Showing papers in "Polymers & Polymer Composites in 2001"
TL;DR: In this paper, solid particle erosion of glass fiber-epoxy composites with the matrix modified by incorporating either carbon black filler or a rubber material known to enhance toughness has been studied, together with a case where both materials are simultaneously included in the resinous matrix.
Abstract: Solid particle erosion of glass fibre-epoxy composites with the matrix modified by incorporating either carbon black filler or a rubber material known to enhance toughness has been studied, together with a case where both materials are simultaneously included in the resinous matrix. How the semiductile behaviour of the thermoset matrix is affected by the matrix modification formed the primary objective of this work. The erosion weight loss was studied with respect to the angle of impingement. Eroded surfaces of test samples were examined under SEM to observe fracture features. For a matrix containing carbon, the angle for peak erosion remained at 45° despite variations in filler content. But in the case of a rubber toughened matrix, a shift of this angle to 30° is noticed suggesting a change in the mechanism of material removal. When carbon filler was added to the rubber-toughened matrix, it appeared to influence the erosion behaviour.
65 citations
TL;DR: In this article, the viscoelastic properties of extruded polyethylene (PE) and a foam made from PE and approximately 40 volume percent of polymer microballoons were investigated.
Abstract: Syntactic foam products are most often made from glass microballoons embedded in a thermosetting polymer matrix, and they have good mechanical and thermal properties. However, the glass microballoons easily break in shear and are therefore very difficult to use for manufacturing methods that cause shearing of the material. Polymer microballoons are an alternative by which it is possible to produce a foamed product using unmodified commercial extruders or injection moulding machines. The present study deals with the viscoelastic properties of extruded polyethylene (PE) and a foam made from PE and approximately 40 volume percent of polymer microballoons. Results are shown from creep tests carried out at three temperatures and with three force levels, and from stress relaxation tests carried out at room temperature and with five deformation levels. The overall conclusion was that for some applications the foam will be the best choice, whereas for others it is more advantageous to use bulk polyethylene.
47 citations
TL;DR: In this article, the vibration reduction ability of thermoplastics (PMMA, PTFE, PA-66 and acetal) and of a thermoset (epoxy) was compared by dynamic flexural testing at ≤ 1.0 Hz.
Abstract: The vibration reduction ability of thermoplastics (PMMA, PTFE, PA-66 and acetal) and of a thermoset (epoxy) was compared by dynamic flexural testing at ≤ 1.0 Hz. Among these polymers, PMMA exhibite...
33 citations
TL;DR: In this paper, the depletion of antioxidants in polyethylene when exposed to water containing different chlorine concentrations was investigated, which relates to the world-wide use of polyylene pipes in water treatment and distribution networks.
Abstract: For many polyethylene products, their working life-span depends on retention by the material of its antioxidant. In dry air, when the working and environmental stresses remain within defined limits, the life-span of the material can be many decades. Immersed in water, for example, the diffusion and loss of antioxidant from the material's surface can increase. Also, some types of aggressive agents, if in the water, can enter the material's surface and migrate into the material to increase the depletion of the antioxidant population. Researched in this study, is the depletion of antioxidants in polyethylene when exposed to water containing different chlorine concentrations. This research relates to the world-wide use of polyethylene pipes in water treatment and distribution networks.
31 citations
TL;DR: In this paper, a Polypropylene (PP) based conductive composites were produced using stainless steel fibres (SSF) as the fillers, and their mechanical properties, electrical conductivity and electromagnetic interference were investigated.
Abstract: Polypropylene (PP) based conductive composites were produced using stainless steel fibres (SSF) as the fillers. Their mechanical properties, electrical conductivity and electromagnetic interference...
30 citations
TL;DR: In this paper, a study of the interlaminar fracture behavior of unidirectional carbon fibre-epoxy matrix composites containing polyethylene terephthalate (PET) interleaving films, with and without...
Abstract: A study has been made of the interlaminar fracture behaviour of unidirectional carbon fibre-epoxy matrix composites containing polyethylene terephthalate (PET) interleaving films, with and without ...
29 citations
TL;DR: In this article, the volumetric expansion of bisphenol-A and aniline-based benzoxazine (BA-a) has been studied by comparing the room temperature density of the cured BA-a under different polymerization conditions with the amorphous BA -a monomer.
