Rod-shaped Component Detection Signal Processing Method Based On Time Reversal

The pile foundation, the steel rebar and the anchor bolt are widely used rod-shaped components in the construction and industry. In the producing process of these rod-shaped components, pores, impurities, cracks and other damages are formed due to the lack of technology,which will bring huge security risks. Therefore,non-destructive testing of the rod-shaped component is of great significance in guaranteeing component quality and promoting safety production. According to the materials, the rod-shaped components can be divided into the pile foundation component and the steel rod component. Their each major non-destructive testing technique is stress wave detection and ultrasonic guided wave detection. This paper conducts an investigation of these two techniques and finds that the multipath effect of stress wave and the multimodal effect of guided wave will easily cause detection signal distortion, which makes it difficult to identify the damage information.In order to improve the detection effect, this paper aims to study on a rod-shaped component detection signal processing method based on the time reversal method, which can foucs damage signal from the detection signal. Through theoretical analysis, simulation and finite element numerical analysis, research on damage signal focusing performance of the time reversal method includes the following aspects:Due to the signal distortion problem of stress wave detection, a stress wave multipath signal focusing model based on time reversal method is established. Simulation results show that this model can effectively suppress the influence caused by the multipath effect and the system noise. Combined with the wavelet packet analysis, a detection signal processing method based on the time reversal is proposed. Analog retransmission simulations and analysis are done to the pile foundation’s engineering detected stress wave signal, the results show that this method can separate and focus the damage signal from the detection signal.Due to the signal distortion problem of ultrasonic guided wave detection, through the analysis of guided wave modes in steel rod, the ultrasonic guided wave multimodal signal focusing model based on time reversal method is established. The simulation results verify that this model can effectively remove the signal distortion caused by guided wave multimodal effect and focus the damage signal, as well as improve the signal to noise ratio at the receiving end. The numerical simulation method of ultrasonic guided wave detection in steel rod based on time reversal method is proposed through the ABAQUS finite element analysis. Comparing the experimental results to theoretical results, it is verified that time reversal method can achieve the energy focusing of damage signal in ultrasonic guided wave detection, and the factors influencing the focus performance are analyzed through comparative studies.