Stress intensity factor calculation through thermoelastic stress analysis, finite element and RPIM meshless method

Abstract

This work aims at determining the stress intensity factor (SIF) for a compact tension specimen (CT) during a fatigue crack growth test with Thermoelastic Stress Analysis (TSA). Additionally, the problem is addressed using advanced discretization techniques, Radial Point Interpolation Meshless method (RPIM) and Finite Element Method (FEM) to obtain a stress distribution and calculate SIF range. Based on an optimization procedure, a functional stress relation was designated where the TSA analysis relies upon. The stress fields obtained with the FEM and the RPIM, are graphically represented and both methodologies are compared with the experimental TSA analysis in the presence of mode I fatigue loading test. The stress field in front of the crack tip is obtained with TSA and used in Williams series expansion, together with an overdeterministic algorithm to compute the SIF under mode I loading. This proposed procedure possesses a hybrid experimental-computational feature in which the SIF determination hinges on a stress field obtained with an optical technique, TSA. The robustness of the numerical FE and RPIM computations were thereby experimentally validated with the achieved SIF solution.