Abstract: The volumetric expansion of bisphenol-A and aniline-based benzoxazine (BA-a) has been studied by comparing the room temperature density of the cured BA-a under different polymerization conditions with the amorphous BA-a monomer. The glass transition temperatures (Tg) of BA-a at various degrees of polymerization have been investigated by differential scanning calorimetry (DSC). The degrees of conversion at different polymerization temperatures were compared with the respective glass transition temperatures. It was found that substantial development of Tg occurs at low degrees of conversion. A fluorinated polybenzoxazine was synthesized from the ring-opening polymerization of hexafluoroisopropylidene-containing benzoxazine monomer. The properties of the fluorine-containing polymer were compared to those of nonfluorinated polybenzoxazine. Fluorine incorporation had a profound effect on the glass transition temperature of polybenzoxazine. The thermal stability also improved upon fluorination.
27 citations
TL;DR: Polymer-matrix composite materials for microelectronics are reviewed in this article in terms of the science and applications, as designed for high thermal conductivity, low thermal expansion, low dielectric constant, high/low electrical conductivity and electromagnetic interference shielding.
Abstract: Polymer-matrix composite materials for microelectronics are reviewed in terms of the science and applications. They include those with continuous and discontinuous fillers in the form of particles and fibres, as designed for high thermal conductivity, low thermal expansion, low dielectric constant, high/low electrical conductivity and electromagnetic interference shielding. Applications include heat sinks, housings, printed wiring boards, substrates, lids, die attach, encapsulation, interconnections and thermal interface materials.
24 citations
TL;DR: In this article, the reinforcement of non-polar ethylene-propylene-diene rubber (EPDM) by the polar metal salts of methacrylic acid was achieved by directly mixing the salt into EPDM at a high level and curing with peroxide.
Abstract: The reinforcement of non-polar ethylene-propylene-diene rubber (EPDM) by the polar metal salts of methacrylic acid was achieved by directly mixing the salt into EPDM at a high level and curing with peroxide. Mechanical properties and crosslink density of the vulcanizates were investigated. Wide-angle X-ray diffraction (WAXD) and Fourier transform-infrared spectroscopy (FTIR) were employed to analyze the reactivity of zinc dimethacrylate (ZDMA) in EPDM compounds before and after vulcanization. It was observed that the commercial ZDMA or magnesium dimethacrylate (MDMA) can greatly improve the hardness and tensile strength of the EPDM vulcanizates, while retaining a high elongation at break. WAXD and FTIR revealed that ZDMA is a reactive filler in the EPDM matrix during peroxide curing. The crosslink density of the vulcanizates was determined by equilibrium swelling. Covalent crosslinks and ionic crosslinks were distinguished by an acidolysis treatment. Ionic crosslinks were greatly improved by increasing the amount of zinc dimethacrylate or dicumyl peroxide, and the relationship between mechanical properties and crosslink density indicates that the tensile strength of the vulcanizate was principally dependent on ionic crosslink density.
23 citations
TL;DR: An amineterminated butadiene-acrylonitrile copolymer (ATBAN) was introduced to polybenzoxazine by the modification of monomer prior to curing as mentioned in this paper.
Abstract: An amine-terminated butadiene-acrylonitrile copolymer (ATBAN) was introduced to polybenzoxazine by the modification of monomer prior to curing. After the thermally induced ring-opening reaction, a mixture of two network structures was formed. Dynamic mechanical analysis (DMA) was used to study the relaxation behaviour in different temperature regions and thermal properties of the modified system were examined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
22 citations
TL;DR: In this paper, a continuous carbon fiber epoxy-matrix composite was simultaneously monitored by measurement of the contact electrical resistivity of the interlaminar interface, which showed that temperature increase caused the resistivity to decrease reversibly within each thermal cycle.
Abstract: Thermal fatigue and temperature of a continuous carbon fiber epoxy-matrix composite were simultaneously monitored by measurement of the contact electrical resistivity of the interlaminar interface. A temperature increase caused the resistivity to decrease reversibly within each thermal cycle, while thermal fatigue caused the resistivity to increase. The increase took the form of a spike increase at the maximum temperature of a cycle in an early stage of fatigue, and took the form of an abrupt increase of the baseline in a later stage of fatigue.
TL;DR: In this article, a 3-D finite element analysis procedure was developed to predict spring-in resulting from anisotropy for both thin and thick angled composite shell structures, and the results of the FE analysis were evaluated together with those from the analytical study and experimental investigation conducted by Jain at the Cooperative Research Centre for Advanced Composite Structures (CRC-ACS) in Australia.
