公开(公告)号：JP2001264026A

公开(公告)日：2001-09-26

申请号：JP2000078514

申请日：2000-03-21

Applicant: NAT INST FOR MATERIALS SCIENCE

Inventor： MURAMATSU YOSHIKI ,  KURODA SEIJI

IPC: G01B11/16 ,  B23K9/095

Abstract: PROBLEM TO BE SOLVED: To provide a method and a measuring instrument, capable of measuring dynamic strain occurring in an object to be welded in the course of welding at desired position, except a molten pool and at a desired time, even under the influence of arc light. SOLUTION: In this method of measuring dynamic strain, a strain measuring point under the influence of arc light is irradiated with a laser beam, and the change and movement of a speckle pattern caused by mutual interference of irregular reflected laser beams are detected on surface of sensors. When the irregularly reflected laser beams are detected on the surface of the sensor, the arc light is shaded by shade tubes, each having a pin hole.