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本文对近年来航空材料研究所在一些飞机结构材料的疲劳裂纹扩展的力学行为、微观机制及其影响因素并结合其在材料研制和产品设计的应用研究成果作一简单的评述。一、疲劳裂纹扩展特征及其微观机制一般工程结构材料的疲劳裂纹扩展大致可分为三个阶段,各阶段扩展机制及主要影响因素不同,由于实际构件和试样受组织结构和外部因素(应力状态、温度、介质等)的影响,疲劳裂纹过程及其断口形态往往是多种多样的。在简单拉伸与双轴向拉伸循环载荷下疲劳裂纹出现的宏观取向和相应的主应力状态不同。最近通过多种材料匹配断口细致观察表明,裂
In this paper, the mechanical behavior, microscopic mechanism and influencing factors of fatigue crack propagation of some aircraft structural materials in recent years by the Institute of Aeronautical Materials are briefly reviewed in combination with their applied research achievements in material development and product design. First, the characteristics of fatigue crack growth and its micro-mechanism General engineering structure of the material fatigue crack growth can be divided into three stages, the expansion mechanism and the main influencing factors in different stages, the actual components and specimens by the organizational structure and external factors (stress State, temperature, medium, etc.), the fatigue crack process and its fracture morphology are often varied. The macroscopic orientation and the corresponding principal stress state of fatigue cracks appear different under simple cyclic and biaxial cyclic loading. Recently through a variety of materials match the fracture careful observation shows that crack