A new PZT-enabled device for monitoring prestress loss in post-tensioned prestressed structures

Anchorage performance monitoring plays an important role in ensuring the safety of prestressed structures. Over the past decades, traditional structural health monitoring (SHM) methods, such as vibration, magnetoelastic, and acoustoelastic methods, have been plagued by low sensitivity and high susceptibility to environmental and temperature interference. Lead-Zirconate-Titanate (PZT)-enabled active sensing method has proven its effectiveness in prestress monitoring. The main contribution of this paper is the development of a new device that utilises the relationship between energy transfer and contact stress at the interface. This device addresses the existing problem of signal saturation and offers higher sensitivity for practical implementation. First, the time reversal (TR) method was used to overcome the problem of low signal-to-noise ratio (SNR) in traditional methods. Based on this, the empirical mode decomposition (EMD) method was employed to process the acquired signals, thereby improving the stability of the data. A quantitative index for monitoring prestress loss was proposed by normalising the peak value of the reconstructed signals. Finally, several repeated experiments were conducted to verify the accuracy of the proposed method.