Stress-singularity and generalized fracture toughness at the vertex of re-entrant corners

✍ Scribed by Alberto Carpinteri

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 866 KB
• Volume: 26
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(87)90086-5

✦ Synopsis

The object of the present paper is the definition of the size scale effects in structural members with re-entrant corners, The interaction between stress-intensity collapse and ultimate strength collapse at the ligament is emphasized. Such interaction is considerable for small sizes and large corner angles. The results of an experimental analysis on PMMA notched beams are reported and discussed. When the re-entrant corner angle is close to 180" the stress-singularity tends to disappear and the generalized stress-intensity factor assumes the physical dimensions of stress. [F][L]-", On the other hand, when the reentrant corner angle is close to 0' the stress-singularity tends to the well-known LEFM value 112 so that the stress-intensity factor assumes the classical dimensions [F][L]m3'2. The experimental evaluation of the shape-function for generalized stressintensity factors is carried out ou statistical bases by assuming non-linear combinations of LEFM function and ultimate strength function. Due to the accidentally very similar aspect of the two functions, the experimental evaluation of generalized fracture toughness results in particular difficulty.