Method and apparatus for detecting stress in an object
AssigneeSira Limited
InventorsMartin J. Webber, Gordon R. Hopkinson
Life of this patent
Estimating the term…
Abstract
Apparatus for measuring stress at a point on an object comprising: means for applying a cyclically varying load of period T to the object; detector means for collecting and measuring thermal radiation from said point over a sample time interval t, wherein t<T; means for determining the phase of the first interval t with respect to the cyclic variation of thermal radiation produced by said point in response to said applied load and, from said collected and measured value of thermal radiation and said phase, for providing a measure of stress at said point.
Claims26
A method of measuring stress simultaneously at a plurality of points on an object, comprising the steps of:
- applying a cyclically varying load of period T to the object, collecting and measuring thermal radiation from a plurality of said points over a sample time interval t, wherein t<T, determining the phase of the first sample time interval t with respect to the cyclic variation of thermal radiation produced by each point in response to said applied load, and, from said collected and measured value of thermal radiation and said phase, providing a measure of stress at each point.
A method of measuring stress simultaneously at a plurality of points on an object, comprising the steps of:
- applying a cyclically varying load of period T to the object, collecting and measuring thermal radiation from a plurality of said points over a plurality of sample time intervals t, wherein t<T, and, from said collected and measured values of thermal radiation determining the peak thermal radiation, and from said peak radiation and from said cyclically varying load, providing a measure of stress at each point.
An apparatus for measuring stress simultaneously at a plurality of points on an object, comprising:
- means for applying a cyclically varying load of period T to the object, detector means for collecting and measuring thermal radiation from said plurality of points over a sample time interval t, wherein t<T, means for determining the phase of the sample time interval t with respect to the cyclic variation of thermal radiation produced by said points in relation to said applied load, and, from said collected and measured value of thermal radiation and said phase, providing a measure of stress at said points, said detector means comprising an array of detectors, and means for interrogating in sequence each of the detectors to determine the value of thermal radiation measured by each detector.
An apparatus for measuring stress simultaneously at a plurality of points on an object, comprising:
- means for applying a cyclically varying load of period T to the object, detector means for collecting and measuring thermal radiation from said points over a plurality of sample time intervals t, wherein t<T, and, from said collected and measured values of thermal radiation, determining the peak thermal radiation, and from said peak thermal radiation and said load, providing a measure of stress at each said point, said detector means comprising an array of detectors, and means for interrogating in sequence each of the detectors to determine the value of thermal radiation measured by each detector.
Dependencies are inferred from the claim text.