CAREER: Development of Nonlinear Modeling Tools for Analysis, Simulation, and Structural Health Monitoring

我们的许多民用基础设施处于严重退化状态。该项目将开发基于振动响应特征的有限信息评估关键结构系统健康状况的方法，为工程师提供一套可靠的工具来评估其持续可行性，并在有限的预算内优先考虑维修和维护。与传统的结构健康监测方法（数据分析在离线/批处理模式）的项目，通过强调算法的效率标准，将开发新的自适应系统识别方法，包括实时损伤检测到一套面向应用的工具。这些工具将通过一个分阶段的实验程序进行评估，包括数值模拟，实验室实验和全面evaluation.Building PI的先前工作，研究将显示在结构健康监测方面的应用非线性识别技术的潜力，并在更广泛的领域结构工程/工程力学。研究目标是：1）发展混合方法，克服非参数和参数建模的困难，用于结构损伤检测; 2）发展非线性实时识别技术，用于结构健康监测和主动控制，并寻求从替代传感器技术中获益; 3）评估从低水平激励或仅从响应测量识别结构动力学的局限性（即，未知激励）; 4）评估从稀疏的振动传感器阵列推断损伤的局限性，并开发使工程师能够容易地检测结构损伤的具有成本效益的方法;以及5）将这些工具应用于其他工程挑战，例如，微机电系统、土壤动力学和航空航天：作为研究项目的补充，还开展了一个综合教育项目。该教育项目有三个主要方面：1）开发用于研究和学生参与的可重复非线性动态测试的实验室设备-通过使用主动控制来合成非线性行为来实现可重复性; 2）开发关于健康监测的研究生课程;和3）夏季外展计划，通过教学，实地考察，实验室演示，和动手测试--所有这些都是与哥伦比亚大学的双重发现中心合作完成的。

Much of our civil infrastructure is in a severe state of degradation. This project will develop methods to assess the health of critical structural systems based on limited information about their vibration response signature, providing engineers with a set of reliable tools to evaluate their continued viability and prioritize repair and maintenance within limited budgets. Unlike conventional structural health monitoring methods (where data is analyzed in an off-line/batch mode) the project, through an emphasis on algorithm efficiency criteria, will develop new approaches in adaptive system identification involving real-time damage detection into a set of application-oriented tools. These tools will be evaluated through a phased experimental program, involving numerical simulation, laboratory experimentation, and full-scale evaluation.Building on the PI's prior work, the research will show the potential of nonlinear identification techniques for application in the structural health monitoring context, and in broader fields of structural engineering/engineering mechanics. The research objectives are: 1) to develop hybrid methodologies, circumventing difficulties associated with nonparametric vs. parametric modeling of nonlinear structural systems for damage detection purposes; 2) to develop nonlinear real-time identification techniques for structural health monitoring and active control, and seek to benefit from alternative sensor technologies; 3) to evaluate limitations in identification of structural dynamics from low-level excitation or from response measurements only (i.e., unknown excitation); 4) to evaluate limitations of inferring damage from vibration sensor arrays that are sparse, and develop cost-effective methodologies that enable engineers to readily detect structural damage; and 5) to apply these tools to other engineering challenges, e.g., MEMS, soil-dynamics and aerospace.Complementing the research project, an integrated educational project is undertaken. This educational project has three main aspects: 1) the development of a lab facility for repeatable nonlinear dynamic testing for research and student participation - repeatability achieved through use of active control to synthesize nonlinear behavior; 2) the development of a graduate-level course on health monitoring; and 3) a summer outreach program to engage underprivileged, inner-city, New York high-school students in the engineering research environment through teaching, field-trips, laboratory demonstration, and hands-on testing - all in collaboration with Columbia University's Double Discovery Center.