求解予裂试件实时裂纹长度的一种新的直接法

本文提出的估算予裂试件实时裂纹长度的直接法，只需单试件的Ｐ－Ｖ记录和对应静裂纹试件塑性位移有限元解，这就避免了在规则化方法中由于几何函数不确定性对计算实时裂纹长度的影响。这一新的直接法的基础是推广的Ｇａｒｗｏｏｄ—Ｅｒｎｓｔ假设，即予裂试件与对应静裂纹试件在载荷、位移分别相等时其实时裂纹长度也相等。本文用实验验证这一假设，并在此基础上提出推论：这两类试件在Ｐ、Ｖ（和α）分别相等时其弹性和塑性位移分量也分别相等。按照这一推论可对予裂试件实时裂纹长度进行估算。文中的五个算例表明，这一直接法与卸载柔度法符合较好。

A New Direct Method for Evaluating Current Crack Length of Precracked Specimen

In this paper, a new direct method for estimating the current crack length of aprecracked specmen is presented.According to this method,only the P-V record of a singlespecimen and the finite element solution of the stationary crack are needed.Thus,inmormalization method, the influence of geometry function changing upon the current cracklength could be avoided. The baSic of this method is the extended Grarwood-Etnst hypothesis,namely,when the load and displacement of a precracked specimen are equal to those of acorresponding stationary crack specimen respectively,then their current crack lengths are alsoequal.This hypothesis St verified experimentally,and an inference is drawn that the elastic andplastic displacement of the above two specmens are equal to eath other respeedvely.By wig thisinference, the current crack length of precracked specimen can be evaluated.Five examplesincluced shown that the results obstained from the direct method agree well with those from theunloading compliance method.