Multiphysics Level-Set Topology Optimization of a Rover Chassis for Extreme Cold Environments

Topology optimization is applied to design a lunar rover chassis to reduce thermal losses while maintaining adequate structural strength and stiffness. Space missions in extreme cold environments, such as the permanently shadowed regions (PSR) of the moon, are designed to reduce the power needed to maintain the minimum temperature for items that cannot operate at very low temperatures, such as electronic components. Energy consumed to maintain the temperature reduces the energy that could be used to operate instruments for improved science return. Consequently, it is essential to have an efficient thermal design while preserving the integrity of the structure. Given the design freedom it offers, topology optimization is an ideal candidate for such a task. In this work, the design of a rover chassis for extreme cold environments is investigated. The chassis is topologically optimized using the level-set method and moments-based meshfree finite element analysis with thermo-mechanical loads while the mass of the chassis is constrained to obtain a lightweight design. The main advantage of moment-based meshfree simulation is that it eliminates meshing-related bottlenecks, especially for large-scale multiphysics topology optimization problems. The objective function is defined as the weighted sum of thermal compliance and structural compliance. Several sets of weights are explored and the optimized designs are compared. The proposed methodology is reusable and extensible making it well-suited for a variety of designs for future space missions in extreme environments. The simulation and optimization tools that are developed in this study are available as a part of the software package, Intact.Generative from Intact Solutions.