Session: 03-04-03: Advanced Machining and Finishing Processes

Paper Number: 116662

116662 - A Model-Based Identification Method of Variable Working Condition for Multi-Toothed Face Milling Process 

During a process of variable cutting parameter, the working conditions, such as material removal rate, cutting force, and so on, are changing along with cutting locations in time domain and spatial domain, resulting in the variations of machined surface quality. For example, multi-toothed milling process is the normal way that applied in face milling for large-scale component with discontinuous multi-holed surface. And variations of milling forces in time domain and space domain are the common behaviors during machining process due to the varies of effective cutting teeth and instantaneous material removal rate, which specifically generate surface variations along feed direction and circumferential direction. The changing milling force is theoretically can be defined as the indicator of machining quality in a process of variable cutting parameter. Therefore, an effective monitoring method for milling forces is essential for the online monitoring of processing quality. For which the core is to propose an identification method to identify practical parameters of working condition in real time. In this paper, a model-based identification method of variable working condition is proposed for multi-toothed milling process.

For the multi-toothed milling process for large-scale component with discontinuous multi-holed surface, the material removal rate is changing along with tool rotation angles and calculated according to the effective contact area between each cutting tooth and workpiece surface, thus resulting the variations of milling forces. The purpose of the proposed model-based identification method of variable working condition is to identify the deviations of cutting forces and practical material removal rate from their nominal values. Firstly, a simulation model of instantaneous milling forces is generated as functions of milling parameters and instantaneous material removal rate. Secondly, for a multi-toothed face milling process of discontinuous multi-holed surface, normal material removal rate curve in time domain is generated through the graphical mapping calculation between milling trajectories and multi-holed surface. Thirdly, with the normal material removal rate curve, the normal milling force curves in time domain can be generated based on the proposed model of instantaneous milling forces in the first step. Fourthly, by comparing the measured practical milling force curves and the simulated normal milling force curves, the corresponding deviation curves for each milling force can be calculated. Finally, an inverse problem-solving method is proposed to minimize the corresponding deviation curves based on the trajectory and milling force simulation along feed direction, thus to identify the deviation of practical material removal rate from the normal. The deviation of practical material removal rate reflects the variation of milling process, surface quality and also the working condition. The proposed methodology will provide an effective way to identify the practical deviations from a normally irregular process of variable cutting parameter.

Presenting Author: Shun Liu Shanghai Jiao Tong University

Presenting Author Biography: Liu is now an assistant professor at Shanghai Jiao Tong University, he has received his doctor degree in 2020.

Authors:

Shun Liu Shanghai Jiao Tong University
Sun Jin Shanghai Jiao Tong University
Qunfei Gu Shanghai Jiao Tong University
Xueming Du Shanghai Jiao Tong University
Yang Xiang Shanghai Jiao Tong University