Abstract: During the manufacture of curved or angled shell composite structures, the enclosed angle of such structures tends to be reduced after cure. This phenomenon is referred to as "spring-in". It is believed that such distortion is caused mainly by the significant difference between the in-plane coefficient of thermal expansion (CTE) and the through-thickness CTE. This might result in a larger out-of-plane contraction than the in-plane contraction during the time that a composite structure is cooling down from the curing temperature. In this paper, a 3-D Finite Element Analysis procedure was developed to predict "spring-in" resulting from anisotropy for both thin and thick angled composite shell structures. The results of the FE analysis were evaluated together with those from the analytical study and experimental investigation conducted by Jain at the Cooperative Research Centre for Advanced Composite Structures (CRC-ACS) in Australia. It was concluded, based on these results, that the FE model gives more accurate results than the analytical model, particularly for thicker composite shells. The corner radius effect, shell thickness effect, and lay-up effect on "spring-in", together with the effect of tool/ part interaction on the total distortion were also discussed. Comparison was made with the experimental results reported by Radford and Rannick.
TL;DR: In this paper, the geometry of the cells of a syntactic foam was characterized using a stereological sampling procedure, and the distribution of cell aspect ratio was estimated, assuming ellipsoidal cells with the major axis in the direction of extrusion.
Abstract: Stereological sampling procedures were used to characterize the geometry of the cells of a syntactic foam The foam, formed by extrusion, consisted of hollow polymeric microballoons in a low-density polyethylene matrix Estimates of cell volume fraction, number density and the mean and standard deviation of volumes of cells were made using design-based methods, which are generally valid without any assumptions about cell shape Additionally, the distribution of cell aspect ratio was estimated, assuming ellipsoidal cells with the major axis in the direction of extrusion In addition to describing the stereological methods used, this paper illustrates how the results of a pilot study can be used to design an efficient sampling protocol
TL;DR: In this article, a superabsorbent poly(acrylic acid)/montmorillonite composite with water absorbency of about 1100 times its own weight (g H 2 O/g) was synthesized by graft copolymerizing acrylic acid onto ultrafine montmorillonites powder.
Abstract: A novel superabsorbent poly(acrylic acid)/montmorillonite composite with water absorbency of about 1100 times its own weight (g H 2 O/g) was synthesized by graft copolymerizing acrylic acid onto ultrafine montmorillonite powder. The influence of the amount of crosslinker, montmorillonite and neutralization degree on the water absorbency of the composites is discussed in this paper.
TL;DR: In this article, a stable drawing process was carried out experimentally using a single-pass rolling technique and the influences of rolling ratio on the structure, molecular orientation, and thermo-mechanical properties of the sheets were investigated.
Abstract: Plastic deformation can be applied to the processing or forming of semi-crystalline polymers. This work concerns the drawing of polypropylene (PP) sheets in order to modify their thermo-mechanical properties. PP sheets were rolled at 110°C to induce molecular orientation. A stable drawing process was carried out experimentally using a single-pass rolling technique. The influences of rolling ratio on the structure, molecular orientation, and thermo-mechanical properties of the sheets was investigated. The original PP sheet was opaque. The rolled PP sheets had smooth surfaces and showed high transparency at high rolling ratios. Dynamic mechanical properties of rolled sheets were evaluated by a non-resonant forced vibration method. The dynamic moduli of rolled sheets increased with increasing rolling ratio. Thermo-mechanical properties were improved by rolling. The improvement in properties can be explained by enhanced molecular chain orientation.
TL;DR: In this paper, the yielding and fracture behavior of epoxy/glass microballoon composites has been studied as a function of filler content, temperature and strain rate, and no increase in elastic modulus, yield stress and fracture toughness was observed.
Abstract: The yielding and fracture behaviour of epoxy/glass microballoon composites has been studied as a function of filler content, temperature and strain rate. No increase in elastic modulus, yield stress and fracture toughness was observed. The compressive yield stress of the composites showed strain rate dependence with more than one rate-activated yielding process. The fracture toughness parameters G g and K c were found to be temperature insensitive. The variations in the measured mechanical quantities are discussed in terms of the observed morphology and thermal behaviour of the epoxy composites.
TL;DR: In this paper, the influence of fiber length, fibre content and surface treatment of the natural fibres on the mechanical properties of poly(butylene succinate) composites was evaluated.
