METHOD AND DEVICE FOR MEASURING CRACK LENGTH AND STRAIN IN STRUCTURE PART AND TEST PIECE

摘要

PURPOSE: To measure crack length and distortion in a test piece by directing rays affected by the test piece toward a position detector and evaluating them by an evaluation electronic circuit. CONSTITUTION: Rays 3 are guided to a scanning mirror 4 from a light source 2. Also, rays 3a are projected to a test piece 1 at a specific angle from the scanning mirror 4. Then, when a measurement point is not defective, the rays 3a change the direction by the test piece 1 according to the incident angle. Further, when a crack 1' exists. the rays 3a are reflected greatly at different angles. A position detector 5 is provided on the path of rays 3b being reflected and crack length is detected related to an evaluation electronic circuit 6 from information generated at the detector 5 by the rays 3b.