Elastoplastic fracture toughness ON test method

摘要

PURPOSE:To provide a displacement detector at the outside of a test piece and to make it possible to perform the test readily by using the measured result of the displacement of an opening or strain at a specified place other than a part on a load line, and indirectly operating the displacement of the place on the load line. CONSTITUTION:A tensile load P is applied on one test piece S in which fatigue crack machining is applied. The magnitude of the load P at this time is measured. A displacement V0 at an opening end or strain at a specified place other than a part on a load line (x) is measured. The load is slightly removed at a plurality of levels of the displacement V0 at the opening end or the strain at the specified place. Compliance and energy which is applied up to this time at each unloading point are operated from the measured result of the relationship between the load P and the displacement V0 at the opening end or the strain at the specified place. The displacement V0 at the opening end and the corresponding energy of the test piece S on the load line (x) are estimated and operated by conversion. The integral value of tensile limits J is obtained from the relationship between the displacement V0 and the corresponding energy on the load line (x).