NERO PROJECT - December 2020
DEVELOPMENT OF ADVANCED SYSTEMS FOR MONITORING THE MANUFACTURING PROCESSES AND BEHAVIOR IN SERVICE OF COMPOSITES BASED ON NON-INVASIVE EMBEDDED SENSORS
NERO has developed advanced monitoring systems based on non-invasive embedded sensors, which allow to carry out more efficient and environmentally sustainable manufacturing and repair processes of composite material structures, and which, in turn, provide information on structural behavior during the life of service of fabricated structures.
NERO initiative was born from the need to control and monitor the manufacturing, repair and service life processes of structures produced in composite materials, an area in full expansion that is experiencing rapid growth in recent years.
Composite materials are currently considered one of the strategic materials in the manufacturing processes of the future, due to the high functional impact and weight reduction they provide in a wide range of sectors. In this way, the monitoring systems that have been developed in the project will contribute to overcoming some of the main barriers for the introduction of these materials in the industrial environment, such as the high consumption of resources, low automation ratios and high percentage of rejects, which will significantly reduce production costs.
Based on this background, NERO project has developed, using ad hoc monitoring techniques based on fiber optic sensors (FBG) and ion mobility (DC), monitoring and control systems for the manufacturing and repair processes of composite in different cases of use and relevant industrial sectors in Galicia, in which composite materials are used intensively: manufacture of boats (naval sector), manufacture of liquid storage tanks (chemical sector) and repair of wind blades (renewable energy sector ). In addition, a system has been designed to monitor the structural behavior of storage tanks in service to detect leaks, through the design of an alert system.
Main results achieved during the NERO project were:
- Robust correlation between the fundamental parameters of the manufacturing/repair processes of composite materials and signals obtained with fiber optic (FBG) and ion mobility (DC) sensors. In Figure 1 a complete curing cycle can be seen, detecting the arrival of resin and the temperature at the different points of the piece, as well as the evolution of curing.
Figure 1 Monitoring results during the manufacturing process by manual lamination with embedded sensors (FBG (red) and DC dielectrics (black)).
- An exhaustive study has been carried out for the three use cases, both at the laboratory level and on a real scale (Figures 2 and 3, respectively), using different manufacturing/repair methods (manual lamination, infusion and filament winding). It should be noted that DC sensors are invasive and therefore have been used in the study of the behavior of each resin to correlate its signal with the FBGs and provide the necessary data for software development. Therefore, only non-invasive FBG sensors, with an approximate diameter of 250 μm, were embedded a posteriori.
Figure 2. Laboratory tests with DC and FBG sensors (left: manual lamination, center: infusion, right: filament winding).
- Once the study was carried out at the laboratory level, it was validated on a real scale at the facilities of each of the end users: wind blade (Galventus), boat (Asteleiros Triñanes) and in a storage tank (Fiberglas) (Figure 3).
Figure 3. Full-scale tests with DC and FBG sensors (left: Triñanes, center: Galventus, right: Fiberglas).
- In the same way, a monitoring software has been developed that allows obtaining online information in-situ on the critical points of the manufacturing/repair (dry-spots, arrival of resin, evolution of curing, delamination, etc.).
- Finally, it should be noted that software has also been developed with an alert system for detecting leaks. Embedded sensors detect strain variations, and therefore not only provide information during manufacturing, but also detect various phenomena that may occur in the material after manufacturing. Therefore, the software has also been validated for the study of the in-service behavior of a chemical storage tank.
Success of the project has been possible thanks to a multisectoral consortium of Galician companies, all of them SMEs, with the complementary skills and knowledge necessary to cover the entire value chain of the project:
GALVENTUS SERVICIOS EÓLICOS, leader of the consortium, with extensive experience in inspection, maintenance, repair and expertise processes of composite material parts in the wind power sector and who in the project scope has been the end user of the monitoring system for wind blade repair.
ASTELEIROS TRIÑANES, shipyard that manufactures and repairs composite boats of different types (dornas, fishing boats, aquaculture auxiliaries) and end user of the NERO monitoring system for the manufacture of boats.
FIBERGLAS, pioneer company in the manufacture of fiberglass reinforced polyester products, reinforced plastics and thermoformed and end user of the monitoring system in manufacturing and performance in service of liquid storage tanks.
RCASTRO/CASTRO COMPOSITES, company specialized in the manufacture and commercialization of all kinds of products related to the composites sector and which has contributed its know-how in the behavior and monitoring of these materials.
TECDESOFT, engineering specialized in the treatment of data from sensor systems or development of real-time supervision platforms, for many sectors, which has been in charge of integrating control software in monitoring systems.
Consortium has had the collaboration of AIMEN Centro Tecnológico, a center specialized in the design, characterization and development of high-performance materials, as well as in the development of sensorization and data treatment systems for advanced manufacturing processes.
NERO project, framed in the CONECTAPEME 2018 program, is financed by Xunta de Galicia through the Galician Innovation Agency (GAIN) and the support of the Ministry of Economy, Entrepreneurship and Industry and is co-financed by FEDER Funds in the framework of axis 1 of the Feder Galicia 2014-2020 operational program.