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541.
542.
以工程应用为出发点,提出了试验机技术状态确定的依据、单次无维修待命时间验证成败判据、特殊气象条件下试验数据处理方法、无维修待命时间验证评估模型.在此基础上,以某型歼击机为例给出了试飞阶段无维修待命时间验证方案设计方法.该方法工程应用性强,可作为试飞阶段外场开展无维修待命时间验证的依据. 相似文献
543.
横向剪切干涉检测方法用于非球面加工过程中检测是经济且高效的方法。从数值模拟的角度,分析了基于像差最小原则的非球面度;模拟了非球面波前的横向剪切干涉图,并利用基于Zernike多项式拟合的最小二乘法进行了波前重建数值模拟,给出了数值模拟结果,为该方法的实际应用提供了理论依据。 相似文献
544.
阐述了武器试验机建设的背景及需求,结合国内外试验机建设经验总结了飞机平台选择、机载火控系统研制、挂装武器飞行性能和机弹分离安全性评估及机载测试测量等试验机建设关键技术,对关键技术提取和具体应用进行了分析并提出了使用原则,明确了主要的指标要求和使用注意事项,以期对相关建设工作起到参考作用. 相似文献
545.
546.
Acceptance sampling plan of accelerated life testing for lognormal distribution under time-censoring
Lognormal distribution is commonly used in engineering.It is also a life distribution of important research values.For long-life products follow this distribution,it is necessary to apply accelerated testing techniques to product demonstration.This paper describes the development of accelerated life testing sampling plans(ALSPs)for lognormal distribution under time-censoring conditions.ALSPs take both producer and consumer risks into account,and they can be designed to work whether acceleration factor(AF)is known or unknown.When AF is known,life testing is assumed to be conducted under accelerated conditions with time-censoring.The producer and consumer risks are satisfied,and the size of test sample and the size of acceptance number are optimized.Then sensitivity analyses are conducted.When AF is unknown,two or more predetermined levels of accelerated stress are used.The sample sizes and sample proportion allocated to each stress level are optimized.The acceptance constant that satisfies producer and consumer risk is obtained by minimizing the generalized asymptotic variance of the test statistics.Finally,the properties of the two ALSPs(one for known-AF conditions and one for unknownAF conditions)are investigated to show that the proposed method is correct and usable through numerical examples. 相似文献
547.
Daniel Hampf Gavin Rowell Neville Wild Tristan Sudholz Dieter Horns Martin Tluczykont 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Night sky brightness is a major source of noise both for Cherenkov telescopes as well as for wide-angle Cherenkov detectors. Therefore, it is important to know the level of night sky brightness at potential sites for future experiments. 相似文献
548.
549.
Recent developments in micro- and nano-satellites have attracted the interest of the research community worldwide. Many colleges and corporations have launched their satellites in space. Meanwhile, the space flexible probe–cone docking system for micro- and nano-satellites has become an attractive topic. In this paper, a dynamic model of a space flexible probe–cone docking system, in which the flexible beam technology is applied, is built based on the Kane method. The curves of impact force versus time are obtained by the Lagrange model, the Kane model, and the experimental method. The Lagrange model was presented in the reference and verified by both finite element simulation and experiment. The results of the three methods show good agreements on the condition that the beam flexibility and the initial relative velocity change. It is worth mentioning that the introduction of vectorial mechanics and analytical mechanics in the Kane method leads to a large reduction of differential operations and makes the modeling process much easier than that of the Lagrange method. Moreover, the influences of the beam flexibility and the initial relative velocity are discussed. It is concluded that the initial relative velocity of space docking operation should be controlled to a certain value in order to protect the docking system. a 2014 Production and hosting by Elsevier Ltd. on behalf of CSAA BUAA. 相似文献
550.
直升机抗坠毁技术是直升机研制中的五大关键技术之一,而抗坠毁试验是验证这一关键技术的重要途径与手段.详细介绍了国外抗坠毁试验技术的发展,对国内近年来开展的抗坠毁试验技术研究工作进行了综合阐述分析,指出了今后我国直升机抗坠毁试验技术的一个重要研究与发展方向. 相似文献