Rapid Identification, Control, and Uncertainty Analysis of Structural Models

本研究项目的主要目标是研究和开发能够准确有效地确定大部分线性但局部非线性和不确定结构系统响应的有效方法。土木、机械和航空航天工程中的结构系统经常遇到局部非线性。然而，对于设计、控制、识别和健康监测，这些局部非线性系统的数值分析就好像整个系统是非线性的一样。这种非线性系统的数值分析可能需要大量的计算。为了实现这一目标，将研究一种利用Volterra卷积积分的新型模型缩减策略，该策略将包括时变的局部特征和反馈特征，并将研究新兴计算架构（如图形处理单元）的使用，以实现高效的数据处理。研究中开发的计算方法将通过应用于一系列相关的基准问题来验证，这些问题包括动力分析、基础隔离建筑的识别和控制、具有非线性轴承的桥梁和桥梁斜拉索。研究结果将使工程师能够有效地设计、识别和优化用于减轻自然灾害影响的被动和半主动非线性响应控制装置。该研究还将有助于更有效地表征结构系统退化的影响。该项目将通过明尼苏达大学和南加州大学的研究生和本科生参与研究项目，为他们提供高级培训。这两个机构的内部项目将被用来招募来自代表性不足背景的学生来参与这个研究项目。为了在今后的研究和实践中得到更广泛的利用，项目的研究结果将通过为正式课程、会议报告和期刊出版物开发的示范模块传播给更广泛的技术界。该研究将整合到调查人员正在进行的涉及小学，初中和高中学生的外展活动中，使他们接触到涉及不确定性的结构动力学和工程设计问题。

The main goal of this research project is to study and develop validated approaches which can accurately and efficiently determine the responses of mostly linear but locally nonlinear and uncertain structural systems. The structural systems in civil, mechanical and aerospace engineering often encounter nonlinearities that are localized. For designs, control, and identification and health monitoring, such locally nonlinear systems are, however, numerically analyzed as if the whole systems were nonlinear. The numerical analyses of such nonlinear systems can be computationally demanding. To accomplish this goal, a novel model reduction strategy utilizing the Volterra convolution integrals will be examined to include time-varying local features and feedback characteristics, and the use of emerging computing architectures such as Graphics Processing Units will be investigated for efficient data processing. The computational approaches developed in the research will be validated through applications to a series of germane benchmark problems involving dynamic analyses, identification and control of base-isolated buildings, bridge with nonlinear bearings, and bridge stay cables.The research results will enable engineers to efficiently design, identify, and optimize passive and semi-active nonlinear response control devices that are used for the mitigation of the impact of natural hazards. The research will also facilitate more efficient characterization of the impacts of structural system degradation. The project will give advanced training to graduate and undergraduate students at the University of Minnesota and University of Southern California through their involvements in the research project. The internal programs at both institutions will be utilized to recruit students from underrepresented backgrounds to work on this research project. For their wider utilization in future research and practice, the project findings will be disseminated to the broader technical community through demonstration modules developed for formal courses, conference presentations, and journal publications. The research will be integrated in the investigators' ongoing outreach activities involving elementary, middle and high school students to expose them to structural dynamics and engineering design problems involving uncertainty.