Fatigue damage welded structure suppressing method and striking mark forming tool

摘要

PROBLEM TO BE SOLVED: To provide a method for suppressing fatigue damage of a welded structure, which can securely suppress the generation of fatigue damage such as a fatigue crack in the weld portion of a welded structure such as a steel bridge, and a tool for forming an impact trace.;SOLUTION: As the tool for forming an impact trace by hammer peening or ultrasonic shock peening on the surface of a base material adjoining the weld bead of a weld portion, a tool 6 for forming the impact trace is used which has a planate impact trace formation surface 7 in the front end thereof, the width of which along the direction intersecting the weld bead at a right angle and the length of which along the weld bead are 3 mm or more and 6 mm or less, the whole shape of which is formed to be circular. The impact trace of which the maximum depth is 0.03 mm or more and less than 0.50 mm is continuously formed along the weld bead to introduce compression residual stress in the toe of the weld bead by the tool 6 for forming the impact trace.;COPYRIGHT: (C)2013,JPO&INPIT