Analysis of Elasto-plastic Thin-shell Structures using Layered Plastic Modeling and Absolute Nodal Coordinate Formulation

A new elasto-plastic thin shell finite element of the absolute nodal coordinate formulation (ANCF) allowing for large deformation and finite rotation is proposed based on the Kirchhoff-Love theory and layered plastic model. The von Mises yield criterion of plane-stress with linear isotropic hardening is adopted in constitutive description of elasto-plastic material. Owing to the plane-stress constraint, special treatment should be given to the stress update algorithm for plasticity. To accommodate the plasticity formulation, the Gauss-point layered integration is inserted into the thickness of the element to produce the internal force. Then, the Jacobian of internal forces is deduced by deriving the consistent elasto-plastic tangent moduli. To accurately track the load-displacement equilibrium path in the buckling analysis of elasto-plastic thin shells, the arc-length method is used. The dynamics of the thin shells is also studied by using the generalized-alpha algorithm. Finally, several static and dynamic examples are presented to verify the accuracy of the proposed formulation.