EXPERIMENTAL AND ANALYTICAL STUDY ON LOCAL FAILURE OF STRUCTURE SUBJECTED TO HIGH TEMPERATURE AND PRESSURE

摘要

In our past paper, the new fracture surface was proposed considering the effects of hydrostatic stress in an elastic-plastic region and in a creep region. In this paper, the mechanism the dominant factors of local failure were studied in an elastic-plastic region. Experimental and analytical study were made using circular plate specimens with a nozzle. The material was a lead alloy (99% Pb-1% Sb). The fracture test was performed in an elastic-plastic region at room temperature. Both ductile fracture and local failure were observed at structural discontinuities, based on the stiffness differences between attached nozzles and plates. In this study, the proposed fracture surface in an elastic-plastic region showed the fracture location accurately, for the both failure modes. It was concluded that the proposed fracture surface is available and useful in order to predict the failure mode and the failure location.