Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 03, 2023 - September 06, 2023
A realistic fragility assessment must be performed to recognize the weaknesses of structures. It is important to set the failure mode appropriately for a realistic fragility assessment. Previous studies have shown that the failure mode of piping systems during earthquakes is fatigue. Conversely, the basis for considering the failure mode of piping systems to be fatigue is based on the occurrence of fatigue under dynamic loading conditions and does not indicate that ductile rupture does not occur. In a study on the ductile rupture of elbow piping, we conducted an in-plane bending test on a full-scale model of a carbon steel elbow. A previous work showed that gradual deformation in the opening and closing direction did not cause ductile rupture. However, there are few experimental data on the ultimate state of elbow piping with ductile rupture of out-of-plane bending. In this study, static tensile loading tests and static cyclic loading tests of carbon steel elbow pipe in the direction of out-of-plane bending. the tensile tests showed that ductile fracture did not occur even when the elbow pipe was subjected to out-of-plane bending deformation with a plasticity factor of 40. Therefore, the possibility of the ductile rupture of elbow pipes during earthquakes is extremely low. In the cyclic loading tests, fatigue cracks occurred at elbow pipes.
