On the Compatibility of Hasselmans Thermal Shock Damage Criteria with Fracture Mechanics

ON THE COMPATIBILITY OF HASSELMAN S THERMAL SHOCK DAMAGE CRITERIA WITH FRACTURE MECHANICS 

By means of a fracture mechanical approach it is shown that si rnultaneous unstable crack propagation is apparently absent in thermal shock cracking. Nevertheless, Hasselman s useful results, which v/ere derived from that notion, are reproduced by th i s approach, 

In the following v/e show how simultaneous unstable crack propagation, which is a central feature of Hasselmarr s model, can be ruled out. In doing so v/e explain our approach, without deriving those results which v/ere published earlier. 

Now let us consider crack propagation starting from some preexisting or initial crack of length 1. The crack begins to propagate at the instant when its 5 reached a critical 

The initial length of the second crack may have been shorter than that of the first one by an incremental length SIq. The tv/o cracks of lengths 1, and lo Slo start to propagate when their energy release rates reach  

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