Analysis of Polygonal Computer Model Parameters and Influence on Fabric Drape Simulation

Contemporary CAD systems enable 3D clothing simulation for the purpose of predicting the appearance and behavior of conventional and intelligent clothing in real conditions. The physical and mechanical properties of the fabric and the simulation parameters play an important role in this issue. The paper presents an analysis of the parameters of the polygonal computer model that affect fabric drape simulation. Experimental research on physical and mechanical properties were performed for nine fabrics. For this purpose, the values of the parameters for the tensile, bending, shear, and compression properties were determined at low loads, while the complex deformations were analyzed using Cusick drape meter devices. The fabric drape simulations were performed using the 2D/3D CAD system for a computer clothing design on a disk model, corresponding to real testing on the drape tester in order to allow a correlation analysis between the values of drape parameters of the simulated fabrics and the realistically measured values for each fabric. Each fabric was simulated as a polygonal model with a variable related to the side length of the polygon to analyze the influence of the polygon size, i.e., mesh density, on the model behavior in the simulation. Based on the simulated fabric drape shape, the values of the areas within the curves necessary to calculate the drape coefficients of the simulated fabrics were determined in the program for 3D modelling. The results were statistically processed and correlations between the values of the drape coefficients and the optimal parameters for simulating certain physical and mechanical properties of the fabric were determined. The results showed that the mesh density of the polygonal model is an important parameter for the simulation results.

Measurement of local shear deformation in fabric drape using three-dimensional scanning

We propose a measuring method of shear deformation in drape using three-dimensional (3D) scanning. We measured the local shear angles in fabric drape based on the Fabric Research Laboratories (FRL) drape test for woven fabrics using the proposed method. We investigate the effects of the relative positions of the node to the center grainlines that cross at the fabric center, and the bending and shear properties of fabric on the shear angles. To measure the local shear deformation, we obtained 3D drape shapes of four different fabrics with three to six nodes. We covered the obtained drape shapes using a fabric model composed of square cells that allowed shear deformation. By calculating the shear angles of the cells, we obtained the local shear deformation. We found that the FRL drape can be characterized by three areas, except for the flat areas of the support disks: (a) areas along the center grainlines with zero or small shear angles within 3°, which could result from single curvature bending; (b) areas in the bias directions with relatively large shear angles over 3°, which could result from double curvature bending; and (c) polygon edges connected by tangents of the support disk with relatively larger shear angles than their surroundings, which could result from both bending and shear deformation, such as folding and wrinkles. By investigating the relationships between areas with large shear angles and the bending rigidity/shear stiffness, we clarified that the bending rigidity indirectly affects the local shear deformation of drape.

A New Approach to Evaluate Fabric Hand Based on Three-Dimensional Drape Model

Fabric quality and performance is assessed subjectively by the customer using an important and complex phenomenon of fabric hand. Objectively, it is evaluated with complicated and expensive instruments, such as Kawabata Evaluation System for Fabrics (KES-F) and Fabric Assurance with Simple Testing (FAST). The present research explores a non-touch objective approach, i.e., three-dimensional (3D) drape model to estimate fabric hand. Fabric hand prediction was testified on different commercial fabrics spanning a wide range of areal weight, thickness, yarn count, and fabric density. Fabric objective ranks based on drape indicators using principal component analysis (PCA) were compared with subjective ranks of fabric hand. Additionally, fabric drape is evaluated three dimensionally and a new drape indicator drape height (DH) is proposed. The cosine similarity results have proved fabric drape as an objective alternate to fabric hand.

Instrumental evaluation of fabric shape retention by image analysis

Fabric shape retention is an essential property for assessing fabric usability and easy-care properties, which needs to be evaluated frequently for quality improvement. At present, certain aspects of shape retention can be characterized by particular devices, such as the crease recovery tester, the fabric drape tester, etc. To effectively and accurately reflect fabric shape retention performance, we developed an automatic crease forming device to simulate fabric crease creation and the shape recovery process in daily life, and objectively assess the shape retention by an image processing method. A specified size specimen was laid flat on the device to create a sharp crease. Then, a video image of the fabric shape recovery is acquired for measuring the evaluation indexes, such as the vertex angle ( VA), height ( H) and shape retention area ( SA). Finally, the results of this proposed method are compared with existing methods. When compared with the existing crease recovery tester, there is good consistency between the VA of the developed measurement system and the recovery angle of the fabric crease recovery tester, which indicates that the proposed method can be used to evaluate the crease recovery of fabrics. Compared with the drapability, there is linear function relationship between the H and SA of the developed measurement system and the draping coefficient of the fabric drape tester, which demonstrates that the proposed method can be used to evaluate the drapability. Therefore, experimental results indicate that the data calculated by our proposed method can be used to determine fabric shape retention.

Physical properties of single jersey derivative knitted cotton fabric with tuck and miss stitches

The effect of different stitch combinations, namely, knit, tuck and miss stitches, on some of the physical properties of single jersey derivative fabrics have been studied. Fabrics which are in common commercial use in the textile industry were selected, and they are used as clothing fabrics. Knitted fabrics from 100% cotton yarn of 19.67 Tex on circular knitting machines were used in the study. The effect of knit structure on areal density, fabric thickness, air permeability, drape ability, stretch and recovery, shrinkage, and low-stress mechanical properties are investigated, and it was found that these properties are significantly affected by loop shape or knit structure, even though other knitting parameters remained the same. It was also found that the presence of tuck and float stitches for a given structure have a significant effect on fabric drape ability, width-wise extensibility, length-wise shrinkage, thickness, areal density and low-stress mechanical properties.

New indicators on fabric drape evaluation based on three-dimensional model

To evaluate the ability of woven fabrics to drape in a more accurate way, a three-dimensional point cloud of a draped woven fabric was captured via an in-house drape-scanner. A new indicator, total drape angle (TDA), was proposed based on the three-dimensional fabric drape to characterize the ability of a woven fabric to drape. The relationship between TDA and the drape coefficient (DC) was analyzed to validate the performance of TDA. The result indicated that TDA is more stable and representative than the traditional DC in characterizing the ability of a woven fabric to drape. In addition, the drape angle distribution function (DADF) of the triangular mesh was employed to describe fabric drape, as well as to bridge the gap between drape configuration and the warp bending rigidity of woven fabric. The results showed that the correlation coefficient between the real warp bending rigidity value and what was predicted warp based on DADF and fabric weight was 0.952.

A New Method for Measuring Fabric Drape with a Novel Parameter for Classifying Fabrics

With huge varieties of fabrics, the first challenge for any performance evaluation is to categorize the vast types of the products into fewer, more homogeneous and akin groups. Classification or sorting is arguably the first step of any scientific investigation, and comparison of product quality is meaningful only when conducted within a group of comparable products. A new criterion termed fabric linear density λ is first proposed in this paper so that fabrics can in general be divided into four groups. The derivation and validation of this parameter are provided. The importance of fabric drape is almost self-evident, but there are still no effective ways to easily measure this fabric attribute. A few existing instruments, notably the Cusick Drapemeter, suffer from low repeatability and low sensitivity and are hence not widely or frequently used. It is demonstrated in this study that, by using the PhabrOmeter, along with the fabric linear density λ, a much more efficient alternative for fabric drape test can be achieved. By actually testing 40 various fabrics, the principle, procedure and results of this method is presented in this paper.