Experimental Development, Tradeoff Analysis and Design Implementation of High Force-To-Volume Damping Technology

John B Mander

Department of Civil Engineering, University of Canterbury, Christchurch

Geoffrey W Rodgers

Department of Mechanical Engineering, University of Canterbury, Christchurch

Department of Civil Engineering, University of Canterbury, Christchurch

J Geoffrey Chase, Caleb S Denmead and Nicholas C Leach

Department of Mechanical Engineering, University of Canterbury, Christchurch

This paper is part of the Bulletin of the New Zealand Society for Earthquake Engineering, Vol. XX, No. Y, Month 2006.

Supplemental dampers are a means of repeatedly dissipating energy without damage to the underlying structure, increasing life-safety and helping provide better serviceability of structures following a major earthquake. High performance (small size) lead dampers are designed and tested to characterise their force-displacement behaviour and produce trade-off curves relating device geometry to force capacity, to parameterise the design space to enable further devices to be designed for structural applications. Peak forces of 120-350kN were obtained for devices that were all able to fit within standard structural connections.

Results show that prestressing the working material is critical to obtain optimal energy dissipation. Although previously characterised as extrusion dampers it is shown that classical extrusion modelling formulations do not strictly work well for this class of damper. Instead a coulomb type of stress-based model is proposed, with relationships presented that are independent of device scale. Empirical reduction factor equations are applied to the New Zealand Structural Design Actions to enable lead extrusion devices to be incorporated into structural design analyses. The overall results indicate that repeatable, optimal energy dissipation can be obtained in a compact device to minimise damage to critical buildings and infrastructure.

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