scholarly journals Monitoring Fatigue Damage of Modular Bridge Expansion Joints Using Piezoceramic Transducers

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3973 ◽  
Author(s):  
Tianyong Jiang ◽  
Yaowen Zhang ◽  
Lei Wang ◽  
Liang Zhang ◽  
Gangbing Song
Keyword(s):  
Fatigue Test ◽  
Fatigue Damage ◽  
Lead Zirconate Titanate ◽  
Comparative Approach ◽  
Active Sensing ◽  
Expansion Joints ◽  
Static Test ◽  
Damage Degree ◽  
Full Penetration ◽  
Modular Bridge Expansion Joints

Modular bridge expansion joints (MBEJs) are commonly used in bridges and are often subjected to fatigue damages, which necessitate fatigue monitoring of MBEJs to ensure the reliable operation of the bridges. In this paper, a stress wave based active sensing approach using piezoceramic transducers is developed to monitor the fatigue damage of MBEJ. A MBEJ involves mainly center beam, edge beam, support bar, support box, sliding bearing, sliding spring, elastomeric strip seal, full-penetration weld and reinforcing plate. In practice, for a MBEJ, the part that is most prone to fatigue damage is the full-penetration weld between the center beam and the support bar. In this paper, a specimen, which is the full-scale center-beam/support-bar (CB/SB) assembly, was designed and fabricated to facilitate the experimental study. The assembly mainly includes center beam, support bar, reinforcing plate, and full-penetration weld. The lead zirconate titanate (PZT) transducer bonded on the support bar was used as the actuator and the PZT transducer mounted on the center beam was as the sensor. Dial indicators were utilized to measure the vertical displacement of the center beam. Two series of tests, including static test, and fatigue test, were performed on the specimen in an alternating fashion. Based on the number of cyclic loading, the experiment was divided into six different stages: 0th cycle (the healthy state), 0.8 million cycles, 1.6 million cycles, 2.4 million cycles, 3.2 million cycles, and 4 million cycles. The signals received by the PZT sensor were analyzed with the help of wavelet packet analysis. In addition, the structure stiffness also was considered as a comparative approach in this paper. Experimental results show that during the fatigue test, the structure stiffness decreases with the number of cycle loading. However, the method can only obtain the fatigue damage impact on the entire structure, and cannot determine the fatigue damage degree of a certain weld. On the other hand, the proposed method can accurately monitor the fatigue damage degree of full-penetration welds. The research results show that the developed piezoceramic enabled active sensing approach can monitor and estimate the fatigue damage in MBEJ in real-time.

Modular Bridge Expansion Joints for Lacey V. Murrow Floating Bridge

1997 ◽  
Vol 1594 (1) ◽  
pp. 163-171 ◽  
Author(s):  
John A. Van Lund ◽  
Mark R. Kaczinski ◽  
Robert J. Dexter
Keyword(s):  
Fatigue Strength ◽  
Fatigue Cracking ◽  
Field Measurements ◽  
The United States ◽  
Limit States ◽  
Expansion Joints ◽  
Lake Washington ◽  
Floating Bridge ◽  
Modular Bridge Expansion Joints ◽  
Washington State Department

The Lacey V. Murrow Bridge (LVM Bridge) is a 2013-m-long floating bridge on Interstate 90 across Lake Washington in Seattle, Washington. Single-support-bar, swivel-joist modular bridge expansion joint systems are located at each end of the bridge between the shore approach spans and the floating pontoons. These joints were designed for 960 mm of longitudinal movement as well as horizontal and vertical rotations caused by wind, wave, temperature, and changes in lake level elevation. A similar joint in an adjacent floating bridge had experienced premature fatigue cracking at welded attachment details because of low fatigue strength. For the LVM Bridge the joint components were fatigue tested and designed by using fatigue limit-states loads, resulting in welded attachment details with improved fatigue strength. In addition, a stiffer center beam and reduced center-beam span lengths produced lower fatigue stress ranges. Joint movements and rotations, fatigue design methodology, results of dynamic analyses, field measurements of the dynamic response, and construction details are described. The total cost of the LVM joints was 1 percent of the final bridge cost. The Washington State Department of Transportation required a 5-year guarantee for the LVM joints. These are the largest modular bridge expansion joints in the United States to be tested and designed for fatigue.

scholarly journals A PZT-Based Electromechanical Impedance Method for Monitoring the Soil Freeze–Thaw Process

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1107 ◽  
Author(s):  
Jicheng Zhang ◽  
Chuan Zhang ◽  
Jiahao Xiao ◽  
Jinwei Jiang
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Soil Freezing ◽  
Impedance Method ◽  
Active Sensing ◽  
Freezing And Thawing ◽  
Engineering Structures ◽  
Electromechanical Impedance ◽  
Freeze Thaw ◽  
Wave Signal

