Isogeometric analysis of multi-patch solid-shells in large deformation

In the context of isogeometric analysis(IGA)of shell structures,the popularity of the solid-shell elements benefit from formulation simplicity and full 3D stress state.However some basic questions remain unresolved when using solid-shell element,especially for large deformation cases with patch coupling,which is a common scene in real-life simulations.In this research,after introduction of the solid-shell nonlinear formulation and a fundamental 3D model construction method,we present a non-symmetric variant of the standardNitsche’s formulation for multi-patch coupling in associationwith an empirical formula for its stabilization parameter.An selective and reduced integration scheme is also presented to address the locking syndrome.In addition,the quasi-Newton iteration format is derived as solver,together with a step length control method.The second order derivatives are totally neglected by the adoption of the non-symmetric Nitsche’s formulation and the quasi-Newton solver.The solid-shell elements are numerically studied by a linear elastic plate example,then we demonstrate the performance of the proposed formulation in large deformation,in terms of result verification,iteration history and continuity of displacement across the coupling interface.