Abstract
The purpose of this study is to investigate the accuracy of the stress intensity factor K analysis using thermoelastic data under bending loads. The stress data in the immediate area of the crack tip cannot be used for K evaluation based on thermoelastic stress analysis because of edge effect cause error of thermoelastic stress data near the crack tip. Stress data in an area away from crack tip are affected by boundary condition. To discuss the K calculated from thermoelastic experiments under bending loads, distribution of the sum of the principal stress obtained from BEM analysis is used instead of actual thermoelastic experiments. Accuracy improvement of K determination under bending loads is shown by the least squares method for K calculation using high term-order terms of stress function.