Experimental Evaluation of Stress-Optical Constants by Caustics

• Published in: International journal of fracture Vol. 171; no. 1; pp. 85 - 90
• Main Authors: Badalouka, B., Papadopoulos, G. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2011; Springer; Springer Nature B.V
• Subjects: Alkalies; Automotive Engineering; Axial stress; Caustics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Civil Engineering; Classical Mechanics; Constants; Crack tips; Cracks; Exact sciences and technology; Fracture mechanics; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Letters in Fracture and Micromechanics; Materials Science; Mechanical contact (friction...); Mechanical Engineering; Physics; Polymethyl methacrylate; Polymethyl methacrylates; Solid mechanics; Stress intensity factor; Stress intensity factors; Stresses; Structural and continuum mechanics; Three dimensional; stress intensity factors; cracks; caustics; contact problems; Plexiglas; Optical constant; Methyl methacrylate polymer; Mechanical contact; Experimental study; Triaxial stress; Edge crack; Caustic surface; Stress intensity factor; Precracked specimen; Crack tip; Structural analysis
• ISSN: 0376-9429; 1573-2673
• DOI: 10.1007/s10704-011-9615-9

A study of the experimental evaluation of the stress-optical constants accurate values was undertaken by the method of caustics. A series of experiments were performed in single edge-cracked specimens made of Plexiglas (PMMA). It was found that the values of the stress-optical constants were varied with the load and the thickness of the specimens. This means that a three-dimensional stress conditions hold in the neighbourhood of the crack tip. The accurate stress intensity factor K I can be experimentally evaluated by accurate values of the stress-optical constants. The present work illuminates the complicated problem of the changing state of stress around cracks and establishes the limits of applicability of the method of caustics for the evaluation of stress intensity factors and the triaxiality factor at crack tip