Airplane Windshield Bird Impact Design Studies

Based on the experiments, finite element method has been employed to investigate the bird impact on windshield in this paper. Dynamic responses of J8?II windshield and effects on the windshield of mechanical properties of windshield and the design of its structure have been discussed tentatively . Results are shown below. With the help of finite element method, equivalent dynamic load has been used to analyze the bird impact on the rigid glass windshield. The key of this process is how to deal with the dynamic load. In this thesis, triangle pulse load has been used, and triangle pulse load, method to calculate the loading time and volume of maximal load are in accordance with the results from the photographs of highpeed camera and dynamic stain gauge. Therefore, triangle pulse load could be applied to other similar windshield. The results have also indicated that stress in bird impact area is the largest and it weakens rapidly out of this area when the windshield is impacted by bird. The stress in edge of glasses along long span is second larger area. The mechanical properties of windshield have drastically affected its ability to resist the bird impact. When the elastic modulus of glass is about 600 times higher than that of film, the windshield has only one neutral layer, the largest stresses lie on the two surfaces of the windshield, and the tension is larger than compression. When the elastic modulus of glass is more than 600 times higher than that of film, each glass layer has an intermediate layer, and the windshield appears to be a superposition structure. What more, the thicker glass, the higher stress. The largest stresses lie on the surfaces of the thicker glass. The rubber seallayer cushions the stress at the edge of glass layers seriously. The resistant ability of windshield has been related to the rigidity of the windshield. The higher rigidity, the higher resistant ability. If the layer thickness of windshield is the same, 3ayer laminated structure is preferred at normal temperature: While laminated structure with more than 3 layers is preferred when the temperature is higher than normal temperature. Having analyzed the results, conclusions could be obtained that the limited resistant ability of 18lwindshield can be improved to 900Km/H and some windshield with new structure has been designed which is thinner and lighter than that of J8.