Nondestructive evaluation of the fatigue damage accumulation process around a notch using a digital image measurement system

• Published in: Optics and lasers in engineering Vol. 41; no. 3; pp. 477 - 487
• Main Authors: Dı́az, F.V., Armas, A.F., Kaufmann, G.H., Galizzi, G.E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2004; Elsevier
• Subjects: Applied sciences; Biological and medical applications; Cyclic deformation; Digital image measurement; Exact sciences and technology; Fatigue; Fundamental areas of phenomenology (including applications); Industrial applications; Light scattering; Low-cycle fatigue; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Optics; Physics; Plastic damage; Digital image measurement; Cyclic deformation; Plastic damage; Light scattering; Low-cycle fatigue; Notched test piece; Mechanical properties; Chromium additions; Plastic deformation; Digital image; Laser beam applications; Experimental study; Optical set up; Low cycle fatigue; Non destructive method; Notch sensitivity; CCD camera; Optical method; Fatigue cracks
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/S0143-8166(03)00018-6

The fatigue damage accumulation process around a notch is studied using a noncontact digital image measurement system. This system incorporates a contrast correlation method to evaluate the level of plastic damage at each point of the studied area of the specimen from two images acquired before and after the introduction of fatigue deformation. A compact tension specimen of 304 stainless steel with a notch radius of 1 mm is analyzed during the first 1000 cycles of the crack growth stage. During this period, the externally given work not only impels the crack growth and its local plastic zone but also generates plastic damage around the notch. The obtained results are used to explain the behavior of cracks emanating from notches.