Hull Fatigue Monitoring using Digital Twins
Holger Mumm, Arne Schulz-Heimbeck, DNV GL SE
Hull fatigue monitoring may serve for various purposes, e.g. operational guidance, hull inspection planning, documentation of consumed fatigue life or enhancement of load assumptions in ship design rules. In recent years, sensor technology, data storage, transfer and processing capabilities have reached such mature levels that hull fatigue consumption can be monitored in real time and further processed for shore-based evaluation. To keep installation and maintenance cost for monitoring systems low, DNV GL researched how to gain most information from as few on-board sensors as possible and how to enhance data storage, processing and evaluation by standardized work flows. Based on a FE-model of the hull, the developed modal decomposition method allows to rebuild the stress histories from global wave loads in the entire hull structure based on a couple of strain sensors only. The method is illustrated by case studies for an ULCV and an FPSO. Further, some insights are presented on the possibilities to store, share and evaluate the measured and processed data on VERACITY, DNV GL’s open collaboration platform for the maritime industry.