Study on mechanical characteristics of accordion metallic damper

This paper presents Accordion Metallic Damper (AMD) as a unique energy dissipating system that originated from the concept of thin-walled tubes used in machinery as the shock absorber. The AMD can perform as a repairable hysteretic fuse in structural frames to enhance the lateral ductility, energy-dissipation and damping potential of the frame systems during earthquakes. The AMD consists of the corrugated thin-walled tubes installed at the brace connection to the frame. The lateral displacement of the braced frame causes yielding of the AMD in axial deformation mechanism and dissipates energy due to forming of plastic hinges along the corrugated tubes in reversed cyclic deformations. In order to evaluate the performance of the AMD for upgrading the seismic behavior of the structures a series of quasi-static cyclic tests were conducted on pre-fabricated corrugated thin-walled tubes and hysteretic load-deformation response, lateral strength, initial stiffness, and dissipated energy was investigated. Numerical studies were also carried out to provide a large parameter results to explore the effect of geometry parameters such as shape, thickness, diameter and length of the corrugated tube on the mechanical properties. The analytical model was created based on finite elements method and nonlinear inelastic analysis with considering large deformation capacity was employed for these studies. The results showed that the AMD exhibited enhanced energy-dissipation and damping potential with stable hysteresis loops and confirmed that the AMD is an excellent energy-dissipating device that can be used for upgrading the seismic behavior of framed structures.