关键词: 销钉接触, 电位法, 测试精度, 边界元法

Abstract: It is well known that the accurate electrical potential function is one of the necessary conditions for guaranteeing the precision of measurement with electrical potential method (EPM). But up to now, there is no published report in the open literature on effect of dowel contact with hole on the measuring accuracy of EPM of compact tension specimen. The new contribution of this paper is that such an effect is studied with boundary element method. The author's analysis shows that the contact of dowel with hole has significant effect on the measuring accuracy of EPM. Firstly, it should be considered whether dowel can be insulated with hole or not. If dowel can be insulated with hole, the optimum measuring to input current. If dowel can not be insulated with hole, point C should be adopted as the place to input current. However, for the case of measuring small crack behaviour, probing sensitivity becomes the main problem, then point A should also be adopted as the place to input current, but the electrical potential function must be correctly modified to eliminate the error of measurement due to the effect of dowel contact with hole.

Key words: dowel contact, electrical potential method, measuring accuracy, boundary element method