Development of a Simulation Methodology to Assess Damage in Composite Structure due to High Velocity Impact by Large Debris

Kurzfassung

The greening of transport has been highlighted in the Paris Agreement in order to participate to a durable development of our society. One of the main ways to fulfil environmental requirements is to reduce of the total energy consumption throughout the whole life of vehicles: that is during their manufacturing, during their utilisation, and during their end-of-life management. A new generation of engines named counter-rotating open rotor (CROR) is one of the technical candidates that are currently investigated, since they could lead to a significant reduction of the energy consumption of civil aircrafts. With the exception of two rows of larger unducted blades, the components of CROR-engines are similar to those of conventional engines. Aircraft configurations with CROR-engines are extremely challenging, since the unducted blades can be hit by foreign objects (hail, debris) or wild life (large bird) at high impact velocities. A further threat is the release of a large unducted blade that could impact the aircraft primary structures like the fuselage, the wings, or the vertical tail. The Institute of Structures and Design of the German Aerospace Centre is therefore contributing to the development of a validated simulation methodology to assess the behaviour of a fuselage under the impact of a composite CROR-blade. In order to investigate this topic, different tasks were successfully performed: determination of a low readiness level high velocity impact test matrix, manufacturing of coupons, quasi-static material characterisation, material card developments, connection of different commercial software to build a simulation process chain (from computer assisted design over pre-processing up to numerical simulations and analysis of results), validation of selected low readiness level impact test simulations, and utilisation of the tool chain to demonstrate the feasibility of damage assessment in composite structures after high velocity impact. The present contribution is part of the Clean Sky 2 project (LPA) and aims to show the state of the investigations conducted at the Institute of Structures and Design. The author acknowledges Airbus for leading the project tasks and the European Commission for the partial funding of those activities.