Disturbance effect of weak Mode-II loading on the fracture of Mode-I crack. (January 2022)

• Record Type: Journal Article
• Authors: Yuan, H.; Xie, Y.J.; Wang, W.
• Is Part Of: Engineering fracture mechanics. Volume 259(2022)
• Publication Date: 2022-01
• Subjects: Multiple-cracks initiation -- Mode-I crack -- Crack-branching; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2021.108149
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: An energy-based model for multiple cracks initiation from a crack tip is proposed. Underlying effects of a weak Mode-II loading on Mode-I crack branching are formulized. The parameter ɛ has been proposed to quantify the underlying effects. Present theory of crack branching applies to dynamic fracture analysis. Present model can capture nearly all of crack branching patterns observed in test. Abstract: For pure Mode-I deformation, there are four energy-based driving forces acting respectively on the corresponding four local boundaries around the crack tip, which determines the basic and underlying fracture configurations. However, these fracture patterns should be broken once weak Mode-II loading arises. The present analysis indicates that for a cracked solid under Mode-I loading with disturbance of weak Mode-II loading, the whole boundary around a crack tip should be divided into six subintervals, on which there are six corresponding energy-based driving forces acting respectively. In this case, the underlying fracture configurations in form of the crack branching are much more likely to be triggered. Meanwhile a small parameter ε has been introduced to quantify the impact of weak Mode-II loading on the energy-based configuration driving forces, critical crack initiation angles and K-based fracture toughness. The typical crack branching behaviours, such as the crack initiation angles and corresponding K-based fracture toughness predicted in present article, agree well with the experimental results and observations. Present theory of crack branching applies to dynamic fracture analysis, and the underlying branching fracture trends predicted by present article can be triggered by impact or even impulse loading. Present investigation would help to refresh the traditional understanding on Mode-I crack branching.