Weave Parameters Research Articles

Multi-Scale Finite Element Analyses of Thermal Conductivities of Three Dimensional Woven Composites

This paper summarizes an extensive experimental and prediction study of thermal conductivities of three-dimensional woven composites (3DWCs). Three kinds of innovative 3D woven architectures are examined, including 2.5D angle-interlock, 2.5D angle-interlock (with warp reinforcement), and 3D orthogonal woven architectures. The differences of thermal behaviors of 3DWCs in plane and out of plane are assessed by using multi-scale finite element analysis. For the validation of models, the thickness direction thermal conductivity of 3DWCs are measured. It is indicated that the predicted results are in good agreement with the experimental results. The effects of weave density and fabric architecture on the distribution of heat flux and temperature have been discussed in this work, which determined the thermal conductivities of 3DWCs. From this study, it can be expected that the need of thermal performance of 3DWCs can obtained according to optimize the weave parameters based on the high designability of 3DWCs.

Mechanical behavior and failure mechanism of 2.5D (shallow bend-joint, deep straight-joint) and 3D orthogonal UHWMPE fiber/epoxy composites by vacuum-assistant-resin-infused

Ultra-high molecular weight polyethylene (UHMWPE) fiber/epoxy composites were fabricated by a vacuum assisted resin infused (VARI) processing technology. The curing condition of composites was at a cure temperature of 80 °C for 3h in a drying oven. The characteristics of 2.5D (shallow bend-joint and deep straight-joint) structure and 3D orthogonal structure were compared. The failure behavior, flexural strength, and microstructures of both composites were investigated. It was found that the flexural property was closely related to undulation angle θ. The flexural strength of 3D orthogonal structure composite was superior to the other two structures composites with the same weave parameters and resin.

A new experimental setup to characterize the dynamic mechanical behaviour of ballistic yarns

Fabrics have been widely used as part of ballistic protections since the 1970s and the development of new ballistic solutions made from fabrics need numerical simulations, in order to predict the performance of the ballistic protection. The performances and the induced mechanisms in ballistic fabrics during an impact depend on the weaving parameters and also on the inner parameters of the yarns used inside these structures. Thus, knowing the dynamic behaviour of yarn is essential to determine the ballistic behaviour of fabrics during an impact.Two major experimental devices exist and are used to test ballistic yarns in a dynamic uniaxial tension. The first one corresponds to the Split Hopkinson Tensile Bars device, which is commonly used to characterize the mechanical properties of materials in uniaxial tension and under high loading. The second one is the transversal impact device. The real conditions of ballistic impact can be realized with this device.Then, this paper deals with a new experimental setup developed in our laboratory and called the ‘tensile impact test for yarn’ (TITY) device. With this device, specific absorbed energy measurements of para-aramid yarns (336 Tex, Twaron™, 1000 filaments) have been carried out and revealed that static and dynamic properties of para-aramid are different.

Effect of Weave Parameters on the Air Resistance of Woven Fabrics

An investigation of the effect of weave parameters, namely Crossing Floating Factor (CFF), Floating Yarn Factor (FYF) and Fabric Firmness Factor (FFF) and the geometrical properties of woven cotton fabrics such as the areal density, thickness and porosity on air resistance is reported. A series of cotton woven fabrics comprising eleven weave structures and having a common count in the warp and weft and fabric sett was produced. Essential data such as the CFF, FYF, FFF, areal density, thickness and porosity were obtained. They were divided into four groups on the basis of their CFF and FFF, with each one designed to represent a particular effect. Air resistance was determined by performing the standard test KES- F8 – API. Analysis of the results shows a strong correlation between the CFF, FYF, FFF and air resistance. Fabrics which have long floats were characterized by lower air resistance, and the fabric which had no float displayed higher air resistance. The thickness is found to be well correlated with air resistance. Thus in addition to the CFF, FYF and FFF, the thickness should also be taken into consideration for predicting the air resistance of fabrics.

