A new experimental technique is developed to determine the onset and evolution of delamination in fiber-reinforced composites under impact loading. The configuration uses a split-Hopkinson bar for low-velocity impact loading and two Polytec laser vibrometer systems for real-time monitoring of the initiation and progression of delamination. The experiment allows the histories of load, displaceme...

Delamination is probably the most serious form of deterioration I which is commonly found in britlge decks. It ultimately results in large scale spalling necessitating costly repairs. This type of failure is believed to be caused chiefly from salt induced corrosion of the reinforcing steel. An instrument designed to detect delamination, and tests conducted to val:iAate its perf'ormance, are .br...

Composite materials are one answer to the growing demand for materials with better parameters of construction and exploitation. Composite materials also permit conscious shaping of desirable properties to increase the extent of reach in the case of metals, ceramics or polymers. In recent years, composite materials have been used widely in aerospace, energy, transportation, medicine, etc. Fiber-...

The essence of the Ebstein's malformation is that the tricuspid valve leaflets do not attach normally to the valve annulus, and the effective orifice is displaced downward into the right ventricular cavity at the junction of the inlet and trabecular components of the right ventricle. Only the septal and posterior leaflets are displaced and divide the right ventricle into two portions. The inlet...

A popular strategy in the treatment of articular cartilage lesions involves the introduction of cell suspensions into the defect void and its closure with a periosteal flap (autologous chondrocyte transplantation technique). We applied this methodology in goats and discovered that all sutured flaps (n = 6 animals) became detached from nonimmobilized joints during the recovery period. The purpos...

Delamination of neural crest (NC) cells is a bona fide physiological model of epithelial-to-mesenchymal transition (EMT), a process that is influenced by Wnt/β-catenin signalling. Using two in vivo models, we show that Wnt/β-catenin signalling is transiently inhibited at the time of NC delamination. In attempting to define the mechanism underlying this inhibition, we found that the scaffold pro...

Neurogenic placodes are specialized regions of embryonic ectoderm that generate the majority of the neurons of the cranial sensory ganglia. Here we examine in chick the mechanism underlying the delamination of cells from the epibranchial placodal ectoderm. We show that the placodal epithelium has a distinctive morphology, reflecting a change in cell shape, and is associated with a breach in the...

adhesion, [ 14,15 ] wetting, [ 16,17 ] and optical characteristics [ 18 ] of surfaces, among other examples. In comparison to other buckling modes, delamination—wherein a supported elastic thin fi lm subject to a compressive mismatch strain undergoes debonding from the substrate and forms blister-like structures—has received relatively little attention with regards to applications in responsive...

A high fidelity delamination failure analysis was developed by combining a local failure analysis with a global fullscale finite element structural analysis to address strength and delamination failure in a single package. The methodology was demonstrated through a local threedimensional pull-off failure analysis and a geometrically nonlinear structural analysis of a five-foot composite helicop...

A new cohesive model for simulating delamination propagation in composite laminates under transverse loads. Running title: A new cohesive model for simulating delamination propagation in composite laminates 2 Abstract In this paper, we propose a new cohesive model to stably and accurately simulate the delamination propagations in composite laminates under quasi-static and low-velocity impact tr...