Numerical Procedure for Connecting Shell and Solid Elements Based on Nitsche's Method

Abstract

In the finite element analysis, a structural element is efficient to represent the overall behavior of simulation models. On the other hand, a solid element is used to evaluate local behavior, such as stress concentration for stepped structures. For the purpose of developing a more flexible modeling for the finite element analysis, it is necessary to propose a numerical procedure for connecting shell and solid elements.
In conventional procedures to connect shell and solid elements, a continuity condition for only displacements is imposed at connecting surface. For applying the continuity condition for displacement fields on the interface between shell and solid elements, unreasonable deformation of solid elements near the interface may be observed.
This paper presents a numerical procedure for connecting shell and solid elements by using Nitsche's method, which imposes the continuity conditions for both displacement and stress vectors on the interface. From this approach, shell and solid elements can be connected with reasonable deformation and stress distribution.