论文部分内容阅读
线弹性断裂力学和全面屈服断裂力学研究之间呈现的连续性导致测试断裂韧性采用一种统一的方法。该法可以分别测定断裂时的应力值和计算K 1c值,或者用实验的标定方法从引伸计位移测定值中推导出裂纹尖端的COD值。提出的实验结果力求说明限制COD法研究范围的极限条件,以便确定能够毫不含糊地使用COD法的范围。加载过程中,用电位法揭示宏观纤维状裂纹的开始扩展及其扩展程度,而缺口断面的直接摄影记录简化了在沿裂纹长度方向的任何位置测量有效COD值。这些结果的实际意义既是根据现行的COD定义也是依据缺陷意义来加以讨论的。
The continuity between linear elastic fracture mechanics and total yield fracture mechanics studies leads to a uniform approach to testing fracture toughness. The method can be used to determine the stress at break and calculate K 1c, respectively, or to derive the COD value at the tip of the crack from the extensometer displacement measured by an experimental calibration method. The proposed experimental results seek to illustrate the limits of the scope of the COD study in order to determine the extent to which the COD method can be used without ambiguity. In the loading process, the onset and expansion of macro-fibrous cracks are revealed by the potential method, while the direct photographic recording of the notched sections simplifies the measurement of effective COD values anywhere along the crack length. The practical significance of these results is based both on the current definition of COD and on the meaning of defects.