D-JOINTS: Composite hybrid joints with electromagnetic compatibility
The D-JOINTS project provided the aerospace industry with novel design tools that are able to cope with the demand for increased output while maintaining the required quality standards and, more specifically, the increased complexity associated with weight reduction in produced parts. The most important features of the D-JOINTS system are the unique methodologies for modelling the engineering change management (EMC) of structural aeronautical joints, and improving the lightning strike protection capabilities of modern airframe assemblies.
The project objective was to achieve new, innovative, composite-metal joints with enhanced lightning strike protection systems by:
- Modelling the thermomechanical and electrical performance of the reference geometry dissimilar joints using numerical analysis
- Improving dissimilar joints including consideration of the electromagnetic performance
- Developing a sizing tool for composite hybrid joints
- Manufacturing and testing a composite nose part with the new dissimilar joints integrated into an aircraft structure
Brunel Composite Centre (BCC)'s role on D-JOINTS incorporated: development of an electromagnetic simulation in order to model the indirect effects of the lightning strike; an electrical conductivity characterisation campaign to address the surface resistance of joint materials and coatings; through thickness conductivity of adherents, including tufted configuration and screening effectiveness; and integration of electrical current and Lorentz forces calculations into the sizing tool, coupled with thermal and mechanical analysis
Following completion, the tool designed within the project provides significant opportunities to improve both the lightning strike performance of joints and the robustness of the overall structure. The combined progress on these two fronts makes the overall, potential improvement bigger than the sum of their parts, as the ability to design with a user-friendly tool is enhanced by the incorporation of novel joining capabilities, and the efficiency of novel joint designs is boosted by the possibility of exploring their abilities in a structured and easy-to-use manner.
Project partners: Evektor; also the Topic Manager, Cranfield University and BCC together with Element Materials Technology.
D-JOINTS received funding from the Clean Sky 2 Joint Undertaking (JU) under grant agreement No. 887042, under the EU’s Horizon 2020 research and innovation programme.