A Statistical Approach for Obtaining the Controlled Woven Fabric Width

Abstract A common problem faced in fabric manufacturing is the production of inconsistent fabric width on shuttleless looms in spite of the same fabric specifications. Weft-wise crimp controls the fabric width and it depends on a number of factors, including warp tension, temple type, fabric take-up pressing tension and loom working width. The aim of this study is to investigate the effect of these parameters on the fabric width produced. Taguchi’s orthogonal design was used to optimise the weaving parameters for obtaining controlled fabric width. On the basis of signal to noise ratios, it could be concluded that controlled fabric width could be produced using medium temple type and intense take-up pressing tension at relatively lower warp tension and smaller loom working width. The analysis of variance revealed that temple needle size was the most significant factor affecting the fabric width, followed by loom working width and warp tension, whereas take-up pressing tension was least significant of all the factors investigated in the study.

Analysis and modeling of 3D Interlock fabric compaction behavior

During the preforming stage in Liquid Composite Molding (LCM), fibrous reinforcements are compacted to obtain the specified fiber volume fraction. Numerous studies have been carried out to understand their compression behaviors. The first objective of this investigation is to study experimentally the influence of the weaving parameters on the compaction behavior of five different 3D Interlock fabrics. In parallel, composite parts were fabricated to perform a microscopic analysis of fabric deformation after compression. The second objective is to provide a model of the experimental results. Since there is no nesting in three-dimensional woven fabrics, the compaction behavior turns out to be easier to predict than for laminates. A model based on experimental observations was devised to connect the compaction behavior with the deformation modes of five fabrics investigated. The good correlation with experiments confirms the assumptions on the main factors governing the compaction and relaxation of 3D Interlock fabrics.

In-plane and through-thickness permeability models for three-dimensional Interlock fabrics

An analytical model has been created to estimate the in-plane and through-thickness permeability of three-dimensional Interlock fabrics. The model is based on the calculation of the pressure drop in the mesoscopic pores, i.e. in the inter-tow spaces of the fabric. Firstly, the dimensions and distribution of the mesopores are determined from the weaving parameters. A mesoscopic permeability model can then be inferred from the fabric structural data. The contribution of the microscopic flow inside the tows is also taken into account by introducing the concept of dual scale porosity. This additional feature is shown to improve the permeability model, which is validated by comparison with the experimental values of principal permeability measured for five different three-dimensional Interlock fabrics.

Finite Element Analysis of 2.5D Woven Composites, Part I: Microstructure and 3D Finite Element Model

A new parameterized finite element model, called the Full-cell model, has been established based on the practical microstructure of 2.5D angle-interlock woven composites. This model considering the surface layer structure can predict the mechanical properties and estimate the structural performance such as the fiber volume fraction and inclination angle. According to introducing a set of periodic boundary condition, a reasonable overall stress field and periodic deformation are obtained. Furthermore, the model investigates the relationships among the woven parameters and elastic moduli, and shows the structural variation along with the corresponding woven parameters. Comparing the results calculated by FEM with the experiments, the veracity of calculation and reasonability based on the Full-cell model are confirmed. In the meantime, the predicted results based on the Full-cell model are more closed to the test results compared to those based on the Inner-cell model.

Shear properties of three‐dimensional woven composite reinforcements

This paper presents a comprehensive experimental study and detailed mechanistic interpretations of the shear deformation of three‐dimensional (3D) reinforcements. Six types of 3D angle interlock glass fiber preforms (3DAP) were fabricated using a range of weave parameters including the fabric density, fabric layer, and yarn linear density. A modified picture frame was developed to ensure a pure shear load during the test. Through a series of comprehensive tests, our results demonstrated that the fabric density played a key role in the mechanical properties of 3DAP and that the reinforcements with low fabric density and yarn linear density were easy to shear. The shear deformation mechanism was analyzed based on the meso‐structure. It is expected that this research will provide preliminary work for building a theoretical model of 3D woven preform. POLYM. COMPOS., 38:244–251, 2017. © 2015 Society of Plastics Engineers

Thermal and mechanical characterization of novel basalt woven hybrid structures

This paper presents a study conducted on the thermal and mechanical properties of basalt hybrid and nonhybrid woven structures. While designing fabrics for various industrial textile applications, the knowledge about the mechanical properties is very important. Strength, modulus, and elongation are the most important performance properties of fabrics governing their performance in high-end applications. The thermal properties of the fabrics, i.e. thermal resistance, thermal conductivity were also studied vis-a-vis physiological behavior. In this work, state-of-the-art evaluation techniques are used, which provide reliable nondestructive measurement of thermal conductivity, thermal resistance, water vapor permeability, and air permeability of fabrics. The effect of structure and composition on the above-mentioned properties of such nonstandard fabrics has been investigated in detail. The results of the study show that effect of fiber composition, weave, and geometrical parameters on thermal and mechanical properties is significant in basalt hybrid fabrics.

