Determination of fracture toughness from thin side-grooved specimens

✍ Scribed by P.K. Poulose

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 868 KB
• Volume: 26
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(87)90197-4

✦ Synopsis

Methods of determining fracture toughness from specimens of thickness lower than that required by ASTM Standard, E399 were studied using aluminum and titanium alloy specimens. In thin specimens in which crack growth initiation is clearly marked by a sudden change in the slope of the load-displacement curve, the stress intensity at the crack growth initiation point was found to be the same as the standard fracture toughness value. Crack growth initiation was more easily identifiable in the aluminum alloys than in the titanium alloy, although the latter was more brittle. Side grooves enable identification of crack growth initiation in thinner specimens, reducing considerably the thickness requirement for fracture toughness testing. A nearly straight crack front was found to be essential for obtaining reproducible results. Sharp and deep side grooves produced fatigue cracks leading at the edges.