ABSTRACT

Fig. 9 shows a typical fringe pattern for such a calcu­ lation set-up. Fig. 8 hows Kj, K X I and max. tangential stress GQ for different kink angles. The kinks show mixed Mode behaviour, where Kj has a maximum at about 7 0 - 8 0 ° kink angle. Looking at the distribution of O Q around the kink tip (Fig. 1 0 ) it becomes obvious that for longer lengths of the kink it will eventually turn parallel to the unstressed edge. This is in good agreement with the experiments and fracture mechanical considerations.