Polygonal scaled boundary isogeometric analysis for Reissner–Mindlin shell structures

In this work, scaled boundary isogeometric analysis is utilized as surface discretization. This is a boundary-oriented approach that is particularly suitable for complex domains and trimmed models. Further, an isogeometric shell formulation based on the Reissner–Mindlin assumptions is presented, enhanced by incorporating a drilling degree of freedom. This extension eliminates the need to distinguish between smooth transitions and kinks. As a result, the scaled boundary parametrization can be applied directly without additional constraints across patch interfaces — an important feature given that the method inherently comprises multiple isogeometric patches. Additionally, a drilling stabilization relaxes the continuity requirements such that a C 0 -parametrization across patches suffices. A selective introduction of scaled-boundary parametrization and suitable polygonal domain tessellation open flexibilities for a part having complex topology, resulting in a model that is analysis-suitable. Several examples demonstrate the applicability of the proposed approach in geometric nonlinear problems including non-trivial domains.