Presentation on theme: "Hawk Measurement Systems Smart Sensor Technology for Bridge Health."— Presentation transcript:
Hawk Measurement Systems Smart Sensor Technology for Bridge Health
Structural Health Monitoring of Bridges Bridge health is an important issue Bridge collapses often result in a large number of casualties, as well as negative social and economic consequences. I-35W Mississippi River Bridge near Minneapolis collapsed on 01/08/2007. 13 people died and 145 were injured. Life span of highway bridges is ~70 years An MIT estimate says, over the next few years, costs for repair and refits amount $ 600 billion a year Structural health monitoring can mitigate problems
Conventional Monitoring Systems Expensive $4,000-15,000 per sensor using wired devices $600 per sensor using wireless devices Point sensor Each sensor can only monitor one spot and one parameter Regular maintenance is costly and necessary Every sensor needs to be powered Bulky
Recently Developed Wireless Sensors 71 wireless sensor nodes with a total of 427 sensing channels were installed on the girder, pylons, and cables in 2009 to monitor cable tension force, temperature and dynamic instability to determine structural performance and find possible damage locations. Wireless sensors also have the disadvantages of conventional sensors. The second Jindo Bridge in South Korea
Subheading: Dot Point Dot Point. Fibre Optic Sensing Distributed sensor can continuously monitor vibration, strain and temperature on structural elements of the bridge for the entire length of optical fibre. Fibre optic cable is easy to install. Fibre optic cable is passive – No electrical power required. Little or no maintenance required. Fibre optic sensing has low cost.
Stress, strain along tensile members and cables Compressive strain on support columns Vibration and resonance effects Emergence of cracks Movement of joints and hinges Temperature Deflection of beam, arch and truss etc. Types of Distributed Monitoring On-site fibre optic sensor gluing procedure (left) and installed fibre optic sensor (right)