Multi-layered shell finite element with interlayer slips

In this study, we develop a multi-layered shell finite element model capable of incorporating interlayer slips for both linear and nonlinear analyses. We derive the total Lagrangian formulation of the shell element to allow for large displacements and large rotations. The shell element effectively represents in-plane interlayer slips within the shell kinematics framework, allowing straightforward modeling irrespective of the number of layers or interlayers involved. Compared to conventional 3D solid finite element models, this multi-layered shell element model requires fewer degrees of freedom (DOFs), resulting in significantly reduced computational costs. The performance of the proposed shell element is demonstrated through various numerical problems.