Isogeometric Kirchhoff-Love shell formulation for elasto-plasticity

An isogeometric thin shell formulation allowing for large-strain plastic deformation is presented. A stress-based approach is adopted, which means that the constitutive equations are evaluated at different integration points through the thickness, allowing the use of general 3D material models. The plane stress constraint is satisfied by iteratively updating the thickness stretch at the integration points. The deformation of the shell structure is completely described by the deformation of its midsurface, and, furthermore, the formulation is rotation-free, which means that the discrete shell model involves only three degrees of freedom. Several numerical benchmark examples, with comparison to fully 3D solid simulations, confirm the accuracy and efficiency of the proposed formulation.