Fit Degree Calculation of an Aircraft Part Manufacturing Process

2014 ◽  
Vol 989-994 ◽  
pp. 3153-3156
Author(s):  
Xiong Fei Huang ◽  
Fang Zhu ◽  
Na Wei

Aircraft manufacturing process normally requires very high precision assembly parts which are achieved in practice by a high-precision machining parts followed by a high coordination degree assembly process. The current practice in aircraft parts manufacturing process is that the manufacturing cycle is long, the rework rate is high and the manufacturing precision is difficult to improve. This can be sometimes infeasible or very costly. In this paper, we consider a fit degree calculation method to achieve precision aircraft parts with economical manufacturing processes. We consider an analytical approach to establish a physical process model to guide the design and machining process of assembly parts, which can assume the fit degree. The results show that the approach can obtain the nearly optimal process parameters at designated fit degree. At last, a case is developed to verify the proposed methods.

2014 ◽  
Vol 543-547 ◽  
pp. 4698-4701
Author(s):  
Juan Wang

During the processing of aircraft and other high precision machinery workpieces, if using the traditional machining methods, it will consume a amount of machining costs, and the mechanical processing cycle is long. In this context, this paper designs a kind of robot intelligent processing system with high precision machinery. And it has realized the intelligent online control on the machining process by using the high precision machining intelligent online monitoring technology and the numerical simulation prediction technology. Finally, this system is introduced into the process of data mining for volleyball game, and designs the partial differential variational data mining model, which has realized the key parameter data mining of volleyball games service system, and has provided reliable parameters and technical support for the training of volleyball players.


2014 ◽  
Vol 707 ◽  
pp. 520-524
Author(s):  
Min Liu ◽  
Jian Luo

In recent years, with the rapid development of economy in Chinese society, the mechanical manufacturing technology is increasingly maturing and requirements for the product quality and product precision is becoming higher and higher, so the development of mechanical manufacturing technology and high precision machining technology has been widely concerned by the relevant departments. According to the actual development of the modern machinery manufacturing technology and the high precision machining technology, on the basis of the principle of mechanical manufacturing, the characteristics of mechanical manufacturing technology and high precision machining should be analyzed thoroughly, meanwhile, the performance of the mechanical manufacturing process and high precision machining technology should be improved, thus, it can provide more theoretical basis and technical guidance for the development of mechanical manufacturing industry.


2009 ◽  
Vol 69-70 ◽  
pp. 446-450 ◽  
Author(s):  
Ding Hua Zhang ◽  
Ying Zhang ◽  
Bao Hai Wu

Due to different datum position and inevitable distortion from the linear friction welding process, the nominal CAD model from the design stage is no longer suitable for the use of the final NC machining, and that is the main problem for precisely machining complex blisk. In this paper, an adaptive machining approach based on adaptive process model for high precision manufacturing of blisk is proposed and developed. Comparing the nominal model with the inspection result, adaptive process model is reconstructed to describe workpiece localization, allowance distribution and composite error compensation for NC machining of blisk accurately. Firstly, the transformation matrix for allowance optimization is searched fleetly by genetic algorithm with constraint conditions. Secondly, using the cross-section curve blending and deformation compensation method, adaptive model for shape distortion is constructed to solve the part-to-part variation machining problem and to realize precision machining for complex geometry blisk. Finally, based on the adaptive process model, tool paths used for the last NC machining process can then be adaptively generated to implement the different processes work. Example shows that the adaptive machining technology of blisk is feasible and the result is of high precision and efficiency.


Author(s):  
Jing Zhang ◽  
Jiexiong Ding ◽  
Qingzhao Li ◽  
Qicheng Ding ◽  
Zhong Jiang ◽  
...  

In the multi-axis high-speed and high-precision machining process, the contouring error and the feed rate of tool tip and affect the quality of machined workpiece and the processing efficiency, respectively. The faster feed motion will result in greater tracking error of each axis. The contouring error which directly affects the quality of machined part is caused by the tracking errors of the axes. Obviously, it is difficult to improve the contouring accuracy and increase the feed rate simultaneously. To this end, a novel optimization model is developed here based on the model predictive control method. First, the feed servo model of translational and rotary axes are established, and the contouring error model is afterwards constructed. Subsequently, the optimization algorithm is derived to achieve the high processing speed, and input constraints are addressed to avoid violation of the performance limitation of the drivers. In addition, contouring error constraint, which is obtained by calculating the contouring error of the processed path, is addressed to high contour accuracy. Finally, a simulation is conducted to verify the effectiveness and superiority of the proposed method.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 607
Author(s):  
Zelong Li ◽  
Yifan Dai ◽  
Chaoliang Guan ◽  
Jiahao Yong ◽  
Zizhou Sun ◽  
...  

