共查询到19条相似文献,搜索用时 201 毫秒
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步降加速寿命试验优化设计Monte-Carlo仿真 总被引:1,自引:0,他引:1
针对加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的步降加速寿命试验优化设计方法.采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计和各应力水平下的特征寿命之和最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的步降加速寿命试验优化设计模型.最后通过实例分析,表明该方法具有可行性、有效性,为电子装备寿命预测的加速试验方案优化设计提供技术支撑. 相似文献
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双应力交叉步降加速寿命试验优化设计Monte-Carlo仿真 总被引:2,自引:0,他引:2
为进一步缩短试验时间,实现产品可靠性的快速评定,在综合应力加速寿命试验优化方案设计的基础上,提出了一种基于Monte-Carlo仿真的双应力交叉步降加速寿命试验优化设计方法。采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计为目标函数,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的双应力交叉步降加速寿命试验优化设计模型。最后通过三次样条插值拟合理论对目标函数进行拟合,降低了仿真规模,提高了试验效率,为电子装备寿命预测的加速试验方案优化设计提供技术支撑。 相似文献
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温度应力下基于步进加速退化试验的电子器件寿命预测 总被引:1,自引:1,他引:0
为实现高可靠性长寿命电子器件的寿命预测,根据Arrhenius模型,结合产品的线性退化轨迹模型,对于温度应力下性能退化性步进加速寿命试验,提出一种不同温度应力下时间折算方法,并且推导了它们之间的变化计算公式。在四种不同的温度下,对某型号集成运放进行步进加速试验,并利用此方法处理数据。结果表明,样品的伪寿命符合对数正态分布,其加速模型符合Arrhenius加速方程,据此可以求出样品中位寿命,实现寿命预测。 相似文献
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1 问题的提出与基本假定1.1 问题的提出步进应力加速寿命试验是产品进行可靠性寿命试验的常用方法,对其试验数据的统计分析,通常是要求知道产品的寿命分布的有关参数与所施加的应力之间有已知的加速寿命模型,而一切的统计分析方法均以此为依据,但在一些实际问题中,加速寿命模型并不知道。本文针对这一情况,采用Bayes分析技术,给出在步进应力加速寿命试验下产品寿命数据的统计分析方法.1.2 基本假定本文给出的统计分析方法是建立在下面几个基本假定之下的。假定1 正常应力水平的S_0,加速应力水平为S_1,S_2,满足 相似文献
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针对加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的步降加速寿命试验优化设计方法。采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计和各应力水平下的特征寿命之和最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的步降加速寿命试验优化设计模型。最后通过实例分析,表明该方法具有可行性、有效性,为电子装备寿命预测的加速试验方案优化设计提供技术支撑。 相似文献
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机载导弹是长期贮存、多次挂飞、一次使用的可维修产品。贮存寿命是机载导弹的重要指标之一,确定和延长机载导弹贮存寿命对保持装备战斗力具有重要作用。结合我国装备定延寿技术发展特点,对机载导弹贮存阶段经历的环境应力进行分析,选择加速试验模型,确定加速应力和试验时间,通过开展加速寿命试验,有效地评估了机载导弹的贮存寿命。并对机载导弹贮存寿命评估的关键技术与发展方向进行了分析,为评估方法的优化奠定了基础。 相似文献
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针对竞争失效产品加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的竞争失效产品加速寿命试验优化设计方法。采用Monte-Carlo对竞争失效产品的加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的竞争失效产品加速寿命试验优化设计模型。最后通过GA-BP神经网络对目标函数进行拟合,降低了仿真规模,提高了试验效率,为电子装备寿命预测的加速试验方案优化设计提供技术支撑。 相似文献
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Accelerated degradation-tests with tightened critical values 总被引:2,自引:0,他引:2
Guangbin Yang Kai Yang 《Reliability, IEEE Transactions on》2002,51(4):463-468
ALT (accelerated life tests) are widely used to provide quickly the information about life distributions of products. Life data at elevated stresses are extrapolated to estimate the life distribution at design stress. The existing estimation methods are efficient and easy to implement-given sufficient life data. However, ALT frequently results in few or no failures at low-level stress, making it difficult to estimate the life distribution. For products whose failures are defined in terms of performance characteristics exceeding their critical values, reliability assessment can be based on degradation measurements by using degradation models. The estimation, however, is usually mathematically complicated and computationally intensive. This paper presents a method for the estimation of life distribution by using life data from degradation measurements. Since the time-to-failure depends on the level of a critical value, more life data can be obtained by tightening the critical value. The relationship between life and critical value and stress is modeled and used to estimate the life distribution at a usual critical value and design stress. The model parameters are estimated by using maximum likelihood. The optimum test plans, which choose the critical values, stress levels, and proportions of sample size to each stress level, are devised by minimizing the asymptotic variance of the mean (log) life at a usual critical value and design stress. The comparison between the proposed and existing 2-level test plans shows that the proposed plans have smaller asymptotic variance and are less sensitive to the uncertainty of the pre-estimates of unknown parameters. 相似文献
