Reliability of the Chevron-notch technique for fracture toughness determination in glass

0178001 - UFM-A 20033010 RIV GB eng J - Článek v odborném periodiku
Boccaccini, A. R. - Rawlings, R. D. - Dlouhý, Ivo
Reliability of the Chevron-notch technique for fracture toughness determination in glass.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 347, 1/2 (2003), s. 102-108. ISSN 0921-5093. E-ISSN 1873-4936
Grant CEP: GA AV ČR IAA2041003
Výzkumný záměr: CEZ:AV0Z2041904
Klíčová slova: Fracture toughness * Glass * Chevron-notch technique
Kód oboru RIV: JH - Keramika, žáruvzdorné materiály a skla
Impakt faktor: 1.365, rok: 2003

The applicability of the chevron-notch (CN) three-point bending test for determining the fracture toughness (KIc) of borosilicate glass was studied. As-received specimens with straight sharp notch were also tested in three-point bending for comparison purposes. It was found that both chevron and straight notched specimen geometries were equally suitable for the determination of fracture toughness in terms of average values and data variability according to Weibull and StudentŽs t -statistics. Further testing with CN geometry showed that annealing of specimens at a temperature (550 8C) higher than the glass transformation temperature led to a lower value of KIc. The difference in mean fracture toughness values (0.75 and 0.64 MPam1/2 before and after annealing, respectively), was ascribed to the different level of compressive residual stresses in the samples. The StudentŽs t -test was applied to confirm the statistical significance of the different KIc values measured. These results demonstrate that the CN technique is well suitedfor reproducible and accurate determination of KIc values in glass.
Trvalý link: http://hdl.handle.net/11104/0074899