Experimental investigation of local damage detection on a 1/15 scale model of a suspension bridge deck

2003 ◽  
Vol 7 (4) ◽  
pp. 461-468 ◽  
Author(s):  
Sungkon Kim
Keyword(s):  
Experimental Investigation ◽  
Damage Detection ◽  
Bridge Deck ◽  
Suspension Bridge ◽  
Scale Model ◽  
Local Damage

EXPERIMENTAL TESTS ON LOCAL DAMAGE DETECTION USING OPTICAL FBG SENSORS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Jin-Hak Yi
Keyword(s):  
Damage Detection ◽  
Environmental Effects ◽  
Detection Method ◽  
Principal Component ◽  
Experimental Tests ◽  
Scale Model ◽  
External Loading ◽  
Local Damage ◽  
Offshore Structure ◽  
Load Variations

In this study, the fiber Bragg grating (FBG)-sensor based local damage detection method is proposed under circumstances with temperature and external loading variations. To compensate the environmental effects, principal component analysis (PCA) is utilized and also the performance of PCA is compared with that of the conventional linear adaptive filter (LF) model. Laboratory tests with a 1/20 scale model of a jacket-type offshore structure with six jacket-legs and a heavy super structure have been carried out for investigating the performance of the proposed damage detection method. From the experimental tests, it is observed that the local damage feature is mostly hidden and difficult to identify due to the environmental effects. By utilizing the conventional LF and PCA models, the effects of the undesirable environmental effects can be efficiently eliminated, and it is also found that the performances of the LF and PCA models are very similar and competitive to each other. However PCA model does not require the information on the temperature and external load variations, hence it can be concluded that the PCA-based local damage detection can be more efficiently applied for FBG-based local damage detection under temperature and external loading variations.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

Macdonald Bridge Suspended Spans Deck Replacement:Construction Engineering Challenges and Solutions

2016 ◽  
Author(s):  
Dusan Radojevic ◽  
Keith Kirkwood
Keyword(s):  
Nova Scotia ◽  
Wind Tunnel ◽  
Service Life ◽  
Bridge Deck ◽  
Suspension Bridge ◽  
Wind Tunnel Testing ◽  
Aerodynamic Stability ◽  
Bridge Superstructure ◽  
Suspended Structure ◽  
Analysis Models

The Angus L. Macdonald Bridge, a major suspension bridge that crosses Halifax Harbour in Halifax, Nova Scotia, opened to traffic in 1955. The bridge deck has reached the end of its service life, and the design of the new bridge superstructure and its replacement sequence were completed in 2014. The entire suspended structure and hangers are now being replaced sequentially during night and weekend closures while the bridge is opened for traffic during the daytime. The erection sequence is supported by sophisticated automated erection analysis models which take into account the geometry of the existing bridge, positioning of the erection equipment on the deck, and hanger and strand jack adjustments that are required during construction. Significant wind tunnel testing and analysis have been performed to ensure aerodynamic stability of the bridge during erection and in its final condition.

Experimental Investigation of Hydraulic-Pneumatic Regenerative Braking System

2015 ◽  
Author(s):  
A. G. Agwu Nnanna ◽  
Erik Rolfs ◽  
James Taylor ◽  
Karla Ariadny Freitas Ferreira
Keyword(s):  
Experimental Investigation ◽  
Kinetic Energy ◽  
Power Output ◽  
Energy Recovery ◽  
Scale Model ◽  
Regenerative Braking ◽  
Gear Pump ◽  
Braking System ◽  
Light Duty ◽  
Overall Efficiency

Design and development of energy efficient vehicles is of paramount importance to the automobile industry. Energy efficiency can be enhanced through recovery of the kinetic energy lost in the form of waste heat during braking. The kinetic energy could be converted into a reusable energy source and aid in acceleration, hence the braking system would contribute to improving the overall efficiency of a vehicle. Hydraulic-Pneumatic Regenerative Braking (HPRB) systems are a hybrid drive system that works in tandem with a vehicle’s engine and drivetrain to improve efficiency and fuel-economy. A HPRB system functions by recovering the energy typically lost to heat during vehicle braking, and storing this energy as a reusable source that can propel a vehicle from a stop. The major advantages of a HPRB system are that a vehicle would not require its engine to run during braking to stop, nor would the engine be required to accelerate the vehicle initially from a stop. The benefit realized by this system is an increase in fuel-efficiency, reduced vehicle emissions, and overall financial savings. An HPRB system aids in slowing a vehicle by creating a drag on the driveline as it recovers and stores energy during braking. Therefore, HPRB system operation reduces wear by minimizing the amount of work performed by the brake pads and rotors. An experimental investigation of Hydraulic-Pneumatic Regenerative Braking (HPRB) system was conducted to measure the system’s overall efficiency and available power output. The HPRB in this study is a 1/10th lab-scale model of a light-duty four wheel vehicle. The design/size was based on a 3500 lbs light-duty four wheel vehicle with an estimated passenger weight of 500 lbs. It was assumed that the vehicle can accelerate from 0–15 mph in 2 seconds. The aim of this work is to examine the effect of heat losses due to irreversibility on energy recovery. The experimental facility consisted of a hydraulic pump, two hydraulic-pneumatic accumulators, solenoid and relief valves, and data acquisition system. The HPRB system did not include any driveline components necessary to attach this system onto a vehicle’s chassis rather an electric motor was used to drive the pump and simulate the power input to the system from a spinning drive shaft. Pressure transducers, Hall effects sensor, and thermocouples were installed at suction and discharge sections of the hydraulic and pneumatic components to measure hydrodynamic and thermos-physical properties. The measured data were used to determine the system’s energy recovery and power delivery efficiency. Results showed that the HPRB system is capable of recovering 47% of the energy input to the system during charging, and 64% efficient in power output during discharging with an input and output of 0.33 and 0.21 horsepower respectively. Inefficiencies during operation were attributed to heat generation from the gear pump but especially due to the piston accumulator, where heat loss attributed to a 12% reduction in energy potential alone.

Yavuz Sultan Selim (3rd Bosphorus) Bridge-Inspection and Maintenance

2018 ◽  
Author(s):  
Abdul Farooq
Keyword(s):  
Health Monitoring ◽  
Bridge Deck ◽  
Road Traffic ◽  
Weather Conditions ◽  
Suspension Bridge ◽  
Bridge Inspection ◽  
Seismic Region ◽  
Inspection And Maintenance ◽  
Wind Climate ◽  
Heavy Rail

The Yavuz Sultan Selim bridge, also known as the 3rd Bosphorus Bridge, was opened to road traffic in August 2016. The stiffened suspension bridge, with a main span of 1408m, overall length 2250m and width 59.4m, is believed to be the first of its type. It is situated in a seismic region and exposed to a severe wind climate. It has been designed and constructed to carry 8 lanes of road traffic and twin track heavy rail-all on a single deck. <p> The bridge has been equipped with a Structural Health Monitoring (SHM) system. The instrumentation allows the monitoring of bridge behaviour. The dehumidification of the towers, bridge deck and suspension cables is also monitored. The ambient weather conditions including wind velocity, humidity and seismic activity are recorded. <p> This paper gives an overview of the inspection and maintenance regime. It also describes the observed performance of the bridge against its predicted behaviour.

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