Damper device using smart materials with self-restoring and self-healing capabilities

Self-restoring seismic damper absorbing both tension and compression using shape memory alloy deformation plates and self-healing polyurethane elastomers

This technology is a damper device for building structures where first and second moving units reciprocate on a guide unit along a load-acting line, connected by a shape memory alloy deformation unit. The moving rod of the operating unit pushes the first moving unit under compressive load and pulls the second moving unit under tensile load, configured so that the polyurethane elastomer is compressed and the deformation unit is stretched in either case.

Conventional friction dampers have fixed friction forces and relative travel distances determined during manufacturing, making it impossible to adjust for the actual energy absorption and displacement required based on brace placement or connection types. Furthermore, once external forces are absorbed, the friction surfaces remain displaced, leading to high costs for replacement or repair after an earthquake.

In this technology, the first pressure flange at the end of the moving rod and the expanded second pressure flange in the middle press against opposing inner walls, forcing the two moving units apart regardless of load direction. Fixing pins on the moving walls slide along guide holes, creating friction between the screwed-in head and the guide wall. The deformation unit connects two plates with a narrowed middle section to concentrate deformation, and two or four moving walls can be arranged orthogonally or in parallel. Applicable to steel building bracing, seismic retrofitting for schools and hospitals, and bridge vibration control, the superelastic alloy returns to its original position after an earthquake, and the elastomer self-heals, allowing for reuse without replacement.

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Key Features:

• A guide unit of a predetermined length along a virtual load-acting line parallel to the direction of tensile or compressive force
• A deformation unit made of shape memory alloy that connects the first and second moving units and undergoes tension and recovery parallel to the load-acting line
• An operating unit equipped with a moving rod, a first pressure flange, and a second pressure flange to pull the second moving unit and push the first moving unit
• A first and second elastomer made of polyurethane that undergo compressive deformation when the operating unit pushes or pulls the moving units

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This invention was developed through the Ministry of Science and ICT's support for the development of core technology for new damping devices using intelligent materials, as well as structural testing and analysis for seismic performance evaluation.

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