Multi-parameter fracture mechanics: crack path in a mixed-mode specimen
A mixed-mode geometry has been chosen to investigate a crack propagation using the multi-parameter fracture mechanics concept. The socalled Williams’ series expansion is used for the crack-tip stress field approximation. It has been shown that application of the generalized fracture mechanics concept can be crucial for materials with specific fracture behaviour, such as elastic-plastic or quasi-brittle one, when fracture occurs not only in the very vicinity of the crack tip, but also in a more distant surrounding. Then, considering the higher-order terms of the Williams’ expansion in fracture criteria (describing the crack stability and/or crack propagation direction) can bring more precise results. The coefficients of the Williams’ expansion must be calculated numerically (for instance by means of the overdeterministic method in this work) for each cracked configuration, which is very time-consuming, and the analysis is very extensive even for a few basic cracked specimen configurations. On the other hand, a suitable choice of the geometrical configuration of the cracked disc enables performing experiments only on the specimens that could prove the theory about the importance of using the higher-order terms.
KeywordsCrack-tip field, Multi-parameter fracture mechanics, Finite element analysis, Mixed-mode, Williams’ expansion.
Document typePeer reviewed
Document versionFinal PDF
SourceFrattura ed Integrita Strutturale. 2019, vol. 13, issue 49, p. 65-73.