摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A drain plug assembly that has particular application for sealing a drain hole in a high voltage battery compartment on a vehicle. The plug assembly includes a plug that inserted into the drain hole. The plug assembly further includes a return spring coupled to the plug and causing the plug to be biased into the drain hole. The plug assembly also includes at least one shape memory alloy device coupled to the plug and a support structure. The SMA device receives an electrical current that causes the device to contract and move the plug out of the drain hole against the bias of the return spring.
摘要:
An active headrest adapted for use with a rear seat, including a translatable, conformable, or otherwise reconfigurable shell, an active material actuator disposed within and drivenly coupled to the shell, and preferably including a linkage system fixedly coupled to the seat and/or shell, wherein the actuator is operable to cause the headrest to achieve one of a plurality of achievable positions.
摘要:
A mirror assembly includes a reflective surface disposed within a housing, and an actuator in operative communication with at least a portion of the housing, wherein the actuator and/or housing comprises an active material element configured to cause or selectively enable the housing and surface to be manipulated.
摘要:
A method of controlling and/or predicting the remaining useful life of an active material actuator, such as a shape memory alloy wire, includes obtaining historical actuation data of an inherent system variable, such as electrical resistance, over a secondary variable, such as time, determining a normal operating envelope having upper and lower bounds based on the data, determining a current profile for a given actuation cycle, and comparing the shape of the current profile to the envelope to determine an out-of-bounds event.
摘要:
A shape memory alloy (SMA) heat engine includes a first rotatable pulley, a second rotatable pulley, and an SMA material disposed about the first and second rotatable pulleys and between a hot region and a cold region. A method of starting and operating the SMA heat engine includes detecting a thermal energy gradient between the hot region and the cold region using a controller, decoupling an electrical generator from one of the first and second rotatable pulleys, monitoring a speed of the SMA material about the first and second rotatable pulleys, and re-engaging the driven component if the monitored speed of the SMA material exceeds a threshold. The SMA material may selectively change crystallographic phase between martensite and austenite and between the hot region and the cold region to convert the thermal gradient into mechanical energy.
摘要:
Active seal architectures adapted for producing a variable sealing and/or closing force between a closure panel and perimeter, includes a mounting clip, a flexible outer layer fixedly connected to the clip, defining an interior space, and longitudinally extending along the perimeter; and an interior structure comprising and reconfigurable by an active material disposed within the space, and operable to impart differing first and second forces upon the layer and panel when the material is activated and deactivated respectively.
摘要:
A system for and method of providing overload protection for an active material actuator, includes a magnetically functioning mechanism comprising, for example, one or more permanent or electromagnets, and/or magnetorheological fluid, and configured to produce a holding force less than the capacity of the actuator, and more preferably, a modifiable holding force responsive to load influencing conditions.