Research On Rotary Ultrasonic Machining Mechanism Based On Finite Element

Quartz, optical glass, ceramics and other hard and brittle materials are widely used. The materials of most products are replaced by glass, ceramics, because they have the quality of good insulation, high strength, and high temperature resistant. Hard and brittle materials exist everywhere from the living necessities to the aviation equipment components. Because of the high strength and high brittleness of hard brittle materials, it is difficult to process them. The conventional machining methods are difficult to meet the product requirements, and the cast is high. Rotary ultrasonic machining is an effective method to machining hard and brittle materials, and compared with the general processing methods it has the quality of high precision, and low roughness values.Rotary ultrasonic machining technology is getting more mature, but the processing is effected by the amplitude, static pressure, rotation rate, abrasive particle shape and other factors, and the high frequency vibration machining process is very complicated. So, with present observation technology it is difficult to observe the interaction process between single abrasive grain and work piece and the formation and expansion of cracks in workpiece. Most researches in the field of material removal mechanism in ultrasonic machining are qualitative researches based on experiments, and there are few researches providing numerical calculation and quantitative analysis.Based on the indentation fracture mechanics model, and the study on rotary ultrasonic machining mechanism, this paper focuses on the removal of the work piece material and does some simulation of the process of abrasive impacting work piece with LS-DYNA. The main work is:1. The work principle of traditional ultrasonic machining and rotary ultrasonic machining is introduced. And an overview of the current two kinds of ultrasonic machining mechanism of material removal is made by introducing domestic and foreign research on ultrasonic machining. The plastic removal model and the brittle removal model of rotary ultrasonic machining material are set up with the analysis of indentation and fracture mechanics. The derivation of the plastic material removal rate and brittle material removal rate is made, and the effects of processing parameters on the material removal rate are analyzed with the mathematical model formula.2. The study on rotary ultrasonic machining mechanism is made with the observation of rotary ultrasonic machining conditions and the simulation of the process of abrasive impacting work piece with LS-DYNA. The grinding, hammer,single impacting and twice impacting model of the eight plane diamond abrasive impacting work piece are set up. The material removal way of rotary ultrasonic machining is intuitively got by the analysis of the simulation results. The effects of amplitude and rotation speed on the tool abrasion are studied by the contact force curves which are obtained in the simulation.