Finite element modeling of bird strikes and parametric evaluation using design of experiments (DOE)

One of the major threats to Aviation industry is the in-flight impact of birds. Aircraft windshields are intensively vulnerable to damage and hence need a certification requirement for a proven level of impact resistance. Bird strike experiments are very expensive and henceforth explicit numerical modeling techniques have grown importance. This compilation mainly relies on the theory of hydrodynamic impact and addresses basic shockwave equations. A smooth particle hydrodynamics based approach is chosen and the numerical simulation is carried out using contact-impact coupling algorithm. The simulation is run using the nonlinear explicit finite element code LSDYNA ver.971, developed by Lawrence Livermore National Laboratories. A traditional design of experiments approach, factorial design, has been utilized to facilitate the economical prediction of factors significantly affecting the pressure response in the bird strike analysis. Impact velocity, bird mass, bird aspect ratio, porosity and obliquity of impact are the various parameters investigated in the present work. The results show that main effects velocity and obliquity of impact, and \u27porosity x obliquity\u27 interaction effect, are the factors significantly affecting the pressure response in a bird strike analysis --Abstract, page iii