Weak-stiffness mirrors are widely used in various fields such as aerospace and optoelectronic information. However, it is difficult to achieve micron-level precision machining because weak-stiffness mirrors are hard to clamp and are prone to deformation. The machining errors of these mirrors are randomly distributed and non-rotationally symmetric, which is difficult to overcome by common machining methods. Based on the fast tool servo system, this paper proposes a high-precision machining method for weak-stiffness mirrors. Firstly, the clamping error and cutting error compensation strategy is obtained by analyzing the changing process of the mirror surface morphology. Then, by combining real-time monitoring and theoretical simulation, the elastic deformation of the weak-stiffness mirror is accurately extracted to achieve the compensation of the clamping error, and the compensation of the cutting error is achieved by iterative machining. Finally, a weak-stiffness mirror with a thickness of 2.5 mm was machined twice, and the experimental process produced a clamping error with a peak to valley (PV) value of 5.2 µm and a cutting error with a PV value of 1.6 µm. The final machined surface after compensation had a PV value of 0.7 µm. The experimental results showed that the compensation strategy proposed in this paper overcomes the clamping error of the weak-stiffness mirror and significantly reduces cutting errors during the machining process, achieving the high precision machining of a weak-stiffness mirror.


2011 ◽  
Vol 110-116 ◽  
pp. 3600-3607
Author(s):  
Mei Chen Liu ◽  
Jie Qiong Lin ◽  
Xiao Qin Zhou

Firstly, the superior performance and industrial application prospects of non-rotationally symmetric (NRS) optical surfaces are detailed. Secondly, those high precision machining processes to generate NRS optical surfaces are overviewed, it’s been stressed that fast tool servo (FTS) based diamond turning has been the most promising, cost-effective, and high precision machining process to generate NRS surfaces. Finally, the recent research progress in FTS based diamond turning of NRS optical surfaces is remarked, both the tool trajectory generation and the FTS actuation techniques are discussed, the limitations of the existing researches are disclosed, and then the academic and technological researches to be urgently carried out are suggested.


Author(s):  
J. Temple Black

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.


2020 ◽  
Vol 499 (3) ◽  
pp. 4418-4431 ◽  
Author(s):  
Sujatha Ramakrishnan ◽  
Aseem Paranjape

ABSTRACT We use the Separate Universe technique to calibrate the dependence of linear and quadratic halo bias b1 and b2 on the local cosmic web environment of dark matter haloes. We do this by measuring the response of halo abundances at fixed mass and cosmic web tidal anisotropy α to an infinite wavelength initial perturbation. We augment our measurements with an analytical framework developed in earlier work that exploits the near-lognormal shape of the distribution of α and results in very high precision calibrations. We present convenient fitting functions for the dependence of b1 and b2 on α over a wide range of halo mass for redshifts 0 ≤ z ≤ 1. Our calibration of b2(α) is the first demonstration to date of the dependence of non-linear bias on the local web environment. Motivated by previous results that showed that α is the primary indicator of halo assembly bias for a number of halo properties beyond halo mass, we then extend our analytical framework to accommodate the dependence of b1 and b2 on any such secondary property that has, or can be monotonically transformed to have, a Gaussian distribution. We demonstrate this technique for the specific case of halo concentration, finding good agreement with previous results. Our calibrations will be useful for a variety of halo model analyses focusing on galaxy assembly bias, as well as analytical forecasts of the potential for using α as a segregating variable in multitracer analyses.


2021 ◽  
Vol 9 ◽  
Author(s):  
Zhigang Bao ◽  
László Erdős ◽  
Kevin Schnelli

Abstract We prove that the energy of any eigenvector of a sum of several independent large Wigner matrices is equally distributed among these matrices with very high precision. This shows a particularly strong microcanonical form of the equipartition principle for quantum systems whose components are modelled by Wigner matrices.


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