• /  3
  • 下载费用: 19.90积分  

weibull_statistical_properti-2

'weibull_statistical_properti-2'
Home The Weibull Distribution Weibull Statistical Properties Weibull Statistical Properties The Mean or MTTF The mean, , (also called MTTF or MTBF by some authors) of the Weibull pdf is given by: (3) where is the gamma function evaluated at the value of . The gamma function is defined as: This function is provided within Weibull++ for calculating the values of Γ(n) at any value of n. This function is located in the Quick Statistical Reference of Weibull++. For the two-parameter case, Eqn. (3) can be reduced to: Note that some practitioners erroneously assume that η is equal to the MTBF or MTTF. This is only true for the case of β = 1 since The Median The median, , is given by: (4) The Mode The mode, , is given by: (5) The Standard Deviation The standard deviation, σT, is given by: 页码,1/3 The Weibull Reliability Function The equation for the three-parameter Weibull cumulative density function, cdf, is given by: Recalling that the reliability function of a distribution is simply one minus the cdf, the reliability function for the three-parameter Weibull distribution is given by: The Weibull Conditional Reliability Function The three-parameter Weibull conditional reliability function is given by: (6) or: Eqn. (6) gives the reliability for a new mission of t duration, having already accumulated T hours of operation up to the start of this new mission, and the units are checked out to assure that they will start the next mission successfully. It is called conditional because you can calculate the reliability of a new mission based on the fact that the unit or units already accumulated T hours of operation successfully. The Weibull Reliable Life The reliable life, TR, of a unit for a specified reliability, starting the mission at age zero, is given by: (7) This is the life for which the unit will be functioning successfully with a reliability of R(TR). If R(TR) = 0.50 then , the median life, or the life by which half of the units will survive. The Weibull Failure Rate Function The Weibull failure rate function, λ(T), is given by: 页码,2/3 See Also: The Weibull Distribution Go to weibull.com Go to ReliaSoft.com ©1996-2006. ReliaSoft Corporation . ALL RIGHTS RESERVED. 页码,3/3
关 键 词:
weibull_statistical_properti
 天天文库所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
关于本文
本文标题:weibull_statistical_properti-2
链接地址: https://www.wenku365.com/p-40985010.html
关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服点击这里,给天天文库发消息,QQ:1290478887 - 联系我们

本站为“文档C2C交易模式”,即用户上传的文档直接卖给(下载)用户,本站只是中间服务平台,本站所有文档下载所得的收益归上传人(含作者)所有【成交的100%(原创)】。本站是网络服务平台方,若您的权利被侵害,侵权客服QQ:1290478887 欢迎举报。

1290478887@qq.com 2017-2027 https://www.wenku365.com 网站版权所有

粤ICP备19057495号 

收起
展开