Adaptive energy absorber for structural isolation and injury mitigation

An energy absorbing strut adapted to absorb energy between two components affixed to first and second ends of the strut comprising,

• the first end coupled with an inner cylinder,
• the second end connected with a hollow rod extending within the inner cylinder, a piston carried by the rod having an outer surface sealing against an inside diameter of the inner cylinder and forming a compression chamber and a rebound chamber bounded by the piston, the rod having an internal passageway communicating with the compression chamber and the rebound chamber,
• a valve assembly including an inertial mass carried by the rod movable axially on the rod between a closed position against an annular rod passageway in the rod and an open position opening the annular rod passageway and allowing the flow of a hydraulic fluid through the rod between the compression chamber and the rebound chamber, and
• a spring acting on the inertial mass biasing the inertial mass toward the closed position,
• the valve assembly further comprising, a damping sleeve having an opening for receiving the inertial mass when the inertial mass moves from the closed position to the open position, the damping sleeve forming an annular internal chamber filled with the hydraulic fluid and an aperture for draining the hydraulic fluid from the internal chamber, the inertial mass moving into the damping sleeve exerting pressure on the hydraulic fluid in the internal chamber urging the hydraulic fluid to drain through the aperture, the spring and the damping sleeve combining to control motion of the inertial mass along the rod between the closed and the open positions.