A head unit system for controlling motion of an object includes a set of secondary object sensors and head unit devices that include shear thickening fluid (STF) and a chamber configured to contain a portion of the STF. The chamber further includes a front channel and a back channel. The head unit system 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.

A head unit system for controlling motion of an object includes a secondary object sensor and a head unit device that includes a shear thickening fluid (STF) and a chamber configured to contain a portion of the STF. The chamber further includes an alternative reservoir and a piston compartment. The head unit system further includes a piston housed at least partially radially within the piston compartment. The piston includes a piston bypass 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.

There is provided a device for mitigating physical shock to an object to which it is attached. The device includes a body having a through-bore extending from one end to another. A sliding mass is positioned within the bore hole such that it can slide within the through-bore. A first end cap is slidingly disposed in said body hollow volume at one end of the body, and a second end cap is slidingly disposed at the other. End cap and body combination is filled with a liquid. Responsive to an impact along the body axis, one of the end caps is partially displaced into the body and at least a portion of the liquid changes phase from a liquid phase to a vapor phase.

A method of attenuating annular pressure buildup within a wellbore. The method includes accessing a wellbore, with the wellbore having an annulus disposed between first and second strings of casing. The method also includes placing a column of cement around the second string of casing generally below the first string of casing. The method further includes pumping a fluid mixture into the annulus, forming a fluid column. The fluid mixture comprises a carrier fluid, and a plurality of compressible particles dispersed in the carrier fluid. Each of the compressible particles is fabricated to partially collapse in response to thermal expansion of the fluid mixture. The method also includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore. The method additionally includes at least partially sealing the annular region along at least one depth above the column of cement to inhibit vertical migration of the compressible particles.

A shock mitigator is provided for mitigating physical shock to a joined object. The shock mitigator includes a hollow body capable of being affixed to the object and having two ends defining a volume therein. A cavitating liquid is disposed in the hollow body volume. At least one end cap is slidingly disposed within the hollow body to seal at least one end thereof. When exposed to a physical shock the cavitating liquid changes phase from a liquid to a vapor, absorbing energy from the shock.

In a fluid-filled cylindrical vibration damping device, an inner shaft member and an outer shaft member are elastically linked by a main rubber elastic body, and fluid chambers in which a fluid is filled are provided to be in communication with each other through an orifice path. The fluid filled in the fluid chambers is a magnetic functional fluid. The fluid-filled cylindrical vibration damping device includes a magnetic unit generating a magnetic field through power conduction. Magnetic path formation members to which the magnetic field is applied by the magnetic unit are arranged on sidewall portions on two facing sides in the orifice path. A magnetic flux concentration part 46 is provided at at least one the magnetic path formation members. A dimension of the magnetic flux concentration part in a length direction of the orifice path is reduced toward an inward side in a facing direction.

A head unit device for controlling motion of an object includes shear thickening fluid (STF), an alternative STF (ASTF), and a chamber configured to contain a portion of the STF and the ASTF. The chamber further includes a piston compartment and an alternative reservoir. The head unit device further includes a reservoir injector configured within the chamber, and a piston housed at least partially radially within the piston compartment. The chamber further includes a set of fluid flow sensors and a set of fluid manipulation emitters to control the reservoir injector to adjust flow of the ASTF from the alternative reservoir to the piston compartment to cause selection of one of a variety of shear rates for a mixture of the STF and the STF within the piston compartment.

A method and system of absorbing the shock force of an impact including a substance which absorbs at least part of the shock force of an impact by changing phase from a first phase to a second phase, and back to the first phase on cessation of the impact force, and a container for the substance for protecting a person from an impact injury.

A linear motion assembly having a static coefficient of friction, S, as measured between an inner component and an outer component, and a dynamic coefficient of friction, .sub.D, as measured between the inner component and the outer component, wherein .sub.S/.sub.D is less than 2.0, such as less than 1.9, less than 1.8, less than 1.7, or even less than 1.6.

Damper includes a housing having proximal and distal ends, a first attachment point proximate the distal end of the housing, a rod having proximal and distal ends at least partially disposed within the housing and moveable relative to the housing between an extended position and a compressed position, a second attachment point proximate the proximal end of the rod, a piston joined to the rod within the housing proximate the distal end of the rod, the piston including a bypass groove having a flow area defined therein to allow fluid to flow from a first side of the piston to an opposing side of the piston, and a first washer disposed proximate a first end of the piston and at least partially covering the flow area of the bypass groove.