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-...

In the present work we present a systematic experimental investigation of the generation and subsequent evolution of dynamic failure modes in sandwich structures subjected to low-speed impact. Model sandwich specimens involving a compliant polymer core sandwiched between two metal layers were designed and subjected to impact loading to simulate failure evolution mechanisms in real sandwich stru...

Additive Manufacturing (AM) has gained a lot of interest due to the freedom produce complex metal geometries directly from designed digital model. Despite high potential AM, process induced imperfections, like pores and microstructural changes layer-by-layer manufacturing, made significant impact on fatigue resistance crack growth behaviour. Consequently, this work aims evaluate effect microstr...

fast fracture is one of the major failure modes in brittle polymers. generally, crack growth in these polymers may occur under combined tensile-shear loading. however, the fracture test data reported previously for some dental restorative resins can not be predicted by using the available fracture criteria.in this paper, a modified fracture criterion is used for estimating the fracture load for...

The influence of tubule orientation on the transition from fatigue to fatigue crack growth in human dentin was examined. Compact tension (CT) and rectangular beam specimens were prepared from the coronal dentin of molars with three unique tubule orientations (i.e., 0 degrees , 45 degrees and 90 degrees). The CT specimens (N=25) were used to characterize fatigue crack initiation and steady-state...

The structural integrity of oxide/metal interfaces is important in many applications. While most attention has focused on the debonding of oxide/metal interfaces by conducting strength and fracture toughness tests, very few investigations have looked at time dependant failure of interfaces under cyclic or static loading. Tests have been conducted on sandwich specimens consisting of 5 100 micron...

The role of metal layer thickness and resultant plastic constraint in the metal layer during the failure of metal/ceramic layered structures is examined under cyclic and static loading conditions. Crack-growth experiments were conducted on sandwich specimens consisting of 99.999% pure aluminum layers bonded between 99.5% pure polycrystalline alumina with the metal layer thickness varying from 5...

The mean and the life-limiting behavior under fatigue of the nickel-based superalloy, IN100, separated (or converged) as a function of stress level and dwell loading. This behavior was related to the control of the life-limiting behavior by the smallcrack growth regime, producing its much slower response to stress level and dwell-time, relative to the mean-lifetime behavior. The lifetime probab...

A numerical technique for planar three-dimensional fatigue crack growth simulations is proposed. The new technique couples the extended finite element method (X-FEM) to the fast marching method (FMM). In the X-FEM, a discontinuous function and the two-dimensional asymptotic crack-tip displacement fields are added to the finite element approximation to account for the crack using the notion of p...

Fatigue properties and cracking behavior of cold-drawn commercially pure aluminum wires (CPAWs) widely used as the overhead transmission conductors were investigated. It was found that the fracture surface of the CPAWs shows an obvious four-stage fracture characteristic, i.e., crack initiation, planar crack propagation, 45°-inclined crack propagation and final rapid fracture. The crack growth m...