Modeling and response of variable longitudinal nonlinear vibration of rapier belt driven by variable speed weft insertion patterns

This paper mainly studies the influence of the longitudinal vibration of the rapier belt driven by different variable-speed weft insertion patterns on the weft insertion process. For designing a variable speed weft insertion pattern, a parametric modeling method of weft insertion based on cosine series was proposed. In parallel, for the nonlinear dynamics of variable length and variable speed moving rapier belt under the action of driving force, the forced vibration model of variable length rapier belt was established based on the finite element method. The system mass, stiffness and damping terms were found to be related to the length of rapier belt. The effects of weft insertion pattern on the motion characteristics, longitudinal vibration and process of rapier belt under different acceleration parameters were analyzed. The results show that the initial acceleration and peak negative acceleration of rapier belt are the key parameters affecting the weft insertion process. The peak value of the speed and acceleration of the rapier belt, the time of entering the shed and the peak value of the internal stress would decrease with the increase of the initial acceleration. When the rapier belt holds the weft and enters the shed, the vibration increases with the increase of the peak value of negative acceleration. Reasonable regulation of key parameters can coordinate the process timing and dynamic characteristics of beat-up, weft insertion and shedding. © 2022 China Textile Engineering Society. All rights reserved.