A theoretical model of semi-elliptic surface crack growth

https://doi.org/10.1016/j.cja.2014.04.012Get rights and content
Under a Creative Commons license
open access

Abstract

A theoretical model of semi-elliptic surface crack growth based on the low cycle strain damage accumulation near the crack tip along the cracking direction and the Newman–Raju formula is developed. The crack is regarded as a sharp notch with a small curvature radius and the process zone is assumed to be the size of cyclic plastic zone. The modified Hutchinson, Rice and Rosengren (HRR) formulations are used in the presented study. Assuming that the shape of surface crack front is controlled by two critical points: the deepest point and the surface point. The theoretical model is applied to semi-elliptic surface cracked Al 7075-T6 alloy plate under cyclic loading, and five different initial crack shapes are discussed in present study. Good agreement between experimental and theoretical results is obtained.

Keywords

Fatigue crack propagation
Linear damage accumulation
Low cycle fatigue
Newman–Raju formula
Semi-elliptic surface crack

Cited by (0)

Shi Kaikai is a Ph.D. student at School of Mechanics and Engineering, Southwest Jiaotong University. His area of research includes fatigue and fracture.

Cai Lixun is a professor at School of Mechanics and Engineering, Southwest Jiaotong University. His current research interests are fatigue and fracture.

Bao Chen is a lecturer at School of Mechanics and Engineering, Southwest Jiaotong University.

Peer review under responsibility of Editorial Committee of CJA.

  1. Download : Download full-size image