Dynamic performance analysis and quantitative evaluation for ultraprecision aerostatic spindle

Author(s):  
Ruocheng Wei ◽  
Chenhui An ◽  
Zhenzhong Wang ◽  
Qiao Xu ◽  
Xiangyang Lei ◽  
...  

For optics used in high-power laser beams, high accuracy requirements in full spatial frequency must be fulfilled. Among them, the allowable root mean square value is less than 5 nm in the PSD1 band. In order to evaluate the dynamic performance of the spindle system and put forward a quantitative index, a novel accurate model of the spindle system was built and a series of dynamic simulations were performed. Harmonic response analysis reveals natural frequencies and frequency response functions. Transient analysis indicates vibration waveforms of the tool-tip. Furthermore, by analyzing surface topography, it can be found that the medium-frequency waviness in the machined surface matches the vibration waveform. Obviously, the medium-frequency waviness is generated by the modal vibration of the spindle system. So that a quantitative index for the aerostatic spindle is proposed: when the amplitude of vibration in transient analysis is smaller than 8 nm, the allowable error in the PSD1 band can be fulfilled.

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774714
Author(s):  
Dongju Chen ◽  
Xianxian Cui ◽  
Ri Pan ◽  
Jinwei Fan ◽  
Chenhui An

In ultra-precision fly-cutting machining, the aerostatic spindle is the key component, which has significant influence on the machined surface quality. The unbalanced spindle directly affects the machining accuracy. In this article, a prediction model of machining surface topography is proposed which involves the effect of the gas film performance of spindle in microscale. With the Weierstrass function, unstable transient response of the aerostatic spindle system is derived by the motion model of the spindle, which response signal represents the surface profile in the ultra-precision machining. Meanwhile, the experiment is performed with different rotation speed of the spindle. And the effect of the unbalanced aerostatic spindle on the surface generation is discussed in time and frequency domain. The conclusion shows that the similar cyclical surface ripple of the workpiece is independent of the spindle speed, and the rotation speed of the spindle and unbalanced spindle directly affects the machining surface topography. This study is quite meaningful for deeply understanding the influence rule of spindle unbalanced error from the viewpoint of machined surface and vibration frequency.


2014 ◽  
Vol 672-674 ◽  
pp. 1540-1544
Author(s):  
Ao Xiang Liu ◽  
Jun Wang ◽  
Jun Xian Kang ◽  
Qiang Zhang ◽  
Jun Sun ◽  
...  

TX1600 boring and milling machining center milling part was studied. The Three-dimensional solid model was established based on Solidworks. Simultaneously, modal analysis was carried out by ANSYS Workbench software, the first six natural frequencies and corresponding modes were acquired. Based on the modal analysis, the harmonic response analysis of milling part was conducted,and the response curves of the three main motion orientation were obtained respectively, the vibration performance of milling part under forces was further explored,and the finite element model was validated. The feasibility of the model to simplify the program was verified by modal and harmonic response analysis. The study provides a good basis in terms of selecting a specific material. The structures and material are optimized. Ultimately, a lot of energy is saved.


2012 ◽  
Vol 446-449 ◽  
pp. 1119-1122 ◽  
Author(s):  
Hui Jun Wu ◽  
Wen Liang Qiu

Based on the anti-seismic research achievements of tired arch bridge at home and abroad, taking River City Bridge in Jilin as an example, a finite element model is established for dynamic performance analysis by general finite element software midas civil. Natural vibration characteristics of tied arch bridge are calculated as a basis for further dynamic calculation. Firstly, choose appropriate seismic waves according to the geological data. Then perform the dynamic response analysis of this bridge under different loading cases. Dynamic responses of this bridge under longitudinal and transverse seismic waves are studied respectively, and the influence of vertical seismic wave is also considered. It is shown that the influence on seismic response of vertical seismic waves is very obvious. The vertical seismic waves should be considered while doing seismic design of tied arch bridges.


Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 107
Author(s):  
Rongchao Jiang ◽  
Zhenchao Jin ◽  
Dawei Liu ◽  
Dengfeng Wang

In order to reduce the negative effect of lightweighting of suspension components on vehicle dynamic performance, the control arm and torsion beam widely used in front and rear suspensions were taken as research objects for studying the lightweight design method of suspension components. Mesh morphing technology was employed to define design variables. Meanwhile, the rigid–flexible coupling vehicle model with flexible control arm and torsion beam was built for vehicle dynamic simulations. The total weight of control arm and torsion beam was taken as optimization objective, as well as ride comfort and handling stability performance indexes. In addition, the fatigue life, stiffness, and modal frequency of control arm and torsion beam were taken as the constraints. Then, Kriging model and NSGA-II were adopted to perform the multi-objective optimization of control arm and torsion beam for determining the lightweight scheme. By comparing the optimized and original design, it indicates that the weight of the optimized control arm and torsion beam are reduced 0.505 kg and 1.189 kg, respectively, while structural performance and vehicle performance satisfy the design requirement. The proposed multi-objective optimization method achieves a remarkable mass reduction, and proves to be feasible and effective for lightweight design of suspension components.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2950
Author(s):  
Vinod Kumar ◽  
Liqiang Duan

Coal consumption and CO2 emissions are the major concerns of the 21st century. Solar aided (coal-fired) power generation (SAPG) is paid more and more attention globally, due to the lesser coal rate and initial cost than the original coal-fired power plant and CSP technology respectively. In this paper, the off-design dynamic performance simulation model of a solar aided coal-fired power plant is established. A 330 MW subcritical coal-fired power plant is taken as a case study. On a typical day, three various collector area solar fields are integrated into the coal-fired power plant. By introducing the solar heat, the variations of system performances are analyzed at design load, 75% load, and 50% load. Analyzed parameters with the change of DNI include the thermal oil mass flow rate, the mass flow rate of feed water heated by the solar energy, steam extraction mass flow rate, coal consumption, and the plant thermal efficiency. The research results show that, as DNI increases over a day, the coal saving rate will also increase, the maximum coal saving rate reaches up to 5%, and plant thermal efficiency reaches 40%. It is analyzed that the SAPG system gives the best performance at a lower load and a large aperture area.


2014 ◽  
Vol 711 ◽  
pp. 520-524 ◽  
Author(s):  
Huan Qin Liu ◽  
Wei Bin Li ◽  
Ruo Yang Wu ◽  
Lin Fei Yan

Based on one 240-meter-high special-shaped RC chimney, the structure’s dynamic performance and elastic-plastic seismic response analysis has been studied in detail. From the analysis, it demonstrates the weak areas in the chimney. The interlayer displacement angle about corresponding performance points under four kinds of loading mode were also acuired, and the response of four loading patterns were analyzed.


2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.


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