CAJ | 학술논문

利用与超声纵波相应的材料声折射率和应力强度因子的关系，并考虑到横波、纵波在材料中的传播速度及其与入射角、反射角的关系，研究了用超声波确定应力强度因子时对波型的选择。发现：一列超声纵波入射于含裂纹的受力试件表面时，由于反射与折射，将有两列超声纵波透过试件后表面，四列超声纵波穿出试件前表面。要用超声波确定应力强度因子，只能采用透出试件前(或后)表面的第一个纵波信号。
이용여초성종파상응적재료성절사솔화응력강도인자적관계，병고필도횡파、종파재재료중적전파속도급기여입사각、반사각적관계，연구료용초성파학정응력강도인자시대파형적선택。발현：일렬초성종파입사우함렬문적수력시건표면시，유우반사여절사，장유량렬초성종파투과시건후표면，사렬초성종파천출시건전표면。요용초성파학정응력강도인자，지능채용투출시건전(혹후)표면적제일개종파신호。
The requirement for wave-mode to determine stress intensityfactor (SIF) by ultrasonic wave is studied. The relationship between SIF and acoustic refractive index corresponding to longitudinal wave is used. The propagating velocities of both transverse and longitudinal waves in specimen and the refractive law are taken into account. It is found that, if a beam of ultrasonic longitudinal wave incidents upon the front surface of a loaded specimen with crack, two beams of ultrasonic longitudinal waves will pass through the rear surface of the specimen and four beams of them will pass through the front surface of the specimen since the reflection and the refraction. So, if ultrasonic wave is used to determine SIF, only the first one passing through the front (or rear) surface of the specimen can be used.