Papers by Author: L.D. Zhu

Abstract: Abrasive jet precision finishing is a new machining method, which injects slurry of abrasive and liquid solvent to grinding zone under without feed condition. The machining is simulated by Finite Element Method (FEM) in the paper. Hydrodynamic pressure on modeling of wedge-like grinding zone between wheel and workpiece on abrasive jet finishing with wheel as restraint was established and simulation, based on Navier-Stokes and continuity equations. The liquid hydrodynamic pressure distributing principle and affecting factor were investigated. The relation hydronamic pressure with grinding wheel velocity was stimulated and verified experimentally. The experiment results show that the simulation results are agreement with experiment, so the simulation model can well forecast hydrodynamic pressure distribution at contact zone.

Abstract: Spindle-bearing system plays a crucial role in superhigh speed grinding, which directly affects machining precision, but it is complex and difficult to get the dynamic performance in experiment. This leads to study how to accurately simulate dynamic performance of spindle-bearing system. So a method which springs and damping units imitate bearing support is proposed in this paper. The proposed method can predict the regular pattern which bearing stiffness and damping ratio affect natural frequency and harmonic response. The research demonstrates that the method predicts well the dynamic performance of the spindle-bearing system and it is close to actual condition, therefore, it can be a reference for dynamic optimization design of spindle-bearing system in superhigh speed grinding.

Abstract: Take a kind of 3-TPT parallel robot as an example, the model of flexible multibody of parallel machine tool is built by using multibody dynamics simulation software ADAMS and finite element analysis software ANSYS. And dynamics equation of flexible body in spatial is also set up, after that the dynamics simulation is carried out. Then the simulation results of rigid bodies are compared with flexible ones, and the results show that the forces applied on flexible bodies appear high nonlinear, so the simulation results of flexible multibody system are more authentic, nicety and can reflect actual dynamics characteristic of parallel robot.