论文部分内容阅读
小裂纹通常是指自然萌生的物理小裂纹(尺寸a=10μm～1mm)。已有研究结果显示,小裂纹扩展阶段的行为与同种材料的长裂纹扩展行为存在显著差异。因此,建立和发展疲劳小裂纹实验方法和测试技术是研究小裂纹问题的重要方面。本文介绍了金属疲劳小裂纹扩展速率试验方法院标(Q/6S 1265—96)的基本要点。 1 小裂纹试样的设计与制备 根据不同的裂纹形状和研究目的,开发出几种典型的小裂纹试样,如带表面裂纹的矩形或圆柱形试样,带角裂纹的方形试样和带有表面裂纹或角裂纹的单边缺口拉伸试样(SENT)。其中,单边缺口拉伸试样已被广泛应用,其特点是:裂纹自然萌生;便于用覆型方法和其他
Small cracks usually refers to the physical initiation of physical small cracks (size a = 10μm ~ 1mm). It has been found that there is a significant difference between the behavior of small crack propagation and the long crack propagation behavior of the same material. Therefore, the establishment and development of fatigue crack test methods and testing techniques is to study the important aspects of small cracks. This article introduces the basic points of the yardstick (Q / 6S 1265-96) for the test method of small fatigue crack propagation rate in metal. DESIGN AND PREPARATION OF SMALL CRACK SAMPLES According to different crack shapes and research purposes, several typical small crack specimens have been developed, such as rectangular or cylindrical specimens with surface cracks, square specimens with corner cracks and ribbons Unilateral notched tensile specimens (SENT) with surface cracks or corner cracks. Among them, unilateral notched tensile specimens have been widely used, which is characterized by: the natural initiation of cracks; easy to use overlay method and other