Effect Of Weave Structure Research Articles

The effect of weave pattern on the mode-I interlaminar fracture energy of E-glass/vinyl ester composites

In this work, the effect of weave structure on the mode-I interlaminar fracture energy ( G Ic) of glass/toughened vinyl ester laminates has been investigated. The matrix material used was commercially available rubber-modified vinyl ester resin, DERAKANE 8084. The glass fibres used were E-glass plain weave, twill weave, quadran 4-harness satin weave, and 8-harness satin weave with weave index of 2, 3, 4 and 8 respectively. The specimens were prepared by a vacuum bagging technique. The mode-I delamination tests have been done at a constant displacement rate of 2 mm/min in an Instron testing machine, using specimens machined in accordance with ASTM D5528-94a. By using a HITACHI S-4500 scanning electron microscope, microscopic details of crack growth in the interply region were examined after fracture testing. The twill-weave laminate with weave index n g=3 yielded the highest value of fracture energy for critical crack propagation ( G Ic). Whilst the 8-harness satin-weave laminate gave the highest value of initial fracture energy ( G Ii). Partial debonding of transversely oriented yarns results in the delamination resistance for twill-weave, quadran 4-harness satin-weave, and 8-harness satin-weave laminates. Fracture of debonded fibres ascribed to as ‘fibre bridging’ was observed in the twill-weave, quadran 4-harness satin-weave and 8-harnes satin-weave laminates. No indications of fibre bridging were observed in the plain-weave laminate.

The effect of weave pattern and crack propagation direction on mode I delamination resistance of woven glass and carbon composites

Abstract The effect of weave structure on the interlaminar fracture behavior of orthogonal woven fabric composite laminates has been examined. Crack propagation along the fill and weft yarns, respectively, was considered for plain, twill and 8H-satin glass/epoxy composites, and a 5H-satin carbon/epoxy composite. Fracture testing employed the mode I fracture DCB test specimen. Microscopic details of crack growth in the interply region were considered after fracture testing. The delamination resistance and the difference in fracture toughness between the fill and weft directions increased with increased weave index. Partial debonding of transversely oriented yarns contributed to the delamination resistance. Fracture of debonded fibers referred to as `fiber bridging' was observed in the twill and satin weave glass/epoxy composites, but not in the plain weave glass/epoxy and the 5H-satin weave carbon/epoxy composites. The interlacing of the yarns limited the extent of fiber bridging.

Effect of woven structure on transient characteristics of cake filtration

Three-dimensional particles deposition on four basic woven structures was studied numerically by analyzing forces acting on the depositing particles and was applied to estimate the change of clarity of filtrate at the initial stage of filtration. The effects of woven structures, feed concentration and particle/pore size ratio on the transient behavior of cake filtration and the variation of medium resistances at the beginning stage of cake filtration were analyzed quantitatively. The simulated results show that the filtration period at the initial stage can be divided into the three modes of standard pore blocking, intermediate blocking and cake formation in accordance with the law of blocking for all types of pores. Furthermore, the critical concentration proposed by previous investigators is also confirmed quantitatively in this study.

Fluid Flow Through Basic Weaves of Monofilament Filter Cloth

The effects of woven structures on fluid flow through basic weaves of monofilament filter cloths are studied numerically using the fluid-flow software FLUENT. The flow pattern and resistance to flow in the interstices are obtained as results of the numerical solution. The results show that the construction of the fabric pores has a significant influence on flow pattern in the interstices and downstream. Plain weave gives the highest fluid flow resistance, while satin weave has the lowest with the same thread count.

Tensile Properties of Carbon Fiber Triaxial Woven Fabric Composites

Triaxial woven fabrics are attractive for industrial applications as a rein forcement of composite materials. In this article, tensile properties and fracture behaviors of carbon fiber triaxial woven fabric composites were discussed by comparing with biaxial woven fabric composites. Moreover, the effect of weave structure on the tensile properties of the triaxial woven fabric composites was investigated. Triaxial woven fabric composites were isotropic in modulus, and anisotropic in strength. Tensile properties of basic woven fabric composites were superior compared to the Bi-Plain and biaxial woven fabric com posites. The fracture mechanisms of triaxial woven fabric composites varied with fiber ori entation. This was observed from experimental data of AE (acoustic emission) mea surement and numerical analysis.

Influence of pore structure on fatigue endurance strength : K.D. Christian. (Toranaga Technologies Inc., Carlsbad, California, USA.)

