Ultrasonic quality control of press-fit joints
A technique for quantitatively evaluating the quality of interference-fit joints by the echopulse method is proposed. A formula is obtained for calculating the value of the coefficient of ultrasound reflection from the site of the joint fit from the measured amplitudes of echo pulses in a free ring and in an assembled joint. It is shown that the reflection coefficient is the main parameter characterizing the quality of an interference-fit joint, i.e., its ability to withstand loads, determined by the maximum value of the torque transferred by a pressure joint, because the reflection coefficient is related to the normal stresses at the contacting surfaces of the joint. To optimize the process of studying the quality of a joint, it is noted that the automation of the testing procedure using the proposed technique is possible and desirable.
This paper discusses the conception of virtual instrument and the application of data collecting system with USB in the hydraulic measurement system, analyzes the basic features of USB and NI Compact-DAQ, and idiographic realizing methods for building the hydraulic test system. Through the test, the each technical specification of system has met the design requirements.