Study On Numerical Simulation Of Aircraft Windshield Under Bird Impact

Windshield is one of the most important and vulnerable parts to birds.Its anti-bird strike research has always been an essential process for each country in the aircraft design process.The research on the problem of windshield bird collision generally uses methods such as experiments or numerical simulations.The experimental research on the windshield of birds is the earliest and most basic method,and finite element simulation is the most convenient and effective tool.In this paper,ANSYS/LS-DYNA finite element software was used to simulate the windshield bird collision process,and the following work was mainly carried out.In this paper,four different finite element models are established,and the most suitable model of windshield bird collision is determined by comparison with the experiment.The study shows that the model four using SPH and custom material model can well simulate the process of bird splashing in high speed impact on windshield,and the results of bird impact response close to the experimental results that can accurately predict the dynamic response of windshield under bird impact.Taking the impact velocity and impact position as variables,the response of windshield and the failure process of windshield during the speed 450km/h~650km/h and the impact position before,1/3,mid and 1/3 points of the bird body are studied.The research shows that the displacement,strain,stress of the windshield surface increase with the increase of the bird's impact velocity,and the time to reach the peak is advanced;the front of the windshield has the strongest anti-bird collision ability,followed by the midpoint and the rear part is the worst;The windshield will break down first on the inner surface under bending.When the windshield at the speed of 600km/h is damaged,a number of cracks with an angle of about 50 degrees from the symmetrical line of the windshield and a small amount of transverse cracks are formed in the impact zone.Studies have shown that DYB-3 PMMA windshields and windshields with large curvatures showed high impact resistance in simulations.Suggestions for redesign of windshields are: The directional tensile plexiglass like DYB-3PMMA is selected for the large cruising speed of aircraft or aircraft where the aerodynamic load was large,and the curvature of the windshield is increased while satisfying the pilot's field of vision to improve the performance of windshield against bird strike.