| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device and a method for measuring the magnitude of stress given to a thin plate such as residual stress in a nondestructive and non-contact manner, quickly and safely, and with high accuracy. <P>SOLUTION: A method for measuring stress of a thin plate comprises the steps of: generating ultrasonic waves by irradiating an inspection object with a pulse oscillation laser beam for generating supersonic waves; further irradiating the object with a laser beam for detecting ultrasonic waves having a wavelength different from that of the pulse oscillation laser beam for generating ultrasonic waves; calculating an intensity waveform of ultrasonic waves generated in the inspection object by using the laser beam for detecting ultrasonic waves subjected to a Doppler shift by the oscillation of the ultrasonic waves generated in the inspection object; performing a frequency analysis of the intensity waveform of the supersonic waves; and calculating the magnitude of stress given to the inspection object from separately-observed two frequencies of plate supersonic waves in an S1 mode at a group velocity of zero, which are generated in the inspection object, by using the relationship between the two frequencies and the magnitude of stress prepared in advance. <P>COPYRIGHT: (C)2013,JPO&INPIT |
