Clinton L. Cummings

Bio: Clinton L. Cummings is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 143 citations.

Mechanics of Elastic Performance of Textile Materials: Part V: A Study of the Factors Affecting the Drape of Fabrics—The Development of a Drape Meter

Abstract: is said to have good draping qualities when the configuration is pleasing to the eye. Obviously, then, the word &dquo;drape&dquo; is a qualitative term. The textile industry realizes the importance of understanding the phenomenon of drape and is anxious to be able to measure it quantitatively. Numerous &dquo;drape tests&dquo; have been reported in the literature, but none have presented any correlation between the data obtained and subjective evaluations. This is largely because of the failure to realize that drape may not be determined conclusively by those tests which involve two-dimensional distortions of the fabric samples. (These

Predicting the drape of woven cloth using interacting particles

Abstract: We demonstrate a physically-based technique for predicting the drape of a wide variety of woven fabrics. The approach exploits a theoretical model that explicitly represents the microstructure of woven cloth with interacting particles, rather than utilizing a continuum approximation. By testing a cloth sample in a Kawabata fabric testing device, we obtain data that is used to tune the model's energy functions, so that it reproduces the draping behavior of the original material. Photographs, comparing the drape of actual cloth with visualizations of simulation results, show that we are able to reliably model the unique large-scale draping characteristics of distinctly different fabric types.

A particle-based model for simulating the draping behavior of woven cloth

Abstract: This thesis presents a model of woven cloth that is capable of reproducing the draping behavior of a variety of fabrics. Here, draping behavior means the final draped configuration of a cloth, consisting of characteristic folds, over a solid object. The model utilizes a new approach, called particle-based modeling, to simulate the mechanical properties of complex materials. In contrast to continuum techniques, particle modeling is founded on the premise that by directly modeling the microstructures of a material and computationally aggregating their interactions correct macroscopic behavior will emerge. Cloth is not a continuous material, but rather a complex mechanism. Cloth's microstructure consists of threads interlaced in a particular weave pattern. Therefore, the model treats the thread crossing as the fundamental modeling unit, which is called a "particle". It is at the level of these particles that constraints are maintained, in the form of potential energy functions, on the relationships between the threads. The constraints maintained in the particle grid embody four basic mechanical interactions occurring in cloth at the thread level. They are thread collision, thread stretching, thread bending, and trellising. An important feature of the model is that its thread-relationship constraints can be defined to simulate specific types of woven materials. This is accomplished by deriving the model's energy functions from empirical mechanical data produced from a standard set of fabric measurement equipment, the Kawabata Evaluation System. Given this capability, a woven material may be measured on the Kawabata System, and a model with the material's mechanical properties may then be defined to confidently simulate its draping behavior on a computer. The validity of the model has been verified by performing two experiments with three different kinds of woven cloth. The first experiment recreates in simulation the standard measurement procedures that are applied to cloth and produces simulated mechanical data. The second experiment performs controlled draping experiments with real cloth, then recreates those experiments with draping simulations utilizing the model. This experiment demonstrates that the model is capable of reproducing the unique large-scale draping structures present in each of the experimental samples.

Drape Prediction by Means of Finite-element Analysis

Abstract: The draping behaviour of fabric treated as an orthotropic shell membrane is predicted by using a geometric non-linear finite-element method, and the results are compared with actual behaviour. A drape tester employing photovoltaic cells was designed and constructed to determine the drape coefficient of fabric specimens of 10-in. diameter. The warp- and weft-direction tensile moduli of these samples were determined by using a Kawahata Tensile and Shear Tester, and literature values of Poisson's ratio were obtained. With this approach, excellent agreement between experimental and predicted drape coefficients resulted. For a 100% cotton plain-weave fabric, a drape coefficient of 68.4% was experimentally determined as compared with a predicted value of 71.0%.

46—the dependence of fabric drape on bending and shear stiffness

Abstract: The dependence of the drape of fabrics on bending stiffness and shear stiffness has been investigated A version of the Fabric Research Laboratories Drapemeter is described, and the drape coefficient obtained is used as a measure of the fabric drape The regression of the drape coefficient on bending length for a large number of fabrics was highly significant, and the addition of shear stiffness to the regression made a highly significant difference The regression equations provide the relations between the variables for the conditions used Theoretical values of drape coefficient for zero shear stiffness were lower than the measured values

21—the measurement of fabric drape

Abstract: It is shown how the method of measuring fabric drape by supporting a circular specimen of fabric between smaller horizontal circular plates has been modified to allow a more sensitive test to be made on very stiff and very limp fabrics. The use of diverging light instead of parallel light is described, and the correction of the results for this change is calculated. A method of determining the drape coefficient by a paper-weighing method is also described.