DETERMINATION OF THE DYNAMIC STRESS INTENSITY FACTORS,K AND K,FOR A MIXED-MODE PROPAGATING CRACK

<正> In this paper,the dynamic propagation problem of a mixed-mode crack was studied bymeans of the experimental method of caustics.The initial curve and caustic equations were derived un-der the mixed-mode dynamic condition.A multi-point measurement method for determining the dy-namic stress intensity factors,KⅠd and KⅡd,and the position of the crack tip was developed.Severalother methods were adopted to check this method,and showed that it has a good precision.Finally,the dynamic propagating process of a mixed-mode crack in a three-point bending beam specimen wasinvestigated with our method.