Papers by Author: Zhi Jun Wu

Abstract: Material constitutive equation plays an important role in Finite Element Analysis (FEA) of metal cutting process. This paper proposes a method to obtain parameters for Power Law model of a Japanese type of alloy steel (SCM440H) for 3-D FEA of face milling process, involving pressure bar experiments and orthogonal metal cutting experiments. Since pressure bar test cannot reach the high strain rate occurred in cutting process, orthogonal cutting experiment was combined to obtain parameters for material model. By this method, the ideal parameters for FEA of the face milling process were finally determined. Face milling experiments were performed to verify the accuracy of the model built.

Abstract: Rotary ultrasonic machining is a hybrid machining process that combines diamond grinding and ultrasonic machining. The mathematical predictive material removal rate models have been developed in rotary ultrasonic machining with a constant pressure. However, there is no report on mathematical predictive cutting force model in rotary ultrasonic drilling at a constant feedrate presently. Since cutting force can not only reflect the processing state, but also affect the machined surface quality, it is necessary to develop a mathematical model for predicting cutting force which can forecast the machining results. This paper presents a mathematical model to predict the cutting force in rotary ultrasonic machining. On the basis of this model, the relations between cutting force and controllable machining parameters are researched by numerical computation method. This paper also researches the influences of spindle speed and feedrate on cutting force by experiments. The results observed through the experiments agree well with the relations generated from the mathematical model, which verify the developed model.