Abstract: Poly(butylene succinate) composites reinforced with short sisal fibre were prepared by melt mixing and subsequent injection moulding. The influence of fibre length, fibre content and the surface treatment of the natural fibres on the mechanical properties of the composites were evaluated. Regarding fibre length, the tensile and flexural properties of the composites had maxima at a fibre length of about 5 mm. The flexural and tensile moduli of the composites increased with increasing fibre content. Although the tensile strength hardly changed, the flexural strength increased up to a fibre content of 10 wt%. The dynamic mechanical analysis of the composites showed that the storage moduli at above ca.-16°C (corresponding to the glass transition temperature of the matrix) increased with increasing fibre content.
TL;DR: In this paper, the mechanical response of knitted glass- and carbon fiber-reinforced polyamide-12 composites was compared both under static (tensile, flexural) and dynamic (perforation impact) conditions.
Abstract: The mechanical response of knitted glass- (GF) and carbon fiber (CF) fabric-reinforced polyamide-12 (PA-12) composites was compared both under static (tensile, flexural) and dynamic (perforation impact) conditions. The GF- and CF-content of the composites produced by hot pressing of 8 layers of planar weft knits containing staple reinforcing GF or CF and PA-12 fibers was practically the same, viz ca. 50 vol%. Dynamic-mechanical thermoanalysis (DMTA) showed a strong stiffness anisotropy: the stiffness of the composites in the wale-direction (W) was markedly higher than in the course-direction (C). The same strong anisotropy was also found for the static tensile and flexural characteristics (stiffness and strength). The mechanical anistropy and the large difference between the stiffness and strength due to tensile and flexural loading were traced to the structure of the knits (unbalanced reinforcement) and their non-planar structure in the composite sheets. The mechanical performance of the knitted CF-reinforced composite was superior to the GF-reinforced version under dynamic perforation impact conditions as well.
TL;DR: In this paper, the Zinc octoate/nonylphenol catalysed thermal cure of bisphenol A dicyanate (BACY) was investigated using non-isothermal differential scanning calorimetry (DSC).
Abstract: The kinetics of the Zinc octoate/nonylphenol catalysed thermal cure of bisphenol A dicyanate (BACY) was investigated using non-isothermal differential scanning calorimetry (DSC). The kinetic parame...
TL;DR: In this paper, polyamide-nitrile rubber blends of high polyamide content (100/0, 70/30, 50/50) were prepared by melt mixing in a Haake Rheocord.
Abstract: Polyamide-nitrile rubber blends of high polyamide content (100/0, 70/30, 50/50) were prepared by melt mixing in a Haake Rheocord. The diffusion of water through the blends was investigated at vario...
TL;DR: In this article, the effects of natural rubber (NR) vulcanizates loaded with kenaf fibres were studied using (hydrated silica, resorcinol and hexamethylene tetramine) as the adhesion system.
Abstract: The mechanical properties and swelling behaviour of natural rubber (NR) vulcanizates loaded with kenaf fibres were studied using (hydrated silica, resorcinol and hexamethylene tetramine) as the adhesion system and compared with those of NR vulcanizates loaded with synthetic polyester short fibres (viscose). The effect of fibre content on the afore mentioned mechanical properties of NR vulcanizates was also studied before and after ageing. The kenaf fibres showed a higher reinforcing effect than that of synthetic polyester fibres and improved the rheological properties. Scanning electron microscopy was used to investigate the surface texture of unreinforced and reinforced vulcanizates.
TL;DR: In this paper, the impact damage resistance of carbon fiber/epoxy matrix composites containing short Kevlar fibres as the interlayer material was studied using low-velocity impact tests.
Abstract: The impact damage resistance of carbon fibre/epoxy matrix composites containing short Kevlar® fibres as the interlayer material was studied. Instrumented low-velocity impact tests were conducted at several temperatures to study the impact fracture and damage mechanisms. The experimental results indicate that short Kevlar fibres improved the impact damage performance. Distinct damage patterns were observed on the front and back faces of the specimens tested at two extreme temperatures; -60°C and 130°C. Cross-sectional microscopy was performed to evaluate sub-surface damage; optical and scanning electron microscopy were used to study the fracture mechanisms of the laminates impacted at different temperatures. The main contribution of the interlayer material to the improvement in impact resistance was the enhanced fibre-bridging with the short Kevlar fibres at the interlaminar regions.
TL;DR: In this article, a colloidal silica was used to treat glass fibres to improve their adhesion to polypropylene resin (PP), and the composites were also treated with a coupling agent and maleic anhydride modified polyethylene emulsion (MAPP) to enhance their interfacial bonding.
