EFFECT OF SPECIMEN SIZE IN STATIC AND DYNAMIC FRACTURE-TOUGHNESS TESTING OF REACTOR VESSEL STEEL A508CL.3

The fracture toughness must be evaluated under the dynamic loading con dition, when the materials are used for structures that are desired to a higher safety and must be taken into account of the effect of dynam ic loading. Moreover, in order to obtain the valid J(Ic) value, a crit erion concerning both specimen thickness B and ligament width b(o) mus t be satisfied, which is called as ''valid condition'' and is describe d as the following equation. GRAPHICS However, this equation is pres ented for the static loading condition and there is no assurance to be able to apply for the case of dynamic loading one. Therefore, under s tatic and dynamic loading conditions, the effects of both B and b(o) o n J(in) value and the flow stress sigma(is) are investigated and the v alid conditions are discussed. The results are presented that the fact or alpha of the above equation is reduced as 20 for b(o) and is increa sed as 28 for B under dynamic loading condition.