Optimal structure design with low thermal directional expansion and high stiffness

Structures with low thermal directional expansion and high stiffness have wide applications where dimensional stability is required when subject to large temperature change or thermal gradient, e.g. the supporting structure of a space camera and many other types of aero-spatial equipment. This article develops a new bi-objective structural topology optimization formulation which aims at design of structures composed of two materials with differing Young's modulus and thermal expansion coefficients to achieve low thermal directional expansion and high stiffness. A three-phase topology optimization technique is adopted to optimize the structures. Black and white (0/1) designs are obtained by using the volume-preserving Heaviside filter and GCMMA method (globally convergent version of the method of moving asymptotes). Three structural examples are shown to illustrate how the structural supports, temperature variation and the weight factors affect the material distribution and the objectives.