Isogeometric analysis of wing structures using multipatch parametrization and penalty-based coupling method

Geometric parametrization and structural analysis play a pivotal role in aircraft structural design. Isogeometric analysis utilizes high-order, high-continuity spline basis functions for field variable discretization, offering superior solution accuracy compared to traditional finite element methods while streamlining data exchange between CAD and CAE systems. In this study, an analysis-suitable geometric parametrization is developed for classical aircraft wing structures, comprising two skins, twenty three ribs, and two spars. The wing geometry is represented using multiple NURBS patches. Within the wingbox formed by ribs and spars, all patch interfaces maintain conformity. Conversely, interfaces between wing skins and the wingbox are deliberately nonconforming to reduce modeling complexity while preserving the skin's high continuity. Reissner-Mindlin shell theory is applied within the isogeometric framework to model structural behavior, and a penalty-based method is implemented to enforce continuity of the displacement field across the nonconforming skin-wingbox interface. A static bending analysis of the complete wing structure is performed, and the results are compared with those obtained from a conventional finite element analysis in ABAQUS for validation. The IGA results show excellent agreement with the FEA reference solution, achieving comparable accuracy with significantly fewer degrees of freedom.