Fatigue Damage Mechanism Analyses of Oriented Sheets of Polymethyl Methacrylate Glasses
To understand the damage mechanism and obtain the fatigue life of the oriented sheets of polymethyl methacrylate (PMMA) glasses, the quasi-static compression tests and the constant amplitude fatigue testing with two notch stress concentration factors are carried out respectively, using the CSS44100 electromechanical universal materials testing machines and a MTS servohydraulic testing machine. The damage region and fracture section of the deformed and failed sheet samples are examined with the aid of an optical microscopy. The results show that, 1) the oriented PMMA glasses drawn through vertical bi-direction have remarkable thermomechanical anisotropic characteristic, that is, it has the higher hardness and strength along the normal direction of the sheet panel, it will burst out and scatters into bigger pieces under the perforation; 2) the S-N curve of the oriented sheet specimens shows that its fatigue life is not sensitive on the notch at lower amplitude stress levels; and 3) the crack initiation of the oriented PMMA glasses often originates the interbeds area or mid region of the notch edge under fatigue cycle loading.
Ahmad Kamal Ariffin, Shahrum Abdullah, Aidy Ali, Andanastuti Muchtar, Mariyam Jameelah Ghazali and Zainuddin Sajuri
W. G. Guo et al., "Fatigue Damage Mechanism Analyses of Oriented Sheets of Polymethyl Methacrylate Glasses", Key Engineering Materials, Vols. 462-463, pp. 36-41, 2011