Asymptotic analysis of pore crack initiation near a free edge
Aurélien Doitrand, Dominique Leguillon
Abstract
The matched asymptotic (MA) approach of the coupled criterion (CC) enables studying crack initiation at a pore located near a free edge, which leads to a competition between three possible crack initiation mechanisms, namely crack initiation in the ligament, at the pore side opposite to the free edge or simultaneously at both pore sides. The mechanism that is the most likely to occur depends on both the pore-to-free edge ligament size and the material characteristic length to pore diameter ratio. Simultaneous crack initiations at both pore sides occur for large enough ligament size. For smaller ligament sizes, unilateral pore crack initiation is more likely to occur, within the ligament for small characteristic length to pore diameter ratios and at the pore side opposite to the free edge otherwise. The CC MA approach enables estimating the initiation remote imposed stress as well as the initiation crack length.