CBS-based topology optimization including design-dependent body loads

In this paper, the inherent problem of the so-called parasitic effect of low density region caused by design-dependent loads is investigated for topology optimization. A CBS (closed B-splines)-based method is developed to solve efficiently the problem in the way of shape optimization. Compared to the standard density method, design variables are unattached to the finite element model and defined by control parameters dominating the parametric equation of the CBS. As a result, design-dependent loads associated with the material layout of a structure are made change indirectly by the boundary variation of the structure. To favour structural reanalyses and sensitivity analysis, the implicit form of the CBS, i.e., level-set function (LSF) is used in conjunction with the fixed computing grid of finite cell method (FCM). A variety of design-dependent body loads is considered for the mathematical formulation of the CBS-based method. Typical examples are given to illustrate that the CBS-based method is free of low density regions in the optimized topology owing to the proper definitions of design variables.