Chengdu Fine Optic Engineering Research Center

Chengdu, China

Chengdu Fine Optic Engineering Research Center

Chengdu, China
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Wang S.,Harbin Institute of Technology | Wang S.,Chengdu Fine Optic Engineering Research Center | An C.,Chengdu Fine Optic Engineering Research Center | Zhang F.,Harbin Institute of Technology | And 3 more authors.
Machining Science and Technology | Year: 2017

Potassium dihydrogen phosphate (KDP) exhibits anisotropic and hydrostatic pressure-dependent mechanical characteristics during processing. However, none of the existed material models is capable of describing the mechanical properties of the crystal. Thus, a new constitutive model, which combines the anisotropic elastic and pressure-dependent plastic model has been proposed in this paper. In addition, the tensile stress failure criterion is adopted as the fracture criterion of KDP crystal. Subroutine of the new material model is programmed and integrated into the commercial finite element software LS-DYNA. On the basis of that, the unknown material parameters of KDP are successfully identified with the aid of the nanoindentation/scratch technique and finite-element simulation. Finally, 2-D and 3-D cutting simulations applying the new model are performed to investigate the influence of cutting parameters on the brittle ductile transition depth and cutting force. The simulation results show good agreement with the KDP cutting experiment results, which confirm the validity and capability of the proposed constitutive model. © 2017 Taylor & Francis Group, LLC.


Yang X.,Chengdu Fine Optic Engineering Research Center | Yang X.,Xiamen University | An C.,Chengdu Fine Optic Engineering Research Center | Wang Z.,Xiamen University | And 3 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2016

The dynamic performance of ultra-precision cutting machine tools is an important factor for its machining accuracy. To improve the precision of the machine tool, a surface topography model is built in this paper and the tool path during the cutting process is achieved by dynamic finite element analysis (DFEA) of the air spindle in ANSYS, surface topography is obtained using MATLAB simulation by combing the model with the tool path, and an experiment is carried out for validation. Results show the simulation surface is highly consistent with the experimental result. Dynamic performance of the spindle is the main factor for texture generation, and optimization of spindle is investigated, DFEA of the optimized spindle shows better performance, and the connection mode between diamond tool and cutter head should be further studied. © 2016 Springer-Verlag London


Liang Y.,Harbin Institute of Technology | Chen W.,Harbin Institute of Technology | Chen W.,University of Strathclyde | An C.,Chengdu Fine Optic Engineering Research Center | And 3 more authors.
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2014

Flycutting is a major machining process for flat-surface machining, which is a typical intermittent-machining process. This paper is dedicated to study the influence of the intermittent-machining force on the workpiece surface generation. In the present study, some defects are identified on the machined surface and found to be corresponded to the tool-tip vibration by the dynamic analysis and the surface-generation simulation. A theoretical model is proposed to capture the dominant factor based on the characteristic. It reveals that the defects are attributed to the changing period of the intermittent-machining force and the dynamic performance of the machine tool. Hence, a surface-generation model is proposed to take account of the tool-tip vibration and the changing of the cutting locus. The simulation results have been found to agree well with the experimental results. © IMechE 2013.


Wang S.,Harbin Institute of Technology | Wang S.,Chengdu Fine Optic Engineering Research Center | An C.,Chengdu Fine Optic Engineering Research Center | Zhang F.,Harbin Institute of Technology | And 3 more authors.
International Journal of Machine Tools and Manufacture | Year: 2016

As a typical brittle material, Potassium Dihydrogen Phosphate (KDP) crystal exhibits anisotropic mechanical property during processing. The most general method to produce smooth and crack-free KDP surface is single point diamond fly-cutting (SPDF). In processing KDP by SPDF, cutting direction has great influence on the cutting force and the quality of the machined surface. Thus, selecting an optimal cutting direction is of great significance in decreasing the cutting force and improving the surface quality. In this paper, influence of cutting direction on the brittle ductile transition (BDT) depth and cutting force in machining KDP crystal has been investigated. Cutting experiments are carried out on the (001), Doubler and Tripler plane of KDP crystal to find out the change law of cutting force and BDT depth related to cutting direction. Theoretical models for calculating the cutting force and conditions for achieving crack-free surface in cutting by circular edge cutter have also been established. The predicted results coincide well with the experiment results, which have proved the validity of the proposed models. The experimental results in this study can provide guidelines for optimizing the processing parameters in fly-cutting of KDP crystal, and the theoretical models can be extended to study the cutting mechanism of other brittle materials. © 2016 Elsevier Ltd. All rights reserved.


Chen W.,Harbin Institute of Technology | Liang Y.,Harbin Institute of Technology | Sun Y.,Harbin Institute of Technology | Bai Q.,Harbin Institute of Technology | An C.,Chengdu Fine Optic Engineering Research Center
JVC/Journal of Vibration and Control | Year: 2015

The pressure distribution in an aerostatic bearing has an important effect on the performance of the associated mechanical equipment. To more accurately predict performance, a new dynamic modeling method has been developed that takes into account the pressure distribution in the bearing by integrating the principle of flow equilibrium and finite element theory. The direct corresponding relationship between the fluid film characteristics and spindle dynamic performance is established using this method. The simulation and experimental results show that the new dynamic modeling method for the aerostatic bearing is more efficient and reliable than traditional modeling methods. © The Author(s) 2014.


