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 regard...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 A1 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.展开更多
基金the National Natural Science Foundation of China (No. 11072205)
文摘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 A1 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.
