• Portemont, Gérald
• Ortiz, Roland
• Alexandre, Peroche
• Coninck, Romain De

Abstract

The present work, performed within the CLEANSKY 2 contract, is part of the ADEC project. The industrial application of the project regards the new advanced rear end. The main objective remains the development of tools and experimental tests for advance rear end aircraft design regarding promising material for reinforcements and weight reduction. The rear-end of large passenger aircrafts needs to be able to withstand several threads to ensure a safe flight. The present work presents the ONERA contribution to the project. The objective is to develop numerical tools and characterization tests in order to deal with promising materials for structural reinforcement (APU failure, debris impact). First, an experimental test campaign has been performed for two different material configurations (with T700/M21 composite) and with hybrid material (ONERA development of laminated composite material based on T700/M21 and added polyethylene films). The T700/M21 carbon/epoxy composite material has been chosen as a reference material for this study, as material characterizations were already available at ONERA. Ballistic performances are compared with other materials (Triaxial braided –AS4C/M36 and aluminium – 2024 T3 - materials). In parallel a numerical investigation is performed with the FE explicit code EUROPLEXUS (used for dynamic impact application -) with the following objectives: - to develop and validate numerical methodologies to simulate selected experimental tests, - to support the development of the future advanced rear-end. The numerical approach is presented regarding industrial needs and rules modelization. Moduli, strengths, poisson ratio and interlaminar fracture toughnesses have been determined from quasi-static tests and dynamic tests for the different materials. The delamination is modelled with cohesive elements associated with a traction-separation law in which the kinematic variable is calculated as the ratio between the displacement and the interface thickness. Finally, a numerical investigation is also presented with T700/LM PAEK (carbon fiber/thermoplastic composite material). Quasi-static and dynamic tests have been performed for inputs model. It should be interesting to compare the performance of it regarding ONERA experience on the T700/M21 and/or hybrid materials. At the conclusion, these simulations are in good agreement with the experimental results. Finally, a qualitative comparison of new material concepts is proposed regarding their reinforcement performance. ONERA is investigating new material in order to reach a higher ballistic limit.

Topics

• impedance spectroscopy
• Carbon
• simulation
• aluminium
• strength
• composite
• thermoplastic
• fracture toughness