Non-linear behavior Simulation of the drying of weft knitted fabric by using mass- spring-damper model and straight forward expansion

In this study، the shrinkage behavior of knitted fabrics during drying is studied. To this end، a model is presented to predict the knitted fabric length changes during the drying process. In order to model the shrinkage behavior، a 1DOF model consisting of a mass، a linear spring and a linear dashpot was used. Considering that the fabric is wet، mass is time dependent and Three-order Straight Forward Expansion method is used to solve nonlinear equations of motion. The results of the model were compared with the experimental results of five samples with different courses density. The results show that the proposed model is capable to predict the length changes of the center of the mass during the process of drying and after that. Error rate is about ten percent for the samples with less Loop length. But by increasing the length of the loop، error rates increases.