DISPLACEMENT AND STRAIN MEASUREMENT BY DIGITAL IMAGE CORRELATION

Abstract

The aim of this thesis is the measurement of a test specimen by image correlation methods for the purpose of extracting displacement measurements and subsequently strain measurements when the loads will be apply. The measurement of displacements and displacement gradients (strains) has always been an important topic in the evaluation of material properties, such as material strengths or fracture parameters and in experimental stress analysis. Optical techniques such as moiré interferometry, holography and speckle inteferometry have been proven to be matured techniques to analyze macroscopic parameters and are being applied successfully in many different applications. However, all the interferometric techniques have stringent requirements for system’s stability. Moreover, the processing of fringe patterns is laborious and time-consuming. This technical difficulty has raised many researchers’ attention and computerized procedures have been developed to automate the processing ...