In this paper,the vector equation of a generaliseddoubly wound helix was derived.Treloar’s pliedyarn geometry could be obtained as a special case ofthe generalised doubly wound helix.The shortest fi-bre length around...In this paper,the vector equation of a generaliseddoubly wound helix was derived.Treloar’s pliedyarn geometry could be obtained as a special case ofthe generalised doubly wound helix.The shortest fi-bre length around the surface of a helical tube(formed by fibre helices)was determined by apply-ing variational principles.The fibre length as calcu-lated by using Treloar’s geometry was compared in-directly with the shortest possible fibre length at dif-ferent levels of yarn deformation when some of Tre-loar’s rigid geometrical constraints were relaxed.Anew idea based on non-concentric circles was intro-duced to approximate the fibre helix movement in atwo-ply yarn.A torsional model of two-ply yarnwas developed and the theoretical predictions werecompared with some preliminary experimental re-sults.展开更多
Modeling the 3D geometric configuration of yarn is the base of building the 3D fabric structure. The surfaces of the yarns are modeled by many facets. To improve the efficiency of modeling, 3D yarn is usually designed...Modeling the 3D geometric configuration of yarn is the base of building the 3D fabric structure. The surfaces of the yarns are modeled by many facets. To improve the efficiency of modeling, 3D yarn is usually designed by Bezier curve, spline curve or B-spline curve on the principle of Computer Graphics. The paper reviews different 3D modeling methods for single yarn from the view of cross-section and central line. Some improvements for a better visual effect such as inserting twist and hairiness are illustrated as well. Based on the single yarn, the folded yarn and some fancy yarns can also be modeled in 3D space as long as the cross-sections of the control sections of the component single yarn are determined. Applications of the various 3D yarns are demonstrated. The advantages and the drawbacks of various methods are explained and compared as well. Comparatively speaking, modeling technology based on spline curve is more convenient and flexible, perhaps it is the most popular tool since it is capable of designing different kinds of yarns mentioned above and gets the maximum support from the different developing platforms such as OpenGL, 3DS-MAX, Solid Works CAD, etc.展开更多
Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeabilit...Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeability of the knitted yarn in the fabric, a liquid transport model is established. The main factors which have significant influences on the liquid transport have been analyzed. It is derived from the argument that the optimal design for the knitted fabric with quick sweat transport property can be obtained.展开更多
Considering the changes of ply yarn 's structure parameters during the axial extension,a new model has been proposed for predicting the tensile curve of polyester twisted ply yarn under large deformation without t...Considering the changes of ply yarn 's structure parameters during the axial extension,a new model has been proposed for predicting the tensile curve of polyester twisted ply yarn under large deformation without the tensile strength tests.The relationships between the structural parameters and tensile properties under large deformation were considered.The feasibility and accuracy of the model were studied by comparing the predictive results and the experimental ones.The structural parameters in the model were acquired under every strain before rupture.The radial dimension and twist angle of the yarn were obtained by an observation platform and image processing technique.The true modulus of the yarn was obtained indirectly from the tensile data of the single yarn and the mathematical equations.The tensile curves of the yarns at different twist levels for predicting were plotted.The results demonstrated that the predicted curve tendency and the values were quite close to the experimental ones.The model exhibited a good applicability to predict the tensile curves for low and medium twist yarns.展开更多
文摘In this paper,the vector equation of a generaliseddoubly wound helix was derived.Treloar’s pliedyarn geometry could be obtained as a special case ofthe generalised doubly wound helix.The shortest fi-bre length around the surface of a helical tube(formed by fibre helices)was determined by apply-ing variational principles.The fibre length as calcu-lated by using Treloar’s geometry was compared in-directly with the shortest possible fibre length at dif-ferent levels of yarn deformation when some of Tre-loar’s rigid geometrical constraints were relaxed.Anew idea based on non-concentric circles was intro-duced to approximate the fibre helix movement in atwo-ply yarn.A torsional model of two-ply yarnwas developed and the theoretical predictions werecompared with some preliminary experimental re-sults.
文摘Modeling the 3D geometric configuration of yarn is the base of building the 3D fabric structure. The surfaces of the yarns are modeled by many facets. To improve the efficiency of modeling, 3D yarn is usually designed by Bezier curve, spline curve or B-spline curve on the principle of Computer Graphics. The paper reviews different 3D modeling methods for single yarn from the view of cross-section and central line. Some improvements for a better visual effect such as inserting twist and hairiness are illustrated as well. Based on the single yarn, the folded yarn and some fancy yarns can also be modeled in 3D space as long as the cross-sections of the control sections of the component single yarn are determined. Applications of the various 3D yarns are demonstrated. The advantages and the drawbacks of various methods are explained and compared as well. Comparatively speaking, modeling technology based on spline curve is more convenient and flexible, perhaps it is the most popular tool since it is capable of designing different kinds of yarns mentioned above and gets the maximum support from the different developing platforms such as OpenGL, 3DS-MAX, Solid Works CAD, etc.
文摘Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeability of the knitted yarn in the fabric, a liquid transport model is established. The main factors which have significant influences on the liquid transport have been analyzed. It is derived from the argument that the optimal design for the knitted fabric with quick sweat transport property can be obtained.
基金“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)The Key(Keygrant)Project of Chinese Ministry of Education,China(No.113027A)
文摘Considering the changes of ply yarn 's structure parameters during the axial extension,a new model has been proposed for predicting the tensile curve of polyester twisted ply yarn under large deformation without the tensile strength tests.The relationships between the structural parameters and tensile properties under large deformation were considered.The feasibility and accuracy of the model were studied by comparing the predictive results and the experimental ones.The structural parameters in the model were acquired under every strain before rupture.The radial dimension and twist angle of the yarn were obtained by an observation platform and image processing technique.The true modulus of the yarn was obtained indirectly from the tensile data of the single yarn and the mathematical equations.The tensile curves of the yarns at different twist levels for predicting were plotted.The results demonstrated that the predicted curve tendency and the values were quite close to the experimental ones.The model exhibited a good applicability to predict the tensile curves for low and medium twist yarns.
