The influence of specimen size and mode of loading on the fracture of graphite

✍ Scribed by P. Marshall; E.K. Priddle

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 369 KB
• Volume: 11
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(73)90329-1

✦ Synopsis

Predictions of graphite strength under tensile and bending loads using fracture mechanics have been compared with experimental data and the currently used Weibull method. The methods are comparable for similar specimens but Weibull's method fails to predict the observed effects for large specimen size differences. Discussion of this failure indicates that the basis of Weibull's theory (a volumetric flaw distribution) may be inapplicable to failure of materials resulting from surface defects. Examination of graphite rods has shown a defect size distribution across the material which leads to prediction of lower strengths for the inner rod regions with respect to the outer regions. Experimental results follow the predicted trend but it is considered that further examination of the fracture mechanics technique must be undertaken before it can be recommended as a design method for graphite materials.