表面涂层处理常用于保护机械零件表面、减少磨损和提高使用寿命，涂层上的应力分布对零件表面破坏有着重要的影响． 文中以聚碳酸酯/环氧树脂为涂层/基体材料，采用光弹实验对受载的涂层/基体进行光弹条纹采集，根据实验条件利用 Abaqus 软件建立涂层/基体的有限元模型，分析不同涂层厚度和载荷下的应力分布情况． 实验和数值分析结果表明:在接触应力场中，最大剪切应力出现在材料的次表层而非表层，随着加载量的增大，最大应力值逐渐向基体扩展;不同涂层厚度下，应力场在结合界面处出现较大的突变，主要是由涂层与基体的材料物理性能不一致导致;光弹实验和有限元法得到的应力分布基本上是一致的．

Coating technology is usually used to protect the surfaces of machine parts and cutting tools,avoid wear and to prolong parts' fatigue life.The subsurface stress distribution in the coating significantly influences the sur- face failure of parts.In this paper,polycarbonate/epoxy was used as a coating/substrate system,and some photoe- lasticity experiments were carried out to collect the photoelastic fringe patterns of the coating/substrate system sub- jected to loads.Then,a finite element model of the coating/substrate system was established with Abaqus,and the stress distribution of the system varying with coating thickness and contact load was analyzed.Experimental and theoretical results show that (1) in contact stress field,the maximum shear stress appears in the subsurface rather than on the surface and extends to the substrate as the load increases; (2) for the system with different coating thickness,the stress suddenly increases at the interface of the coating to the substrate,which is caused by the difference in material properties between the coating and the substrate; and (3) stress distributions obtained via photoelasticity experiment are basically consistent with those obtained via finite element method.