Enabling Qualification of Hybrid Structures for Lightweight and Safe Maritime Transport
Priority AxisTechnological and Social Innovation
Lead partnerStichting Materials Innovation Institute (M2i)
Project budget3 777 816 €
ERDF amount2 266 689 €
The drivers to reduce weight in traditionally heavy loaded structures such as ships demands the development of durable, lightweight solutions that can withstand such loads under extreme conditions. The combination of steels and composites in adhesively bonded structures can reduce weight while preserving strength, leading to lighter and stronger ships. 10% weight reduction triggers a reduction of up to 7% in fuel consumption. The potential savings, along to the manufacturing advantages, have motivated the shipbuilding industry to explore the use of adhesively bonded hybrid joints in primary structures, capable to withstand high loads and guaranteeing safety. Currently, no certification guidelines exist to orient the industry when certifying new designs using such hybrid assemblies, which limits their to secondary structures. QUALIFY will provide the necessary knowledge to remove these technological and regulatory barriers, enabling their use in primary structures in shipbuilding.
The project aims to remove the technological and regulatory barriers that currently prevent the widespread application of hybrid structures (metal/composite) in the industry. It will deliver the knowledge and the guidelines that the industry needs to pursue certification of adhesively bonded hybrid joints for primary structures in marine applications. The objectives we set to tackle this aim are:
- Objective 1: Evaluate the long term structural performance of the adhesively bonded hybrid joint under representative operational and environmental conditions;
- Objective 2: Develop a reliable inspection and maintenance methodology for adhesively bonded hybrid joints;
- Objective 3: Develop a procedure (Guidelines) for the qualification of adhesively bonded hybrid joints in primary structures in marine applications.
- Tests to assess the sensitivity to the environment of the adhesive material properties and the structural performance of the joint - at different scales;
- Tailored equipment to evaluate the performance of the hybrid joint under combined loading and environmental conditions;
- Accelerated tests type 1 = Rapid determination of basic fatigue properties for design purposes - at different scales;
- Accelerated tests type 2 = Testing of corrosion assisted fatigue to evaluate components in a representative environment and at different scales.
- Monitoring and inspection protocol;
- Structural health and condition monitoring tests;
- Guidelines for the qualification of adhesively bonded hybrid structures in primary structures for marine applications.
Cross border approach
The approach proposed requires a combination of capabilities and experiences not available within the national borders of individual participants. A blend of expertises is needed, which our consortium brings together: micromechanical modelling (Cambridge); characterisation and modelling of environmental effects on the operational lifetime of marine structures (TU Delft); accelerated testing methodology to reflect 20 years of operational life in one month of testing (UGent). These are state-of-the-art capabilities, complemented by access to unique testing infrastructure that is not available elsewhere in Europe (UGent, WMC). Our project also requires the commitment of industrial users with experience and intterest on hybrid structures (DAMEN, BAE Systems, Parkwind) and that of classification societies such as Lloyd's Register, Bureau Veritas, as well as management and dissemination capabilities (M2i and the observer partners network) to reach a wide industrial audience.
The primary goal of Qualify is to provide guidance and examples validated through testing for certification of adhesively bonded composite-metal hybrid primary structures for maritime applications. The project is a cross-border collaborative effort between knowledge institutions (5), end-users (3), and classification societies (2). To enable the qualification of adhesively bonded joints, the whole system must be qualified.
Ghent University (Belgium) leads the work on the long term structural performance of the adhesively bonded hybrid joints under representative operational and environmental conditions. Experiments and simulations at material, coupon, and full scale tests levels under fatigue and static loads in aged and unaged conditions are almost completed. The remaining activities are full scale level tests, simulations and validations against the experimental results. The lack of an inspection and monitoring protocol to orient the end-users on the inspection techniques that can reliably assess the structural health of the joint is being addressed in Qualify.
Delft University of Technology (The Netherlands) leads the development of a reliable inspection and maintenance methodology for adhesively bonded hybrid joints. A number of eight techniques were employed at the aforementioned scale levels and the obtained data was correlated with the integrity status of the joints. The monitoring and inspection protocol will be soon finalized in collaboration with classification societies and end-users. In the absence of maritime classification societies there would be no guideline standards for vessels.
Bureau Veritas (France) and Lloyd's Register (United Kingdom) lead the development of the guidelines for the qualification of hybrid adhesive joints. A draft of the roadmap for the qualification of hybrid joints is being written. It comprises the following sections: introduction to adhesive joints, design map, design assessment, constituents characterization, durability, manufacturing, and inspection and monitoring. To date, the focus has been on establishing and maintaining a live risk register to capture progress and outstanding hurdles to certification.