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In this paper, modal analysis of ball end mills is modeled by finite element to work out natural frequency and chatter model in tooling system and to calculate the limit curve of stability in single degree freedom system. The effect of cutter flute length and cutter tooth number on maching stability area is also discussed. The results of research show that steady critical cutting depth of milling system declines while the cutter flute length increases, but the trend is not linear, which shows increase partly. An engineering optimization design is made on milling cutter geometrical parameters based on this conclusion.

By combining cutting experiment with finite element method (FEM) simulation, the effect of cutting speed on cutting force, cutting temperature and workpiece surface residual stress has been studied in precision hard turning of hardened steel GCr15 with PCBN. The research results indicate that with rise of cutting speed, cutting force somewhat decreases and periodically changes because of metal softening effect, while cutting temperature increases and its maximum lies near tool tip on the interface of cutting chip and cutting edge, and residual stress largely decreases in a small area under workepiece surface and distributes clearly like a spoon. FEM simulation and experimental results are in good agreement.

A cutting chatter forecast method based on continuous wavelet feature and multi-class spherical Support Vector Machines is studied in this paper. The method based on continuous wavelet transform extracts the cutting vibration signal feature and uses multi-class spherical Support Vector Machines to discern the chatter. In order to simplify computational complexity when binary classification SVM turn to multi-class classification, the algorithm makes every kind of samples have a spherical SVM. In the feature space identified the test sample and spherical SVM centre distance as a decision-making function. Experiments show that using combine spherical SVM with continuous wavelet feature Vector has good recognition effect in the milling chatter recognition system. Chatter inoculation forecast accuracy reaches 95%, and chatter outbreak forecast accuracy reaches 97.5%.

To improve the processing efficiency and Surface qualityof impeller. Impeller processing difficulties as a major object of study were researched by this paper. Using UG7.5 impeller processing module, Based on the impeller feature division idea and to optimize the impeller machining path.Finally, Through it carried out the tool path generation and simulation and verify the feasibility of processing. To effectively enhance programming efficiency and processing quality.

In this paper, modal analysis of ball end mills is modeled by finite element to work out natural frequency and chatter model in tooling system and to calculate the limit curve of stability in single degree freedom system. The effect of cutter flute length and cutter tooth number on limit curve of stability in single degree freedom system is also discussed. The research results show that steady critical cutting depth of milling system declines while the cutter flute length increases, but the trend is not linear, which shows increase partly. An engineering optimization design is made on milling cutter geometrical parameters based on this conclusion.

In the detection process of the ball detector, surface can not unfold effectively, which brings about that the camera can not capture the image which we want, resulting in a high rate of defect and at a low efficiency in the test with the ball detector. In order to solve this problem, the optimized design on the mechanical control parts of the expansion organization was carried out, besides, kinematics analysis model the expansion organization and a motor control timing schedule were created by ADAMS, enabling expansion process consistent with the mathematical modeling. To a certain extent the optimization results improve overall performance of the system, which plays a guiding role in the improvement of the system.

In this paper, FEM is used to simulate the three stages of catastrophic shear occurrence, expansion and shear band formation when serrated chips are formed under adiabatic shear behavior in high-speed machining of hardened steel GCr15 with PCBN tool. By comparing data of simulation and experiment on chip morphology characters, it is indicated that they are in good accordance. Hereby, the author has analyzed strain and temperature distribution in adiabatic shear band, and dynamic characters of cutting force . The research results show that adiabatic shear band begins from tool tip and extends to workpiece free surface, and it is characterized by large strain and high temperature. In addition, it results from adiabatic shear behavior that cutting force waves regularly in a numerical range.

A 3D model is established in this paper to simulate cutting process of PCBN tool cylindrical cutting hardened steel GCr15 using ABAQUS/Explicit. The model effectively overcomes serious element distortions and cell singularity in high strain domain caused by material large deformation by adopting shear failure criteria and element deletion criteria. In this study cutting force, cutting temperature, surface residual stress field as well as side flow are forecasted of hard cutting process with chamfering tool preparation. It shows that satisfactory results could be obtained by FEM. The simulation results provide theoretical basis for studying hard cutting mechanism and selecting the best cutting condition in practical.