Design of Components With Optimized Microstructure

The ability to optimize shape and microstructure creates tremendous potential for designing lightweight high-performance structural components, but this potential can only be realized if design procedures are effectively linked to fabrication techniques. In this paper we describe such links. The key to this work is to base the topology optimization on a unit cell that matches the physical unit cell used in the fabricated object. Distortion and rotation of the unit cell can control effective material properties at all locations within the component by affecting changes in density, degree of anisotropy, and orientation of principle material axes. Advances in solid freeform fabrication (SFF) and related hybrid fabrication techniques make production of components with complex microstructures feasible. This paper describes the complete design process, from specializations of topology optimization to interpretation of optimization results and communication of design information to SFF machines. The process includes a new procedure to establish the orientation of an orthotropic material for multiple loading cases.