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采用人工免疫算法的加速寿命试验分析方法 总被引:3,自引:3,他引:0
极大似然估计是加速寿命试验统计分析中常用的分析方法,但似然函数的优化问题是该方法广泛运用的主要障碍,常用的似然函数优化算法对初值要求高,而且容易陷入局部最优解.为了有效地解决上述问题,在似然函数的优化中引入了人工免疫算法,提出了一种采用人工免疫算法的步降应力加速寿命试验分析方法.利用人工免疫算法在解决多维复杂函数优化问题时强大的全局寻优能力,有效地解决了似然函数的优化问题.最后通过实例验证表明,采用人工免疫算法的步降应力加速寿命试验分析方法是有效的,而且在统计分析中避免了查统计用表,能够很方便的实现计算机编程计算,有较大的工程应用价值. 相似文献
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Sheng-Tsaing Tseng Chin-Hsiung Hsu 《Reliability, IEEE Transactions on》1994,43(3):503-510
In product research and development, one might wish to select the most reliable of several highly-reliable competing products. Both type-I and type-II accelerated life tests (ALT) are well-known to estimate and compare the life of highly reliable (nonrepairable) products within a reasonable testing time. A common decision problem is to choose the better plan for achieving the above goal. This paper proposes an intuitive selection rule for each ALT plan, and then derives the respective optimal ALT sampling plan when the acceleration factor (AF) is known and unknown. Finally, some criteria of Mackay are used to compare the two plans. From a practical point of view, the type-II ALT sampling plan is more convenient, and needs smaller sample size than the type-I ALT sampling plan. Nevertheless, the latter has shorter mean duration time and life testing time than the former 相似文献
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Accelerated Life Test Planning With Independent Weibull Competing Risks With Known Shape Parameter 总被引:1,自引:0,他引:1
This article presents methodology for accelerated life test (ALT) planning when there are two or more failure modes, or competing risks which are dependent on one accelerating factor. It is assumed that the failure modes have respective latent (unobservable) failure times, and the minimum of these times corresponds to the product lifetime. The latent failure times are assumed to be s-independently distributed Weibull with known, common shape parameter. Expressions for the Fisher information matrix, and test plan criteria are presented. The methodology is applied to the ALT of Class-H insulation for motorettes, where temperature is the accelerating factor. Two-level, and 4:2:1 allocation test plans based on determinants, and on estimating quantiles or hazard functions, are presented. Sensitivity of optimal test plans to the specified Weibull shape parameter is also studied 相似文献
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《Microelectronics Reliability》2014,54(12):2675-2681
An early life failure mechanism was discovered on a 0.25-µm 40 V GaN FET technology. Through accelerated life testing (ALT), it was determined that the early life failure mechanism was thermally accelerated with a high activation energy, which means that it is not a concern a normal operating conditions up to the maximum rated junction temperature. Subsequent improvements to the process resulted in elimination of the early life failure mechanism. With the improved process, single-mode ALT lifetime distributions and excellent reliability performance down to low failure fractions were demonstrated. 相似文献
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为了获得白光OLED的寿命信息,通过加大电流应力开展了二组恒定和一组步进应力相组合的加速寿命试验。采用威布尔函数描述白光OLED的寿命分布,利用双线性回归法(BRM)估计出威布尔参数,确定了加速寿命方程,对白光OLED寿命是否符合威布尔分布进行了Kolmogorov-Smirnov检验,并利用自行开发的寿命预测软件计算出平均寿命和中位寿命。数值结果表明,恒定步进应力加速寿命试验方案是切实可行的,白光OLED的寿命服从威布尔分布,寿命应力关系满足线性Arrhenius方程,精确计算的加速参数可实现在短时间内OLED寿命的预测。 相似文献
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The purpose of this paper is to present a method of statistical analysis of Accelerated Life Test (ALT) data which allows to drop assumptions usually made on the type of life distribution function at each stress level and the life-stress relationship. The method proposed can be used to derive life distribution function for nominal stress level based on a number of accelerated non-censored tests. The method can be especially useful in a variety of areas where the assumptions on life distribution function and/or life-stress relationship is not well justified by empirical or theoretical model. 相似文献