Project ISAT: Non-invasive acoustic structural health monitoring system for PUR-based coating systems

Project duration: 01.01.2019 – 31.12.2021

The aim of the “Megayachschaum” project is to develop novel coating systems for ship hulls that meet the requirements for a surface coating better than is the case with the current epoxy resin-based coating systems. The novel material should have improved material properties, especially with regard to material defects such as cracking or delamination, and should be applied automatically by robot.

The project is a collaborative project with a total of 7 partners from industry and research.

In the sub-project of ISAT, the development of a non-destructive, robust and online-capable Structural Health Monitoring System (SHM) for the spatially resolved measurement of damage to the ship’s hull is planned, which is especially adapted to the novel coating system developed in the project. Surface acoustic waves and the acoustic measurement methods developed at ISAT will be used for monitoring.

The aim is to develop a sensor system suitable for the monitoring of large areas of the ship’s hull that ensures large-scale online monitoring of the innovative coating system during operation and makes a significant contribution to quality assurance. The focus of the subproject is on the development of non-invasive acoustic monitoring methods for the detection of damage to the ship’s outer wall and inner wall. The sensor systems to be developed are to be specially adapted to the forms of damage occurring in the coating system. It is planned to develop a sensor array with which a spatially resolved fault detection on the ship’s hull is possible. With the aid of the acoustic sensor system developed by ISAT, faults in the application process as well as cracks or delaminations in the coating are to be detected and localised by the carrier substrate.

Together with the project partners, the SHM system will initially be qualified on a laboratory scale with regard to measurement accuracy and resolution. The sensors will then be scaled up step by step in order to validate them in a large-area test setup with shipbuilding structures in a typical operating environment under changing climatic conditions. In the course of the project, ISAT will develop its own stand-alone electronics for sequential control of the converter arrays, as well as electronics for data acquisition and a data logger for data transmission. The aim is the spatially resolved real-time detection of damage during ferry operation of the test vehicle at sea and thus the further development of innovative acoustic, non-invasive, online-capable and low-maintenance acoustic measurement methods from proof-of-concept to an application prototype with electronics for its use on the ship.

The acoustic SHM system to be developed is to be used for quality assurance of ship hull coatings and to contribute to an extension of the life span of the ship, to a shortening of the shipyard times and consequently to a cost saving by more efficient repair cycles.