...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Mechanical Design >Comparison of Probability and Possibility for Design Against Catastrophic Failure Under Uncertainty
【24h】

Comparison of Probability and Possibility for Design Against Catastrophic Failure Under Uncertainty

机译：不确定性下针对灾难性故障设计的可能性和可能性的比较

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper compares probabilistic and possibility-based methods for design under uncertainty. It studies the effect of the amount of data about uncertainty on the effectiveness of each method. Only systems whose failure is catastrophic are considered, where catastrophic means that the boundary between success and failure is sharp. First, the paper examines the theoretical foundations of probability and possibility, focusing on the impact of the differences between the two theories on design. Then the paper compares the two theories on design problems. A major difference between probability and possibility is in the axioms about the union of events. Because of this difference, probability and possibility calculi are fundamentally different and one cannot simulate possibility calculus using probabilistic models. Possibility-based methods tend to underestimate the risk of failure of systems with many failure modes. For example, the possibility of failure of a series system of nominally identical components is equal to the possibility of failure of a single component. When designing for safety, the two methods try to maximize safety in radically different ways and consequently may produce significantly different designs. Probability minimizes the system failure probability whereas possibility maximizes the normalized deviation of the uncertain variables from their nominal values that the system can tolerate without failure. In contrast to probabilistic design, which accounts for the cost of reducing the probability of each failure mode in design, possibility tries to equalize the possibilities of failure of the failure modes, regardless of the attendant cost. In many safety assessment problems, one can easily determine the most conservative possibilistic model that is consistent with the available information, whereas this is not the case with probabilistic models. When we have sufficient data to build accurate probabilistic models of the uncertain variables, probabilistic design is better than possibility-based design. However, when designers need to make subjective decisions, both probabilistic and possibility-based designs can be useful. The reason is that large differences in these designs can alert designers to problems with the probabilistic design associated with insufficient data and tell them that they have more flexibility in the design than they may have known.
机译：本文比较了不确定性下基于概率和可能性的设计方法。它研究了有关不确定性的数据量对每种方法有效性的影响。仅考虑故障是灾难性的系统，其中灾难性意味着成功与失败之间的界限很明显。首先，本文考察了概率和可能性的理论基础，重点研究了两种理论之间的差异对设计的影响。然后，本文比较了两种关于设计问题的理论。概率与可能性之间的主要区别在于事件并集的公理。由于存在这种差异，因此概率和可能性计算从根本上是不同的，并且无法使用概率模型来模拟可能性演算。基于可能性的方法往往会低估具有许多故障模式的系统的故障风险。例如，名义上相同的组件的串联系统发生故障的可能性等于单个组件的发生故障的可能性。在设计安全性时，这两种方法试图以根本不同的方式最大化安全性，因此可能会产生明显不同的设计。概率将系统故障的可能性降到最低，而可能性将不确定变量与其系统可以承受的无故障标称值的标准化偏差最大化。与概率设计相反，后者考虑了降低设计中每种故障模式的可能性的成本，而可能性则试图使故障模式的故障可能性均等，而与伴随的成本无关。在许多安全评估问题中，可以轻松确定与可用信息相一致的最保守的可能性模型，而概率模型则并非如此。当我们有足够的数据来建立不确定变量的准确概率模型时，概率设计要比基于可能性的设计更好。但是，当设计人员需要做出主观决策时，概率设计和基于可能性的设计都可能有用。原因是这些设计之间的巨大差异可以提醒设计人员注意与数据不足相关的概率设计问题，并告诉他们设计方面的灵活性比他们所知道的更大。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号