Interaction between a Large Crack and a Small Crack

摘要

In the past investigations on fatigue of riveted lap joints have shown thatfatigue cracks do occur simultaneously at several rivet holes in the same critical rivet row (multiple-site damage). Elastic fracture mechanics calculations on K-values were made for some crack configurations related to this problem. Results suggest a small interaction between a large crack and a small collinear crack if there is still a substantial ligament in between. However, for residual strength net section yielding of the ligament should be considered. The calculations made for simple crack configurations have a limited value only. More elaborate finite-element calculations are necessary for a more correct modelling of the complex load transmission in a riveted lap joint. Experimental work is anyhow required.