Embedded flaws for crack path control in composite laminates

作者：Orifici Adrian C^*; Wongwichit Phisit; Wiwatanawongsa Nuth

来源：Composites Part A: Applied Science and Manufacturing , 2014, 66: 218-226.

DOI：10.1016/j.compositesa.2014.08.012

• Laminates
• Delamination
• Fracture
• Mechanical testing

An experimental investigation was conducted on using small flaws purposefully introduced into composite laminates to control growth of interlaminar cracks and through-thickness crack branching. Mode I crack growth specimens were used to study branching through 0 degrees, 90 degrees and 45 degrees plies. The results showed that crack growth through 0 degrees plies could be promoted by a ply gap, but this was not as controllable as combining a ply gap with a pre-crack to create a "crack branch flaw". Crack branching through 45 degrees plies could be controlled using crack branch flaws, and also promoted controllably using ply gaps. Crack branching through 90 degrees plies was seen without any flaws, but was better controlled with embedded delaminations. Using these outcomes, crack branching through two quasi-isotropic laminates was demonstrated. The results have application to improved damage tolerance and fracture toughness, by taking advantage of high toughness crack growth mechanisms.

• 出版日期2014-11