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The purpose of this paper is to conveniently and accurately design partial knitting knitted fabrics based on matrix transformation.

Using mathematical modeling, the pattern diagram block matrix and process design matrix of partial knitting knitted fabrics are established, and the process knitting diagram with parameter information is generated. Based on the establishment of the mathematical model of the process knitting diagram, a loop deformation method based on three-dimensional (3D) coordinate point matrix transformation is proposed.

The matrix transformation method can provide a suitable deformed loop mode for partial knitting knitted fabrics and helps to generate a 3D modeling diagram conveniently.

This paper proposed a method of design and modeling of partial knitting knitted fabric based on matrix transformation. Taking the 3D modeling effect of conventional partial knitting as an example to test the modeling method, the results show that after matrix transformation, the loop model can realize the rapid transformation and calculation of the coordinates of the control point and generate a 3D modeling diagram.

The purpose of this paper is to elucidate the stress-strain relationships of single-jersey knitted fabrics from uniaxial tensile test followed by deformation behavior using finite element analysis. In order to elaborate the study, high, medium and low tightness knitted fabrics were selected and deformation of fabrics analyzed in course, wales and bias directions (0, 45 and 90 degrees).

This study focussed on uni-axial tensile test of produced test samples using Instron 6021 tester and a development of single-jersey knitted loop model using Auto Desk Inventor software (ADI). The knitted fabric material properties and knitted loop model was imported to ANSYS 12.0 software.

Due to structural changes the tightness and thickness of knitted fabric decreases with increase in loop length The tensile result shows maximum breaking strength at course direction (13.43 kg f/mm2 at 2.7 mm) and maximum extension at wales direction (165.77 kg f/mm2 at 3.3 mm). When the loop length increases, the elongation of fabrics increased and load carrying capacity of fabrics reduced. The Young's modulus, Poisson's ratio and shear modulus of fabrics reduced with increase in loop length. The deformation of fabrics increased with increase in loop length. The increase in loop length gives large amount of structural changes and it is due to slacking or jamming in loops and loosening in dimensions. When comparing the deformation results, the variation within the fabric is higher and structural damage little more when increasing the loop length of the fabric.

From ANOVA test, stress and strain distribution was statistically significant among course, wales and bias directions at 95 percent confidence level. The values got from Instron test indicates that testing direction can alter its deformation. In deformation analysis, comparing both experimental and prediction, high amount of structural changes observed in wales direction. The used tetrahedral elements can be used for contact analysis with high accuracy. For non-linear problems, consistent approach was proposed which makes the sense to compare with experimental methods. The proposed model will make possible developments and the preliminary validation tests shows good agreement with experimental data.

Fabric-object friction force is a fundamental factor in cloth simulation. A large number of parameters influence the frictional properties of fabrics such as fabric structure, yarn structure, and inherent properties of component fibers. The purpose of this paper is to propose a novel technique for modeling fabric-object friction force in knitted fabric simulation based on the mass spring model.

In this technique, unlike other studies, distribution of friction coefficient over the fabric surface is not uniform and depends on the fabric structure. The main reason for considering non-uniform distribution is that in various segments of fabric, contact percent of fabric-object is different.

The proposed technique and common methods based on friction coefficient uniform distribution are used to simulate the frictional behavior of knitted fabrics. The results show that simulation error values for proposed technique and common methods are 2.7 and 9.4 percent as compared with the experimental result, respectively.

In the existing methods of the friction force modeling, the friction coefficient of fabric is assumed uniform. But this assumption is not correct because fabric does not have an isotropic structure. Thus in this study, the friction coefficient distribution is considered based on fabric structure to achieve more of realistic simulations.

In this paper two methods for 3Dimensional modeling of the plain weft knitted structures are presented. The aim is models to be more realistic concerning yarn cross section properties. The first model is based on the assumption that yarn cross section changes to ellipse-like form in the areas with high curvature. The second one is a discrete particle model of the loops, which takes into account the local changes of the yarn following from the contact forces. It calculates actual yarn geometry on the contact places iteratively, as general nonlinear compression behavior of the yarn is assumed.

The purpose of this paper is to develop mathematical relationships to calculate the loop length to knit compact plain knitted fabrics and to validate the model using the fabric parameters of commercial fabrics.

Ellipse defines the shape of the head of a knitted loop and straight lines define the arms of a knitted loop. The mathematical relationships developed relate the yarn count to the loop length of compact knitted fabrics. The experimental data and the data from previous similar research validate the accuracy of the mathematical model.

The model can calculate loop lengths to knit compact plain knitted fabrics in terms of thickness of the yarn and the coefficient defined to express the ratio of minor axis to major axis of the ellipse that defines the shape of the head of the loop. The mathematical model can deliver several loop lengths to produce compact plain knitted fabrics for different values of this coefficient. For commercial fabrics the error of the model was 0.53%.

The present model defines the head of the loop as an ellipse. The uniqueness of the present model is that several ellipses can exist for any given yarn thickness for a range of values assigned to the minor axis of the ellipse. The accuracy of the model against experimental data ascertains that the model is closer to the reality for commercial fabrics and proves the uniqueness of the model. Further, this model is an ideal and a simple model to introduce knitted loop configurations in teaching knitted fabric geometry.

Multilayer weft knitted fabrics possess many advantages, such as strongly stereoscopic patterns, soft handling and adjustable thickness of apparel and home textiles use. However, it is difficult to predict the final visual effects before the productive process because of the three-dimensional (3D) effect caused by the connecting yarn of the fabric. The purpose of this paper is to realize a realistic simulation of the fabric.

