Open Student Projects

Mechanical analysis of the system behavior of an impact echo sensor payload for non-destructive drone inspection applications

The Uncrewed Aerial Concrete Inspection System (UACIS) research project represents the introduction of modern and highly capable drone technology to non-destructive testing. Drones are hereby identified as the key to efficiency and effectiveness in non-destructive testing (NDT). In particular, bridges, containments or cooling towers are the focus of structural inspections due to their aging structure and limited accessibility. In addition to non-contact inspection, the drone system is also able to apply mechanical contact forces to component surfaces in almost any orientation. Areas that are otherwise difficult to access are thus also reachable for contact inspection techniques. The drone used in this project is a platform developed by Voliro. Based on this platform, the development of a drone-based impact echo measurement payload was realized. The impact echo method is a NDT technique where elastic stress waves are excited in the inspected structure with a hammer or a steel ball, and the reflections are measured and analyzed in the frequency domain. This technique can be used to measure wall thicknesses, but also to find defects such as flaws or delaminations in concrete. It is very important to understand the transient and dynamic response of the entire measurement system as it is very sensitive to its own stiffness and resonance behavior as well as to external noise. Furthermore, the structural coupling between the hammer and the sensor also influences the dynamics and thus the measurement quality. The objective of the current project is to experimentally investigate and analyze the dynamic behavior of the payload structure as well as the interaction between the sensor and the inspected structure by means of high-speed camera analyses as well as laser vibrometer measurements to visualize the wave shapes. This project is concluded in co-operation with the industrial partner SVTI, the Swiss Association for Technical Inspections. The Laboratory for Non-Destructive Evaluation at SVTI develops the concrete sensor payloads for the drone platform.

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Type of thesis: BT, ST, MT

Project start: spring semester 2023 or upon agreement