scholarly journals Health Status Monitoring of Cuplock Scaffold Joint Connection Based on Wavelet Packet Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Liuyu Zhang ◽  
Chenyu Wang ◽  
Gangbing Song
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Wavelet Packet ◽  
Experimental Results ◽  
Wavelet Packet Analysis ◽  
Monitoring Method ◽  
Structural Health ◽  
Index Matrix ◽  
Joint Connection ◽  
The Stability

The cuplock scaffolds are widely used as a temporary facility in the bridge and other constructions. The looseness of cuplock scaffold connection plays a significant role in the stability of the structure. Contemporary structural health monitoring method is reviewed in this paper at first, and then we proposed wavelet packet analysis based method. In order to detect the looseness of cuplock connection, three stress PZTs and three shear PZTs used as transducers are mounted onto vertical bar and cross bars of cuplok scaffold. Wavelet packet analysis is applied to analyze the transmitted signal energy between two PZTs through cuplok connection. Experimental results show that shear PZT has better performance than stress PZT to be used as actuator and sensor for the wavelet packet analysis based structural health monitoring. Besides, a sensor looseness index matrix (SLIM) is derived to indicate the looseness of the cuplock connection. The experimental results show that looseness index increases as the connection gets loose.

scholarly journals Effect of Adhesive and Its Aging on the Performance of Piezoelectric Sensors in Structural Health Monitoring Systems

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1342
Author(s):  
Xuerong Liu ◽  
Yuanming Xu ◽  
Xiangyu Wang ◽  
Yunmeng Ran ◽  
Weifang Zhang
Keyword(s):  
Shear Strength ◽  
Elevated Temperature ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Signal Amplitude ◽  
Signal Propagation ◽  
Negative Influence ◽  
Experimental Results ◽  
Monitoring Method ◽  
Structural Health

Adhesive and its aging can have influence on the Piezoelectric (PZT) elements in structural health monitoring (SHM) systems. However, the current research pays little attention to the effect of adhesives in SHM systems, and the mechanism of adhesive aging on monitoring signals is still unclear. In the present study, the relationship between types of adhesives, adhesive thickness, accelerated aging, and monitoring signal was analyzed in detail. The study was carried out with three kinds of epoxy resin AB adhesive (AW106, E-30CL, and E-120HP) and bonding thicknesses (0.01, 0.05, and 0.12 mm), and the elevated temperature was 100 °C for 45 days. The signal-based monitoring method was used to extract the characteristic parameters. The experimental results indicated that the standard shear strength and thickness of the adhesive may have a combined effect on the monitoring signal. Increasing the thickness may enhance the shear strength between PZT and the matrix. For the effectiveness of monitoring the signal propagation, however, increase in thickness may have a negative influence. Moreover, the elevated temperature will bring the signal amplitude to a peak in the first period of aging, and the highest point appears in 10 to 15 days. Nevertheless, with the increase of aging time, the adhesive will finally be degraded, resulting in the decrease of the signal amplitude. The experimental results may provide useful information for practical monitoring in the SHM field.

scholarly journals Structural Health Monitoring Method of Pantograph–Catenary System Based on Strain Response Inversion

2021 ◽  
Vol 9 ◽  
Author(s):  
Sheng Liu ◽  
Yibo Wei ◽  
Yongxin Yin ◽  
Tangzheng Feng ◽  
Jinbao Lin
Keyword(s):  
Structural Health Monitoring ◽  
Contact Force ◽  
Health Monitoring ◽  
Data Consistency ◽  
Inversion Method ◽  
Maximum Speed ◽  
Strain Response ◽  
Monitoring Method ◽  
Structural Health ◽  
Catenary System

Pantograph-catenary system provides electric energy for the subway lines; its health status is essential to the serviceability of the vehicle. In this study, a real-time structural health monitoring method based on strain response inversion is proposed to calculate the magnitude and position of the dynamic contact force between the catenary and pantograph. The measurement principle, calibration, and installation detail of the fiber Bragg grating (FBG) sensors are also presented in this article. Putting this monitoring system in use, an application example of a subway with a rigid overhead catenary is given to demonstrate its performance. The pantograph was monitored and analyzed, running underground at a maximum speed of 80 km/h. The results show that the strain response inversion method has high measurement accuracy, good data consistency, and flexibility on sensor installation. It can accurately calculate the magnitude and location of the contact force exerted on the pantograph.

scholarly journals Effect of Adhesive Debonding on the Performance of Piezoelectric Sensors in Structural Health Monitoring Systems

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5070 ◽  
Author(s):  
Liu ◽  
Xu ◽  
Li ◽  
Wang ◽  
Zhang
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Research Work ◽  
Piezoelectric Sensor ◽  
Systematic Investigation ◽  
Monitoring Method ◽  
Structural Health ◽  
Negative Effect ◽  
Inherent Frequency ◽  
Slow Rise

Piezoelectric (PZT) ceramic elements are often subjected to complex loads during in- service lifetime in structural health monitoring (SHM) systems, and debonding of both excitation actuators and receiving sensors have a negative effect on the monitoring signals. A first systematic investigation of debonding behaviors by considering actuators and sensors simultaneously was performed in this paper. The debonding areas of actuators were set in different percentage range from 0% to 70%, and sensors in 0%, 20%, 40% and 60%. The signal-based monitoring method was used to extract the characteristic parameters of both the amplitudes and phases of received signals. Experimental results revealed that as the debonding areas of the actuators increase, the normalized amplitude appears a quick decrease before 35% debonding area of actuators and then a slow rise until 60% of debonding reached. This may be explained that the 35% debonding turning point correspond to the coincidence of the excitation frequencies of peripheral actuators with the inherent frequency of the central piezoelectric sensor, and the 60% be the result of the maximum ability of piezoelectric sensor. The degrees of debonding of actuators and sensors also have significant influence on the phase angle offset, with large debonding of actuators increases the phase offset sharply. The research work may provide useful information for practical monitoring of SHM systems.

Structural Health Monitoring of Composite Plates Subjected to Impacts Using the Electromechanical Impedance Technique

2008 ◽  
Author(s):  
Karina M. Tsuruta ◽  
Leandro R. Cunha ◽  
Raquel S. L. Rade ◽  
Domingos A. Rade
Keyword(s):  
Structural Health Monitoring ◽  
Impact Energy ◽  
Health Monitoring ◽  
Fiber Composite ◽  
Composite Plates ◽  
Carbon Fiber Composite ◽  
Monitoring Method ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Functional Relations

The aim of this paper is to evaluate the use of the Structural Health Monitoring (SHM) technique based on the concept of electromechanical impedance for the assessment of low-energy impact damage in laminated carbon-fiber composite plates. The experiments were carried-out by using an especially designed pendulum, and were planned in such a way to accommodate a range of test conditions, such as impact energy and dimension of the impacting piece. Also, it was investigated the influence of the frequency band in which the impedance functions are measured. Additionally, statistical metamodels were built aiming at establishing functional relations between the values of the damage metric and impact energy for single and multiple impacts. The obtained results demonstrate the capability of the monitoring method to identify various damage levels corresponding to different impact conditions.

Sign in / Sign up

Export Citation Format

Share Document