A procedure for simulation-assisted identification of ultrasonic wave attenuation in heterogeneous materials and its application to the detection of fracture in concrete beams

In this study, a novel procedure for identification of ultrasonic wave attenuation in heterogeneous materials based on signal energy was presented. The main objective was to develop a method for simple and robust determination of wave characteristics for further use in numerical modelling of ultrasonic wave propagation including attenuation of signals. Experimental investigations supported by numerical simulations were proposed as an approach to determine the mass proportionality coefficient in the Rayleigh proportional damping model. A number of concrete samples with different sensor configurations were investigated to prove the efficiency of the developed algorithm. The limitations of the established approach were characterized, specifically the maximum frequency that can be considered should be determined in advance. The ability of the proposed method to detect fracture in concrete samples under three-point bending was initially verified for further development of the attenuation-based diagnostic technique.