Abstract A limitation of current reliability-based design Standards is their dependence on imprecise estimates of the probability of failure. These imprecise estimates do not, by themselves, provide a dependable basis for explicit risk-based decision-making. Therefore reliability-based Standards depend on Code calibration to determine acceptable levels of the estimated nominal probabilities of failure, which hinders further rationalisation and innovation. The paper discusses uncertain failure probabilities and defines a related characteristic failure probability that provides a dependable basis for risk-based decision-making. Uncertain probability estimates arise from epistemic uncertainty and they can be described by their own probability distributions. The paper discusses probability distributions of uncertain probabilities of failure, with examples of uncertainty arising from the sampling variability for design based on prototype testing in accordance with provisions in Australian Standards and an AISI Standard, and also sampling variability in the estimation of a design wind load based on wind speed data. It is shown that the characteristic failure probability provides a dependable basis for assessing the acceptability of extremely uncertain probabilities of structural failure.

中文翻译：

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结构设计标准可靠性不确定

摘要 当前基于可靠性的设计标准的局限性在于它们依赖于对故障概率的不精确估计。这些不精确的估计本身并不能为明确的基于风险的决策提供可靠的基础。因此，基于可靠性的标准依赖于规范校准来确定估计的名义故障概率的可接受水平，这阻碍了进一步的合理化和创新。本文讨论了不确定的故障概率，并定义了相关的特征故障概率，为基于风险的决策提供了可靠的基础。不确定的概率估计来自认知的不确定性，它们可以用它们自己的概率分布来描述。论文讨论了不确定失效概率的概率分布，例如，根据澳大利亚标准和 AISI 标准的规定，基于原型测试的设计采样可变性引起的不确定性示例，以及基于风速数据的设计风载荷估计中的采样可变性。结果表明，特征失效概率为评估极其不确定的结构失效概率的可接受性提供了可靠的基础。