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

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.