Optical Metrology and Optoacoustics Techniques for Nondestructive Evaluation of Materials

Abstract

In this chapter, the authors consider the Optical MetrologyOptical metrology and Optoacoustics Optoacoustics techniques as a powerful and versatile tool for solving problems of nondestructive evaluationNondestructive evaluation of materials and structural elementsStructural element. The chapter contains a summary of all subsequent six chapters. Methods for single- and dual-wavelength two- and three-step temporal phase shifting interferometryPhase shifting interferometry (PSI) with unknown phase shiftsUnknown phase shift are described in Chap. 2 . In Chap. 3 , it is shown that these methods can be successfully applied to determine the surfaceSurface roughnessRoughness parameters of materials and to study the development of the fatigue process zoneFatigue process zone (FPZ) in thin metal CT-specimensCompact tension specimen (CT-specimen) under cyclic loads and the fatigue macrocrackFatigue macrocrack initiationMacrocrack initiation. Chapter 4 is devoted to new methods of two-stepTwo-step phase shifting digital speckle pattern interferometry (DSPIDigital speckle pattern interferometry (DSPI)) and correlation DSPICorrelation DSPI, as well as to application of these techniques for studying surface deformationSurface deformations fields in materials and detection of surfaceSurface defects in metal and composite specimens. New methods of Speckle MetrologySpeckle metrology are proposed in Chap. 5 . In particular, the method for extraction the unknown phase shiftUnknown phase shift between speckle interferogramsSpeckle interferogram (SI) using sample Pearson correlation coefficientSample Pearson correlation coefficient (SPCC) and the method of three-frameThree-frame digital speckle pattern interferometryDigital speckle pattern interferometry (DSPI) that is used in fringe projection interferometryFringe projection interferometry are described in this chapter. Chapter 6 is devoted to methods for analyzing the speckle patternsSpeckle pattern of materials surfacesSurface. In particular, the optical-digital speckle correlationOptical-digital speckle correlation (ODSC) and digital image correlationDigital image correlation (DIC) methods for assessment of the stress–strain stateStress-strain state of materials, as well as the method for detection of subsurface defectsSubsurface defect excited by ultrasonic wavesUltrasonic wave (US wave) are considered and analyzed. The mathematical modeling of the physical phenomena of elastic wave interactionElastic wave interaction between the crackCrack and interfaces is considered in Chap. 7 . The modeling is based on the Wiener–Hopf method, which makes it possible to find the necessary characteristics of the field with a given accuracy and provide a simple physical interpretation of their properties. Thus, combining Optical MetrologyOptical metrology and OptoacousticsOptoacoustics with mathematical modeling of elastic waves interacting with interface defectsInterface defect become the powerful tools for nondestructive testingNondestructive testing (NDT) and technical diagnosticsTechnical Diagnostics (TD) of materials and products.