On the stability of cracks in flexure specimens

✍ Scribed by L. S. Sigl

• Publisher: Springer Netherlands
• Year: 1991
• Tongue: English
• Weight: 626 KB
• Volume: 51
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00045810

✦ Synopsis

Maps bounding stable and unstable crack propagation in three-point flexure beams are established using stability criteria for cracking in brittle solids. Results are presented for straight through and chevron notched cracks at different loading conditions, i.e. at constant load rate, crosshead speed and specimen deflection rate. Stability is governed by a number of variables, such as the loading speed, the compliance ratio of an unnotched beam and the testing machine, the fracture toughness and geometry of the flexure specimen, and the velocity and shape of the crack. For each loading environment these variables merge into a single nondimensional parameter characterizing the stability of a propagating crack. Implications for precracking and toughness testing are outlined and some guidelines for the proper design of cracking experiments are finally established.