Development of an Innovative Extension for Fatigue Life Monitoring Using a Piezoelectric Sensor

Engineering structures, such as bridges, wind turbines, airplanes, ships, buildings, and offshore platforms, often experience uncertain dynamic loadings due to environmental factors and operational conditions. The lack of knowledge about the load spectrum for these structures poses challenges in terms of design and can lead to either over...

Monitoring Flexural Fatigue Life of Asphalt Concrete by Piezoelectric Sensors: Strategy for fatigue life prediction and damage detection based on load history on any asphalt matrix

This dissertation endeavors to introduce a novel supervised Structural Health Monitoring (SHM) methodology for the detection of damage and the prediction of fatigue life in asphalt concrete materials. Grounded in the principles of S-N (strain-number of cycles until failure) curves, this research addresses the intricate task of proficiently...

Development of a retrofit layer with an embedded array of piezoelectric sensors for transient pressure measurement in maritime applications

Measurement of transient pressure distribution on maritime structures is important for the assessment of the hydrodynamic loads applied. The commonly used pressure sensors are mostly bulky, need to be bolted to the structure, and/or only provide point-wise measurements. In this paper, an elastic matrix layer with a network of embedded...

Feasibility evaluation for development of composite propellers with embedded piezoelectric sensors

Marine propellers made of fibre-reinforced composites have demonstrated the potential to outperform metallic propellers in terms of efficiency and under-water noise radiation. For full realisation of this potential in a tailored design process with realistic constraints, accurate information on the hydrodynamic loads acting on composite...

Pea electromagnetic distortion reduction by impedance grounding and pulsed voltage electrode configurations

Space charges are one of the main challenges facing the constantly increasing use of extruded high voltage direct current (HVDC) cables. The Pulsed Electro-Acoustic (PEA) method is one of the most common procedures for space charge measurements of insulation. One issue with the PEA method is distortion due to the crosstalk between the applied...

Influence of the pulse voltage injection configuration on the electromagnetic distortion in space charge measurements using the PEA method

The Pulsed Electroacoustic Method is one of the most common methods for space charge measurements in solid dielectrics. This method involves applying a voltage pulse across the dielectric under test, which modifies the electrostatic force balance across the dielectric, creating an acoustic signal that can be measured externally. This work...

Influence of the Pulsed Voltage Connection on the Electromagnetic Distortion in Full-Size HVDC Cable PEA Measurements

Nowadays, with the widespread use of High Voltage Direct Current (HVDC) cables in power systems, the measurements of space charges in full-size cables are becoming more relevant. One of the most common methods used for space charge measurements is the Pulsed Electro-Acoustic (PEA) method. This paper analyzes two factors that influence the...

Surface Acoustic Mode Aluminum Nitride Transducer for micro-size liquid sensing applications

The thesis focuses on the investigation of thin-film surface acoustic wave (SAW) devices for liquid sensing applications. The piezoelectric material is a thin film of Aluminum Nitride (AlN), a CMOS compatible material, deposited by pulse DC reactive sputtering technique. A CMOS compatible process is developed and employed to fabricate the AlN/Si...