Elastomeric Damper for Displacement Control

Elastomeric Damper with Seismic Isolation Bearing Detachment Prevention Based on Selective Magnetization of Magnetic Materials

This technology is an elastomeric damper that places a damping unit consisting of ferromagnetic plates and spherical magnetic materials between opposing connection plates. It absorbs seismic energy by selectively magnetizing the magnetic materials to either constrain or release the relative movement between the plates. The stiffness is variably adjusted as the magnetic materials, encased in an elastic film, deform under external forces.

Conventional seismic retrofitting often involves increasing the stiffness or mass of structural members, leading to excessively large cross-sections and inefficiency. Furthermore, rubber or lead seismic isolation bearings installed in bridges and other structures are prone to displacement or detachment during major earthquakes, and are difficult to maintain or reuse post-seismic events.

This technology uses coil current to magnetize the magnetic materials, adjusting damper stiffness as needed, and incorporates flexural coupling members and compression springs for additional energy dissipation. It can be retrofitted onto existing rubber or lead bearings. Applicable to high-rise buildings and long-span bridges, it reduces repair costs and recovery time by allowing for the reuse of bearings after an earthquake.

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Key Features:

• A second connection plate provided on the opposite side of the first connection plate, moving parallel to it when an external force is applied
• A damping unit comprising a plurality of ferromagnetic plates spaced apart between the connection plates, moving parallel to the first connection plate under external force
• Spherical magnetic materials coated in an elastic film that deform elastically under external force, connecting the ferromagnetic plates via selective magnetization to constrain relative movement
• A structure further including coils wound around the ferromagnetic plates to magnetize the magnetic materials when current is applied, and coupling members that absorb energy through flexural deformation

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