Abstract: Colloidal silica was used to treat glass fibres to improve their adhesion to polypropylene resin (PP). The glass fibres were also treated with a coupling agent and maleic anhydride modified polypropylene emulsion (MAPP) to enhance their interfacial bonding. The surfaces of the glass fibres were observed by scanning electron microscopy (SEM). Because colloidal silica made the surfaces of the glass fibres rougher, PP could anchor on the surface of glass fibres to improve the fibre/PP bonding. These results were proved by using a microbonding pull-out test. The composites of glass fibres and PP were fabricated by means of a twin screw extruder and an injection moulding machine. The tensile strength and flexural strength were determined and the fracture surfaces were observed by SEM to establish the contribution of the surface treatment. The test results demonstrate that the tensile strength of the composites reinforced by those glass fibres treated with colloidal silica first and then with coupling agent and MAPP was 73.4% higher than that of composites reinforced with untreated glass fibres, and 24.0% higher than that of composites without colloidal silica but still treated with coupling agent and MAPP. As for the flexural strength, the colloidal silica, coupling agent and MAPP-treated composite was 75.9% stronger than the untreated ones and 22.3% stronger than materials without colloidal silica but treated with both coupling agent and MAPP.
TL;DR: In this paper, the interfacial bonding between carbon fiber and epoxy resin was evaluated by measuring the interlaminar shear strength (ILSS), tensile strength before and after impact (TAI), and flexural strength.
Abstract: Polypyrrole (PPy) was deposited on carbon fibres via the oxidation-polymerization of pyrrole (Py) with ferric ions. These PPy-deposited carbon fibres were then made into composite boards with epoxy resin. The interfacial bonding between carbon fibre and epoxy resin was evaluated by measuring the interlaminar shear strength (ILSS), tensile strength before and after impact (TAI), and flexural strength. Experimental results show that deposition of PPy can improve the ILSS, tensile strength, and flexural strength. Furthermore, TAI is also reduced by the deposition of PPy. The interfacial bonding was the highest when the carbon fibre was immersed in 20 wt% FeCl 3(aq) and then reacted with 0.5 M Py in acetonitrile for 20 min.
TL;DR: In this paper, 50 mm glass fibres were used to prepare acrylonitrile butadiene rubber (NBR) phenolic-glass fibre composites by two-roll mill method.
Abstract: Mechanical properties of short fibre composites depend strongly on the fibre length. Therefore, in preparing short fibre composites, processing conditions are of great importance as they affect the final fibre length. In this study 50 mm glass fibres were used to prepare acrylonitrile butadiene rubber (NBR) phenolic-glass fibre composites by two-roll mill method. Fibre breakage during processing was studied and the fibre critical length was calculated. On the basis of the critical length, the usefulness of the two-roll mill method for preparing glass-NBR-phenolic composites with the specified formulation was assessed.
TL;DR: In this article, a linear generalized relationship was obtained between die swell and maximum recoverable deformation for all the gum and filled acrylate rubber systems except neat ACM, where there was a slight increase in activation energy.
Abstract: Rheological, mechanical and dynamic mechanical thermal properties of gum and filled acrylate rubber (ACM), fluoro rubber (FKM) and their blends were studied. The systems exhibited pseudo plastic flow behaviour. The shear viscosity of the blends decreased with higher concentration of ACM. There was little effect of temperature on the viscosity of the blends at different shear rates. Addition of filler to the 50/50 (w/w) ACM/FKM blend increased the shear viscosity. The equilibrium die swell decreased with increasing loading of carbon black and was affected by the filler type. A linear generalized relationship was obtained between die swell and maximum recoverable deformation. The activation energy of the melt flow process decreased with an increase in shear rate for all the gum and filled systems except neat ACM, where there was a slight increase in activation energy. The mechanical properties of the filled compounds improved linearly with filler loading. Tan δ peak temperature did not change with filler loading although the values of tan δ maximum decreased. The storage modulus of the blends increased with increasing filler loading, indicating the presence of polymer filler interactions.
TL;DR: In this paper, the authors investigated the effect of amine terminated butadiene-acrylonitrile (ATBN) rubber on the fracture toughness of an unsaturated polyester resin and composites.
