Abstract
To measure the deformation of the structural material, an irradiated grid or grating fabrication method has been developed. Using a laser projector, squire grid or parallel grating was irradiated to the specimen that has luminous or photochromic paint on the surface. After ten minutes irradiation, a grid or grating can be observed of bright and dark parts. Bright parts were irradiated by laser beam and can be observed in 1 minute. 3-point bending test was performed after ten minutes irradiation of laser, and grid could be observed during 3-point bending test.
