Mohamad Faizul Yahya

Effect of impactor shapes and yarn frictional effects on plain woven fabric puncture simulation

Research in modeling and simulation of woven fabrics has been quite intensive in the past decade. The simulation studies presented confined consideration of crimp and extension roles in the damage deformation process, in particular tensile and puncture. Most simulation works are struggling to relate internal yarn interactions with respective damage modes due to the unit cell approach. Hence, in the present study, an alternative finite element analysis approach was proposed to model yarn crimp and extension response during puncture based on the validated uniaxial tensile and puncture models. Puncture stress–strain, post-impact kinetic energy and damage evolution of full-scale woven fabrics models were evaluated with two impactor shapes and three friction levels. The results show that puncture damage behavior is the critical dependent of the magnitude of impactor shapes and yarn frictional contacts. Good comparisons with the experimental and previous studies demonstrate the approach’s suitability for modeling textile in composites.

Uniaxial failure resistance of square-isotropic 3D woven fabric modelled with finite element analysis

The article presents an extensive experimental test and finite element simulation of plain 1/1 woven fabric subjected to uniaxial loading. Square woven fabric is configured to allow systematic investigation of weave effects under uniaxial tensile load. The geometric fabrics models consisting of warp and weft yarns are imported to finite element analysis package, ABAQUS, for mechanical performance simulation. Simulated and experimental stress-strain validation of plain is reported to have strong positive correlation of 0.9986 and 0.999 in warp and weft direction, respectively. Further analysis is performed on the validated models such as stress distribution groups and maximum stress regions.

Effects of metal filament’s alignment on tensile and electrical properties of conductive hybrid cover yarns

AbstractOf late, a significant amount of research has been carried out using metals for conductive fabrics and composites to obtain the desired level of electromagnetic shielding along with physical and mechanical properties for its durability. However, incorporating these metallic filaments as core or as an integral part of core deteriorate the mechanical properties of textile yarns and ultimately the fabrics’. Moreover, the transparency of fabrics to high frequency/smaller wavelength waves further increases with the attempt to increase the metallic filament diameter. This study, therefore analyses the effects of metallic filament alignment in order to improve the mechanical properties of the resultant hybrid yarns, and devises an alternative method to increase the amount of conductive filament without increasing the diameter of the conducting wire in hybrid yarn structures. The results suggest that the tensile properties of the proposed hybrid cover yarns with conductive filament as covering component is superior as compared to the yarns having a conductive filament in the core, however, the electrical resistance increases with an increase in conductive filament length. The tenacity, elongation and initial modulus values were enhanced several times by incorporating the conductive filament as spiral covering. Moreover, with the proposed alignment method, the amount of copper in hybrid yarn can be increased up to some extent by changing the number of turns of covering component.

An alternative approach to design conductive hybrid cover yarns for efficient electromagnetic shielding fabrics

E-Textiles have gained enormous attention due to their specific characteristics in various non-conventional applications such as electromagnetic shielding materials. With the advent of various high frequency-driven devices, the need to restrict the non-ionizing radiations from their undesired effects became imperative. Due to the ease of production, better electrical conductivity and durability, the conductive hybrid cover yarns with continuous metallic filaments have earned its place as the most convenient form of yarns to develop E-textiles. However, controlling the amount of conducting material in yarns poses a challenge as the increase in size of the metallic filaments are associated with reduced electromagnetic shielding effectiveness due to increased stiffness of yarns, which resists in proper interlacement and hence causes openness in fabrics. The proposed design of conductive hybrid cover yarns is proven to have better tensile properties and modulus, therefore this design is more suitable to produced fabrics with higher cover factors. The amount of conducting material in the proposed design increased significantly without changing the size of the continuous filaments. Moreover, 99.9% shielding effectiveness is achieved with this increased metal content in fabrics in S-band and partly C-band microwave frequencies.

Tensile and Flexural Properties of Composites Made from Spinning Waste

ABSTRACT Spinning especially combed yarn produces considerable waste fibre. These fibres are sold at very low price for fillings. An investigation of converting these wastes to some form of value-added material was successful in forming a composite material made from natural fibre. Cotton combing noils and blowing waste were fabricated into thin composite boards using polyester resin at room temperature utilising a compression method. Tests on tensile and flexure properties of these composites were evaluated against 100% polyester resin plaques. It was found that composites made from cotton waste were stronger than polyester without the reinforcement. Some possible applications of these composites are thin boards or panels that can be used to replace wood and fibre-board products.

