Energy-Dissipating Elastomer Friction Damper

Seismic Damper for Structures with Adjustable Friction via Selective Magnetization of Elastic-Coated Magnetic Particles

This technology is an energy-dissipating elastomer friction damper that places a friction disk between two friction plates. It features multiple spherical magnetic particles, each encased in an elastic coating, which are selectively magnetized via coil current to adjust the relative rotational restraint—or friction—between the contact surfaces.

As major earthquakes become more frequent, the demand for seismic retrofitting to prevent structural collapse and secondary damage has grown. However, early technologies relied on increasing the stiffness or mass of members, leading to uneconomical designs with excessively large cross-sections. Existing friction-type damping devices have fixed friction levels, making it difficult to adjust damping performance in response to varying vibration intensities.

This technology selectively applies current to coils to change the connectivity of the magnetic particles. By maintaining flexible contact through the deformation of the elastic coating, it provides variable friction damping based on vibration intensity. The structure is compact, using a shaft and fastening mechanism to secure the plates and restrict non-rotational movement. It can be applied to building seismic retrofitting, plant equipment supports, and infrastructure vibration control, allowing a single device to adapt its damping level from minor tremors to major earthquakes.

‍

‍

Key Features:

• First friction plate, a friction disk forming a first contact surface with the first friction plate, and a second friction plate forming a second contact surface on the opposite side
• A shaft member and fastening means based on a contact mechanism that restricts relative movement between the first friction plate, friction disk, and second friction plate, excluding relative rotation
• Multiple spherical magnetic particles coated with an elastic film that connect the first and second contact surfaces through selective magnetization to restrict relative rotation between the plates
• A cylindrical spacer that separates the two disk plates and a coil wound in a screw shape between them to magnetize the magnetic particles through selective current application

‍