Topology optimization methods have been developed over the past three decades to optimize the structural design of composite parts. It is now possible to fabricate complex structures generated from topology optimization with additive manufacturing techniques such as large-scale polymer composite deposition. However, large-scale polymer composite deposition produces strutures with anisotropic material properties. This directional orienation affects the structural response of the part and the structure’s behavior during the printing process where thermal stress can led to unacceptable distortion. This paper presents a topology optimization approach that considers the structural response of the product during its use and the printing process employed in its manufacturing. A finite element-based topology optimization algorithm is developed to model structures under weakly coupled thermomechanical loads and anisotropic material properties. Design derivatives are evaluated using the adjoint variable method for the weakly coupled thermal-mechanical system. An optimality criterion-based algorithm maximizes the stiffness of a two-dimensional design space over material density and direction. We consider a steady-state thermal response where the resulting thermal stresses are included in the mechanical optimization. This weakly coupled thermal analysis and material direction optimization includes the anisotropic Young’s modulus and thermal stresses present in large-scale polymer deposition and extends topology optimization to weakly coupled thermomechanical systems with design-dependent temperature fields. Examples are given to demonstrate our proposed weakly coupled system topology optimization.
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