2018 Volume 74 Issue 2 Pages I_147-I_158
In the finite element analysis, it is important to evaluate the local behavior at the portion where the thickness is discontinuous or near the corners. If such structure is discretized with structural elements, the numerical results are often unreliable, because the plane stress condition is assumed in the transverse direction and the incompressibility could not be considered appropriately. Thus, the authors proposed that the effective procedure of discretizing the model is to connect shell and solid elements properly by using Nitsche's method.
When the different types of elements are connected at the boundary including corners, the stiffness near such boundary may become larger than that of the model discretized with only one type of element. Thus, the authors propose the approach to avoid this problem by improving the mesh geometry near the boundary.
The proposed procedure can be applied to the elastoplastic problems, but it is necessary to divide the domain so that the plastic region does not progress on the connecting interface. This is because the numerical calculation becomes unstable due to the disorder of the stress state when discontinuous stress state is connected.
This paper presents a numerical procedure for connecting shell and solid elements in elastoplastic problems. In the proposed approach, shell and solid elements can be coupled with reasonable deformation near the connecting interface, only when the plastic range is not included on the connecting interface.
