Topology optimization of thermo-elastic structures with temperature-dependent material properties under large temperature gradient

In this work, high temperature and large temperature gradient are addressed for the first time in the topology optimization of thermo-elastic structures. The conventional assumption of constant material properties (CMPs) is broken through with the full consideration of temperature-dependent material properties (TDMPs) including thermal conductivity, elastic tensor, and coefficient of thermal expansion. Nonlinear heat conduction is thus implemented to give varying temperature fields in thermoelasticity. The maximum displacement of the specified region is taken as the objective function in the formulation of the optimization problem. The Kreisselmeier-Steinhauser (KS) function is employed to approximate the regional maximum displacement/temperature. Corresponding sensitivity analyses, which are carried out using the adjoint method, theoretically reveal how TDMPs affect the thermo-elastic optimization problem. Typical numerical examples are investigated to validate the proposed approach. The results show that the use of TDMPs produces optimized structures of high fidelity with displacements precisely predicted and temperature constraints rigorously satisfied under large temperature gradient, while thermo-elastic analysis and optimization with CMPs lead to undesirable designs with significant inaccuracy.