Abstract: Improvement to the fracture toughness of an unsaturated polyester resin and composites by the addition of amine terminated butadiene-acrylonitrile (ATBN) rubber has been investigated. Addition of 6pph ATBN rubber gave a modest gain in fracture toughness of the resin. Electron microscopy studies showed that large agglomerates of a mixture of the rubber and the base resin were formed rather than discrete droplets of the rubber, and this is considered to be the reason for the modest gain in fracture toughness. Unidirectional glass fibre reinforced composites, made with ATBN toughened resin, showed significant gains in inter-laminar fracture toughness. The increased inter-laminar fracture toughness of the rubber modified resin is considered to be due to a combination of localised bonding between rubber/resin agglomerates and the glass fibres, and the lower tensile strength and flexural modulus of the rubber modified resin.
TL;DR: In this paper, the effect of the curing system and curing parameters, mechanical properties, ageing resistance, and crosslink density of NBR/EPDM blends has been investigated, and the results of dynamic mechanical investigations showed differences in the glass transition temperatures, which increased with increasing of the sulphur content in both single and binary accelerator systems.
Abstract: The effect of the curing system and curing parameters, mechanical properties, ageing resistance, and crosslink density of NBR/EPDM blends has been investigated. The curing characteristics of the blends were affected by the accelerator type and the sulphur concentration. The sulphur/benzothiazyl-disulphide (S/MBTS) vulcanizing system offered the best scorch safety, whereas those single and binary accelerator systems based on tetramethyl thiuram disulphide (TMTD) provided faster cure. The MBTS single accelerator system was able to crosslink the EPDM phase better and consequently displayed better mechanical performance than the other systems based on tetramethyl thiuram disulphide (TMTD). Higher thermal stability was also achieved in blends containing higher levels of sulphur, probably because of increased crosslinking in the EPDM phase. The results of dynamic mechanical investigations showed differences in the glass transition temperatures, which increased with increasing of the sulphur content in both S/MBTS and S/MBTS/TMTD vulcanizing systems. Formulations based on S/TMTD single accelerator systems gave the lowest values of Tg, and the amount of sulphur did not affect this property.
TL;DR: In this article, the dynamic viscoelastic properties of long organic fibres (aramid fibre, polyvinyl alcohol fibre, VF and polyamide fibre) reinforced polypropylene in the molten state were investigated.
Abstract: This paper deals with the dynamic viscoelastic properties of long organic fibre (aramid fibre (KF), polyvinyl alcohol fibre (VF) and polyamide fibre (PA6)) reinforced polypropylene in the molten state. Long organic fibres mixed with polypropylene fibres by an apparatus called a fibre separating and flying machine were compression moulded into 3mm thick composites. Dynamic viscoelastic properties ofthese composites were measured in the molten state using a rotational parallel plate rheometer. It was found that the dependence of angular frequency on storage modulus, G', for long organic fibre reinforced polypropylene is different from that of volume fraction of fibre, V f and the relationships depend on the characteristics of the reinforcing organic fibres. The slope of the dynamic viscosity, η'vs. angular frequency, ω curves increases gradually up to 45 degrees with increasing Vf. Influence of fibre content on dynamic viscoelastic properties depends on the organic fibre used. For low fibre content, G' increases with increasing V f in the same way as η'. However, the opposite trend is observed for high fibre content composites. It can be deduced that there is an apparent yield from the relations between complex viscosity, η * and complex modulus, G * . The yield value, G * increases gradually with increasing fibre content and approaches a fixed value. All of the long organic fibre reinforced polypropylenes studied here are more sensitive to temperature than inorganic fibre reinforced composites.
TL;DR: In this paper, a statistical analysis for the fiber strength and breaking strain is presented to test the experimental data relating to the fiber deformation, and the output of the analysis supports the concept that the Weibull model is a good technique to specify the statistical distribution for strength and bending strain of fibres and of suitable to investigate, is the deformation behaviour of fibrous polymeric materials in general.
Abstract: This work deals with the plastic deformation of polypropylene, PAN-based carbon and Kevlar fibres at different gauge lengths and uses the Weibull model. A statistical analysis for the fibre strength and breaking strain is presented to test the experimental data relating to the fibre deformation. The mechanical parameters such as fibre strength, breaking strain and Young's modulus have been studied as a function of gauge length. It was found that both strength and breaking strain increase as fibre gauge length decreases, while the Young's modulus increases with increasing gauge length and depends on both strength and breaking strain. The output of the analysis supports the concept that the Weibull model is a good technique to specify the statistical distribution for strength and breaking strain of fibres and of suitable to investigate, is the deformation behaviour of fibrous polymeric materials in general.