Exploration of non-destructive testing of anchorage quality of metal anchored bar system with ultrasonic guided wave

This paper manages to perform non-destructive testing of anchored integrity of metal bar in anchored bar system by use of ultrasonic guided wave through theoretical analysis, simulation analysis and experimental study of the properties of guided wave propagating in the metal bar of anchored bar system. The theoretical models of free bar and end anchored bar are established for anchored bar system. In combination with boundary conditions, etc., the time domain response for the displacement, velocity and acceleration of propagation of ultrasonic guided wave are solved and obtained. Based on this model, the parameters that affect the anchorage quality of anchored bar are analyzed. Furthermore, theoretical curve was compared with finite element simulation curve. The two curves are in good agreement, which justifies that the theoretical model can correctly reflect the vibration properties of anchored bar and the propagation law of guided wave. By means of experimental studies, quantitative analysis was performed as to the properties of ultrasonic guided wave propagating in the metal bar of anchorage system, subsequent to which the general law of the wave velocity change and amplitude decay is deduced in respect of longitudinal ultrasonic guided waves of different frequencies propagating in anchored bars of same size or different sizes. Under the same conditions, waves at high frequency propagates faster than ones at low frequency, but the former´s energy attenuates quicker than the latter´s. And the decay extent of their amplitude can be used to qualitatively determine the anchorage quality of metal anchored bar.