Ielina T. Development of scientific bases of prediction of structural characteristics of knitwear in the process of its deformation

Ielina T.V. Development of scientific bases of prediction of structural characteristics of knitwear in the process of its deformation. – Manuscript. Thesis for obtaining the scientific degree of Doctor of Sciences in Engineering for the specialty 05.18.19 – technology of textile materials, sewing and knitting goods. – Kyiv National University of Technologies and Design, Kyiv, 2021. The dissertation is dedicated to the development of methods and means of designing structural characteristics of knitwear in the process of its deformation. The paper theoretically substantiated and developed a frame model of stretched knitted structure and described an algorithm for creating on its basis a three-dimensional model of knitted structure in a deformed state. A mass-spring model of knitwear has been developed, for which the use of effective rigidity coefficients for three intervals of stretching along courses and wales directions is scientifically substantiated. A three-dimensional geometric model of a multifilament thread in the weft-knitted structure was developed. Theoretically substantiated and developed a geometric model of rib knitted stitches of macro level, considering the nature of the transformation of the elastic mid-surface of the knitted shell in the process of stretching along the course direction. А mesomodel of the knitwear structure in the deformed state is developed, taking into account the change in the shape and size of the boundaring and internal elementary contours of the loop under arbitrary stretching. A mathematical model of deformation of the section of the knitted product of a tubular shape, made with rib stitch, pulled on a surface that can be approximated with a truncated cone, has been developed. A computer program for the construction of a three-dimensional mesomodel of a weft-knitted structure undergoing the action of a uniaxial stretching along the course or wale direction, has been developed. An algorithm and a computer program designed for three-dimensional macromodeling of a fully fashioned knitwear containing rib knitted sections, have been developed, providing building the unfolds of its individual parts on the plane. A database of knitting parameters of rib knitted structures of various raw material composition in dry-relaxed and deformed states and empirical coefficients that determine the ability of knitted material to change shape and size under the influence of tensile loads has been formed. The method of technological calculation of a fully fashioned knitted products has been improved. A design and technology for the manufacture of adaptive cuffless socks with a predicted level of stretching has been developed. Key words: knitwear, structural characteristics, deformation, frame model of stretching, three-dimensional modeling, air flux modeling.