Study On The Vibration Characteristics Of Yarn Bundle Of Tufted Carpet Loom

With the comprehensive development of all fields of society,people are paying more and more attention to noise problems in the working environment,especially in the textile industry.The noise problems in textile equipment have a great negative impact on the health of textile workers,the service life of textile equipment,and the production efficiency of products.The tufted carpet loom has high-end tufting technology and is one of the high-end textile equipment.In the process of weaving different types of carpets,the tufted carpet loom regulates the tension of the yarn bundles by controlling the rotation speed of the jacquard wheel,which in turn controls the height of the carpet loop pile.Yarn bundle path is tedious and complex,almost in contact with every important part,and there is a coupling relationship.Under the working conditions,yarn bundles tend to produce lateral and axial vibration due to different direction forces.Therefore,it is of great practical significance to study the mechanical and vibration characteristics of the yarn bundles for the noise source identification and noise reduction processing of the carpet equipment,electronic roller tension control and the textile equipment design and planning.This paper mainly studies the dynamic vibration characteristics of yarn bundles under certain conditions through comparison between theoretical analysis and experimental results.First,in order to characterize the visco-elasticity of yarn bundles,it is necessary to choose a suitable viscoelastic constitutive model to establish the constitutive equation of yarn bundles.Analyze the stress and strain characteristics of viscoelastic materials and the principles of the four common constitutive models and their respective advantages and disadvantages.The electronic strength tester is used to perform creep experiments on three common carpet yarns,and experimental data are collected several times.The constitutive model is used to fit the creep experimental data and analyze the fitting results.The appropriate constitutive model is selected to characterize the viscoelastic properties of the yarn bundle.Then,analyze the transmission path characteristics of tufting carpet yarn looms,and understand the performance characteristics of the yarn bundles in the moving state.The key part of the yarn bundle contact with the jacquard wheel and aluminum stick is selected to perform dynamic modeling and analysis of vibration characteristics.Analyze the method and principle of dynamic modeling,use the method suitable for yarn bundle modeling to establish the geometric equation,the equation of motion.Combining with the constitutive equation,establish the dynamic equation of yarn harness,and use Galerkin truncation method and adaptive variable step algorithm to solve the vibration equation of yarn bundles.Then,using MATLAB software to simulate the vibration characteristics of the yarn bundle under different conditions and using control variable method to analyze the effect of the yarn bundle material,length change,tension change on the dynamic transverse vibration frequency and amplitude of the yarn bundle.Finally,For the tufting carpet looms of the Donghua University laboratory,laser vibrometers were used to test the vibration signals of the yarn bundles under three different working conditions respectively,and the maximum frequency of the yarn vibration signal was obtained through the fast Fourier transform process.Meanwhile,under the same experimental parameters,the vibration characteristics of the yarn bundles are numerically simulated,and its frequencies and amplitudes are analyzed.In addition,the experimental results of the vibration test of the yarn bundle and the theoretical solution results are compared and analyzed to verify the accuracy of the dynamic vibration equation established in this paper.