SOME PROBLEMS CONCERNING THE J_Ic DETERMINATION BY MEANS OF A SINGLE SPECIMEN

The present paper deals with the method of locating the crack initiation point inJ_(IC) determinahon by means of a single specimen. The first is an analytical method forcalculating crack length variations during monotonic loading from the load-displace-ment record alone, and the second is based on And-sectional measurements of C. T. O. D.Results of application of these methods are presented which demonstrate the effective-ness of the methods proposed. In additional, some recent experimental results are also reported which substanti-ate the slip-line field proposed earlier for the CT specimen, the result for the limit loadP_L, and the J-U relation obtained by us.