Bridge Dynamics
Teknologidagene 2013
Clarion Hotel & Congress Trondheim
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Ole Andre Øiseth Department of Structural Engineering
Faculty of Engineering Science and Technology
Norwegian University of Science and Technology
Research activities Structural Dynamics
• Wind actions
– Tall buildings and cable-supported bridges
• Wave actions
– Submerged tunnels, and floating bridges
• Earthquake engineering
– Buildings and bridges
• Ice induced vibrations
– Ice induced actions on bottom fixed structures. Highly relevant for some bridges
• Vibrations induced by moving loads
– Interaction between pantograph and contact lines for electric railroad systems
– Bridge dynamics – Rail, Road and Pedestrian
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Education and structural dynamics
• Number of Master students supervised:
– 2010 – 13
– 2011 – 5
– 2012 – 26
– 2013 – 11
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Research activities Structural Dynamics
• Benefits of measurements
– Verify state of the art methods - for predicting dynamic response
– Discover phenomena - that can’t be modeled by the current state of the art
– Model uncertainty and structural reliability
– Inverse force identification
– Make new load models with improved accuracy
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The Hardanger Bridge measurement project
• Research questions:
– How well can we capture the dynamic response of the bridge?
• Vortex shedding induced vibrations (low mean wind velocities)
• Buffeting vibrations in strong wind
• Traffic induced vibrations
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The Hardanger Bridge measurement project
• Research questions:
– Are the methods used to characterize the wind field adequate for long span bridges in Norwegian fjords?
• Can the wind field be approximated as stationary?
• Can the wind field be approximated as homogeneous?
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The Hardanger Bridge measurement project
• The measurement system (CSI instruments)
– 9 Ultrasonic anemometers (Gill windmaster pro)
– 20 accelerometers (3 axis)
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• Linear frequency domain analysis
Development of computational analysis tools
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Transfer function
Wave loads
Wave induced response
Development of computational analysis tools
• Time domain analysis
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Wave loads
Wave induced response Time integration (linear/non-linear)
Development of computational analysis tools
• Flutter
– The mean wind velocity where the system is not able to dissipate energy.
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