The estimate of the effect of z-pins on the strain release rate, fracture and fatigue in a composite co-cured z-pinned double cantilever beam

• Published in: Composite structures Vol. 68; no. 1; pp. 53 - 63
• Main Authors: Byrd, Larry W., Birman, Victor
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2005; Elsevier Science
• Subjects: Applied sciences; Composites; Crack; Double-cantilever beam; Exact sciences and technology; Fatigue; Forms of application and semi-finished materials; Fracture; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Physics; Polymer industry, paints, wood; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Technology of polymers; Z-pinned joint; Fatigue; Z-pinned joint; Fracture; Double-cantilever beam; Crack; Energy release; Propagation velocity; Volume fraction; Strain energy; Crack arrest; Fatigue fracture; Crack propagation; Pinned joint; Standard test; Curing(plastics); Fracture toughness test; Double cantilever beam; Strain rate
• ISSN: 0263-8223
• DOI: 10.1016/j.compstruct.2004.02.014

The paper illustrates the effect of z-pins on the strain energy release rate in composite co-cured double cantilever beams (DCB) subject to a standard fracture toughness test. The conclusions obtained as a result of the solution illustrate that z-pins can provide drastic enhancement in fatigue and fracture properties of a co-cured z-pinned composite joint, even if their volume fraction is low. The strain energy release rate for loading and geometry combinations that do not result in immediate fracture was significantly reduced as a result of using z-pins. This slows the rate of the crack propagation if it is governed by the Paris law. Moreover, z-pins can completely arrest the crack. Although the analysis was performed for DCB specimens, the conclusions can be extrapolated to a general case of co-cured z-pinned joints.