TEST PIECE FOR FATIGUE LIFE EVALUATION AND FATIGUE LIFE EVALUATION METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a test piece and a fatigue life evaluation method, capable of evaluating a fatigue life of a pipe by surely causing a crack in a welded portion of an inner surface of the pipe.;SOLUTION: A test piece 1 for fatigue life evaluation having a welded portion 3 between two metal piping portions 2 having the same shape is cut out from a pipe. A surface corresponding to the inside of the pipe, of the test piece 1 is formed in the same shape as the inside of the pipe. A surface corresponding to the outside of the pipe, of the test piece 1 has a continuous curve in connecting portions 6 between the welded portion 3 and the metal piping portions 2. A ratio of a distance from a central axis C of the test piece 1 to respective apexes corresponding to the inside and the outside of the welded portion 3 is set to 1 or more. The test piece 1 is arranged so as to be deviated from a load central axis so that the load central axis of a fatigue life evaluation device is located in a direction of the inside of the pipe from the central axis C. A tensile load and a compression load are repeatedly applied to the test piece 1 arranged in this way, and the number of repeated times until a fatigue crack occurs in the welded portion 3 or the connecting portions 6 is acquired.;COPYRIGHT: (C)2013,JPO&INPIT