22-01-2026 - Lecture Hall D

PostDoc presentation

Acoustic emission monitoring of composite marine propeller blades using embedded piezoelectric sensors

Arno Huijer

To reduce both carbon emissions and underwater noise, the maritime sector is exploring flexible composite propeller blades as an alternative to traditional metal ones. These composite blades offer promising gains in fuel efficiency and noise reduction, but their fatigue life remains uncertain.
My research investigates how acoustic emission monitoring can track damage in flexible composite propellers. This evolved from small-scale coupon experiments to full-scale submerged fatigue testing of propeller blades. The latter includes the recording of damage progression with embedded sensors, surface mounted sensors, and hydrophones. Early results show that these sensing methods can detect acoustic signatures of damage both before and after fatigue degradation, demonstrating their potential for reliable structural health monitoring.

22-01-2026 - Lecture Hall D

PostDoc presentation

Impact Localization using Time Reversal of Guided Ultrasonic Waves

Nikolaos Papanikolaou

Marine structures operate in a complex environment and face the risk of high and low velocity impacts. Without proper detection, such events can result in severe structural damage or environmental disasters. Reliable impact identification is therefore required to ensure safety, minimize environmental risks, protect assets, and support informed decisions in structural integrity assessment.
When an impact occurs part of its energy is released in the form of stress waves. In thin-walled structures, such as ship hulls, these propagate long distances as Guided Ultrasonic Waves (GUW) while carrying information about the impact source. The objective of this research is to localize impacts and estimate their energy from the recorded impact-induced GUW signals. To achieve this, an analytical framework that exploits the Time Reversal property of GUW is developed.
Experimental validation indicates that passive GUW monitoring can be used to reliably localize impacts across different structural scales, highlighting its potential for future use in practical Structural Health Monitoring systems.