用断裂力学方法研究材料蠕变和疲劳裂纹扩展中,一个很重要的问题是如何精确测量裂纹扩展量,特别是微量短裂纹扩展量。若干年来人们一直沿用交流电位法和直流电位法测量裂纹。但交流法存在集肤效应,直流法抗干扰能力差,往往得不到满意的结果。美国通用电气公司研究发展中心通过近年来对交直流电位法优缺点的分析对比,提出一种测量裂纹扩展的新技术,称为翻转直流电位法。这种方法综合了交直流 One of the most important issues in the study of creep and fatigue crack propagation using fracture mechanics is how to accurately measure the amount of crack propagation, especially the amount of micro-crack propagation. For years, people have been using the AC potential method and the DC potential method to measure cracks. However, there is a skin effect exchange method, DC method poor anti-interference ability, often without satisfactory results. Research Center of General Electric Company of the United States through the recent years, the advantages and disadvantages of AC-DC potentiometric analysis and comparison proposed a new measure of crack propagation, called flip DC potential method. This method combines AC and DC