直流电位降裂纹测深仪的数值标定

摘要

直流电位降法(DCPD)是实时测量裂纹长度(深度)的重要方法之一,其原理是在试样的两端施加恒定电流,使之在试样厚度方向上产生恒定的电场,含裂纹试样中的电位分布将会受到裂纹形状和尺寸的影响.为了验证直流电位降法测量裂纹动态长度的可行性和标定电位降与裂纹长度的关系,文中设计了一个合有半圆表面裂纹的试样,并利用有限单元法对试样的电位场进行了数值模拟分析,为直流电位降裂纹测深仪研制和重要参数标定提供一定的理论基础.%Direct current potential drop (DCPD) method is an important approach in the in-situ measuring of crack growing length, which principle is to apply a constant current at both ends of the specimen , and to produce a constant electric field along the thickness direction of the specimen. The current potential distribution in the specimen will be affected by the crack growing length. In order to verify the feasibility of measuring crack growing length by directional current potential drop method, and to calibrate the relation of potential drop and crack growing length, a specimen with semi-circular surface crack is designed, and the current potential field in the specimen is numerically simulated and analyzed , which provide a theoretical basis of developing new crack growing monitor and calibrating parameters in direct current potential drop method.