共查询到19条相似文献,搜索用时 189 毫秒
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利用杭州湾中部一年实测波浪资料,分析了实测波高分布、波周期分布和波高周期联合分布。基于双参数威布尔分布模式,采用最小二乘法拟合得出波高分布和波周期分布模式,并与其他理论分布模式作了比较。结果表明:(1)双参数威布尔分布对杭州湾中部实测波高分布的拟合效果好于Gluhovski分布,而且该模式在实测波周期分布上的拟合效果也相对优于孙孚分布和侯一筠分布,但威布尔分布在对大周期比区域的预测值偏小,而其他两者分布则偏大。(2)实测联合分布与孙孚理论的联合分布有所不同。(3)威布尔分布的拟合系数与相关波参数的关系较为复杂,其中周期分布的威布尔系数与谱宽度有较好的相关性,由此可改进威布尔分布的拟合效果。(4)偏东向的流速对波高分布和波周期分布存在微弱的影响。 相似文献
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燃油泵组件是机电一体化的产品,其在使用中获得的故障数据存在不同失效机理的情况,因此一重威布尔分布无法准确描述产品失效机理,而混合分布通过将多种失效分布进行耦合,能够充分描述产品失效机理。本文将二重三参数威布尔混合分布模型应用在舰船发动机附件故障分析中,基于某型燃机燃油泵组件的故障数据,通过数据分析直方图确定故障模型与模型初始化参数,通过Matlab非线性曲线拟合方法来估计二重三参数威布尔混合分布的参数。研究方法及成果能够为燃油泵组件可靠性分析及优化改进提供一定的借鉴。 相似文献
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本文依据收集的断路器寿命试验数据,通过拟合优先度检验确定了断路器寿命分布符合威布尔分布模型,利用极大似然估计估算出双参数威布尔分布的参数值,从而得到该型断路器寿命的累积失效分布函数、失效密度函数和可靠度函数,求得断路器的平均故障间隔时间,为断路器的寿命评估提供了依据。 相似文献
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叶冠吾 《上海海运学院学报》1990,11(1):68-71
在符合威布尔分布的疲劳寿命数据处理中,采取通用的威布尔概率纸作图法,凭目力试凑,难以逼真地确定其分布函数的三个参数。本文按作图法顺序,将数据在计算机上应用最小二乘法拟合,可以迅速而准确地得出威布尔分布的参数值。 相似文献
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基于威布尔分布的舰船装备故障分析 总被引:3,自引:0,他引:3
传统的舰船故障分析多由早期故障期、偶然故障期和耗损故障期三阶段的故障分布组合而成,没有统一的数学表达式。统计表明现代舰船大量装备不存在耗损故障期。为了满足舰船故障分析的需要,提出基于二参数的威布尔函数的故障率分布,并对该分布进行了卡方检验,结果表明威布尔分布能很好的描述舰船装备的故障率。 相似文献
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通过对管道振动试验数据的分析,选用威布尔分布的概率密度函数进行拟合,得到涡激升力的频谱表达式。通过管道振动的频响函数得到管道的振动位移的频谱图形,并与实测数据进行对比,结果表明:计算值与实验值吻合较好,中心频率基本相等,幅值稍有偏差。 相似文献
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根据通信设备的故障规律建立模型,采用威布尔分布模型进行模型检验与参数计算;通过卡方检验函数来实现本系统中模型的可信度检测,给出函数实现流程,并以某型通信设备为样本验证系统的可靠性。 相似文献
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针对电子设备突发故障预测问题,在一定置信度的前提下,基于样本的故障数据对总体的分布进行极大似然估计和分布拟合检验,确定其分布规律,进而基于故障数据分布函数建立电子设备突发故障预测模型,对电子设备未来一段时间内的突发故障概率进行预测,并进行实例分析,验证了预测模型的合理性. 相似文献
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基于Weibull分布计算造船设备故障发生概率 总被引:1,自引:0,他引:1
设备故障的发生发展过程都有其客观规律,研究故障规律对制定维修对策,以至建立更加科学的维修体制是十分重要的.本文应用Weibull统计方法对设备故障规律进行分析,并计算出设备的可靠度和故障率.统计分析是故障管理中重要的手段,是制定管理目标的主要依据. 相似文献
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《Marine Structures》2002,15(3):233-250
Reliability-based design analysis of the fatigue life of the connectors of the five sections of the 2-km long US Mobile Offshore Base (MOB) is demonstrated. A performance function is defined in terms of the nominal stress range, inherent defect or starter crack, and appropriate material properties, which are considered random variables. The reliability analysis is performed for a sea state 1–8 (SS1–8) random loading having a Gumbel distribution. Where possible, uncertainty data for random variables are obtained from published data relating to the fatigue of metal and metal alloys. Otherwise, judgmental coefficients of variation are prescribed for purposes of demonstration. The fatigue life is assumed to follow the Weibull distribution. The reliability function is defined in terms of the mean life and the total uncertainty in the fatigue life. Preliminary reliability calculations suggest that current design stress levels be reduced to meet the current fatigue life target reliability level for the MOB connectors. An illustrative design is demonstrated and the metal selected for a fatigue design of the connectors for 10 million cycles with a reliability of 0.99 at a nominal stress of 203 MPa is HY-130 steel. 相似文献
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This paper aims to assess the uncertainty on the extreme mooring loads of floating system considering short-term variability. Two environmental contour approaches based on the inverse First and Second Order Reliability Methods are employed to identify critical sea states that may give rise to extreme loads. The uncertainty related to the construction of environmental contours is addressed including significant differences due to marginal distribution fitting, parameter estimation methods and joint models. Three measured datasets are analysed using a known conditional joint distribution and proposed mixed copula model. 3-h time domain numerical simulation for each sea state is conducted and the characteristic extreme responses of mooring lines subjected to design loads are assessed. The uncertainties due to various statistical models including the average conditional exceedance rate method as well as global maxima, peak-over-threshold method combined with Gumbel distribution, Generalized Extreme Value distribution, Generalized Pareto distribution and 3-parameter Weibull distribution are investigated and quantified. It is observed that marginal distributions, joint models and parameters estimation methods have apparent effect on design loads estimation, and the extreme tensions of the semi-submersible platform shows significant difference using various probabilistic models. The results indicate that those epistemic uncertainties should be account for in the reliability analysis or safety factor calibration for mooring systems. 相似文献