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有效的方法，可以准确，有效地确定大部分线性，但局部非线性和不确定的结构系统的响应。 在土木、机械和航空航天工程中，结构系统经常遇到局部非线性问题。然而，对于设计、控制、识别和健康监测而言，这种局部非线性系统被当作整个系统是非线性的来进行数值分析。这种非线性系统的数值分析可以计算要求。为了实现这一目标，一种新的模型简化策略，利用沃尔泰拉卷积积分将被检查，包括随时间变化的局部特征和反馈特性，并使用新兴的计算架构，如图形处理单元将进行调查，以有效的数据处理。本研究所发展之计算方法将应用于一系列相关之基准问题，包括基础隔震建筑物、非线性支座桥梁及斜拉索之动力分析、识别及控制，使工程师能有效地进行设计、识别及控制，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。这项研究还将有助于更有效地描述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该研究项目，为他们提供高级培训。这两个机构的内部计划将被用来招募来自代表性不足的背景的学生从事这项研究项目。为了在今后的研究和实践中得到更广泛的利用，将通过为正式课程、会议介绍和期刊出版物开发的示范模块，向更广泛的技术界传播项目结果。这项研究将被纳入调查人员正在进行的涉及小学、初中和高中学生的外联活动，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.