Research On The Prediction Of The Number Of Drafted Fibers Based On Fiber-mechanical Multi-field Coupling

The traditional roller drafting system occupies an irreplaceable position in the spinning process.The quality of its mechanism directly affects the quality of the yarn,the energy consumption of the mechanism,and the efficiency of the enterprise.With the increase of the operating speed of textile equipment,the effect of the dynamic coupling of fibers,fiber assemblies and high-speed spinning equipment cannot be ignored,showing that the actual production speed of current drafting equipment is far lower than that of the equipment itself The achieved mechanical speed makes it difficult to further increase productivity.In order to solve this problem,it is very meaningful to study the coupling effect of roller drawing system and fiber.In this dissatation,the prediction of the number of fibers in any cross section of the sliver during the drafting process is used as the research content.Through theoretical analysis,mathematical model establishment,solution analysis,and experimental verification,the movement of the sliver under the roller draft is carried out Comprehensive and systematic analysis.This dissatation has laid a solid theoretical foundation for improving the yarn quality,increasing the drafting production speed,and improving the drafting equipment.In the first part,after a detailed analysis of the drafting mechanism,the movement requirements and stress conditions of the fibers in the drafting area are summarized.Based on the relative motion relationship between fibers,the concept of a whisker ring zone was proposed,and a friction model of the fiber was established.At the same time,the frictional force of the fibers in the ring zone during the corresponding analysis was analyzed.The relationship between friction and empirical constants is also analyzed.In the second part,on the basis of the first part,the characteristics of mechanical drafting equipment are considered,and the principle of conservation of mass and momentum is used to establish a drafting-mechanical coupling model under specific boundary conditions.Because of the uncertainty constant in the model,an initial parameter identification method based on genetic algorithm was proposed to determine the uncertainty constant,and then the number of fibers of any cross section of the predictable sliver during the drafting process was derived The mathematical model is also analyzed,and the relationship between the number of fibers in any cross section of the sliver and the speed of the sliver is discussed and analyzed at different draft multiples.In the third part,in order to verify the accuracy of the model,a simple drafting experimental platform is set up,and different drafting experiments are designed for different drafting multiples.Firstly,the properties of the fiber were measured using testing methods such as instruments,and then the mechanical equipment parameters were set accordingly.During the experiment,five points were taken as the intercept points for predicting the number of fibers,which were divided into input port quantitative points,output port prediction points,and variable speed prediction points(a total of 3 points),in order to ensure the accuracy of experimental data collection The method of manual counting was adopted for quantification.Experimental results show that the model has better predictability.According to the experimental data and mathematical model,other parameters affecting the number of fibers in the model are also discussed and analyzed.According to the current problems of drafting,this dissatation combines fibers with machinery to establish a fiber-mechanical coupling model.By solving the model,the actual motion process of the fiber in the drafting is analyzed,and the effect on the drafting effect is obtained.Significant parameters.This study provides a theoretical basis for the quality analysis of roller drawing,and provides theoretical support for ensuring the uniformity of the sliver under high-speed drafting in the later stage.