Analysis of curved cracks emanating from adjacent holes

This article provides a new method for the comprehensive treatment of crack s of curved trajectory, emanating from adjacent holes under constant amplit ude fatigue loading. The theoretical formulations of the newly formed curve d crack are based upon the use of a piece-wise subcrack model and the super position of single dislocation solutions, which reduce the original problem into the solution of singular integral equations in terms of dislocation d ensity functions. The resulting integral equations are then solved using Ch ebyshev polynomial expansions, yielding the stress intensity factor (SIF). The SIF solutions are used in conjunction with the strain energy release ra te criterion to determine the potential incremental fatigue crack growth ex perienced by a plate containing two adjacent holes. The theoretical predict ions are verified with the experimental results;of an aluminum 7075 plate c ontaining two arbitrarily oriented adjacent holes subject to constant ampli tiude fatigue loading. The results reveal good agreement between the theore tical predictions and the experimental findings. (C) 1999 Elsevier Science Ltd. All rights reserved.