Modeling Plain Woven Composite Model with Isotropic Behavior

Research in woven fabric composites modeling and simulation has been extensively done in the past decade. The simulation issue is associated with estimating yarn transverse isotropic property. Most simulation models are attempting to achieve high level of accuracy with unit cell approach. Thus, in the present study, an alternative finite element analysis approach was designed to model uniaxial tensile performance of Kevlar-based plain woven fabric with isotropic material property. The dynamics of a finite element model were investigated at a wide range of mesh levels. The results show that the plain woven fabric failure critically depended on the yarn and woven fabric structure. Good comparisons were achieved with experimental work, and further application in more complex weaves is suggested.

Finite element analysis of impactor shapes effects on puncture damage of plain woven fabric

The article presented finite element analysis work on modelling impactor shape effects on plain woven fabric puncture damage. Woven fabric models were developed with ABAQUS finite element analysis software package. Large scale woven fabric models consisting of 112 yarns in both warp and weft direction were developed with ABAQUS preprocessor module prior to simulation analysis. Woven fabric model development procedure for finite element analysis was based on the validated uniaxial tensile model reported in the earlier publication. Four impactor shapes for the simulation were flat, hemispherical, conical and ogival. The simulation results were analyzed in terms of stress-strains, post-impact kinetic energy and damage evolution. The research proposed that crimp interchange and yarn extension are two important mechanisms in woven fabric puncture.

Characterization based on the thermal capabilities of metallized fabrics equipped with hybrid conductive yarns for protective clothing

Abstract Electronic textiles are recognized for their conductive characteristics in various fields of research including medicine, communications, power and for the development of protective clothing. Out of the several types of conductive textile available, multi-component yarns and fabrics, produced from continuous copper filament as spiral covering on hybrid cover yarns, have never been investigated for their thermal capabilities. In this study, characterization based on the thermal properties for conventional copper core yarn’s fabric and newly developed copper cover yarn’s fabrics was carried out. The results demonstrate better conductivity of copper cover yarn’s fabrics as compared to the copper core conventional fabrics, which is attributed to its better conduction due to greater percentage of copper and direct contact between the heat flux transducers. With the higher porosity values for the newly developed fabric, the liquid water, water vapour and air transport capabilities, which are key aspects of thermal comfort, significantly improved.

Tensile Strength and Evenness of Kenaf/Polyester Blended Rotor-Spun Yarn

This paper reports on some properties of kenaf/polyester blended yarns which were spun using rotor spinning at different rotor speeds and fibre blends ratio. The blended yarns were spun at 50,000; 60,000; and 70,000 rpm rotor speeds. The kenaf and polyester fibres were mixed at the carding process at percentages of 5/95, 10/90 and 15/85, respectively. The size of the yarn was kept constant at 40 Tex. It was found that with higher percentage of kenaf fibres, the yarn tensile strength decreases at every rotor speed. The yarns produced from 5/95 blending ratio at rotor speed of 60,000 rpm have the highest strength among the other yarn samples. The yarn imperfections also showed similar trend as the tensile strength. The study also showed that the yarn evenness and imperfections were lowest for yarns with the least percentage of kenaf fibres.

Proceedings of the International Colloquium in Textile Engineering, Fashion, Apparel and Design 2014 (ICTEFAD 2014)

Electrospraying is a method of generating a fine mist through electrostatic charging. It is used for producing polymer droplets at submicron range, which enhances functional properties of the substrate after deposition by providing thin level coating and larger surface area. In this research, in order to impart multifunctionality to substrate, the two distinct polymers thermoplastic polyurethane (TPU) and poly vinyl chloride (PVC) are electrosprayed simultaneously by specially designed nozzle. Energy dispersive spectroscopy (EDS) was used to confirm the bicomponent droplet fabrication. The results show that new electrospraying system demonstrated the feasibility of producing bicomponent TPU/PVC polymer droplets.