Patent ID: 11906488
Assignee: HILL ENGINEERING, LLC
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for measuring residual surface stress in a component under test having one or more strain gauges mounted along predetermined axes and operationally coupled to a strain measurement system which generates an output proportional to changes in strain as a stress state of the component under test is changed, the method comprising: locating a machining appliance and the component under test in appropriate relative positions so that cuts are made into a surface of the component under test (CUT); probing a surface proximate to a region of the intended cuts and mapping a surface profile of the region; locating a point determined by placement of the one or more strain gauges near which material is to be removed from the CUT so that pre-existing residual surface stress at the point is altered; machining a feature starting at the point, and at a predetermined angle relative to the surface based on the mapped surface profile, wherein the machining includes a plurality of light cuts without introducing additional surface stress from the machining, so that residual surface stress in an area proximate to the feature is interrupted from a bulk of the CUT, and wherein the predetermined angle is maintained throughout the feature during the machining and based on the mapped surface profile; and measuring a change in surface strain resulting from the machining for use in calculating residual surface stress of the CUT.