Bird Strike Impact Dynamics, Finite Element Numerical Simulation Study

It is a very important project for birds to strike aircraft structures in airframedesigns and aPpIication practices, meanwhiIe, which aIso possesses of the values ofin-deep scientiflc research and theoretical exPloration. This research work on birdstriking has a long history and already got plentiful achievemellts in theories andexperiments, howevef, still a long way no doubt waits to go for sophisticated researchwork on it more detailed to aPply to airframe engineering quantitatively Incombination wth the technical reformation of the birdstrike experimelltal system inour laboratory, this thesis deeply studies and analyses the numerica1 comPutation andsimulation methods to birdstrike dynamic response problem based on finite-elemefit-method (FEM)numerical emulation and modem large-scale scientfic comPutationsoftware. Through the research work, the author has experienced the scientificcomPutationa1 methOds and numerical simulation practice, which also laid a strongwork backgrOund for further research on birdstrike ruin to airframe by means ofscientific computation. In summary the major research work in this thesis can bedrawn as follows:1. The techncal data and research infOrmation from woridwide aviation historyabout bird striking to airframe have been colleCted and reviewed more carefullyThe evolutions of bird striking load models and FEM numerical compatationmethods to bird strike also have been sununarized. This informational researchmakes great help to position further thesis work scientifically2. The scielltific comPutational theories and methods on bird strike to thewindshield of aircraft have been systematically studied and summed uP in thisthesis, such as FEM comptltational principles and procedures to elastic dynamicproblems under the conditions of small and non-linear finite deformation, 3Dviscous elastic constitUtive theory and incremelltal expression under theconsideration of the rate effect of non-metallic materials like the aircraftwindshield, and the numerical compatational principles and key constitutions fOrimpact-contact dynamic subjects. Meanwhile, a modified Newmark differencescheme and computational procedures has been proposed for FEM dynamicincremental load method to the non-linearity of geometry and material.3. Wth aPplication of Large-scale computational software ANASYS-DYNA, thecase of elastic impact to each other of two recta-ngular cross-section rods has beenimplemented and also compared with theoretical results, which maks goodagreement and draws very helpful practical experiences tO use some techncalparameters in the program. Eventually, the a real-world aircraft windshield shellstructure impacted by a flying bird has been simulated through FEM numericalcomputation, and meanime, an engineering predical experimeni of bird stTikingto the windshield in some type of aircraft has been performed. The carefulcomparisons and studies tO tWo resultant data have found a very satisfiedcoincidence.