University System of Maryland

Techno-sciences, Inc. (corporation)

Gm Global Technolgoy Operations, Inc.

Gm Research & Development

Wei Hu

Norman Mark Wereley

Gregory Hiemenz

Alan L Browne

Peter Che-Hung Chen

Nancy L Johnson

Young Tai Choi

Min Mao

Grum Tamrat Ngatu

Chandra S Namuduri

John C Ulicny

Curt Steven Kothera

Gang Wang

Vaibhav Vora

Eugene Cook

An adaptive energy absorption system for a vehicle seat is disclosed, utilizing an adaptive energy absorber or variable profile energy absorber (VPEA) for mitigating occupant injury due to extreme vehicle movement (e.g., during a vehicle shock event), and/or for mitigating vibration experienced by an occupant of the vehicle seat during normal vehicle operating conditions. The adaptive energy absorption system achieves the aforementioned objectives for a wide range of occupant weights and load levels. An alternate configuration of a dual-goal energy absorption system is also disclosed that enables both shock mitigation and vibration isolation.

Method of determining impact severity and adaptive impact attenuation

A rotary vane magnetorheological energy absorber, which enables a longer stroke capability in a more compact configuration than conventional magnetorheological devices, is disclosed. This novel device design is attractive for applications where long stroking capability, high force dynamic range, device size, and device weight are important. The improved magnetorheological energy absorber comprises an internal or external flow valve and a hollow body enclosing fixed and rotary vanes as well as magnetorheological fluid. Fluid flow in the valve is restricted as a solenoid is activated, thus adjusting the capability of the device to react torque. Various flow valve configurations are disclosed, as well as various motion translation mechanisms for translating linear motion to rotary motion for use of the rotary vane magnetorheological energy absorber. The improved design minimizes the amount of magnetorheological fluid required as compared to conventional linear stroke energy absorbers, thus minimizing device weight.

Rotary vane magnetorheological (MR) energy absorber

A MagnetoRheological Fluid Elastic (MRFE) lag damper system for adaptive lead-lag damping of helicopter main rotors. Embodiments include snubber dampers especially for hingeless helicopter rotors, and concentric bearing dampers. The snubber lag dampers include a flexible snubber body defining a cavity, a flexible or rigid interior (e.g., center) wall subdividing the cavity, and a flow valve in the interior wall or external to the cavity. The flexible snubber body may comprise elastomeric materials and metal rings stacked together to create a sealed MR fluid cavity. The shear deformation of the snubber body induces MR fluid flow through the valve, controlled by a magnetic field in the valve. An MRFE concentric bearing damper is also disclosed, comprising a pair of concentric tubes with elastomeric material injected and cured in an annular gap between the two tubes, and an MR fluid reservoir with piston-mounted MR valve housed inside the innermost tube.

Magnetorheological fluid elastic lag damper for helicopter rotors

A method of designing a magnetorheological (MR) fluid energy absorbing damper is provided that uses hydromechanical analysis with lumped parameters to allow a determination as to whether a potential damper design will provide predetermined characteristics, such as a desired dynamic force range and maximum piston velocity, with a selected MR fluid and yield stress and preferably meeting predetermined geometric limitations.

Method of designing magnetorheological fluid energy absorbing device using hydromechanical analysis

An adaptive energy absorption system for a vehicle seat is disclosed, utilizing an adaptive energy absorber or variable profile energy absorber (VPEA) for mitigating occupant injury due to extreme vehicle movement (e.g., during a vehicle shock event), and/or for mitigating vibration experienced by an occupant of the vehicle seat during normal vehicle operating conditions. The adaptive energy absorption system achieves the aforementioned objectives for a wide range of occupant weights and load levels. Various configurations of dual-goal energy absorption apparatuses that enable both shock mitigation and vibration isolation are disclosed.

Adaptive energy absorption system for a vehicle seat

An energy absorbing device is provided that includes a damper assembly having inner and outer concentric tubes and a piston movable within the inner tube. The damper assembly is configured to form bi-fold valve-type cavities to operatively connect an inner chamber of the inner tube with an outer chamber formed between the inner and outer tubes. A magnetorheological fluid fills the chambers and the bi-fold valve-type cavities. The magnetorheological fluid preferably contains coated magnetic particles at about 10 to 60 percent by volume. Electrical coils adjacent the bi-fold valves are selectively energizable to such that the energy absorbing device provides a tunable damping force, preferably over the entire range of velocities of the piston, especially in automotive applications.

Bi-fold valve-type magnetorheological fluid energy absorbing device

An adaptive energy absorption system for a vehicle seat is disclosed, utilizing an adaptive energy absorber or variable profile energy absorber (VPEA) for mitigating occupant injury due to extreme vehicle movement (e.g., during a vehicle shock event), and/or for mitigating vibration experienced by an occupant of the vehicle seat during normal vehicle operating conditions. Various configurations of dual-goal energy absorption apparatuses using both VPEA and fixed load energy absorbers (FLEAs) that enable both shock mitigation and vibration isolation are disclosed. A semi-active control absorption system, comprising a VPEA and FPEA configured to work in series, is also disclosed.

A magnetorheological fluid damping system includes a hydraulic cylinder, a piston head, a piston rod, and a porous valve. The hydraulic cylinder is configured for disposing magnetorheological fluid therein. The piston head is disposed within the hydraulic cylinder and has first and second sides defining first and second chambers within the hydraulic cylinder. The piston head is configured to be in sliding engagement with the hydraulic cylinder. The piston rod is connected to the piston head. The porous valve includes a magnetorheological fluid pathway, has first and second fluid connections, and is configured to dampen the flow of the magnetorheological fluid between the first and second fluid connections in accordance with a magnetic field. The first fluid connection is fluidly connected to the first chamber and the second fluid connection is fluidly connected to the second chamber. The magnetorheological fluid pathway at least partially directs magnetorheological fluid flow through a porous media.

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Rockville, MD, United States of America

Wei Hu