Mechanical Engineering Commons^™

Nondestructive Evaluation And Structural Health Monitoring Of Manufacturing Flaws And Operational Damage In Composite Structures, Robin James

Theses and Dissertations

Advanced composite materials have begun to be used extensively in the manufacturing of aerospace structures. Composite aerospace structures can develop complex types of damages during the manufacturing stages and operational lifetime. This creates an indispensable demand for appropriate nondestructive evaluation (NDE) and structural health monitoring (SHM) methods that are tailored to specific types of damage. This dissertation addresses innovative methods for NDE and SHM of manufacturing flaws and operational damage in composite structures.

For the NDE of manufacturing flaws in carbon fiber reinforced polymer (CFRP) composites, an eddy current testing (ECT) NDE method has been developed by conducting multiphysics modeling …

Artificial Intelligence Approaches For Structural Health Monitoring Of Aerospace Structures, Kimberly A. Cardillo

Theses and Dissertations

Structural health monitoring (SHM) and non-destructive evaluation (NDE) have been a significant research topic to help with damage detection in aerospace structures. SHM and NDE techniques are based on extracting damage sensitive features to determine the criticality of damage and lifetime of a structure. Acoustic emission (AE) signal detection is an important technique in SHM and NDE especially for fatigue crack growth. AE signals for thin aerospace structures consist of ultrasonic guided Lamb waves that propagate through the structure. This thesis focuses on AE signal repeatability, load at which AE signals occur, feature extraction, artificial intelligence and electro-mechanical impedance of …

Structural Health Monitoring And Non-Destructive Inspection Of Composite And Metallic Structures, Asaad Qasim Migot

Theses and Dissertations

Structural Health Monitoring (SHM) and Nondestructive Testing (NDT) techniques are being used as effective tools for investigating variety of civil, mechanical, and aerospace applications. In recent years, these techniques become such incredible tools for continuously monitoring of various structures. The aim of the dissertation work is to develop SHM and NDT methodologies for acoustic emission sources localization, damage detection and quantification in metallic and composite structures using a network of sensors, guided wave and developed imaging methods. This work is implemented through preparing metallic and composite specimens, setting up experiments, designing efficient networks of sensors, modeling guided wave interaction with …

Physics-Based Approaches For Structural Health Monitoring And Nondestructive Evaluation With Ultrasonic Guided Waves, Md Yeasin Bhuiyan

Theses and Dissertations

The engineering infrastructures have a growing demand for damage monitoring systems to avoid any potential risk of failure. Proper damage monitoring solutions are of a great interest to this growing demand. The structural health monitoring (SHM) and nondestructive evaluation (NDE) offer appropriate online and offline damage monitoring solutions for a variety of mechanical and civil infrastructures that includes unmanned aerial vehicles (UAV), spaceships, commercial aircraft, ground transportation, wind turbines, nuclear spent fuel storage tanks, bridges, naval ships, and submarines. The fundamentals of the ultrasonic SHM and NDE consist of multi-disciplinary fields. The dissertation addresses SHM and NDE using ultrasonic guided …

Fiber Optic Guided Wave Sensors For Structural Health Monitoring, Erik Frankforter

Theses and Dissertations

Risks and costs associated with aging infrastructure have been mounting, presenting a clear need for innovative damage monitoring solutions. One of the more powerful damage monitoring approaches involves using ultrasonic guided waves which propagate through a structure and carry damage-related information to permanently bonded sensors. Ultrasonic fiber-optic sensors are one of the most promising technologies for this application: they are immune to electromagnetic interference, present no ignition hazard, and transmit their data over tens of kilometers. However, before they can be widely employed, several limitations need to be overcome: poor sensitivity, unidirectional sensing, and loss of ultrasonic functionality due to …