A comparison of finite element solution for J-integral analysis of compact pecimen

The materials with high toughness are used for large structures, and the method of evaluating the soundness of structures tends to shift to the application of elasto-plastic fracture mechanics instead of linear one. As the parameter controlling the starting of growth or the transition from stable growth to unstable growth of cracks and other defects in large structures, the method of utilizing J-integral has been attempted. As the analysis of J-integral for the cracks in structures in nonlinear problem, the numerical solution of high reliability must be obtained. The round robin test was carried out from May to the end of 1979 to clarify the cause of dispersion of the result by Wilson-Osias, the dispersion of J-values for compact specimens, and the factors to improve the accuracy of the numerical solution of J-integral. Only compact specimens were examined, and the material was A533B. The standard problem and non-standard problem were set up. The conditions of analysis and the results of analysis are reported. In the standard problem, for which the dimensions of specimens, the equations of constitution, mesh division and displacement function were specified, J-values agreed within the range of 10% dispersion in all the results. In the non-standard problem, considerable dispersion was shown. (Kako, I.)