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Uncertainty Quantification and Management in Ambient Modal Identification

环境模态识别中的不确定性量化和管理

基本信息

批准号：
EP/N017897/1
负责人：
John Mottershead
金额：
$ 72.35万
依托单位：
University of Liverpool
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FN017897%2F1
关键词：
Uncertainty Quantification Management Ambient Modal

项目摘要

The modal properties of a structure include primarily its natural frequencies, damping ratios and mode shapes. Their information is indispensable for design against dynamic loads such as wind, earthquake and human excitation. Uncertainty arises due to the lack of knowledge and modelling limitations and this generally increases project risk. Modal identification has long been recognised as an effective means for uncertainty mitigation in structural dynamics. Theoretically it is possible to identify the modal properties based on only the 'output' vibration response of structures without knowing the 'input' excitation. This type of test, called 'ambient vibration test', has now become the primary and most sustainable means for its high implementation feasibility, robustness and economy. In the absence of loading information and with data collected under uncontrolled field environment, however, the identification results have significant variability and low repeatability. This has limited the economic benefit of ambient vibration tests and undermined the scientific significance of their identification results. This has been well-recognised but there has been no quantitative account for its origin or how to control it.This project aims at developing a comprehensive fundamental methodology for quantifying and managing the uncertainties of the modal properties of civil engineering structures identified from ambient vibration data. At the scientific core is a set of 'uncertainty laws', analogous to the laws of large numbers of data in classical probability, that expresses fundamentally the identification uncertainty of modal properties explicitly and quantitatively in terms of test configurations such as measurement noise, environmental load intensity and the number and location of sensors. Due to complexity of the problem, it is unlikely to obtain insightful results for general situations. The project aims at fundamental expressions with insights governing the dominant behaviour of the remaining identification uncertainty under realistic situations. The project objective is achieved through a comprehensive programme comprising fundamental theory development, extensive verification with synthetic, laboratory and field data, and knowledge transfer with industry. A practical guide for planning and performing ambient vibration test shall be produced incorporating scientific findings of the project and experience of the team members with input from industry partners.

结构的模态特性主要包括其固有频率、阻尼比和振型。它们的信息对于设计抵抗风、地震和人体激励等动态载荷是不可或缺的。不确定性是由于缺乏知识和建模的局限性而产生的，这通常会增加项目风险。模态识别一直被认为是结构动力学中消除不确定性的有效手段。从理论上讲，在不知道结构的“输入”激励的情况下，仅根据结构的“输出”振动响应来识别结构的模态特性是可能的。这种类型的测试，称为“环境振动测试”，现已成为主要的和最可持续的手段，其高实施的可行性，鲁棒性和经济性。然而，在缺乏载荷信息和在不受控的现场环境下收集数据的情况下，识别结果具有显著的可变性和低重复性。这不仅限制了环境振动试验的经济效益，而且削弱了环境振动试验识别结果的科学意义。这已经得到了很好的认可，但一直没有定量的帐户，其起源或如何控制it.This项目的目的是开发一个全面的基本方法，量化和管理的不确定性的土木工程结构的模态特性，从环境振动数据。在科学的核心是一组“不确定性定律”，类似于经典概率中大量数据的定律，它从根本上明确和定量地表达了模态特性的识别不确定性，如测量噪声，环境载荷强度和传感器的数量和位置。由于问题的复杂性，不太可能在一般情况下获得有见地的结果。该项目的目的是在基本表达式的见解支配的主要行为，在现实情况下，其余的识别不确定性。该项目的目标是通过一个全面的计划来实现的，该计划包括基础理论的发展，合成，实验室和现场数据的广泛验证，以及与工业界的知识转移。应编制一份规划和执行环境振动试验的实用指南，该指南应结合项目的科学发现和团队成员的经验以及行业合作伙伴的投入。