EXPERIMENTAL AND NUMERICAL ASSESSMENT OF PRESTRESSED LEAD EXTRUSION DAMPERS

The study presents an experimental and numerical assessment of the Prestressed Lead Extrusion Damper (P-LED), an emerging energy dissipation device which provides energy dissipation through the plastic extrusion of lead, and achieves high specific output force by preloading of the working material. Tests are performed according to the European standard EN 15129. The damper shows a rigid-plastic behaviour with an essentially rectangular hysteresis loop, resulting in an effective damping of 0.55 regardless of the imposed deflection, and is able to sustain multiple cycles of deformation at the basic design earthquake displacement without degradation of the output, providing maintenance-free operation even in presence of repeated ground shakes. A 3D finite element model of the P-LED is formulated and used in a parametric study to investigate the influence of the device dimensions on the output force. The numerical data points are fitted by a simple model which can be used for designing the damper to a specified quasi-static force.