FRAME MODEL OF STRETCHING OF WEFT-KNITTED FABRICS IN THE COURSEWISE DIRECTION

Abstract

Purpose. The purpose of this study is to develop a mathematical description of the transformation of the frame model of weft-knits under the action of tensile forces in the courswise direction for further three-dimensional modeling of the knited structure.

Methodology. Methods of theoretical analysis and synthesis, basics of knitting theory, methods of geometric modeling and parameterization were used in the research process.

Findings. Considering the knitwear stretching during the use of the clothing is one of the determining factors of the quality of design decisions. When stretching the weft-knitted fabrics in the coursewise direction, the configuration of its individual stitches’ changes, as well as the thread’s cross-section due to the force interaction between the adjacent structure elements. To simulate the physical and mechanical behavior of knitwear under the stretching, it is suggested using a complex model of knitwear deformation, that includes the suggested frame model of uniaxial coursewise stretching of knitted fabrics. An algorithm for constructing a frame model of stretching a sample of knitted fabric in the coursewise direction is described in the paper. The algorithm is based on the structure parameters, including the wale spacing and course spacing in a dry relaxed state, the relative elongation of the sample at the time of modeling, number of wales and courses in the sample, the coefficient of courses narrowing.

Scientific novelty. The paper investigates the features of the transformation of the knitting structure during stretching in the coursewise direction and offers algorithmic and mathematical support for the automated generation of the mesh frame in the context of three-dimensional modeling, which provides for the possibility of considering the dynamics of deformation of knitted fabric undergoing tensile deformations.

Practical value. Frame model of the weft-knits deformation and algorithm of mesh-frame construction suggested in the paper, form the basis for determination of coordinates of characteristic points of the structural elements of the knit in a state of uniaxial tension for construction of a three-dimensional model of thread a deformed knitted fabric.