A monitoring system for a dual-stage, separated gas/fluid shock strut may comprise a controller and a tangible, non-transitory memory configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform various operations. Said operations may include calculating, by the controller, a secondary chamber nominal pressure, determining, by the controller, a shock strut stroke associated with the secondary chamber nominal pressure, calculating, by the controller, a volume of oil in an oil chamber of the shock strut, calculating, by the controller, a volume of gas in a primary chamber of the shock strut, calculating, by the controller, a secondary chamber inflation pressure, and calculating, by the controller, a volume of oil leaked into the primary chamber of the shock strut.

A monitoring system for a dual-stage, separated gas/fluid shock strut may comprise a controller and a tangible, non-transitory memory configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform various operations. Said operations may include determining, by the controller, a shock strut stroke at which a secondary chamber of the shock strut is activated, calculating, by the controller, a volume of oil in an oil chamber of the shock strut, calculating, by the controller, a volume of gas in a primary chamber of the shock strut, and calculating, by the controller, a volume of oil leaked into the primary chamber of the shock strut.

A variable stiffness structure includes a first negative stiffness element configured to buckle in a first direction, a second negative stiffness element configured to buckle in a second direction opposite to the first direction, and an actuator operatively coupled to ends of the first and second negative stiffness elements to control a stiffness of the variable stiffness structure. The first negative stiffness element and the second negative stiffness element are mode-3 buckling beams.

A damper having a hydraulically-adjustable preload. The damper includes a main damper cylinder, a damping piston and a damping rod movable within the main damper cylinder. A surface feature and a sleeve with a preload flange are coupled to a portion of an exterior surface of the main damper cylinder. The sleeve is movable with respect to the surface feature in a direction along the axis of the main damper cylinder. A spring is located surrounding a portion of the external surface of the main damper cylinder, and has one end abutting the preload flange and another end coupled to the damper. The sleeve and the surface feature are disposed such that a change in an amount of hydraulic fluid between the sleeve and the surface feature causes the preload flange to change a preload on the spring.

A head unit system for controlling motion of an object includes a secondary object sensor and a head unit device that include shear thickening fluid (STF) and a chamber configured to contain the STF. The chamber further includes a front channel and a back channel. The head unit device further includes a piston housed at least partially radially within the piston compartment and separating the back channel and the front channel. The piston includes a first piston bypass and a second piston bypasses to control flow of the STF between opposite sides of the piston. The chamber further includes a set of fluid flow sensors and a set of fluid manipulation emitters to control the flow of the STF to cause selection of one of a variety of shear rates for the STF within the chamber to control motion of the object with regards to a secondary object.

A fluid damping structure is provided that includes an inner and outer annular elements, first and second ring seals, first and second outer annular seals. The inner annular element has an outer radial surface and a plurality of annular grooves disposed in the outer radial surface. The outer annular element has an inner radial surface. A damping chamber is defined by the inner and outer annular elements, and the first and second inner ring seal. A first lateral chamber is disposed on a first axial side of the damping chamber. A second lateral chamber is disposed on a second axial side of the damping chamber. A plurality of fluid passages are disposed in at least one of the inner annular element or the inner ring seals. The fluid damping structure is configurable in an open configuration and a closed configuration.

A monitoring system for a dual-stage, separated gas/fluid shock strut may comprise a controller and a tangible, non-transitory memory configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform various operations. Said operations may include calculating, by the controller, a secondary chamber nominal pressure, determining, by the controller, a shock strut stroke associated with the secondary chamber nominal pressure, calculating, by the controller, a volume of oil in an oil chamber of the shock strut, calculating, by the controller, a volume of gas in a primary chamber of the shock strut, calculating, by the controller, a secondary chamber inflation pressure, and calculating, by the controller, a volume of oil leaked into the primary chamber of the shock strut.

A monitoring system for a dual-stage, separated gas/fluid shock strut may comprise a controller and a tangible, non-transitory memory configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform various operations. Said operations may include determining, by the controller, a shock strut stroke at which a secondary chamber of the shock strut is activated, calculating, by the controller, a volume of oil in an oil chamber of the shock strut, calculating, by the controller, a volume of gas in a primary chamber of the shock strut, and calculating, by the controller, a volume of oil leaked into the primary chamber of the shock strut.

A shock absorber includes: a cylinder; a piston slidably inserted into the cylinder; a piston rod connected to the piston and extending outside the cylinder; a main valve that generates a damping force; a pilot chamber that applies pressure to the main valve; an introduction passage that introduces the fluid into the pilot chamber; a pilot passage that communicates the pilot chamber and a downstream side of the main valve with each other; and a control valve provided in the pilot passage. In an upstream side of the pilot passage from the control valve, the pilot passage is provided with a first orifice, a first passage provided in parallel with the first orifice, a first check valve that is opened at a predetermined differential pressure and allows a flow toward the control valve through the first passage, and a second orifice.

A control arrangement for a frequency-dependent damping valve having a control pot and an axaially displaceable control piston that axially limits a control space in the control pot and is connected to the damping valve device via an inlet connection. A spring element is arranged between the control piston and the damping valve that introduces a spring force axially into the control piston and the damping valve. When the control piston displaces towards the damping valve and the spring element increases the pressing pressure of the valve disks to increase the damping force. An axial position of a stop in the control arrangement is adjusted by plastic deformation of the pot base. A deformation portion produced by the plastic deformation and a depression partially receives the guide bush. A cross section of the depression corresponds to an outer cross section of the guide bush received in the depression.