论文标题
通过数据子集对结构系统的不确定性量化
Uncertainty Quantification of Structural Systems with Subset of Data
论文作者
论文摘要
量化不确定性对材料特性的影响以及输入地面运动对结构响应的影响是实施基于绩效的地震工程(PBEE)框架的重要步骤。在各种不确定性来源中,输入地面动作的变异性,又称记录对记录,会极大地影响评估结果。本文的目的是量化混合不确定性来源的结构反应中的不确定性。在本文中,提出了多种矩阵完成方法并将其应用于案例研究结构。矩阵完成方法是通过仅针对一小部分分析进行分析来估计整个输入参数的分析结果的手段。我们提出的方法的主要算法贡献是双重的。首先,我们开发了一种用于选择代表性模拟子集的抽样技术,该技术允许提高估计响应的准确性。无监督的机器学习技术用于此目的。接下来,通过合并对可用部分模拟的回归模型,进一步完善了不确定性量化的矩阵完成方法。回归模型改善了初始抽样,因为它提供了对结构响应的粗略估计。最后,提出的算法应用于多度自由度系统,并估计结构响应(即位移和碱基剪切)。结果表明,所提出的算法可以通过仅在集合的一小部分进行分析来有效地估算一组非线性模拟的响应。
Quantification of the impact of uncertainty in material properties as well as the input ground motion on structural responses is an important step in implementing a performance-based earthquake engineering (PBEE) framework. Among various sources of uncertainty, the variability in the input ground motions, a.k.a. record-to-record, greatly affects the assessment results. The objective of this paper is to quantify the uncertainty in structural response with hybrid uncertainty sources. In this paper, multiple matrix completion methods are proposed and applied on a case study structure. The matrix completion method is a means to estimate the analyses results for the entire set of input parameters by conducting analysis for only a small subset of analyses. The main algorithmic contributions of our proposed method are twofold. First, we develop a sampling technique for choosing a subset of representative simulations, which allows improving the accuracy of the estimated response. An unsupervised machine learning technique is used for this purpose. Next, the proposed matrix completion method for uncertainty quantification is further refined by incorporating a regression model that is trained on the available partial simulations. The regression model improves the initial sampling as it provides a rough estimation of the structural responses. Finally, the proposed algorithm is applied to a multi-degree-of-freedom system, and the structural responses (i.e., displacements and base shear) are estimated. Results show that the proposed algorithm can effectively estimate the response from a full set of nonlinear simulations by conducting analyses only on a small portion of the set.