Takeshi Miyajima

Ultrasonic method for measurement of depth of surface opening flaw in solid mass

The present invention provides a method for ultrasonic measurement of mainly the depth of a flaw possibly existent in a solid mass and opening to the surface of the solid mass. An ultrasonic wave is transmitted into the solid mass by scanning an ultrasonic probe back and forth on the surface of the solid mass with respect to a flaw in the solid mass, a threshold of a predetermined level is set for a curve defined by levels of echoes of the ultrasonic waves reflected from the flaw according to the position of probe, the area under the curve and above the threshold is integrated for the range of movement of the probe, and the depth of the surface opening flaw is measured using as an evaluation index the value of the integrated area of the area. The method according to the present invention is applicable to nondestructive, easy, accurate and realtime measurement of the depth of weld cracking in a welded portion, fatigue cracks in a stress-concentrated portion of members of a machine, etc.

Method of measuring factor of stress concentration by utilizing ultrasound

The present invention provides a method of measuring, by utilizing ultrasound, the factor of stress concentration at a stress-concentrated portion of a member, comprising the steps of emitting ultrasound for incidence upon the stress-concentrated portion of the member in stressed state, increasing the stress in said stressed state, comparing the acoustic pressure of the reflected wave from said stress-concentrated portion between before and after the stress is changed, for thereby measuring the factor of stress concentration and by which the factor of stress concentration of a member composing a machine or the like in a static or dynamic state can be measured easily, real-time, quantitatively, nondestructively and highly accurately.