Multi-physics topology optimization for 3D-printed structures

General topology optimization optimizes material layout within a given design space based on structural aspects. In this paper, structural topology optimization is extended to enable optimization of thermal performances. A novel multi-physics interpolation scheme is proposed and its link with 3D-printed structures is explained. Each design variable now has three optimal states: one state represents the surrounding air, having weak structural and thermal material characteristics; another state represents the solid structure with good structural, but less efficient thermal properties; a third state symbolizes a weight-efficient mesh-structure, improving the structure's thermal conductivity while retaining some structural integrity. The optimization study is performed using the GCMMA algorithm with a weighted-sum mono objective. One part of the equation aims to maximize stiffness, while the other attempts to minimize the thermal transmittance. The design domain of choice is a 2-dimensional roof component that is simply supported at the edges. Results show that using this multi-physics optimization strategy can be very useful to find the optimal trade-off between structural integrity and thermal efficiency. The maximum deflection and U-value of the optimized components are also compared to more traditional design approaches. The topologically-optimized solutions clearly outperform the others