Study of the propagation of concave semi-elliptical shaped breathing cracks in rotating shafts

•We analyze the propagation of a concave crack contained in a rotating shaft.•We considers the nonlinear behavior due to the breathing crack model.•We develop an algorithm which allows obtaining the crack front evolution.•We study the evolution of the concave crack considering the opening/closing state of the crack. When a cracked shaft rotates, the crack contained in it progressively opens and closes during a revolution. Accordingly, the behavior of the shaft becomes nonlinear. In this paper, the propagation of concave semi-elliptical shaped cracks contained in rotating shafts has been studied considering the nonlinear effect of the breathing crack. To study the propagation, we propose an integration algorithm based on the Paris-Erdogan Law which allows determining the crack shape evolution of concave breathing cracks in rotating shafts. The Stress Intensity Factor used by the algorithm to analyze the propagation has been computed using the four parametric expression for concave cracks proposed by the authors in a previous work. By now, it has not been found in the literature propagation studies of concave surface cracks in rotating shafts that consider the breathing mechanism of the crack.