilinear Kinematic Hardening.

The benefit of Explicit Dynamics over implicit solvers such as Static or Transient Structural is that the contact algorithm is very robust. However, this sheet rolling problem is not too difficult and can be made to work in Static Structural.

The problem with Explicit Dynamics is the very tiny time steps it is required to take. The time step is dictated by the materials and the smallest element in the whole model. The way to reduce your wait time is to move things faster than in real life, but not so fast that the inertia forces start to become significant.

I recommend you start with Static Structural. Make the roller bodies have a Stiffness Behavior of Rigid. Put 8 linear elements through the thickness of the sheet. Try a 2D plane strain model as that will solve very fast if you can get the boundary conditions the way you need them. For a 2D model, you need surfaces in the XY plane.