The effect of weave structure on the interlaminar fracture behavior of orthogonal woven fabric composite laminates has been examined. Crack propagation along the fill and weft yarns, respectively, was considered for plain, twill and 8H-satin glass/epoxy composites, and a 5H-satin carbon/epoxy composite. Fracture testing employed the mode I fracture DCB test specimen. Microscopic details of crack growth in the interply region were considered after fracture testing. The delamination resistance and the difference in fracture toughness between the fill and weft directions increased with increased weave index. Partial debonding of transversely oriented yarns contributed to the delamination resistance. Fracture of debonded fibers referred to as `fiber bridging' was observed in the twill and satin weave glass/epoxy composites, but not in the plain weave glass/epoxy and the 5H-satin weave carbon/epoxy composites. The interlacing of the yarns limited the extent of fiber bridging.

Effect of weave structure on mechanical fracture behavior of three-dimensional carbon fiber fabric reinforced epoxy resin composites

In this study, an epoxy resin was reinforced by three-dimensional (3-D) carbon fiber fabrices (orthogonal nonwoven type). The purpose of the study was to investigate the effect of weave density (5 mm type and 7·5 mm type (spacing between two Z axis yarn bundles are 5 mm and 7·5 mm, respectively)) and directional reinforcement (3D and 5D) on the mechanical fracture behavior of these 3-D composites. A comparison with a traditional two-dimensional (2-D) composite is also presented. The results revealed that the tensile strength of the 2D CFRP was 2–2·5 times greater than that of 3D CFRP and about three times greater than that of the 5D CFRP. Also, the 3D CFRP was 3–4 times, and the 5D CFRP was five times, more deformable than the 2D CFRP composite. In Charpy impact tests, the impact strengths of 3D and 5D structural composites were found to be 2 and 2·5 times greater than those of 2D composites, respectively. From falling weight impact tests, we found that the impact energy of 3-D composites was higher than that of 2-D composites, and the ductility index of 3-D composites was also higher than that of 2-D composites. We concluded that the impact toughness of 3-D composites was better than that of 2-D composites. The flexural and shear strengths of these materials are also discussed.

Effect of woven structure on flexural and shear fracture behaviour of three-dimensional carbon-carbon composites

The various structures and yarn-bundle spacing of 3D-5 (three directions, 5 mm), 5D-5 (five directions, 5 mm), and 3D-7.5 (three directions, 7.5 mm) preforms are fabricated into three-dimensional carbon-carbon (C/C) composites. The fracture behaviour is different due to the increased number of arrangement directions and fracture toughness. The flexural strength, short-beam shear strength, and microstructure of fractured specimens were investigated to study the mechanical behaviour of these composites. The results revealed that the strengths of the three-dimensional composites were larger than the five-dimensional ones in all reinforcement structures, but five dimensions were better than three dimensions in fracture toughness. The five-dimensional composites showed stepwise fracture, and the three-dimensional vertical fracture. In the aspect of yarn-bundle spacing, the flexural strength of the 7.5 mm type (spacing between twoZ axial yarn bundles is 7.5 mm) was higher than the 5 mm type, while the short-beam shear strength was contrary, Furthermore, according to SEM observations, the fractural surface was ruptured along theZ-axis, indicating that a stress concentration would exist in the fringe of theZ-axis, and that theZ-directional fibres arrested delamination propagation.

Flow Through Fabric-like Structures

A method is presented for the visual investigation of flow through fabrics. The fabric pores are considered as orifices, and the effect of weave structure on the fluid flow is investigated in the range of Reynold's numbers 10 to 400. For this investigation, a liquid is forced past models representing the four possible combina tions of yarns in a woven fabric interstice, and the fluid motion is visualized by using air bubbles, which are detected by means of a suitable light source, as the distinguishing medium. Since both the fluid and the construction material for the models and viewing chamber are translucent and possess the same refractive indices, it is possible to obtain uninterrupted, undistorted visualization of the fluid flow through and past the fabric-like structures. Visual and photographic investi gations of the flow are made in various significant planes normal to the fabric-like structures, or parallel to the direction of flow. The resulting photographs are analyzed and interpreted to provide information concerning the effect of fabric construction and variation of Reynold's num ber on the area available for the passage of fluids through each pore type, or the so-called "effective pore area." It is shown that the four pore types do not behave like geometrically similar orifices, so that for a given diameter/pitch ratio the effective pore area is not the same in all cases. This area decreases with increasing Reynold's number. Except at very low Reynold's numbers, the effec tive pore area proves to be less than the actual minimum pore area, but greater than the pro jected area, with the exception of the plain-weave pore type. Assuming a minimum cross- sectional pore area, as determined by graphical analysis, it is shown that the effective pore area/minimum pore area ratio is almost a constant for all four pore types of the models tested at a Reynold's number of 400.