1 2014 SIMULIA Community Conference www.3ds.com/simulia Bird Strike Simulation in Assuring Aircraft Safety Ravi Katukam, Chirag Soni InfoTech Enterprises Ltd, Hyderabad Ravi.Katukam@infotech-enterprises.com Abstract: Bird strike Simulation helps in assuring aircraft safety, in eliminating cost & effort required for practical tests. There has been significant research done on various ways of doing bird strike simulation, till date Aerospace & defense Industry is concerned with two key issues 1.Comparative assessment of available methods 2. A FE model for fastener failure and fastener hole embrittlement. Current paper addresses relevant issues for today’s industry towards a universally accepted method of bird strike analysis Finite element based computational methods. First part of current research aims at bring out comparison between analysis methods along with their pros and cons, the Explicit analysis capabilities of Abaqus were used for modeling the phenomenon using three methods LAGRANGIAN, COUPLED LAGRANGIAN-EULERIAN (CEL) and SMOOTH PARTICLE HYDRODYNAMICS (SPH). Results are compared with published literature based on the standard experimental data. Critical parameters like HUGONIOT pressure and Stagnation pressure are compared from each study. Merits in all the three methods and bird models are presented with a view to guide the user in choosing an appropriate method depending on time and resource availability. A first of its kind Bird Strike Simulation Index (BSSI) proposed with FEM setup time, run time and accuracy as parameters, BSSI will be a holistic guidance for industrial user. Second part of the paper deals the most challenging issue of fastener modelling for dynamic loads. Analysis of bird impact modeling onto metallic riveted panels, which are typically idealized models for many practically used airframes structures like wing, flap, trailing edge, leading edge, are done using pure Lagrangian and SPH method. In high velocity bird strike scenario, fasteners will experience both shear and tensile loads and failure of aircraft structures are also governed by fastener failure modes. The fasteners behavior is modeled to simulate the failure due to shear load, tensile load and combined loads. Tensile and shear damage modes are simulated by supplying stiffness values in all connectors. This was possible because large variety of fastener modeling methods available in Abaqus. Results are in good agreement with published experimental results. In reality aircraft components usually contain large number of fastener holes which will significantly define the failure behavior of components of assembly due to micro level embritlement around fastener hole. A first of its kind methodology for fastener hole and fastener damage is implemented which could successfully interlinked to the global impact failure with local micro embritlement. Keywords: Bird strike, Fastener damage, Coupled Eulerian Lagrangian analysis (CEL), Pure Lagrangian, Smooth particle hydrodynamics (SPH), Abaqus/Explicit, Hugoniot pressure, Stagnation pressure. Fastener Modeling, Fastener hole embrittlement, micro crack initiation, Damage model for Fastener, Bird strike simulation index (BSSI) 2014 SIMULIA Community Conference 64