Theoretical Study of Crack-Tip Singularity Fields in China

Abstract

Crack-tip singularity studies play a dominant role in various aspects concerning fracture and fracture mechanics. Significant advances have been made by Chinese scholars engaged in this field. A systematic, but by no means conclusive, review is attempted here to outline their major progress and to guide the international reader to obtain an access to a portion of fracture research data contributed from Chinese literature. Theoretical framework on crack-tip singularity expansion, classification of the governing differential equations, and the contiguity conditions crucial to the asymptotic assembly are discussed briefly at the beginning part of the review. Attention is then focused on various particular cases in stationary cracks, quasistatically growing cracks, and dynamically propagating cracks. A great number of solutions concerning the above-mentioned crack status with respect to different nonlinear material prescriptions are reviewed. Preliminary studies of the three-dimensional effect on crack-tip singularity fields (most have been pursued for elastic material) as well as the interplay of damage during the process of crack separation have also been carried out actively in China. Some typical results are cited here to give insights into research in these two aspects. The applications of crack-tip singularity study are highlighted by the establishment of theoretical resistance curves based on singularity field calculations. Experimental verifications of those theoretically derived curves as well as their employment in structure integrity assessment are described.