J-INTEGRAL PARAMETERS AND FRACTURE CRITERION FOR SECONDARY STRESSES

J integral parameters in the presence of secondary stresses are systematically reviewed and studied. Based on the results of elastic-plastic finite element analysis, comparisons and comments on their conservation and relevance are presented. It turned out that J′ integral whose physical meaning is clear for the largest range of conditions is reasonably chosen as the most valid fracture parameter, and a new J′ criterion is established for secondary stresses.