Novel Structural Health Monitoring and Damage Detection Approaches for Composite and Metallic Structures

Authors

Shervin TashakoriFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Mechanical Engineering

First Advisor's Name

Ibrahim N. Tansel

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Cesar Levy

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Yiding Cao

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Dwayne McDaniel

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Igor Tsukanov

Fifth Advisor's Committee Title

Committee member

Keywords

Structural Health Monitoring, Damage Detection, Composite, Bond Inspection, Load Monitoring

Date of Defense

6-11-2018

Abstract

Mechanical durability of the structures should be continuously monitored during their operation. Structural health monitoring (SHM) techniques are typically used for gathering the information which can be used for evaluating the current condition of a structure regarding the existence, location, and severity of the damage. Damage can occur in a structure after long-term operating under service loads or due to incidents. By detection of these defects at the early stages of their growth and nucleation, it would be possible to not only improve the safety of the structure but also reduce the operating costs. The main goal of this dissertation is to develop a reliable and cost-effective SHM system for inspection of composite and metallic structures. The Surface Response to Excitation (SuRE) method is one of the SHM approaches that was developed at the FIU mechatronics lab as an alternative for the electromechanical impedance method to reduce the cost and size of the equipment. In this study, firstly, the performance of the SuRE method was evaluated when the conventional piezoelectric elements and scanning laser vibrometer were used as the contact and non-contact sensors, respectively, for monitoring the presence of loads on the surface. Then, the application of the SuRE method for the characterization vii of the milling operation for identical aluminum plates was investigated. Also, in order to eliminate the need for a priori knowledge of the characteristics of the structure, some advanced signal processing techniques were introduced. In the next step, the heterodyne method was proposed, as a nonlinear baseline free, SHM approach for identification of the debonded region and evaluation of the strength of composite bonds. Finally, the experimental results for both methods were validated via a finite element software. The experimental results for both SuRE and heterodyning method showed that these methods can be considered as promising linear and nonlinear SHM approaches for monitoring the health of composite and metallic structures. In addition, by validating the experimental results using FEM, the path for further improvement of these methods in future researches was paved.

Identifier

FIDC006883

ORCID

https://orcid.org/0000-0001-7165-2418

Recommended Citation

Tashakori, Shervin, "Novel Structural Health Monitoring and Damage Detection Approaches for Composite and Metallic Structures" (2018). FIU Electronic Theses and Dissertations. 3753.
https://digitalcommons.fiu.edu/etd/3753