Dealing with the plane behaviour of a composite quasi-unidirectional elementary ply made of E glasslpolyester, this paper contributes to the study of impact phenomena on ceramic/composite bi-layered targets. Firstly, a quasistatic modelisation of the elementary ply behavior, in plane tensile and plane shear, is presented. It allows a good description of the residual strains and of stiffness los...

A literature review has been carried out relating to the damage and fracture behaviour of composite laminates based on woven fabric reinforcement containing a stress raiser in the form of either a circular hole or of a mechanically fastened joint – the tensile failure modes in these two types of problem are very similar. Closed form and finite element based approaches that enable the stress dis...

This paper investigates the fatigue behaviour of pseudo-ductile Quasi-Isotropic (QI) interlayer hybrids with un-notched and open-hole configurations. Two different types QI were evaluated; HighC, carbon to glass thickness ratio 0.29, that is made thin-ply M46JB-carbon/epoxy Xstrand-glass/epoxy prepregs, LowC, 0.19, T300-carbon/epoxy standard-ply S-glass/epoxy prepregs. The hybrid configurations...

This paper presents a 1 m long self-deployable boom that could be folded around a spacecraft. Previously developed simulation techniques are used to analyze this two-hinge boom, made from two-ply plain weave carbon fiber laminate. A stress-resultant based failure criterion is used to study safety of the structure during both stowage and dynamic deployment. A safe design that latches without any...

this paper aims at investigating the effects of weld nugget size and expulsion on the mechanical properties of low carbon steel resistance spot welds using tensile-shear test. mechanical performance of spot welds are described in terms of failure mode, peak load and failure energy obtained from the tensile-shear test. the effects of voids and porosity as well as electrode indentation associated...

there are limited documents about hiv patients switched to second-line antiretroviral therapy (art) in resource-limited countries. we aimed to assess the efficacy of second-line art for hiv patients following first-line art failure. this was a cohort study of hiv/aids patients with first-line art treatment failure switched to second-line art between january 2004 and march 2014, who followed for...

This paper presents the first conceptual study into creating a Plantae-inspired vascular network within a fibre-reinforced polymer composite laminate, which provides an ongoing self-healing functionality without incurring a mass penalty. Through the application of a 'lost-wax' technique, orthogonal hollow vascules, inspired by the 'ray cell' structures found in ring porous hardwoods, were succe...

This study presents an approach that uses the refined zigzag element, {2,2} RZE in conjunction with progressive failure criteria to predict the ultimate strength of composite laminates based on only ply-level strength properties. The methodology involves four major steps: (1) Determination of accurate stress and strain fields under complex loading conditions using {2,2} RZE -based finite elemen...

The effect of using thin plies to increase the bearing strength composite laminates has been investigated. A series 5 theoretically identical stiffness with varying proportions were manufactured a single material system. Four specimens from each plate tested for and damage was subsequently characterized an optical microscope. results show that performance in terms stiffness, at onset damage, ul...

Streptococcus pneumoniae is one of the most common etiologic agents of community-acquired pneumonia, particularly bacteremic pneumonia. Pneumolysin, a multifunctional cytotoxin, is a putative virulence factor for S. pneumoniae; however, a direct role for pneumolysin in the early pathogenesis of pneumococcal pneumonia has not been confirmed in vivo. We compared the growth of a pneumolysin-defici...