It is important to conduct research on the soil freeze–thaw process because concurrent adverse effects always occur during this process and can cause serious damage to engineering structures. In this paper, the variation of the impedance signature and the stress wave signal at different temperatures was monitored by using Lead Zirconate Titanate (PZT) transducers through the electromechanical impedance (EMI) method and the active sensing method. Three piezoceramic-based smart aggregates were used in this research. Among them, two smart aggregates were used for the active sensing method, through which one works as an actuator to emit the stress wave signal and the other one works as a sensor to receive the signal. In addition, another smart aggregate was employed for the EMI testing, in which it serves as both an actuator and a receiver to monitor the impedance signature. The trend of the impedance signature with variation of the temperature during the soil freeze–thaw process was obtained. Moreover, the relationship between the energy index of the stress wave signal and the soil temperature was established based on wavelet packet energy analysis. The results demonstrate that the piezoceramic-based electromechanical impedance method is reliable for monitoring the soil freezing and thawing process.

scholarly journals Damage Detection of Common Timber Connections Using Piezoceramic Transducers and Active Sensing

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2486 ◽  
Author(s):  
Fang Han ◽  
Jinwei Jiang ◽  
Kai Xu ◽  
Ning Wang
Keyword(s):  
Damage Detection ◽  
Lead Zirconate Titanate ◽  
Failure Modes ◽  
Low Cost ◽  
Energy Levels ◽  
Stress Waves ◽  
Active Sensing ◽  
Timber Structures ◽  
Signal Energy ◽  
Timber Connections

Timber structures have been widely used due to their low-cost and environmental-friendly properties. It is essential to monitor connection damage to ensure the stability and safety of entire timber structures since timber connection damage may induce catastrophic incidents if not detected in a timely manner. However, the current investigations on timber connections focus on mechanical properties and failure modes, and the damage detection of timber connection receives rare attention. Therefore, in this paper, we investigate the damage detection of four common timber connections (i.e., the screw connection, the bolt connection, the decussation connection, and the tooth plate connection) by using the active sensing method. The active sensing method was implemented by using a pair of lead zirconate titanate (PZT) transducers: one PZT patch is used as an actuator to generate stress waves, and the other works as a sensor to detect stress waves after propagating across the timber connection. Based on the wavelet packet energy analysis, the signal energy levels of received stress waves under different damage extent are quantified. Finally, by comparing the signal energy between the intact status and the damage status of the timber connection, we find that the energy attenuates with increasing severity of the connection damage. The experimental results demonstrate that the active sensing method can realize real-time monitoring of timber connection damage, which can guide further investigations.

Structural Fatigue Analysis on Expansion Joints of Diversion Penstock of Hydropower Station

2011 ◽  
Vol 117-119 ◽  
pp. 262-268
Author(s):  
Jia Dong ◽  
Gen Hua Yan
Keyword(s):  
Fatigue Damage ◽  
Dynamic Effect ◽  
Water Diversion ◽  
Structural Vibration ◽  
Hydropower Station ◽  
Expansion Joints ◽  
Structural Fatigue ◽  
Safety And Reliability ◽  
Normal Water ◽  
Cumulative Fatigue Damage

Abstract: The section of diversion penstock near the powerhouse behind dam in some hydropower station is equipped with expansion joints, which is used to remedy deformation of penstock in axial and lateral due to the variation of temperature and foundation subsidence. When the hydropower station is in normal water diversion and power generation, the discharged flow generates fluctuating loads, induces structural vibration of guide cylinder of expansion joints, gives rise to cumulative fatigue damage of guide cylinder and also leads to weld joints in guide cylinder cracking to fall off. When generating unit is in the condition of load rejection, expansion joints bears not only the fluctuating pressure loads of the flow, but also undergoes the shock from water-hammer pressure as well, so this demands higher requirement for the safety and reliability of expansion joints structure. It has important engineering value for ensuring safety and reliability of water-diverting power generating system to conduct researches on dynamic effect that fluctuating loads having on expansion joints guide cylinder structure and cumulative fatigue damage of terminal weld of guide cylinder

Fatigue and Damage Tolerance Substantiation Approach for a Regional Jet

2014 ◽  
Vol 891-892 ◽  
pp. 1688-1693
Author(s):  
Toshiyasu Fukuoka ◽  
Kaoru Tsukigase ◽  
Keisuke Kumagai
Keyword(s):  
Fatigue Test ◽  
Fatigue Damage ◽  
Material Properties ◽  
Damage Tolerance ◽  
Full Scale ◽  
Structural Configuration ◽  
Component Level ◽  
Regulatory Requirement ◽  
Analysis Methodology ◽  
Structural Tests

The overview of the fatigue and damage tolerance substantiation approach for a 70-90 seat class regional aircraft named Mitsubishi Regional Jet, which is now under development by Mitsubishi Aircraft Corporation, is presented. To comply with the new regulatory requirement for prevention from widespread fatigue damage, full-scale airplane fatigue test will be performed with simulating actual airplane structural configuration and typical loading spectra expected in service. In addition to widespread fatigue damage, damage tolerance evaluations assuming manufacturing defect or in-service damage are being performed. Hundreds of structural tests from coupon level to sub-component level are to be used to verify the material properties and analysis methodology.

