Study on the dynamic characteristics of a virtual-axis hybrid polishing machine tool by flexible multibody dynamics

Abstract

This paper establishes the dynamic equations of the spatial rigid-flexible coupling multibody systems for a five-coordinate virtual-axis hybrid polishing machine tool, namely model JDYP51 developed by the authors. The dynamic characteristics of the hybrid machine tool are studied in detail by means of the theory of dynamics of a flexible multibody system and the finite element models of the whole machine tool and each leg respectively. The dynamic simulation of the machine shows that the elastic deformation of each leg is very small during the movement of the machine and the influence of the flexibility of each leg on the trace of moving platform is not obvious due to the characteristics of joints. At the beginning of the movement of the machine, the fundamental frequency of parallel mechanism easily leads to vibration of the machine. Therefore, the stable status of polishing can be obtained at all periods of the movement of the machine except the beginning of the movement.