Experimental Investigation And Numerical Simulation On Are Windshields Of Airerafts Subjected To Bird Impact

The strike between flying birds and aeroplanes frequently results in damage of aircraft structures. The serious events of bird-striking can lead to unacceptable losses of aircraft and crewmembers. Normal flying is faced with more and more serious menace made by bird-striking with increasing flying speed of aircraft and the economic loss is increasing year after year. Manufacturers and users have paid closed attention to bird-striking accidents since 1960's. In this study the dynamic response pf a circular arc windshield subjected to bird impact is carried out with experimental investigation and computer simulation in order to meet the need in designing new force aeroplanes.In experiments, the bird body launched by a big air gun impacts the full scale windshield of the aeroplane to simulate striking between a flying bird and a flying plane. The samples of windshields are offered by manufacturers of China and France. The displacement history curves of different points in the symmetry center line of windshield glass and the strain history curves of many points on the surface of windshield glass are obtained. The whole deformation process of the bird bodies and windshield glass are recorded using the high-speed camera and the vidicon. It is found in the test that there is no difference in the intensity of both types of glass. The critical velocity at which the bird body impacts the glass at middle point to result in break of the glass is 570-580km/h. The maximum displacement value is 0.5-1.5 times as much as the thickness of the glass. It is observed from the result of test that the bird bodies basically show liquid characteristics in the process of impact and that the relative parts of the plane affect the dynamic response'of windshield glass. It is found from strain measurement results that the magnitude of strain along the direction of the symmetry line of windshield glass reverses to show re-striking in impact.A finite element model including full-scale circular arc windshield glass and the relative parts of the plane is established using LS-DYNA3D V.950 code in the computer simulation and is validated using the result from the test. The bird body is described using ALE(Arbitrary Lagrange'-Eulerian method). The data in aspects of displacement, strain, stress and contact from in the process of deformation are obtained. The deformation and failure mechanism of circulararc windshield glass is discussed. The possible location where failure can carry out is given. The computer simulation provides the engineers in the department of researching and designing new force planes with valuable data, and on basis of these data an more excellent test will be designed again.