Using electronic speckle interferometry for the accurate determination of the residual stresses in welded joints and structural members

摘要

The solution of problems associated with the need to increase the reliability and longevity of welded structures requires the evaluation of the residual stresses formed during manufacture and service. In the group of the currently available methods for experimental determination of the residual stresses in the structures~(1-5), special attention has been given to the method of the probing hole~2, in which a continuous or blind hole is drilled at the investigated point on the surface of the object, and the strains caused by elastic unloading of the volume of the material during the release of residual stresses are measured in the vicinity of the hole. The stresses are measured using special strain gauges bonded in accordance with the specific procedure. The values of these strains are subsequently used to calculate the main directions and appropriate values of the residual stresses, using calculation or analytical models. A number of difficulties associated with the application of the bonded strain gauges can be eliminated using laser interferometry methods.