Applicability of the Chevron-Notch Technique for Fracture Toughness Determination in Glass

0177886 - UFM-A 20023072 RIV GB eng C - Konferenční příspěvek (zahraniční konf.)
Dlouhý, Ivo - Chlup, Zdeněk - Boccaccini, A. R.
Applicability of the Chevron-Notch Technique for Fracture Toughness Determination in Glass.
Fracture Mechanics Beyond 2000 /14./. Vol. 1. Sheffield: EMAS Publications, 2002 - (Neimitz, A.; Rokach, I.; Kocanda, D.; Gološ, K.), s. 481-489
[European Conference on Fracture /14./. Cracow (PL), 08.09.2002-13.09.2002]
Grant CEP: GA AV ČR IAA2041003; GA MŠMT ME 491
Výzkumný záměr: CEZ:AV0Z2041904
Klíčová slova: fracture toughness * glass
Kód oboru RIV: JH - Keramika, žáruvzdorné materiály a skla

The applicability of the chevron-notch (CN) three-point bend 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 fracture toughness determination in terms of average values and data variability according to Weibull and Student's t statistics. Testing with CN geometry showed that annealing of specimens at a temperature (550oC) 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.
Trvalý link: http://hdl.handle.net/11104/0074789