| 摘要 |
A device for dampening vibrational energy propagated along a beam has contact surfaces made of a shape memory alloy. The dampening device is positioned either within a hollow beam, or around and outer surface of the beam to be dampened. When the device is placed within a hollow beam, the device has an outer dimension that is slightly larger than an inner diameter of the beam, thereby placing the shape memory alloy contact surfaces in a selected pre-stressed condition. If the dampening device is placed around an outer surface of the beam, the device has an inner diameter that is slightly smaller than an outer diameter of the beam, thereby placing the shape memory alloy contact surfaces in a selected pre-stressed condition. Preferably, the contact surfaces are pre-stressed at a level sufficient to be near the threshold of the pseudo-elastic plateau region of the alloy's stress-strain property curve. Alternatively, the SMA may be selected and subjected to a heat processing treatment such that it is in the martensitic phase at a desired range of temperatures, in which it is believed the device will be used. As a result, the device made of SMA exhibits superelastic properties when used in the selected range of temperatures, omitting the need to pre-stress the SMA elements.
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