Wang S.-F.,Harbin Institute of Technology | Wang S.-F.,Chengdu Fine Optic Engineering Research Center | An C.-H.,Chengdu Fine Optic Engineering Research Center | Zhang F.-H.,Harbin Institute of Technology | And 2 more authors.
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2016

This paper researches the thermal field distribution of a Potassium Dihydrogen Phosphate (KDP) crystal in fly-cutting process, and explores the influence of cutting temperature on the fly-cutting process of KDP crystal. Firstly, the thermal-mechanical coupled Finite Element Method (FEM) was conducted to simulate the fly-cutting process of KDP crystal and to obtain the temperature fields under different cutting depths. Then, a fly-cutting machine and a nanoindentation instrument were used to cut the KDP crystal at different speeds. It was found that the microscopic morphologies of the chip formed under different cutting speeds are greatly different, and this may result from the different temperature rises at different cutting speeds. Finally, the chip formed under lower cutting speed was heated at different temperatures and the morphology of the heated chip was observed. The simulation results demonstrate that the temperature in the cutting zone rises to as much as 110℃ when the cutting depth increases to 200 nm. Moreover, the experiment results indicate that the chip morphology will change at 100℃. It concludes by simulation and experiments that the maximum temperature exceeds 100℃ in fly-cutting of KDP crystal. So, it suggests that the effect of cutting temperature on the mechanical property and removal process in fly-cutting of KDP crystal should be considered. © 2016, Science Press. All right reserved.


Chen W.,Harbin Institute of Technology | Lu L.,Harbin Institute of Technology | Liang Y.,Harbin Institute of Technology | Sun Y.,Harbin Institute of Technology | And 2 more authors.
Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering | Year: 2015

The flatness of the KH2PO4 (KDP) crystal has important effect on the inertial confinement fusion system. The method to improve the flatness of KDP crystal and its implementation in the machine tool design is presented in this paper. The finite element model of the whole machine tool is built up to describe the tool tip displacement with the cutting force along the cutting path. The influence of the axial and radial bearing stiffness of the aerostatic spindle on the machined surface flatness is discussed. Furthermore, a novel adjusting mechanism which is used to adjust the squareness between the spindle and the slide is designed, and a new machining process is proposed to improve the flatness of the machined surface. The machining trials are carried out to evaluate and validate the effectiveness of the presented approach and simulation. © 2015 Institution of Mechanical Engineers.


Zong W.J.,Harbin Institute of Technology | Li Z.Q.,Harbin Institute of Technology | Zhang L.,Harbin Institute of Technology | Liang Y.C.,Harbin Institute of Technology | And 5 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2013

Diamond tool has significant influences on the finished surface quality in fly cutting of potassium dihydrogen phosphate (KDP) crystals. In this work, the nanoindentation and dimensional analysis are employed to establish the material constitutive equation of KDP crystals, i.e., the variation curve of flow stress vs. plastic strain. As expected, a novel 3D finite element (FE) model is developed for diamond fly cutting of KDP crystals, and the generation of 3D surface topography is simulated by multi-run cutting calculations, in which the movements of diamond tool are configured to be identical to the actual feed rate and cutting velocity. Subsequently, the coordinates of the nodes on the topmost surface as freshly machined are collected to evaluate the surface roughness, which enables the detailed analyses of the effect of diamond tool geometries on the achieved surface roughness of KDP crystals. The results suggest an optimal selection of tool geometries, i.e. -25 rake angle and 8 clearance angle. With the increment of tool nose radius, surface roughness decreases correspondingly. Moreover, the larger defect or sharpness of tool cutting edge produces the worse surface roughness. Diamond fly cutting experiments are carried out with different rake angles, in which the cutting parameters are the same as the values used in FE simulations. The measured surface roughness has a satisfied consistency with the simulated data, which demonstrates that the developed 3D FE cutting model and the related simulations are reliable. © 2013 Springer-Verlag London.


An C.H.,Harbin Institute of Technology | An C.H.,Chengdu Fine Optic Engineering Research Center | Zhang Y.,Harbin Institute of Technology | Xu Q.,Chengdu Fine Optic Engineering Research Center | And 4 more authors.
International Journal of Machine Tools and Manufacture | Year: 2010

Axis orientation stability of aerostatic bearing spindles has great influence on machining precision of ultra-precision fly cutting machines used for processing ultra-precision optical components of large diameter. Mid-spatial frequency errors (amplitude<0.1 μm, wavelength about 100 nm) always existed on the machined surfaces along feeding direction. Generally, the waviness errors on processed surfaces will impact the performance of workpiece used as optical components greatly, and the tilting motions of spindles were believed to be the main source which produced the waviness errors. In this paper, to study the tilting motions of spindles, the Euler dynamic equations of angular displacements of spindles were proposed, and analytic solutions of the equations were also presented. At the same time, the 3D surface profile simulations of workpieces based on analytic solutions of Euler equations were achieved. The simulation results have been verified by lots of experiments on an ultra-precision fly cutting machine. At last, the inertia tensor criterion which can decrease the waviness errors of machining surface was represented, and it can be applied to instruct the structure design of aerostatic bearing spindles. © 2009 Elsevier Ltd. All rights reserved.


Wang G.,Chengdu Fine Optic Engineering Research Center | Ma P.,Chengdu Fine Optic Engineering Research Center | Qiu F.,Chengdu Fine Optic Engineering Research Center | Hu J.,Chengdu Fine Optic Engineering Research Center | Yan D.,Chengdu Fine Optic Engineering Research Center
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2012

An experimental study on ultrasonic cleaning of optics was carried out. Optimization of the cleaning process was performed through comparative experiments with different cleaning reagents and temperatures. The optimized cleaning process removes both organic pollutants and inorganic pollutants effectively. After optimized cleaning, the optics surface shows no additional damage, with the contact angle less than 6°, and no pollutant particles larger than 1 μm left. Ultrasonic cleaning attains a better cleaning effect than manual cleaning.

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