Topology optimization of weakly coupled thermomechanical systems for additive manufacturing.

Abstract

Topology optimization is a design optimization method that generates structures with complex geometries that are ideally suited for additive manufacturing. Most additively manufactured structures have anisotropic material properties, especially those composed of fiber-filled polymers. In addition, residual thermal stresses arise from nonisothermal cooling processes during manufacturing. This thesis presents a new topology optimization-based approach that incorporates both material anisotropy and weakly coupled thermomechanical loading into the design computations. Here, design derivatives are evaluated using the adjoint variable method specifically for the weakly coupled thermomechanical system. Two separate update schemes, the optimality criterion-based update scheme and the globally convergent method of moving asymptotes, minimize the compliance or strain energy within the design space over material density and anisotropic orientation. The relative performance of the objective functions and update schemes are compared to determine how to best optimize these structures.