Simulation And Experimental Study On The Stability In Milling Of Thin-Walled Components

Thin-walled structure is easy to deform and vibrate in machining. The machining skill craft of thin-walled components has become one of important labeling to judge the aviation industry. In order to machine the thin-walled structure stably, the chatter mechanism of machining of is analyzed theoretically and machining methods to suppress the chatter are explored based on high-speed milling experiments. The main work in this paper is generalized as follows.1. Built the mechanistic model of milling thin-walled structure components via identifying the cutting force coefficients. Building the mechanistic model is the most important work to study the distribution of cutting forces and the influence to chatter. The cutting force coefficients of specific unit of cutting tool and workpiece are identified via the orthogonal milling experiments based on the compensation method of modification of inertia effect. The cutting force coefficients are verified by the use of experimental results and simulation results. Based on the analysis and comparison of existed document, the instant rigidity force model are built and verified experimentally in this paper.2. Predicted the stability in milling of thin-walled structure components. How to predict the stability in the milling process of thin-walled structure components is essential to optimize the cutting parameters and increase the machining quality. The dynamic model of thin-walled structure including dynamic behaviors of both the machine-cutter subsystem and workpiece-fixture subsystem is analyzed. The stability lobes for predicting the machining instability are acquired from the TF (transfer function) and the modal parameters of two subsystems via the hammer impact tests. Against the thin-walled structure components, a new criterion of the milling stability is put forward. The influences of the modal parameters of two subsystems and the cutting parameters are studied through the simulation analysis.3. Built the machining vibration model of the beam type thin-walled structure. Exploring the machining vibration law of thin-walled structure is very important to the production. The possible motion states of the milling system and the possible machining stability are identified according to the different methods in the milling process of thin-walled structure. Regarding the beam type thin-walled structure which is very easy to vibrate, the machining vibration models for low axial cutting depth and low radial immersion milling are established, respectively. The models are verified through experiments and simulation analysis.4. Carried out the craft experiments of controlling the machining chatter vibration of thin-walled structure components. The experiments of milling of the thin-walled structure are executed and the influences of different cutting parameters to the machining stability are analyzed. The chatter controlling methods are explored from the different points. On one hand, the control results of applying the different signals to the machining chatter are simulated according to the specific modal parameters and the cutting parameters. On the other hand, the varying spindle speed milling tests are carried out on the specific machine tool and a new varying spindle speed method of suppressing chatter by varying spindle frequency control based on DSP is proposed. These facilitate the chatter suppress of the thin-walled structure components.