Quantifying mass changes with ambient vibration measurements
Quantifying mass changes with ambient vibration measurements
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DOI：
10.1016/j.engstruct.2021.113745
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发表时间：
2022-03
影响因子：
5.5
通讯作者：
Zachariah Wynne;Tim Stratford;Thomas P. S. Reynolds
中科院分区：
文献类型：
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作者：
Zachariah Wynne;Tim Stratford;Thomas P. S. Reynolds
静载荷是结构设计过程中的关键未知因素之一。虽然动态称重站和称重传感器允许在小区域或小型结构上测量负载，但它们不适用于更复杂的结构，例如大跨度桥梁或大型建筑物，并且可能非常昂贵。操作模态分析可以揭示用加速度计测量的土木结构动态行为的变化，有可能提供一种低成本、耐用的技术来估计使用中质量的变化。为此，必须以足够的精度估计结构的动态参数，然后使用足够鲁棒的质量变化估计方法进行处理，以适应噪声和测量误差。本文介绍了一种估计质量变化的新技术，即随机采样质量估计（RSME），并将其应用于实验室规模梁结构的实验数据。 RSME 纳入了动态参数估计中的不确定性，并且如果质量变化的位置已知，则允许对应用于结构的总质量变化进行最小二乘估计，或者通过新颖的图形实现来预测单个集中质量变化的大小和位置。对于添加到梁上的单个质量，92.0% 的质量位置预测误差小于跨度长度的 2%，69.4% 的添加质量大小预测在±10 g 范围内，大约是梁质量的 0.05%。对于并发附加质量位置，梁上存在 2 个或更多附加质量时，质量总变化的估计平均误差为 2 g，大约为梁质量的 0.011%。
The static loading is one of the key unknowns in the structural design process. While weigh in-motion stations and load cells allow load to be measured over small areas or small structures, they are not viable for more complex structures such as long-span bridges or larger buildings, and can be prohibitively expensive. Operational modal analysis can reveal changes in the dynamic behaviour of civil structures measured with accelerometers, potentially offering a low-cost, durable technique for estimating changes of mass in-service. In order to do this, the dynamic parameters of the structure must be estimated with sufficient accuracy, and then processed using a mass change estimation method robust enough to accommodate noise and measurement error. In this paper a new technique for estimating changes in mass, random sampling mass estimation (RSME), is introduced and applied to experimental data for a laboratory-scale beam structure. RSME incorporates the uncertainty in the estimates of the dynamic parameters and allows least-squares estimation of the total change in mass applied to a structure if the locations of the changes in mass are known, or prediction of both the magnitude and location of a single concentrated change in mass through a novel graphical implementation. For individual masses added to the beam, 92.0% of mass location predictions have errors smaller than 2% of the length of the span and 69.4% of added mass magnitude predictions are within±10 g, approximately 0.05% of the mass of the beam. For concurrent added mass locations, the mean error of the estimates for the total change in mass where 2 or more added masses are present on the beam is-2 g, approximately 0.011% of the mass of the beam.