提出了热变形精确分析理论与一种仿真方法以保证热误差影响下机械零件的最佳配合。从微观分子力学理论出发, 在充分考虑材料属性、温度以及形体边界约束对热变形影响的基础上, 提出了热力转换热变形分析理论, 将零件热变形问题等效为力变形问题。针对一组铝制空心圆柱体零件进行了热变形测量实验, 给出了基于ANSYS Workbench仿真环境的热力转换热变形仿真方法, 并对比分析了实验结果与仿真结果。结果显示: 铝制空心圆柱体零件受高温变形时, 不同内外径尺寸的空心圆柱体其热膨胀系数是不相同的; 外圆径向热膨胀系数大约是内圆径向热膨胀系数的2倍; 基于热力转换理论的仿真结果与实验结果吻合较好, 吻合度达到98%以上, 验证了热力转换热变形分析理论的合理性和有效性。提出的方法弥补了ANSYS Workbench传统热分析完全忽略形体边界约束影响零件热变形的缺陷, 为后期热鲁棒性结构设计提供了重要参考。

An accurate analysis theory of thermal deformation and a simulation method were proposed to ensure the optimum performance of mechanical aparts affected by thermal errors. From the view of microscopic molecular mechanics theory, an analysis theory of conversion of thermal into mechanics for thermal deformation was put forward, by which the thermal deformation of a part was equivalent to the force deformation by taking the effect of material properties, temperatures and the boundary constraints of shape on thermal deformation into account fully. Then, measurement experiments of thermal deformation of hollow cylinder parts were carried out, and a simulation method of thermal deformation based on ANSYS Workbench was given. Finally, simulation and experiment results were compared. The results show that thermal expansion coefficients of the outer circle are approximately twice that of the inner circle in the radial direction when an aluminum alloy hollow cylinder part is deformated under a high temperature. Meanwhile, the simulation results based on the proposed theory are consistent with the experimental results very well and the fit is more than 98%, which validates the rationality of our theory. As the method makes up the drawback that traditional thermal analysis of ANSYS Workbench completely ignores the physical boundary constraints affecting part thermal deformation, it provides an important reference for the structure design of thermal robustness subsequently.