Abstract: An actuator comprising an SMA element and a thermally responsive element that adjusts bias stress improves high ambient temperature operation.

Abstract: An actuator comprising an SMA element and a thermally responsive element that adjusts bias stress improves high ambient temperature operation.

Abstract: A device for cycling a component between a first condition and a second condition includes an element and a reset apparatus connected to and driven by the element. The element is formed from a shape memory alloy, wherein the alloy is transitionable between a martensite crystallographic phase and an austenite crystallographic phase in response to a thermal energy source. The apparatus is actuatable by the element from an initial state in which the alloy has the martensite phase and the component is in the first condition, to an actuated state in which the alloy has the austenite phase and the component is in the second condition. The apparatus is resettable from the actuated state to a reset state in which the alloy transitions from the austenite to the martensite phase while the component is in the first condition, and further resettable from the reset state to the initial state.

Abstract: A clutch for selective transmission of torque and power, utilizing pairs of coded arrays of permanent magnets affixed respectively to the driving member and the driven member. A shape memory alloy actuator brings to driving member and the driven member into proximity to engage the clutch via a higher-order mutual magnetic correspondence between the coded magnetic regions of the permanent magnet arrays. Also provided is a clutch having a magnetorheological fluid between the driving member and the driven member, to increase the torque and power transfer through the fluid when its viscosity is increased by the magnetic field of the arrays in proximity. Sets of corresponding teeth on the driving member and driven member mesh when the rotation of the members is synchronized, providing positive direct drive to prolong the service life of the fluid.

Abstract: The geometric stiffness of structural sheet metal panels, such as those employed in motor vehicles, may be increased, without major increase in the mass of the panel, by application of a coating of a structural polymer. However conventional means of applying such a polymer layer require multiple applications to achieve a desired thickness. By incorporating magnetic particles in a resin, and subjecting the resin to a magnetic field as it is applied, the desired thickness may be achieved in a single application. Embodiments appropriate to the application of such a resin to both magnetic and non-magnetic materials are described.

Abstract: An actuator adaptable for tunable stiffness control is provided, including a stiffness element including a smart material, and a magnetically actuated biasing element. The biasing element is configured to provide a non-linear or variable bias force on the stiffness element. The smart material may be a shape memory alloy, and the biasing element may be configured to include a permanent magnet, an electromagnet, a magnetic shape memory alloy, or a combination of these. The stiffness element and the biasing element of the actuator may be configured in parallel with each other, or may be configured in series with each other. The bias force may be provided in response to an input defined by one or more of fatigue, functional degradation, aging, shakedown, elongation, and operating environment of the stiffness element of the actuator, or defined by an operating characteristic of the actuator or a device controlled by the actuator.

Abstract: A stiffness control system and apparatus includes one or more stiffness elements which are each activated by a smart actuator including a smart material which may be one of a shape memory alloy (SMA), a magnetorheological (MR) fluid, an electrorheological (ER) fluid, and a piezo-stack. The stiffness control system includes a first and second interface adaptable to transmit input loads and a plurality of stiffness elements. A first stiffness element is operatively connected to the first and second interfaces and is continuously responsive to a change in system operating characteristics including input loads. A second stiffness element is selectively activated by the smart actuator so as to selectively respond to a change in system conditions. The continuous response of the first stiffness element can be selectively combined with the activated response of the second stiffness element to dynamically control system stiffness.

Abstract: A hinge is provided for pivotably mounting a first attachment member to a second attachment member. A first member is attached to the first attachment member. A second member pivotably engages the first member and is disposed within the first member. The second member is configured for attachment to the second attachment member. An annular cavity is disposed between the first member and the second member. The annular cavity maintains a spaced relationship between the first member and the second member. A magnetorheological fluid is disposed within the annular cavity. A magnetic field generating member is configured to produce a change in a shear strength of the magnetorheological fluid within the annular cavity. The magnetorheological fluid applies a variable resistance torque between the first member and the second member for controlling a pivoting motion between the first member and the second member.

Abstract: A real-time continuous damping module includes a flow channel that is configured to allow fluid to flow between a first chamber and a second chamber of a cylindrical tubular member when a pressurizing device exerts a pressure on the fluid within the first chamber. A variable damper assembly is configured to control a flow of fluid through the flow channel. The variable damper assembly includes a damper configured to variably obstruct an opening of the flow channel. A magnetic shape memory element is configured to variably control a position of the damper within the opening of the flow channel. The magnetic shape memory element exhibits changes in shape when exposed to a magnetic field. An electromagnetic device regulates the magnetic field for variably controlling the position of the damper within the flow channel by changing the shape of the magnetic shape memory element.

Abstract: A stiffness control system and apparatus includes one or more stiffness elements which are each activated by a smart actuator including a smart material which may be one of a shape memory alloy (SMA), a magnetorheological (MR) fluid, an electrorheological (ER) fluid, and a piezo-stack. The stiffness control system includes a first and second interface adaptable to transmit input loads and a plurality of stiffness elements. A first stiffness element is operatively connected to the first and second interfaces and is continuously responsive to a change in system operating characteristics including input loads. A second stiffness element is selectively activated by the smart actuator so as to selectively respond to a change in system conditions. The continuous response of the first stiffness element can be selectively combined with the activated response of the second stiffness element to dynamically control system stiffness.