Local Stiffness Modeling Method for Thin-Walled Blades Based on Abaqus Secondary Development

Abstract

Complex thin-walled structures are prone to elastic deflection and machining deformation under cutting forces due to their low structural stiffness, complex curved geometries, and significant local thickness variations, thereby deteriorating dimensional accuracy and surface integrity. To address the difficulty of conventional finite element analysis in accurately characterizing local stiffness variations over complex surfaces, this study proposes a surface stiffness modeling and analysis method for complex thin-walled components using a turbofan engine blade as the research object. First, a three-prone finite element model of the blade is established in Abaqus, including material property definition, section assignment, and mesh generation. Nodal information and surface normal vectors of the predefined target surface are then extracted. Concentrated loads are sequentially applied along the nodal normal directions under predefined boundary constraints, and static analyses are performed to obtain nodal displacement responses. Based on the relationship between the applied normal load and the corresponding normal displacement, the local stiffness of each discrete surface point is calculated to construct a surface stiffness distribution model of the blade. The results demonstrate that the proposed method can effectively characterize stiffness variations across different regions of the blade surface and identify low-stiffness weak areas, providing a basis for machining deformation prediction, process parameter optimization, and support scheme design.