基于均匀化理论的小变形纬编针织物线圈形态有限元分析

为解决针织物在平幅印染过程中线圈拉伸易变形的问题,以纯棉纬编针织物为研究对象,基于小参数渐近展开和多尺度均匀化方法,建立针织物宏观-细观位移变化率和应变变化率的计算模型,分析低应变状态下针织物拉伸时线圈形态变化的规律.结果表明:针织物受均匀载荷拉伸时,线圈变形具有不均匀性,变化规律与线圈的空间位置、幅宽以及导布辊间距相...

Finite element analysis of loop shape in weft knitted fabrics with small deformation based on homogenization theory

In order to explore the problem of easy deformation of knitted fabrics in the process of open-width printing and dyeing,a cotton plain weft knitted fabric was taken as the research object.Based on asymptotic expansion of small parameters and homogenization of multi-scale perturbation analysis under small strain,a calculation model for macroscopic and microscopic change rate of displacement and strain of the knitted fabric was built.The model was used to analyze the loop shape change under small deformation,and the results show that when the knitted fabric is stretched by uniform load,the deformation of the loop is non-uniform,and the deformation is related to the position of the loop,width and the distance between guide rollers.The convex cloth guide roller can improve the difference of loop deformation.The calculated value of loop deformation of knitted fabric is found consistent with the measured value under the uniform and non-uniform load,and the maximum error is 9.6%.This means that the combination of homogenization theory and finite element technology can be used to further analyze the macro and micro deformation of multi-component and multi-specification knitted fabrics,and it can also provide theoretical guidance for tension control of open-width printing and dyeing equipment of knitted fabric,and for the layout design of cloth guide rollers and development of roll shape(concave convex roller)of variable diameters.