Patent ID: 7377179
Filing Date: 2008-05-27
Classification: G01N

Abstract:
1. An apparatus for analyzing stress, comprising: an element adapted to be mounted to a structure, the element having a material property that degrades over time due to stress cycling of the structure during service operation of the structure; a sensor coupled to the element for detecting a condition of the property of the element, and neither the sensor nor the element have a source of power; a detector for providing wireless power to and wirelessly communicating with the sensor to detect the condition of the property of the element and adapted to ascertain a level of fatigue and prediction of residual life of the structure, the detector being non-invasive, non-destructive, and remote relative to the element and the sensor; wherein the element comprises a plurality of elements, each of which has a different physical property than other ones of the elements to increase a fidelity and sensitivity to fatigue cycle prediction of the structure; and wherein a first fixture is secured to the structure, a second fixture is mounted to the structure, spaced apart from the first fixture and displaceable relative to the first fixture, and the plurality of elements extend between the first and second fixtures, and the physical property is length.