Multiscale Isogeometric Topology Optimization with Unified Structural Skeleton

This paper proposes a multiscale isogeometric topology optimization (ITO) method where the configuration and layout of microstructures are optimized simultaneously. At micro scale, a shape deformation method is presented to transform a prototype microstructure (PM) for obtaining a series of graded microstructures (GMs), where microstructural skeleton based on the level set framework is applied to retain more topology features and improve the connectability. For the macro scale calculation, the effective mechanical properties can be estimated by means of the numerical homogenization method. By adopting identical non-uniform rational basis splines (NURBS) as basis functions for both parameterized level set model and isogeometric calculation model, the isogeometric analysis (IGA) is integrated into the level set method, which contributes to improving the accuracy and efficiency. Numerical examples demonstrate that, the proposed method is effective in improving the performance and manufacturability.