Health monitoring of cuplok scaffold joint connection using piezoceramic transducers and time reversal method

Abstract

Cuplok scaffolds are widely used to form temporary supporting structures when constructing bridges and other structures all over the world. The safety and stability of cuplok scaffolds are important issues during construction. Cuplok scaffolds are subjected to various types of vibrations, which may loosen the cuplok connection, negatively impacting the stability of the structure and even leading to severe accidents. In this paper, the authors propose a time reversal (TR) method to monitor the looseness status of the cuplok connection by using stress wavebased active sensing. Lead zirconate titanate (PZT), a commonly used piezoceramic material with a strong piezoelectric effect, is employed. In the proposed approach, PZT patches are used as sensors and actuators to monitor the cuplok joint looseness. One PZT patch is bonded to the vertical bar and two PZT patches are bonded to the cross bars of the cuplok scaffold. The PZT patch on the vertical bar is used as an actuator to generate a stress wave and the other two PZT patches are used as sensors to detect the propagated waves through the cuplok connection, the looseness of which will directly impact the stress wave propagation. The TR method is used to analyse the transmitted signal between the PZT patches through the cuplok connection. By comparing the peak values of the TR focused signal, it can be found that the peak value increases as the tightness of the cuplok connection increases. Therefore, the peak value of the TR focused signal can be used to monitor the tightness of the cuplok connection. In addition, the experimental results demonstrated that the TR method is superior to the energy method in consistency, sensitivity and anti-noise properties.

Tension Monitoring of Wedge Connection Using Piezoceramic Transducers and Wavelet Packet Analysis Method

“…A piezoelectric lead zirconate titanate (PZT)-based technique is often used in active monitoring the safety state of structures over their entire life cycle due to great features such as their broadband frequency response and the ability of being employed as actuators or sensors [25][26][27]. The recent research has shown that low cost PZT patches can be used for vibration detection [28,29], energy harvesting [30], stress wave generation [31,32], damage detection [33,34] and structural health monitoring [35][36][37][38].…”

Connection looseness detection of steel grid structures using piezoceramic transducers

“…[25][26][27][28][29] The usefulness of the piezoceramic ultrasonicbased bolted connection interface loosening detection of pipe-like structures has been demonstrated by both numerical and experimental methods. 23,[30][31][32] This article aims to perform a further study on detecting the BSJ looseness of SGSs. A PZT wave energy-based method is applied in the BSJ looseness detection research under several common conditions, to establish the relationship between ultrasonic wave energy attenuations and bolt loosening levels by both experimental validation and numerical finite element analysis (FEA) simulation.…”

Feasibility Study of Steel Bar Corrosion Monitoring Using a Piezoceramic Transducer Enabled Time Reversal Method

“…Two properties, namely spatial focusing and temporal focusing, enable the TR operated signal to have a high signal to noise ratio (SNR) [27]. Zhang et al [28] proposed a TR method using stress wave-based active sensing in order to detect the state of looseness of a cuplock connection. Mustapha et al [29] used a method to detect corrosion damage in reinforced concrete beams, which is based on the time reversal of the guided waves.…”