Events Calendar

Oral Defense Dissertation

Speaker: Dongyu Zhang, Ph.D. Candidate, Astani Department of Civil and Environmental Engineering

Talk Title: Controlled Susbstructure Identification for Shear Structures

Abstract:
Abstract:

Shear structure models are widely used to model the dynamics of building structures; therefore, developing the techniques, which can accurately identify the parameters of a shear structure, plays a vital role in establishing efficient and reliable structural health monitoring systems for building structures.
In this dissertation, applying the “divide and conquer” strategy of substructure identification (SI), a series of innovative SI methods for shear structure are developed. A shear structure is divided into many two-story standard substructures. An ingenious induction identification procedure is applied to identify the parameters of the whole structure from top to bottom inductively. Numerical simulation results verify that these substructure identification methods provide accurate identification results.
One of the most important features of these SI methods is that the analytical results of the identification error is obtained, which demonstrates that the identification accuracy is simply controlled by the structural responses near the substructure natural frequency. This important discovery provides the ability to easily improve the identification accuracy by accordingly changing the substructure responses via specially designed structural control systems. Several controlled substructure identification methods were proposed, using different structural control systems to improve the accuracy of the SI methods. Moreover, since the accuracy of the proposed controlled SI methods directly depends on the close-loop controlled structural responses rather than on the control systems themselves, these controlled SI methods are proved to be quite robust to possible control system errors.
To overcome the limitations of the previous SI methods, a loop substructure identification method is proposed which makes use of the dynamic equilibrium of only one standard substructure to formulate a loop identification sequence and identify all parameters of that substructure once for all. Compared with the previous SI methods, the loop SI method is able to perform the structural identification of any part of a shear structure with only three floor acceleration responses; more importantly, the loop substructure identification can be carried out with knowing the structural mass information.
Furthermore, a new approach is proposed to extend the SI methods originally developed for shear structures to more realistic but complex frame structures. The study shows that the proposed approach is able to accurately structural damage of columns in a frame structure

Host:

Location: Kaprielian Hall (KAP) - 209

Audiences: Everyone Is Invited

Contact: Evangeline Reyes