Level Set-Based Topology Optimization with Manufacturing Constraint of Manufacturing Directions via Fictitious Physical Model

摘要

Recently, novel improvements of topology optimization techniques have been introduced. They can be applied to a number of engineering applications regarding multi-physics or multi-disciplinary optimization. Especially for the exploration of complex structures, approaches based on the level set-based topology optimization method enables design of structures of definite shape. The level set-based approach represented by the zero iso-surface of the level set function which is defined in the design domain decides the location with the positive value. However, manufacturing cost for the designed structure needs to be considered. Conventional manufacturing processes, such as casting and molding, require fulfillment of geometric conditions, i.e. the open and closed condition of the molds. A good remedy example can be seen as injection blow molding. Nevertheless, the injection molding method is limited to specific materials or designs. Thus, we developed a level set-based topology optimization method regarding manufacturability. The method incorporates a geometrical constraint in the optimization procedure. The model made by this method can be produced through classical manufacturing processes. In the same sense, the structural boundary is represented as the iso-surface where the complex shapes can be handled by topology optimization which is free of gray-scales. In addition, the method generates an optimized structure that prevents non-manufacturable voids or undercut geometries. The voids or undercut of the design are designated as constraints and they are implicitly described by a fictitious physical model. The undercut geometries and the interior voids can be highlighted through the advection-diffusion equation. In consequence, an optimized shape regarding manufacturability is generated from the method. Several engineering application examples arc provided for the demonstration.