Dynamics Analysis of the Rigid-Flexible Coupling Lifting Comprehensive Mechanism for a Rotary Dobby

This paper addresses the problem of dynamics analysis of the rigid-flexible coupling lifting comprehensive mechanism for a rotary dobby, which is the important part of the loom. To provide a physical model basis for a precise dynamics model, the finite element method was used to discretize the bending arm of the rotary dobby effectively. Combining with the modal synthesis techniques, the dynamic model of the bending arm was established by using Kane’s formulation, and it laid a foundation for analyzing the dynamic performance of the heald frame. By comparing virtual prototype simulation results with the numerical calculation results of the bending arm, the correctness of this model was verified. Based on the established dynamic model, the modal truncation method is used to simplify the dynamic model; in addition, the influence of parameters such as the speed of the dobby, the warp tension, the movement distance of the heald frame, and the thickness of the bending arm on the dynamic characteristics of the heald frame was analyzed. Last, the sensitivity analysis (SA) method is used to analyze the effects of each parameter. The results show that it is appropriate to select the first four modes to calculate, and increasing the speed greatly or increasing the warp tension, the shedding performance is obviously worse, while the shedding performance of the loom can be optimized by reducing the shedding range or increasing the thickness of the bending arm.