Experimental research on residual stress measurement for tubule surface

Tubules are one of the most significant parts in mechanical field, and they are widely used in every field of manufacturing equipment. With thes development of technology, tubules are extensively used in the field of aerospace engines and hydraulic pipe. Therefore, it becomes more and more crucial to test the residual stress of tubules. In this paper, an ultrasonic method involving the longitudinally critically refracted (LCR) wave was used to measure the tubule surface residual stress. The special sensor was actuated by a piezoelectric wafer and ultrasonic transducer. An examination of the transmission principle of ultrasonic waves in the tubules revealed that measurements of the residual stress of the tubule´s surface using LCR waves were feasible.