In this paper a structural optimization procedure is applied to an aircraft wing leading edge to improve its capability to withstand bird strike events. First, an experimental-numerical correlation, aimed to calibrate the numerical model against experimental data on a bird strike event, has been performed. In the frame of first step, an estimation of the reliability of the full 3D FEM numerical model adopted to simulate the dynamic event with a reduced error has been given. The onset and the propagation of the damage has been taken into account in order to obtain a realistic deformation of the structure as a consequence of the impact event by means of the Finite Element code Abaqus explicit. Then, the crashworthy design of the leading edge has been performed by adopting the commercial optimization tool ModeFrontier in conjunction with the FE explicit code Abaqus. A dedicated python routine has been used to define a fully parametric simplified wing leading edge model. In order to fulfil the aerodynamic requirement, the external surfaces have been considered fixed during the optimization; therefore, only the internal leading edge components and the skin characteristics has been optimized. As optimization variables, the geometrical properties of the skin and the number and the geometrical properties of the stiffeners have been chosen. The global mass of the model, the stress levels, the maximum deformation and the global stiffness have been considered as constraints. As objective function the energy dissipated due to material failure and to the plastic deformations as been selected. This energy is somehow a measure of the capability to dissipate the impact energy due to a bird strike event. The best configuration provided by the optimization procedure, has been finally compare with the starting configuration in order to assess the added value of the new proposed design in term of energy dissipation and crashworthy structural behaviour.
Crashworthy design of an aircraft wing leading edge to withstand bird impact events
Riccio A.
2018
Abstract
In this paper a structural optimization procedure is applied to an aircraft wing leading edge to improve its capability to withstand bird strike events. First, an experimental-numerical correlation, aimed to calibrate the numerical model against experimental data on a bird strike event, has been performed. In the frame of first step, an estimation of the reliability of the full 3D FEM numerical model adopted to simulate the dynamic event with a reduced error has been given. The onset and the propagation of the damage has been taken into account in order to obtain a realistic deformation of the structure as a consequence of the impact event by means of the Finite Element code Abaqus explicit. Then, the crashworthy design of the leading edge has been performed by adopting the commercial optimization tool ModeFrontier in conjunction with the FE explicit code Abaqus. A dedicated python routine has been used to define a fully parametric simplified wing leading edge model. In order to fulfil the aerodynamic requirement, the external surfaces have been considered fixed during the optimization; therefore, only the internal leading edge components and the skin characteristics has been optimized. As optimization variables, the geometrical properties of the skin and the number and the geometrical properties of the stiffeners have been chosen. The global mass of the model, the stress levels, the maximum deformation and the global stiffness have been considered as constraints. As objective function the energy dissipated due to material failure and to the plastic deformations as been selected. This energy is somehow a measure of the capability to dissipate the impact energy due to a bird strike event. The best configuration provided by the optimization procedure, has been finally compare with the starting configuration in order to assess the added value of the new proposed design in term of energy dissipation and crashworthy structural behaviour.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
