基于材料试验数据不确定性的最低允许结构强度的估计
Jeffrey T Fong1, N Alan Heckert1, James J Filliben1
1National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
概括
本研究引入了一种新的三步方法,通过解决模型选择,实验室规模和全面规模的不确定性,准确估计全尺寸组件的最小断裂强度. 该方法量化了统计模型中的不确定性,以改善工程设计的允许性.
科学领域:
- 工程 工程师 工程师 工程师
- 材料科学 材料科学 材料科学
- 统计 统计 统计 统计
背景情况:
- 估计全尺寸元件的最小断裂强度涉及三个关键的不确定性:模型选择,实验室尺寸强度和全尺寸强度.
- 准确的估计对于可靠的工程设计和安全至关重要.
研究的目的:
- 开发和介绍一种新的三步方法,用于估计全尺寸元件的最低强度.
- 量化工程应用的统计建模和强度预测中的不确定性.
主要方法:
- 用一个复合的适合度指标来选择实验室测试数据的最佳统计分布 (从五个候选者中).
- 选择分布的参数估计不确定性,实验室尺度最低强度确定在95%的置信度.
- 使用覆盖概念 (99%的A基和90%的B基) 在95%的置信水平上估计了全尺度允许的最低强度.
主要成果:
- 开发的以不确定性为基础的方法应用于四种工程材料的六组故障强度数据.
- 该方法成功量化了模型选择,参数估计和全尺度强度预测中的不确定性.
- 结果表明,该方法适用于各种工程材料.
结论:
- 拟议的三步方法为估计具有量化不确定性的全尺度组件强度提供了可靠的框架.
- 这种方法提高了设计可容量的可靠性,特别是在关键的航空航天部件中.
- 该研究强调了不确定性量化在材料强度预测中的重要性.
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