STUDY ON FAST CRACK PROPAGATION AND ARREST. (2ND REPORT, GEOMETRY DEPENDENCE OF THE BEHAVIOR).

The dynamic stress intensity factors are presented for the fast running crack of the double-cantilever beam type specimens with various heights machined from the model material PMMA. The dynamic stress intensity factors decrease at the beginning of the crack propagation phase, remain almost unchanged in the next stage, and then increase in all specimens. After this period the behavior of then stress intensity factors varies with the specimen's geometry. The values of the stress intensity factors at three characteristic points in the stress intensity factor-crack extension curve are discussed with relation to the crack arrest.