Resistance To Penetration Of Functionally Graded Plates And Aircraft Balance Beam Legs Bird Hit By Numerical Simulation

There are two parts in the paper.One is on the behavior of penetration resistance of functionally graded armour made of metal Matrix Composites (MMCs) which is a new material subject. Because of the excellent behavior of MMCs, it attracts many researchers' attention. Much work has been done to develop the MMCs, and many MMCs with different reinforcement and volume fraction were developed. The Functionally Graded Material (FGM) becomes more and more important since the excellent resistance of penetration. The other is on the birdstrike of aircraft structure. With the development of the aircraft performance at low altitude and high speed,as well as marked progress of eco-environmental protection, the issue of birdstrike to aircraft has been concerned more and more.Numerical simulation on penetration resistance of functionally graded material armour has been performed. In the same time numerical simulation on birdstrike of aircraft structure was done by LS-DYNA.The results show that:(1) The penetration resistance of functionally graded layered armour made of metal Matrix Composites (MMCs) is better than that of the Aluminum plate;(2) The penetration resistance of the functionally graded layered armour whichlay_up is 0%/57%/0%/26%/0%/12%/0% is the best;(3) The resistance penetration of the the functionally graded layered armour can be greately promoted through optimizing the lay_up and volume fraction of the reinforced particle;(4) The functionally graded armour in which the particles distribute continuous has better behavior of resistance penetration when the volume fraction of the reinforcements are constant;(5) The higher volume fraction of the reinforcements at the surface of FGM and the more non-homogeneous the reinforcements distribution, the higher thesurface Young's Modulus and the flow stress are;(6) The behavior of penetration resistance of the functionally graded armour in which the particles distribute continuously is better than that of homogeneous steel plate;(7) The functionally graded armour provedes a important approach for the optimization and design of the resistance penetration;(8) The numerical results of simulation of the bird striking the aircraft structureshow that the finite element model of the balance leg is effective;(9) The numerical results show that the structure internal force is relative largewhen the bird strikes the top of the balance leg;(10) The process of the birdstrike is thaf.after the bird penetrting through the front skin of the balance leg and striking the front beam,the bird is broken up in three parts. One part of the bird sticks on the web of the front beam, and the other two parts are partited by the beam and flied away. The whole structure of the balance leg can support birdstrike for 3.6Kg weitht and 530 Km/h speed of the bird.