Numerical Analysis of Crack Propagation in Cyclic-Loaded Structures

TLDR

An improved theory is proposed for the crack‑growth analysis of cyclic‑loaded structures. The theory models crack growth by treating the crack‑tip stress‑intensity‑factor range ΔK as the controlling variable, incorporates the load ratio R and instability near the material fracture toughness Kc, and is implemented in a computer program that predicts crack propagation and time to failure in cyclic‑loaded structures. Excellent correlation is found between the theory and extensive experimental data.

Abstract

An improved theory is proposed for the crack-growth analysis of cyclic-loaded structures. The theory assumes that the crack tip stress-intensity-factor range, ΔK, is the controlling variable for analyzing crack-extension rates. The new theory, however, takes into account the load ratio, R, and the instability when the stress-intensity factor approaches the fracture toughness of the material, Kc. Excellent correlation is found between the theory and extensive experimental data. A computer program has been developed using the new theory to analyze the crack propagation and time to failure for cyclic-loaded structures.