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 thermosetting polymer composite composition (such as thermosetting SMC composition) or a thermosetting adhesive composition containing reduced-volume hollow shape-memory alloy particles in the thermosetting polymer composite composition or adhesive composition experiences little or no volume loss during a curing at a temperature above the transformation temperature for the particles.

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

Abstract: A thermosetting polymer composite composition (such as thermosetting SMC composition) or a thermosetting adhesive composition containing reduced-volume hollow shape-memory alloy particles in the thermosetting polymer composite composition or adhesive composition experiences little or no volume loss during a curing at a temperature above the transformation temperature for the particles.

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: 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: An actuator configured for tunable stiffness control and method is provided. The actuator includes a plurality of stiffness elements, one or more of the stiffness elements including a shape memory alloy (SMA). At least one of the elements has a stiffness characteristic different from another of the stiffness elements. The stiffness elements are actuable individually or in combination to provide an intermediate actuation output, which may be provided by partially transforming the smart material of one or more stiffness elements during actuation. Two or more of the stiffness elements may be actuable in combination to provide a combined output which may be non-linear, or may be functionally substitutional for an individual output of another stiffness element. The actuator may be actuable to provide a first and second output for the substantially same input, or may be selectively actuable to offset degradation of one or more of the stiffness elements.

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 method of modeling a Shape Memory Alloy (SMA) element to predict a response of the SMA element includes obtaining the resistivity of the SMA element over a range of a physical property of the SMA element; correlating variations in the obtained resistivity with respect to the physical property of the SMA element to identify behavioral differences in the resistivity for the different phases of the SMA element; calculating a rate of change of the resistivity of the SMA element over a period of time; calculating the derivative of the rate of change in the resistivity of the SMA element over the period of time; and comparing real time data of the physical property to the derivative of the rate of change to predict the response of the shape memory alloy element.

Abstract: A method of improving the speed and consistency of response of a shape memory alloy actuator under varying ambient and operating conditions. The method includes probing the shape memory alloy by periodically determining an electric signal strength at which it will undergo forward or reverse phase transformation, while avoiding actual phase transformation; priming the shape memory alloy by bringing it close to phase transformation; initiating phase transformation; and maintaining the shape memory alloy in the phase transformed state. The electric signal strength at which the shape memory alloy will undergo phase transformation is determined by identifying a cusp feature in the electric resistance of the shape memory alloy which closely precedes phase transformation.

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: Tunable structural member for a vehicle generally comprises an active material adapted to selectively undergo a change in at least one attribute in response to an activation signal. The change in the at least one attribute results in a change in the mechanical properties of the tunable structural member. Active materials generally include shape memory alloys, shape memory polymers, magnetorheological fluids and elastomers, piezoelectrics, electroactive polymers, and the like.

Abstract: A reconfigurable tool and/or die geometry and methods of use generally comprise forming at least a portion of a shape defining surface with a shape memory material. In response to an activation signal, the shape memory material changes geometry of the shape defining surface to provide a means for forming parts with different geometries from the same tool and/or die. In an alternative embodiment, an insert for a tool and/or die can be used, wherein the insert has at least a portion of its shape defining surface formed of a shape memory material. Also disclosed are processes for forming a first part with a defined geometry and a second part with a defined geometry different from the first part defined geometry using a reconfigurable tool and/or die as well as a reconfigurable insert with a standard tool and/or die.