Pump shaft cracking has become an emergent issue recently in power industry. Prediction of residual life for a cracked shaft relies on accurate stress intensity factor calculations. Because of the three-dimensional nature of the cracked shaft problem, it is prohibitively expensive to obtain a complete stress intensity factor solutions library with three-dimensional finite-element method.
The expensive task of performing the three-dimensional fracture analyses can be alleviated by using an alternating analytical procedure. The alternating analytical procedure utilizes two analytical solutions: (a) the solution for an elliptical crack embedded in an infinite domain and (b) the solution for an infinitely long, uncracked cylinder subjected to arbitrary surface loadings. Because no finite-element mesh is required in the alternating analytical technique, the efforts to accomplish this study has been reduced significantly.
Cracked shafts under tensile, bending, and torsional loads are studied in this paper. K solutions for a wide range of crack geometries are presented. The K solutions can be applied in shaft residual life studies.