Effect of polyurethane with different elastic modulus on the response of aircraft windshield against bird strike

摘要

The analysis of windshield against bird strike is necessary for reducing the disastrous consequences. The flat windshield which involves two pieces of glass together with a polyurethane interlayer is often used in the aircraft. The mechanical property of the polyurethane interlayer is an important factor of affecting the response of windshield against bird strike. This effect is investigated in this work by simulating the bird impacting the flat windshields with the polyurethane of different elastic modulus. The bird is modeled with SPH method. The calculation results indicate that the elastic modulus of polyurethane affect the response of windshields in many points. For the elastic modulus of 5 MPa, the thickness of polyurethane interlayer is compressed by 16% during the striking. The compressive effects decrease the contact force and the displacement of windshield to some extent. Especially, the major principle stresses in the inner and outer glass are decreased by the compressive effects significantly. It is found that the major principle stresses in the outer glass are 103 MPa lower than those of the case with the elastic modulus of 600 MPa. The relatively small stress in the glass means that the windshield can afford more serious impact and has the better impact resistance.