The authors applied to the curve and surface model to simulate the knitted fabric, instead of previous single loop model by NURBS. Macro simulation is more suitable for the fabric with the 3D effect because of the quick, real and convenient simulation. This research includes experiments on the structural parameters concerning the regular sag of multilayer weft knitted fabrics, and analysis of parameter data and the simulation process with the aim of realizing a computer simulation of the fabric, especially with a sense of reality. The Digital Elevation Model was also applied to build a simulated 3D model.

To obtain the values for the change rules, different samples were used and the outputs of the model were found to be close to the experimental results. The thickest and thinnest lengths and the changing curves between them were established. Patterned simple multilayer weft knitted fabric could be simulated through the results of the research. It is possible to simulate different real fabrics using their materials and expected effects. The authors are going to improve the model to simulate the complicate large-scale jacquard fabrics in further research.

The results will be useful for establishing a computer surface simulation system for stereo perception of fabrics.

The authors put forward the concept of surface warpage degree (R). It is an important factor affecting the fabric stereo feeling. The larger the value of R, the stronger the stereo sense of the fabric. It could be applied to most 3D fabric. A thickness difference testing method was proposed to characterize the stereo perception of fabrics. It is possible to simulate different real fabrics quickly without the model of the woven loop.

Double-jacquard technique is referred as the most advanced technology for forming patterns on both layers of a 3D fabric knitted on a double-needle bar warp-knitting machine. In order to realize the computer-aided design and simulation of jacquard patterns, the purpose of this paper is to propose a mathematic model for representation of jacquard structures and an improved mass-spring model to improve the simulation of structural deformation behavior.

Primarily, it analyzes the jacquard patterning method and displacing principle to design jacquard structures on each layer and linking structures of two layers. Based on that, a loop geometry defined by six key points and segmental lines is built to transfer the jacquard bitmap and lapping movements into a fabric of loops and therefore realizing patterns visualization. Afterwards, an improved mass-spring model is built to simulate structural deformation, in which the fabric is simplified as a mesh of uniformly distributed mass particles. Each loop is treated as a massless particle while underlaps are referred as structural springs connecting loops particles. Elastic forces of these springs on each loop particle is calculated according to the Hook’s law and Newton’s second law, and then based on the explicit Euler’s equations, motion state of each particle is solved including the velocity and the shift.

Based on the above method, a simulator for double-layer jacquard fabrics is developed via Visual C++ language to visualize the patterned fabrics with pitting effects. With a jacquard shoe fabric as an example, this simulation model is proved to be practical and efficient by comparing the simulation result and real fabric.

Because of limited researches, 3D simulation modeling of this double-layer jacquard fabric will be studied in the further research.

The implement of this simulation method will offer the industries a time-saving and cost-saving approach for new fabrics development.

This approach can be used as a reference for simulating other knitted fabrics with jacquard patterns, such as jacquard garment fabrics and home textile fabrics.

A method for predicting the material consumption of a sweater is presented before it is knitted. It can be achieved with the five basic models combined with the parameters related to the dimensions of the knitting machine and needles. The paper aims to discuss these issues.

Based on the parameters of the needle bar flat knitting machine, the sweater is modeled with five basic structures. The mathematical expression of each basic structure can be derived with corresponding parameters under some consumptions. In following, the predictive weight of the sweater can be formulated with the expression of the length of the basic structures and the linear density of the yarn.

To evaluate the performance of the proposed scheme, experiments of three types of sweaters on four different knitting machines are carried out. The results show that the proposed method can achieve the performance with the bias values by percentage ranging from −1.54 to −2.84 percent.

Due to the present limited research, more experiments could not be carried out. To improve the performance and robustness of the proposed method, statistical performance measures such as the statistical mean and variance in massive experiments will be studied in the further research.

The evaluation of the material consumption can be obtained before it is knitted with the known basic parameters related to the machine and yarn.

This paper derives the general expressions of five basic structures based on the corresponding parameters of knitting machine. The predictive weight of the sweater is expressed according to the above basic structures before the sweater is knitted.

The weft-knitted two-side jacquard fabric has the characteristics of complicated design principle and hard technical design. The purpose of this paper is to realize the computer-aided design of weft-knitted two-side jacquard fabric, and provide a certain reference for the development of this type of fabric.

The weft-knitted two-side jacquard fabric is divided into weft-knitted two-side similar pattern jacquard fabric and weft-knitted two-side independent pattern jacquard fabric. In order to achieve the purpose of this study, firstly, the structural characteristic of weft-knitted two-side jacquard fabric is analyzed. Then, the design principle of weft-knitted two-side jacquard fabric is studied. Next, the technical model of weft-knitted two-side jacquard fabric is established. Finally, the CAD flow chart of weft-knitted two-side jacquard fabric is proposed to realize the rapid product development.

Based on the above method, through the development example of weft two-side similar pattern jacquard fabric and weft two-side independent pattern jacquard fabric, the computer-aided design of the weft two-side jacquard fabric is verified.

Because of limited research studies, three-dimensional computer-aided design of weft-knitted two-side jacquard fabric loop structure will be studied in the further research, and the technical design speed needs to be improved to meet the needs of large patterns and positioning patterns.

The computer-aided design of weft-knitted two-side jacquard fabric will offer a certain reference for product development, technical principles, performance research and computer simulation for the in-depth study of the fabric.

The computer-aided design of weft-knitted two-side jacquard fabric will simplify the fabric design process and improve the efficiency of new fabric development, and provide the industries a time-saving and cost-saving approach for new fabrics development.

The author analyzes the structural characteristic of the fabric by the physical fabric, summarizes design principle of the fabric through production process, uses mathematical methods to establish a three-dimensional technical model of the fabric, and proposes the CAD flow chart of weft-knitted two-side jacquard fabric, which has good theoretical significance and practice of weft-knitted two-side jacquard fabric.