Mechanical Engineering Commons^™

Guided Wave Based Integrated Structural Health Monitoring And Nondestructive Evaluation, Zhenhua Tian

Theses and Dissertations

Damage detection and health monitoring are critical for ensuring the structural safety in various fields, such as aerospace, civil and nuclear engineering. Structural health monitoring (SHM) performs online nondestructive evaluation (NDE) and can predict the structural remaining life through appropriate diagnosis and prognosis technologies. Among various SHM/NDE technologies, guided ultrasonic waves have shown great potential for fast and large area SHM/NDE, due to their sensitivity to small defects and capability to propagate long distances. Recent advances in guided wave based SHM/NDE technologies have demonstrated the feasibility of detecting damage in simple structures such as metallic plates and pipes. However, there …

Structural Health Monitoring Using Linear And Nonlinear Ultrasonic Guided Waves, Yanfeng Shen

Theses and Dissertations

The dissertation addresses Structural Health Monitoring (SHM) using linear and nonlinear ultrasonic guided waves, with an emphasis on the development of analytical and numerical models of guided wave propagation and interaction with linear and nonlinear structural damage.

An analytical model was developed based on the exact Lamb wave solution for the simulation of Lamb wave propagation and interaction with damage. The damage effects were inserted into the model using complex valued wave damage interaction coefficients (WDICs). The analytical procedure was coded as a framework into a MATLAB Graphical User Interface (GUI), and the software WaveFormRevealer (WFR) was developed as a …

A Study Of Compressive Sensing For Application To Structural Health Monitoring, Vaahini Ganesan

Electronic Theses and Dissertations

One of the key areas that have attracted attention in the construction industry today is Structural Health Monitoring, more commonly known as SHM. It is a concept developed to monitor the quality and longevity of various engineering structures. The incorporation of such a system would help to continuously track health of the structure, indicate the occurrence/presence of any damage in real time and give us an idea of the number of useful years for the same. Being a recently conceived idea, the state of the art technique in the field is straight forward - populating a given structure with sensors …

Smart Rotating Machines For Structural Health Monitoring, Dmitry Leonidovich Storozhev

ETD Archive

The objective of this thesis is to explore an innovative approach to the on-line health monitoring of rotating machinery in the presence of structural damage using active magnetic bearings (AMBs). First, the detailed model of the rotor with the breathing transverse crack is developed using finite element method. Next, the experimental data from the rotating magnetically levitated healthy and cracked shafts, under specially designed external excitation force, was collected, analyzed and compared with the computer simulation. The obtained results demonstrate that the presented on-line health monitoring technique is very effective for detection of the structural damage in rotating machinery, and …