Papers by Author: K. Cheng

Paper TitlePage

Authors: Zhen Long Wang, Yu Fang, Wan Sheng Zhao, K. Cheng
Authors: Yong Da Yan, T. Sun, Shen Dong, Ying Chun Liang, K. Cheng
Authors: X.C. Luo, K. Cheng, R. Ward
Abstract: This paper attempts to correlate surface functionality generation with machining conditions by computer simulation and machining trials. The linear and nonlinear machining conditions, such as feed rate, built-up-edge, shear- localized chip formation, regenerative chatter are modelled in the light of their physical features. They are the inputs to the integrated surface topography generation model. The dynamic tool path is calculated through the dynamic cutting force model and surface response model. The surface is generated by transforming the tool profile onto the workpiece surface along the dynamic tool path. All of these models are integrated in a user-friendly Matlab Simulink environment. On the basis of the Simulink model, the dynamic simulation is performed to predict the 3D machined surface topography and its functionality. The simulation results have been validated by precision turning trials. The spectrum analysis of the machining dynamics and surface topography shows that surface generation is highly affected by the nonlinear factors in precision turning process. A case study shows the feasibility of generating some functional surface for some product/component through controlling machining variables.
Authors: Y.H. Yang, Shi Jin Chen, K. Cheng
Abstract: A novel fast tool servo driven by piezoelectric actuator for precision diamond turning is designed in this paper. To overcome the inherent hysteresis and drift nonlinearity effect of the piezoelectric actuator, a closed-loop control system is established using strain gauge integrated in the actuator for position feedback, which has compact structure and can avoid interference in the machining. Furthermore, a fuzzy PI control algorithm is presented. It has not only the advantages of agility and adaptability of fuzzy control, but the characteristics of high accuracy of PI arithmetic. At last, experiments are carried out and the results show that the fuzzy PI control provides significantly better tracking accuracy and robustness against hysteresis and drift effects.
Authors: X.W. Liu, K. Cheng, D. Webb, X.Q. Jiang, S.J. Xiao, A.P. Longstaff, M.H. Widiyarto, L. Blunt, D. Ford
Authors: Wen Jun Zong, Dan Li, T. Sun, K. Cheng
Abstract: In this paper, a coupled thermo-mechanical FE model is proposed to simulate the cutting temperature’s distribution produced in diamond turning. Simulated results indicate that the heat converting from plastic work has prominent effects on the distribution shape of cutting temperature field, and with an increment in cutting velocity, the locating site of maximal cutting temperature shifts from the contact area between tool tip and chip root to the contact area between rake face and chip. Cutting edge radius has minute influence on the distribution shape of cutting temperature field, but the bigger the cutting edge radius is, the higher the maximum cutting temperature in cutting region. Rake angle also has slight effects on the maximal temperature when it is more than 10○. While clearance angle reaches to 6○, the maximum cutting temperature approaches the smallest.
Authors: Shi Jin Chen, Q.L. Pang, K. Cheng
Abstract: In this paper, a finite element model of a two-dimensional orthogonal metal cutting process is used to simulate the chip formation, cutting forces, stress, strain and temperature distributions. Two deformable parts are involved in this model: the workpiece and the cutting tool. To make the results of the simulation agree the orthogonal cutting test better, the separation surface between the chip and the machined surface is not predefined in this simulation. The chip-separation criterion is based on the Johnson and Cook law. This work will help as a reference to tackle more complex cutting processes such as oblique and discontinuous cutting.
Authors: Qing Liang Zhao, Ming Jun Chen, Ying Chun Liang, Shen Dong, K. Cheng
Showing 1 to 10 of 13 Paper Titles