Shape Design Optimization using Isogeometric Approach

Finite-element-based shape optimization has faced some bottleneck problems such as design parameterization and design remodeling during optimization. In this paper, as a remedy for these problems, an isogeometric-based shape design optimization method is developed incorporating with T-spline basis. In the shape design optimization procedure using a standard finite element approach, the design boundary should be additionally parameterized for the smooth variation of the boundary; otherwise, the optimal design usually tends to fall into an unrealistic irregular shape. In an isogeometric approach, however, the NURBS basis function that is used in representing the geometric model in the CAD system is directly used in the response analysis, and the design boundary is already expressed by exactly the same NURBS function as used in the analysis. In addition, the use of T-spline basis instead of NURBS can reduce the number of degrees of freedom, so that the optimal solution can be obtained more efficiently while maintaining exactly the same design shape.