热力耦合作用下支撑平台的拓扑优化

Topology Optimization of Supporting Platform Structures under Thermo-Mechanical Loads

在光电经纬仪支架结构优化设计中,为了减少支撑平台变形对被支撑对象工作性能的影响,引入连续体拓扑优化技术进行结构设计。对支撑平台结构进行优化设计,使得受载荷时支撑平面的变形量减少。根据两种支撑平台的结构形式及可能工作的环境,建立位移最小热力耦合拓扑优化数学模型。应用材料属性有理近似模型(Rational approximation of material properties,RAMP)对弹性模量及热应力进行插值,并推导目标函数对设计变量的敏度,用Matlab编程,在Comsol脚本环境下对支撑平台结构在三种工况下分别进行拓扑优化设计。对比经验设计结构与拓扑优化设计的结构支撑平面的变形值,结果显示经优化后的结构支撑平面变形明显得到改善,证明了方法的正确性,为支撑平台结构设计提供可靠的理论基础。

In order to reduce the effect to the performance of supported object caused by the deformation of sup porting platform, a topology optimization of continuum mechanism model was presented in the paper. The optimiza tion of supporting platform structures can reduce the deformation of the loaded supporting surface. Based on two struc ture forms of supporting platform under fixed load cases, a thermo mechanical topology optimization model was es tablished to aim at the minimum displacement. In the optimization model, the elastic modulus and thermal stress were calculated using the rational approximation of material properties method （RAMP）. The detailed derivation of sensitivity analysis was proposed. The optimized supporting platform under three load cases was carried out using Matlab programming under Comsol script environment. Compare it with the deformation of supporting surface of the supporting platform designed under the empirical design, the result shows that the former is much better, and proves the validity of the method. The research provides a reliable methodology foundation for the design of the supporting platform.