In this work, fracture behavior of multilayered unidirectional graphite/epoxy composite (T800/3900-2) materials is investigated. Rectangular coupons with a single-edged notch are studied under geometrically symmetric loading configurations and impact loading conditions. The notch orientation parallel to or at an angle to the fiber orientation is considered to produce mode-I or mixed-mode (mode-...

An assessment is made here of the role played by the micropolar continuum theory on the cracked Brazilian disc test used for determining rock fracture toughness. By analytically solving the corresponding mixed boundary-value problems and employing singular-perturbation arguments, we provide closed-form expressions for the energy release rate and the corresponding stress-intensity factors for bo...

This paper presents a new method for continuum based shape sensitivity analysis for a crack in a homogeneous , isotropic, and linear-elastic body subject to mixed-mode (modes I and II) loading conditions. The method is based on the material derivative concept of continuum mechanics, domain integral representation of an interaction integral, and direct differentiation. Unlike virtual crack exten...

Denda and Marante [1] have developed the boundary element method for the mixed mode fracture analysis of multiple curvilinear cracks in the general anisotropic solids in two dimensions for which in-plane Mode I, II, and out-of-plane Mode III, of fracture are coupled. They have developed the crack tip singular element (CTSE) to model any curvilinear cracks, including center and edge cracks. The ...

Adhesive joints are continuously emerging as candidate to replace traditional fastening systems, such as riveting or welding, in primary structural applications. A wide class of components belonging to electronic, automotive and aerospace industries contains adhesive joints, however, the reliability during service constitutes a major technical problem as these contain flaws. Therefore, their us...

A planar crack generically segments into an array of "daughter cracks" shaped as tilted facets when loaded with both a tensile stress normal to the crack plane (mode I) and a shear stress parallel to the crack front (mode III). We investigate facet propagation and coarsening using in situ microscopy observations of fracture surfaces at different stages of quasistatic mixed-mode crack propagatio...

Interfacial fracture of adhesive bonds undergoing large-scale yielding is studied using a combined experimental/ finite-element approach. The full range of in-plane mode mixity is produced over bond thickness ranging from 30 to 500 lm using the scarf and the ENF joint geometries. Novel techniques for introducing pre-cracks and surface decoration, together with in situ observations, facilitate a...

In this paper, we report on an experimental study of spontaneous, mixed-mode, crack propagation in weakly bonded similar and dissimilar materials. A unique experimental configuration is proposed to induce spontaneous crack growth events along the interfaces. The cracks nucleate from tiny circular holes and are triggered by an exploding wire. They subsequently propagate under the action of a con...

1 The Effect of Cohesive-Law Parameters on Mixed-Mode Fracture R. B. Sills and M. D. Thouless Department of Mechanical Engineering Department of Materials Science & Engineering University of Michigan Ann Arbor, MI 48109-2125, USA Abstract Cohesive-zone models of fracture provide a framework that allows a smooth transition between a strength-based approach to fracture and an energy-based approac...