Investigation of thermoelastic compliances considering finite strain

Topology optimization of thermoelastic structures is of significance in many engineering applications such as for additive manufacturing, metamaterials, and soft robotics. To ensure that a structure performs adequately over a wide range of thermoelastic loading conditions and thermal expansion, incorporating the finite strain theory in the design strategy is critical. In this study, we investigate the two energy-based objective functions, namely the end compliance and strain energy under thermomechanical conditions. The numerical examples considered indicate that the optimized layout is highly dependent on the selected objective function; such differences among the layouts can be attributed to the manner in which the structure accommodates the changing temperature. The end compliance is minimized by leveraging the direction of the thermal load to offset the mechanical load, while the minimization of the strain energy contributes to the strength of the structure by limiting the thermal contribution to the overall stress within the structure. Furthermore, we show the effects of different strain assumptions on the optimality of layouts. Thus, this study reveals the significance of adopting each thermoelastic compliance and highlights the importance of accounting for structural nonlinearity when considering the thermal effect. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Topology optimization of thermoelastic structures is crucial for various engineering applications. Incorporating the finite strain theory is critical in designing structures that can withstand different thermoelastic loading conditions. This study investigates two energy-based objective functions, namely end compliance and strain energy, under thermomechanical conditions. The results show that the optimized layouts differ depending on the objective function selected, highlighting the significance of considering the thermal effects and structural nonlinearity.