Effect of a micro-crack on the kinked macro-crack. (August 2018)

• Record Type: Journal Article
• Authors: Li, Xiaotao; Yang, Hongda; Zan, Xiaodong; Li, Xu; Jiang, Xiaoyu
• Is Part Of: Theoretical and applied fracture mechanics. Volume 96(2018)
• Page Start: 468
• Page End: 475
• Publication Date: 2018-08
• Subjects: Micro-crack -- Kinked macro-crack -- Stress intensity factor -- Plastic zone; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2018.04.003
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: Solution of an infinite plane containing a kinked macro-crack and a micro-crack is presented. The stress field, stress intensity factors and plastic zone are obtained. Effect of the micro-crack on the kinked macro-crack is analyzed. The experimental observation of several micro-cracks near a kinked macro-crack is shown. Abstract: The solution of an infinite plane containing an arbitrarily located micro-crack and a kinked macro-crack is presented based on the distributed dislocation technique (DDT). The stress field, the plastic zone of the macro-crack tip (PZ) and the stress intensity factors at the macro-crack tip (SIFs) are obtained. The influence of the micro-crack on the kinked macro-crack is investigated. The results show the effect of the micro-crack on SIFs increases with the micro-crack length increasing, the distance d decreasing and the micro-crack angle decreasing. The micro-crack has an amplifying effect on mode I SIF at about - 80 ° < θ < 60 °, while it has a shielding effect at about - 90 ° < θ < - 80 ° and 60 ° < θ < 90 ° . The micro-crack has an amplifying effect on mode II SIF at about - 90 ° < θ < 20 °, while it has a shielding effect at about 20 ° < θ < 90 ° . The micro-crack ahead of PZ has a little amplifying effect on PZ. As the micro-crack is close to the macro-crack tip, plastic zones of the micro-crack tip and macro-crack tip will join together. PZ is split into two pieces by the micro-crack located in PZ. The micro-crack behind PZ has no effect on PZ. These results are helpful to analyze the fracture or fatigue behaviors of materials.