Progress in Fracture Mechanics in Japan

Abstract

This chapter describes the progress made in the field of fractured mechanics in Japan. The fracture mechanics studies in Japan may be said to have progressed along two lines of disciplines. The strength of materials approach had been predominant in the fracture mechanics studies in Japan until the early part of the 1960s. The physico-morphological school was oriented to treat the problem in fracture of glass as stochastic process, and thereafter, the extensive stochastic studies have been started on the fracture of metals. This stochastic approach is currently a school in Japan known as stochastic theory of fracture of solids. Another line of study, although it is essentially strength of materials approach, was characterized in Japan Society for Naval Architecture. The concept of combined micro and macro fracture mechanics coupled with both stress concentrations by crack as macro stress raiser and by crystal dislocations as micro stress raiser was proposed by Yokobori at the early part of the 1950s and mathematically formulated and criterion was derived. Furthermore, the extensive studies on thermal activation or rate-process theory and also nucleation theory of time-dependent fracture of solids, especially metals were started from the early 1950s.