Engineering Commons^™

Acoustic-Emission Monitoring Of Lap Joint Fatigue Cracks, Siddharth Kannan

Theses and Dissertations

Structural integrity is a pivotal consideration in the field of engineering applications, and understanding the behavior of materials and joints under various loading conditions is critical. This thesis presents a novel approach to detect and analyze fatigue induced cracks in various test specimens using Piezoelectric Wafer Active Sensors. This approach is widely used in Structural Health Monitoring applications involving acoustic emissions that can be captured using PWAS which in turn gives the surface response to applied stresses. The ultimate goal of the research is to identify the length of a fatigue crack originating from lap joints and to develop a …

Developing A Prototype Energy Harvesting Device For Powering Wireless Onboard Condition Monitoring Sensor Modules For Railway Service, Martin Amaro Jr.

Theses and Dissertations

An energy harvesting system is being developed to power a wireless bearing health monitoring device. In contrast to other monitoring systems, this wireless monitoring device is a low-powered onboard solution. Powered by a 3.7-Volt lithium-ion battery, the device can continuously function for several months on a single charge. By implementing an energy harvesting system, the life of the battery can be increased reducing the overall maintenance, electronic waste, and time needed to replace the batteries. The harvesting system uses thermoelectric generators to convert the heat generated in the bearings into electricity. The system is composed of aluminum heat sinks, a …

Assessing The Effectiveness And Efficacy Of Wireless Onboard Condition Monitoring Modules In Identifying Defects In Railroad Rolling Stock, Lee R. Cantu

Theses and Dissertations

Many industries have begun shifting into the Internet of Things (IoT) in the 21st century. To help ease this transition for the rail industry, The University Transportation Center for Railway Safety (UTCRS) has partnered with Hum Industrial Technology, Inc. (HUM) to help complete the development of a Wireless Onboard Condition Monitoring system named the ‘Boomerang™’. This product allows customers to schedule proactive maintenance on their railcars to replace defective wheels and/or bearings, saving them time, money and potentially preventing costly catastrophic derailments. The UTCRS research team has established thresholds to determine defective bearings utilizing thermal and mechanical sensors.

The effectiveness …

Monitoring The Progress Of Damage In A Sicf-Sicm Composite Nuclear Fuel Cladding Under Internal Pressure Using Acoustic Emission, Luis H. Alva

Theses and Dissertations

The relation between the progress of damage and the acoustic emission (AE) activity of a nuclear grade Sif-SiCm composite tubing under internal pressure was studied. The nuclear grade Sif-SiCm composite tubing is manufactured by the company General Atomics (GA) and made of nuclear grade HI Nicalon type S fiber preforms following a chemical vapor infiltration (CVI) technique. Sif-SiCm composites are good candidates to replace current nuclear fuel cladding materials because of the good chemical stability and strength at high temperatures. In this work, a Sif-SiCm composite tubing was tested under internal pressure at room temperature (RT) to study the damage …