Real-time study of high-cycle fatigue damage using the averaged speckle dynamics

Abstract

The theory of the method permitting a study of damage accumulation in high-cycle fatigue of reflecting and transparent objects using the time-averaged speckle images is briefly discussed. The formulas that relate the relative displacement vector of the scattering centres to the time-average intensity and the temporal autocorrelation function of this intensity at some observation point are presented. A technique identifying the component of the relative displacement vector as local plastic deformations emerge during fatigue testing is discussed. The issue of real-time recording and processing of the speckle images using the conventional personal computers and special-purpose video systems with function-oriented processors based on homogenous computing environment is discussed. Processors with homogenous architecture allow assurance of the highest possible image processing performance within the order of 10-teraflops/s. The specimens, the optical system, the equipment for fatigue testing, the USB camera and the software used in high-cycle fatigue experiments are discussed. The possibilities and prospects for application of this technique and equipment in evaluation of the remaining life of some object types are discussed. © 2019 Published under licence by IOP Publishing Ltd.