The main objective of the DAHLIAS project is to optimise hybrid joining (Refill Friction Stir Spot Welding, RFSSW, with an adhesive sealant bond) for application in aircraft structures. RFSSW is a solid-state joining technology especially applicable to lightweight alloys in similar and dissimilar configurations. The process has been successfully applied to difficult-to-weld and non-weldable alloys and is considered a potential replacement of mechanical fastening. Overlap joints in aircraft structures require the use of sealants for corrosion protection reasons. Using sealants with an adhesive function would complement the high quality joints produced by RFSSW by not only protecting against corrosion but also contributing to the overall mechanical performance of the structure. To achieve the main goal of this project a work plan consisting of eight work packages has been devised. Two work packages are focused on the RFSSW process development using standard samples with and without adhesive sealant. In parallel the adhesive sealant technology, including surface pre-treatment will be developed. The hybrid joining solution developed in this project will be compared to conventional joining technologies to define its potential. Hybrid joining brings a number of advantages to production and performance of aircraft structures. The change from differential to integral design introduces new challenges in the analysis of mechanical performance. Hence, the damage tolerance behaviour of hybrid joints is also investigated in this project. Quality control methods will be investigated by selecting NDT methods and by process control based on online monitoring of parameters. In the last phase of this project technology demonstrators will be produced to evaluate the capabilities of the proposed technology in actual aircraft structures. The consortium (3 R&D and 2 industrial partners) has the exact fitting, prooven expertise and high excellence. HZG (coordinator) holds key patents.

LATECOERE is the world independent leader on the “aircraft doors” market and wants to strengthen this position. ELCOCOS project is the right opportunity to maintain this leadership and to improve the European industry competitiveness as a whole. ELCOCOS consortium is a strong and complementary partnership of leading European industrials and research organizations in the area of aerospace and material development. ELCOCOS is composed of four companies whose expertise will help to develop a composite door using infusion (LRI) technologies as per the aforementioned call: - LATECOERE for the project management, door design and sizing, composite coupons and door tests; - CORIMA TECHNOLOGIES for the composite tooling design and manufacturing; - COMPOSITADOUR for the lay-up; and - INSTITUT DE SOUDURE (ISA) for the Injection process. ELCOCOS objectives are to: - reduce development cost, - decrease the weight of the structure, - improve significantly the recurring cost, and - reduce the industrialization cost. ELCOCOS consortium will fully define technical and cost performances of an optimized infused structure. Predicting the fibre and resin behaviour, correlated with physical specimen, mastering the infusion process through numerical simulation, optimizing the curing cycle thanks to a self-heated composite mould, the final objective of ELCOCOS is to manufacture a full scale demonstrator representative of what could be the next generation of airframe structures comparable to door structures. ELCOCOS is fully in line with the call. The considered technical WPs, tasks and deliverables fit with the call for proposal. A project management WP is also considered. Specific actions are made to ensure dissemination of project results and sustainability of the action. Measurable KPIs and risks are also considered. ELCOCOS consortium is composed of the expected skills, capabilities and certifications expected from the applicants allowing the successful achievement of the project.