Showing papers in "Composites Science and Technology in 1996"

TL;DR: In this paper, the authors evaluated the initiation of cracking and delamination growth in a unidirectional glass/epoxy composite under mode I, mode ZZ, and mixed mode I + II static loading.

TL;DR: In this paper, a vigorous mechanics foundation is established for using a representative volume element (RVE) to predict the mechanical properties of unidirectional fiber composites, and the effective elastic moduli of the composite are determined by finite element analysis of the RVE.

TL;DR: In this article, an analytical method considering the effects of fiber length and fiber orientation distributions for predicting the tensile strength of short-fiber-reinforced polymers (SFRP) was presented.

TL;DR: In this article, the effect of fiber waviness on stiffness and strength reduction of unidirectional composites under compressive loading was investigated and the results were in good agreement with predictions based on the analytical models.

TL;DR: In this paper, the authors analyzed the results of several selected experimental studies concerned with impact and post-impact compression damage and failure, of continuous carbon-fibre/epoxy composites, in order to predict their residual strength.

TL;DR: In this paper, a study of failure in unidirectionally-reinforced fiber composites loaded in tension normal to the fibers was conducted, where the failure was governed by failure of the matrix rather than fiber/matrix debonding.

TL;DR: In this paper, the mechanical performance of various 3D woven composites (monolithic and sandwich) by comparison of in-plane properties (stiffness and strength), damage tolerance, energy absorption capability and fracture mechanical properties is presented.

TL;DR: In this paper, the thermal properties of plain-weave fabric-reinforced composite laminates obtained from micromechanical analyses and a two-scale asymptotic homogenization theory are presented.

TL;DR: In this article, three epoxy systems of interest as composite matrix materials are examined for their yielding and failure behavior under uniaxial, biaxially, and triaxial stress states, and a criterion for this mode of failure is proposed as the critical dilatational strain energy density.

TL;DR: In this paper, a beam can be designed which does not curve under a steady-state through-thickness temperature variation, independent of the actual temperature values, within the limitation of constant material properties of the constituents.

TL;DR: In this paper, a micromechanical model has been developed where the cyclic fatigue effect is ascribed to interfacial wear between fibres and matrix, and the macroscopic behavior is experimentally observed from the lifetime diagram and the evolution of the stress/strain loops with the number of cycles applied.

TL;DR: In this article, discrete voids of different sizes were simulated by embedding PTFE monofilaments, tubes and strips at the midplane of unidirectional glass fibre and carbon-fibre/epoxy plates.

TL;DR: In this article, the authors investigated the damage mechanisms and the associated mechanical response of a 2D reinforced composite of carbon fibers in an SiC CVI-processed matrix subjected to uniaxial tensile and compressive loadings at room temperature.

TL;DR: In this article, a continuous electroplating device was used to plate nickel over the surface of the carbon fibers, and the optimum thickness of the coating is 0.2-00.5 μm.

TL;DR: In this paper, a modified statistical theory for microcomposite strength as a function of length was developed to incorporate this a effect, where both the expected doubling and tripling of the Weibull shape parameter as compared to that of the fiber and the predicted a effect for micro composite length were observed.

TL;DR: In this article, a three-dimensional geometric description for a large range of two-dimensional woven architectures is proposed which can serve as a basis for stiffness and strength modelling of fabric composites.

TL;DR: In this article, the elastic properties of knitted-fabric-reinforced composites are investigated and upper and lower bounds for the elastic moduli are found with the Voigt and Reuss method, respectively.

TL;DR: In this paper, a model of grid structure deformation and failure was developed and implemented in a computer code, and parametric studies were run on a variety of grid structures types and geometries.

TL;DR: In this paper, the authors measured the moisture absorption characteristics, longitudinal shear modulus and loss factor, and the interlaminar shear strength of polymer composites, with a view to assessing the feasibility of the use of dynamic measurements as a nondestructive tool for determining the structural integrity of polymer composite degraded by moisture.

TL;DR: In this article, the distributions of strain energy release rate at the crack fronts of double-cantilever beam (DCB) and end-notched flexure (ENF) specimens have been analyzed by means of the plate finite element.

TL;DR: In this paper, the authors focus on the modelling of interfacial debonding effects on the overall behavior of randomly oriented discontinuous-fibre composites containing matrix microcracks.

TL;DR: In this article, the authors investigated the transverse impact of plate-like composite specimens and showed that an accurate prediction of the development of matrix cracks and delaminations during impact requires the use of energy criteria, taking into account the appropriate fracture toughness values, depending on the interface and mixed mode loading.

TL;DR: In this article, failure initiation in polymer-matrix composites loaded transverse to the fibers is investigated by a numerical parametric study where the effects of constituent properties, interphase properties and thickness are examined.

TL;DR: In this paper, the authors measured the fracture and toughening mechanisms in interlayered carbonfiber/epoxy composites and determined the primary variables were: (1) the diameter of the interlayering particles; (2) the thickness of interply; and (3) the ductility of the matrix resin.

TL;DR: In this article, the yarn-yarn interactions at the crossing points are found to consist of two components, a pressureindependent adhesive component and a pressure-dependent frictional one, of which the latter is proved to be dominant.

TL;DR: In this article, a three-cell model is proposed, constructed on the basis of the microstructure analysis of braided structural composites which can be produced by four-step braiding (four-direction, 4D) without or with the addition of uniaxial reinforced yarns.

TL;DR: In this paper, a general analysis method is presented to predict matrix cracks in composite laminate, together with the resulting degradations of laminate properties, as functions of temperature or thermal cycles.

TL;DR: In this article, a new scheme for average effective permeability is proposed that does account for the transverse flow between the adjacent layers, which is a function of the in-plane and transverse permeabilities, the thickness of each layer, as well as the total length of the mold.

TL;DR: In this article, it was shown that oblique tabs significantly increase the maximum shear stress at failure and that unlike straight-tabbed specimens failing in the tabbed area, oblique-tabed specimens failed neatly in the gauge section.

TL;DR: In this paper, the unit cell geometry of warp-knit yarns is identified along with idealized cross-sectional shapes of insertion and stitch yarns, and a geometric model is developed relating the geometric parameters and process variables.