Fatigue Performance of Grade R4 and R5 Mooring Chains in Seawater

2014 ◽  
Author(s):  
Jonathan Fernández ◽  
Walther Storesund ◽  
Jesús Navas
Keyword(s):  
Fatigue Test ◽  
Fatigue Damage ◽  
Fatigue Tests ◽  
Design Methods ◽  
Full Scale ◽  
Fatigue Performance ◽  
Test Program ◽  
Gas Industry ◽  
Fatigue Design ◽  
Cumulative Fatigue Damage

With more than 50.000 tons in service to date, the Oil&Gas Industry has the need to understand the tension fatigue performance of grade R5 chains in straight tension, and corroborate the validity of the existing design methods. The chain fatigue design curves in API and DNV are based on fatigue tests obtained in the nineties and early two thousands. However the tests were performed on lower grades such as ORQ, R3 and R4, and small chains, 76 mm diameter being the largest studless chain tested. The industry has moved towards the use of large studless chains, especially in permanent units, where chain diameters above 150 mm are not unusual. This paper gathers information from a full scale fatigue test program on grade R4 and R5 studless chains, performed in seawater and with diameters between 70 mm and 171 mm. The chains being tested are actual production chains supplied for different drilling units and large permanently moored production floating units. The paper analyses the data and determines tension-tension fatigue curves based on API and DNV methods for computation of cumulative fatigue damage, regardless of other damaging mechanisms. Improved fatigue capacity is obtained with respect to the above recommended design methods.

scholarly journals Real-Time Monitoring of Timber-Surface Crack Repair Using Piezoelectric Ceramics

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Huien Meng ◽  
Wenwei Yang ◽  
Xia Yang
Keyword(s):  
Real Time ◽  
Lead Zirconate Titanate ◽  
Surface Crack ◽  
Wavelet Packet ◽  
Damage Index ◽  
Piezoelectric Ceramics ◽  
Strength Development ◽  
Active Sensing ◽  
Surface Cracks ◽  
Crack Repair

Real-time assessment of timber-surface crack repair is crucial to the stability and safety of timber structures. Epoxy resin was used to repair timber cracks, and the active sensing technique using piezoelectric ceramics was applied to monitor the repair process of timber surface cracks in real time. Sixteen wood samples were designed for axial compression tests and active monitoring tests. A pair of lead zirconate titanate patches was pasted on the surface of the timber specimens as actuators and sensors for signal transmission and reception, through wavelet packet analysis, the variations in the signal amplitude, and wavelet coefficients. The relationship between the wavelet packet energy of the monitoring signal and the ultimate bearing capacity of the specimens at different periods after grouting was established. Based on the root-mean-square deviation, the damage index, DI, was introduced to evaluate the repair degree of timber surface cracks quantitatively. The results showed that the active sensing method can evaluate the strength development in timber-surface crack repair in real time.

scholarly journals Prestress Monitoring of a Steel Strand in an Anchorage Connection Using Piezoceramic Transducers and Time Reversal Method

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4018 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Liuyu Zhang ◽  
Laijun Liu ◽  
Linsheng Huo
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Time Reversal ◽  
Stress Wave Propagation ◽  
Suspension Bridges ◽  
Active Sensing ◽  
Sensors And Actuators ◽  
Anchorage System ◽  
Steel Strand ◽  
Peak Value

Steel strands are widely used in cable stay or suspension bridges. The safety and stability of steel strands are important issues during their operation period. Steel strand is subjected to various types of prestress loss which loosens the wedge anchorage system, 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 wedge anchorage system by using stress wave based active sensing. As a commonly used piezoceramic material, Lead Zirconate Titanate (PZT) with a strong piezoelectric effect is employed. In the proposed active sensing approach, PZT patches are used as sensors and actuators to monitor the steel strand looseness status. One PZT patch is bonded to the steel strand, one PZT patch is bonded to the wedges, and another PZT patch is bonded to the barrel. There are three different interfaces of the wedge anchorage system to monitor the steel strand looseness status. In the first method, the PZT patch on the steel strand is used as an actuator to generate a stress wave and the PZT patch on the wedge is used as a sensor to detect the propagated waves through the wedge anchorage system. In the second method, the PZT patch on the steel strand is used as an actuator to generate a stress wave and the PZT patch on the barrel is used as a sensor to detect the propagated waves through the wedge anchorage system. In the third method, the PZT patch on the wedges is used as an actuator to generate a stress wave and the PZT patches on the barrel is used as a sensor to detect the propagated waves through the wedge anchorage system, of which the looseness will directly impact the stress wave propagation. The TR method is utilized to analyze the transmitted signal between PZT patches through the wedge anchorage system. Compared with the peak values of the TR focused signals, it can be found that the peak value increases as the wedge anchorage system tightness increases. Therefore, the peak value of the TR focused signal can be used to monitor the tightness of the steel strand. In addition, the experimental results demonstrated the time reversal method’s reliability, sensitivity and anti-noise property.

Dynamic numerical analysis of single-support modular bridge expansion joints

2016 ◽  
Vol 22 (1) ◽  
pp. 1-12
Author(s):  
Xinzhe Yuan ◽  
Ruiqi Li ◽  
Jian'guo Wang ◽  
Wancheng Yuan
Keyword(s):  
Numerical Analysis ◽  
Expansion Joints ◽  
Modular Bridge Expansion Joints
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