Effect of weave frequency and amplitude on temperature field in weaving welding process

The welding with weaving has been used widely to obtain better weld quality by avoiding lack of side wall fusion and improve the weld efficiency by obtaining the wide weld bead. But the effect of weave frequency and weave amplitude on the temperature field is not clear. In the present paper, a coordinate transformation method is put forward to simulate the weave welding process. The temperature distribution during the welding with weaving under different weave parameters are compared and discussed. Comparison between experimental and simulation results reveals a good agreement. The peak temperature and the average temperature in weld seam center decreased due to the increasing of the weave amplitude and weave frequency. But the weave frequency has less effect on the average temperature.

Designing of engineered fabrics using particle swarm optimization

Purpose – The purpose of this paper is to design woven fabrics with desired quality and low manufacturing cost by optimizing the weave parameters such as count, crimp and thread spacing of warp and weft yarns. Design/methodology/approach – To fulfill this goal, the authors endeavor to devise a searching mechanism based on particle swarm optimization (PSO) for efficiently finding the appropriate combination of weave parameters. Findings – The experimental validation confirms that the proposed method has an excellent search capacity to obtain the best combinations of weave parameters for producing the fabrics with requisite quality at low cost. Practical implications – The quick response capability of the system would benefit the fabric manufacturers for efficient determination of the required weaving parameters to produce the engineered fabrics. Originality/value – This paper offers a maiden application of PSO technique to design engineered products in textiles. The method is easy to implement and it is computationally inexpensive as fewer parameters are involved.

A study on correlation between warp tension and weaving condition

In connection with an effect on development of dynamic model of beat-up process, beat-up force and weaving condition, this study has investigated a correlation of 4 kinds of weaving factors (warp tension, weft thickness, weft density and shedding height) that affect beat-up force through an experimental method and analytic method. A simulator was developed to imitate beating, shedding, and insertion motions for weaving and the experiment was performed using the simulator. The experiments showed following results: First, the beat-up force increased proportionally as the warp tension increased. Second, the beat-up force increased with the increase of the weft thickness. Third, the beat-up force was exponentially inversely proportional to the weft density. Finally, the beat-up force was increased with the increase of the shedding height. Various experimental and simulation methods were performed to investigate the contribution of the principal weaving parameters to the beat-up force.

Evaluation of Elastic Properties of Satin Composites

Advancements in the numerical modelling of 3D woven composites have allowed improved understanding of the mechanical behaviour and in turn aided the design and analysis of new materials. The objectives of this paper are to utilise FEA (Finite Element Analysis) methods to determine the elastic properties of a given woven composite. The investigation focuses on satin weaves, considering both 5-harness and 8-harness varieties. Multi-scale analysis results of an RVE are used to formulate the stiffness matrix and consequently determine the elastic properties; these will be compared to published analytical methods and experimental results. Further investigations considering the effect of weave parameters on the elastic properties are conducted.

Engineering design of woven fabrics using non-traditional optimization methods: A comparative study

This work aims to design woven fabrics with desired quality at optimum manufacturing cost by choice of suitable weaving parameters such as count, crimp and thread spacing of warp and weft yarns. To fulfill this goal, we endeavor to devise search based non-traditional optimization methods such as genetic algorithm, particle swarm optimization and simulated annealing for efficiently finding the appropriate combination of weave parameters. The quick response capability of the non-traditional optimization methods would benefit the fabric manufacturers for efficient determination of the required weaving parameters to produce the engineered fabrics. The experimental validation confirms that the particle swarm optimization is most suitable technique for engineering design of woven fabrics.

