ABAQUS modeling: how to bend and twist a sheet into a spiral

[robertt3]

I need to bend and twist a sheet into a spiral, but it is difficult to make it by setting moment at one side of the sheet with the other fixed. Maybe there is a more effective way to do this?

 

[FEA way]

It should be easier to do it by applying a rotation angle instead of moment. Maybe you could do it in 2 steps - twist and then bend.

 

[robertt3]

Thanks for your kind reply. However, in the following step, the sheet will be applied higher temperature to expand and the former bending and twisting will be unloaded. It seems that your rotation method is not suitable for this situation.

 

[FEA way]

Does this analysis represent some physical manufacturing process ? Maybe you could simulate it using rigid tools. If not then the simplified approach with prescribed moment/rotation should suffice. As long as it's elastic deformation, it can be recovered in subsequent steps (multistep analyses are useful in such cases) when you remove the loading/boundary condition.

 

[robertt3]

If I remove the boundary condition in the subsequent steps, will the deformation caused by the subsequent load disappear?

 

[FEA way]

Removing (deactivating) a boundary condition makes the solver replace it with equivalent forces and ramp them down to zero during the whole step (assuming that a static analysis is used). So you can simulate unloading this way.

 

[robertt3]

Thanks for your advice. BTW, do you know how to bend the beam by setting rotation on its free side? I coupled the free side with continuum distribution, and apply rotation at the key point. But the beam only bends in a

very small area near the free side.

 

[FEA way]

Check the "90°-Bending of an Elastic Strip" example on mkraska's GitHub. It's for CalculiX but syntax is almost exactly the same as in Abaqus.

 

[robertt3]

Thanks a lot!