Influence of Weaving Parameters on Aging Performance of Polyester Oxford

Aging performances of polyester oxford with different weaving parameters were analyzed. Filament fineness and fabric density were key parameters. The filaments’ tensile strength, the characteristic groups on the fiber surface by FTIR and the determination of terminal carboxyl group were tested, and then the changes of characteristic groups were analyzed by internal standard working curve methods. It was resulted that during the former aging, the orientation of fibers were destroyed, meanwhile the ester bonds on carboxyl decreased and ester bonds on (C-O-C) formed, and during the later aging, etching on the surface of fibers made the ester bonds sharp decreasing. Compared with different fineness, thicker fibers with one more stretch process have the higher degree of orientation, and then prolong the aging. Then compared with different fabric density, the higher density can prolong the aging, provided of no frictions harm fibers during weaving.

Abrasion evaluation of spliced and parent yarns with a new simulator abrader tester

In order to evaluate the abrasion effect on both spliced and parent yarn performances, a newly developed abrader tester simulating the real cumulative weaving stresses is used. Three weaving parameters: loom speed, splice positions during weaving and yarn tension are tested to simulate the mechanical behaviour of spliced and parent thread yarns. The results show that the spliced yarn’s abrasion resistance, expressed by lifetime cycle numbers, is more affected by the weaving parameters used in our developed abrader simulator tester than by others. In this work, the results obtained by our simulator abrader tester and the cyclical tensioning ones are compared to regression analysis models. According to the highest coefficients of determination ranging from 0.955 to 0.999, it is found that a good prediction of spliced and parent yarn breakages is possible. Comparing two interesting splice positions on the loom: the splice beat-up position and the splice shedding one, we conclude that the splice shedding position increases breakage rate.

Compressibility Behaviour of Warp Knitted Spacer Fabrics Based on Elastic Curved Bar Theory

Nowadays, the mechanical characterization of 3-D spacer fabrics has attracted the interest of many textile researchers. These Spacer fabrics present special mechanical and physical characteristics compared to conventional textiles due to their wonderful porous 3-D structures. These fabrics, produced by warp knitting method, have extensive application in automobile, locomotive, aerospace, building and other industries. In these applications, the compressibility behaviour plays a significant role in the fabric structural stability. This compressibility behaviour could be affected by different knitting parameters such as density of pile yarn, fabric thickness, texture design etc. The aim of this paper is to introduce and develop an appropriate elastic theoretical model to predict the compressibility behaviour of warp knitted spacer fabric (WKSF). Three theoretical models are proposed, based on modelling pile yarns as the curved bars and are improved in three steps: a) with same curvatures in weft and warp directions (model A), b) curved bar for warp direction and cantilever bar for weft direction (model B), and c) curved bars with two different curvatures in weft and warp directions considering the curvature variations under loading (model C: improved model). The results obtained by the proposed models have been compared with previous model based on simply cantilever bars theory in literature. The results show that the simulation data obtained by the model C are closer to the experimental results comparing to the models A and B. Model C based on different weave parameters could better predict the elastic compressibility behaviour of this kind of WKSF in order to compare with previous models.

Studies on Automatic Recognition System of Fabric Weaves’ Parameters

In virtue of having some periodicity in space, the fabric weave pattern can be recognized by using computer image process technology. Firstly, the reflected image and transmissive image of fabric were scanned and disposed. Then its image of two-dimensional power spectrum and image of autocorrelation were obtained by means of Fourier transform technology. Finally the fabric weave parameters can be calculated, including density of warp and weft, the size of warp and weft and the yarn numbers of weave repetition etc. Based on foregoing theory, this paper develops automatic recognition system of fabric weave parameters, which is worth of popularizing.

Effect of fabric compaction and yarn waviness on 3D woven composite compressive properties

3D-woven fabrics incorporate through-thickness reinforcement and can exhibit remarkable inter-laminar properties that aid damage suppression and delay crack propagation. However, distortions in the internal architecture such as yarn waviness can reduce in-plane properties, especially in compression. The degree of yarn waviness present in a 3D woven fabric can be affected by a range of factors including weave parameters and manufacturing-induced distortions such as fabric compaction. This paper presents a thorough analysis of the effect of fabric compaction and yarn waviness on the mechanical properties and failure mechanisms of an angel-interlock fabric in compression. Tests were conducted on coupons moulded to different volume fractions and data compared to previous measurements of local yarn angle. Major findings show the importance of yarn straightness on compressive strength and how this can be affected by optimising moulding thickness. Failure initiation was also found to be heavily influenced by weave style and yarn interlacing.