The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Joris Degrieck - One of the best experts on this subject based on the ideXlab platform.
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numerical and experimental investigation of the shock and steady state pressures in the Bird material during Bird Strike
International Journal of Impact Engineering, 2017Co-Authors: Frederik Allaeys, Geert Luyckx, Wim Van Paepegem, Joris DegrieckAbstract:Abstract The impact of a Bird on a structure can, in the first place, be characterized by the pressure exerted on that structure. In Bird Strike research, the first step towards Bird Strike modelling is therefore often the investigation of these impact pressures. During impact, two subsequent regimes can be distinguished: a shock and steady state regime. These regimes are characterized by an initially very high shock pressure and a much lower steady state pressure. How relevant the shock regime is during Bird Strike however can still be questioned. This paper will reveal some key parameters that influence the shock regime, based on the conclusions of several SPH simulations and an experimental test campaign. A zoom on the numerically obtained shock pressure pulse is made, which shows that the impact pressure and duration correspond very well with the theory. Slight tilting of the projectile however can increase the pressure up to 190% of the analytical value. The elastic energy as a measure for the presence of the shock regime is introduced. This shows that the shock regime is relatively negligible for hemispherical ends. The steady state pressures obtained from the simulations are investigated and finally, the analytical values and numerical results are compared to a series of experimental impact pressure measurements with real and (porous) gelatine Birds.
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characterization of real and substitute Birds through experimental and numerical analysis of momentum average impact force and residual energy in Bird Strike on three rigid targets a flat plate a wedge and a splitter
International Journal of Impact Engineering, 2017Co-Authors: Frederik Allaeys, Geert Luyckx, Wim Van Paepegem, Joris DegrieckAbstract:Abstract To validate the increasingly used numerical models for optimization and verification of the designs subjected to Bird Strike, initial (calibration) tests are a necessity prior to full scale testing. Bird Strike calibration tests on rigid targets specifically, give a valuable insight in the complex behaviour of a Bird. This paper presents the results of a series of Bird Strike tests and simulations on three rigid targets (a plate, a wedge and a splitter) to quantify the forces originating from the change of momentum and splitting of the Bird. In this study, momentum transfer is the key parameter to compare Birds with different masses, materials, speeds, etc., as proposed in the reference works from the 20th century. The main purpose of this paper is fourfold: (i) to introduce another way to measure momentum transfer on these kinds of structures and therefore get more consistent results, (ii) to show that gelatine generates similar impact forces as real Birds, (iii) to point out that apart from the change of direction of the momentum, the deviatoric and/or dissipating constitutive behaviour of the Bird also plays an important role and (iv) to show that a simple plate structure can be used to measure the residual energy of the Bird remainders after an impact event. In a series of numerical simulations, the performance of a SPH Bird with an EOS material model is used to validate the analytical models.
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development and validation of a set up to measure the transferred multi axial impact momentum of a Bird Strike on a booster vane
International Journal of Impact Engineering, 2017Co-Authors: Frederik Allaeys, Geert Luyckx, Wim Van Paepegem, Joris DegrieckAbstract:Abstract Reaction force has always been one of the main characterization parameters for impact events. Today, a set of force transducers are a common and valuable tool to measure reaction forces. But the force signals are often influenced by vibrations of the supporting structures. Many other attempts were already taken in the past to use other methods to measure force, such as ballistic pendulums, Hopkinson bars, etc., all having their advantages and disadvantages. In this work, a multi-axial force measurement tool is developed to serve in a test campaign of Bird Strike experiments on booster vanes. The idea is to give some well-chosen mass three rotational degrees of freedom and acquire the transferred rotational momentum from an optical measurement, which is a direct measure for the impact force. The tool is validated experimentally and numerically using a simplified steel vane.
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use of projection moire for measuring the instantaneous out of plane deflections of composite plates subject to Bird Strike
Optics and Lasers in Engineering, 2008Co-Authors: W Van Paepegem, Joris Degrieck, Assen Shulev, Jana Harizanova, Alexander Moentjens, Ventseslav SainovAbstract:Abstract For the new generation aircraft families, the use of fibre-reinforced plastics is considered for the leading edge of the wings. However, this leading edge is very prone to Bird Strike impact. This paper presents the use of the projection moire technique to measure the instantaneous out-of-plane deflections of composite plates subject to Bird Strike. Very strict constraints with regard to (i) high-speed image acquisition, (ii) vibrations of the impact chamber, and (iii) projection and observation angles, complicated substantially the development of the set-up. Moreover, the high frame rates (12,000 fps) required a very intensive illumination. In the optimized configuration, a specially designed grating with gradually changing period is projected by means of special halide hydride lamps through one of the side windows of the impact chamber onto the composite plate riveted in a steel frame. The digital high-speed camera is mounted on the roof of the impact chamber and records through a mirror the object surface with the projected fringe pattern on it. Numerical routines based on local Fourier transform were developed to process the digital images to extract the phase and the out-of-plane displacements. The phase evaluation is possible due to the carrier frequency nature of the projected moire pattern. This carrier frequency allows separation of the unwanted additive and multiplicative fringe pattern components in the frequency domain via the application of a proper mask. The numerical calculations were calibrated for the Bird Strike on an aluminum plate, where the plastic deformation could be checked after the test.
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projection moire measurement of the deflection of composite plates subject to Bird Strike impact
Proceedings of SPIE the International Society for Optical Engineering, 2007Co-Authors: Assen Shulev, Joris Degrieck, W Van Paepegem, Jana Harizanova, Alexander Moentjens, Ventseslav SainovAbstract:For the new generation aircraft families, the use of fibre-reinforced plastics is considered for the leading edge of the wings. However, this leading edge is very prone to Bird Strike impact. This paper presents the use of the projection moire technique to measure the out-of-plane deflections of composite plates subject to Bird Strike. Very strict constraints with regard to: (i) high speed image acquisition, (ii) vibrations of the impact chamber, and (iii) projection and observation angles - complicated substantially the development of the set-up. Moreover, the high frame rates (12000 fps) required a very intensive illumination. In the optimized configuration, a specially designed grating with gradually changing period is projected by means of special Metal Hydride lamps through one of the side windows of the impact chamber onto the composite plate riveted in a steel frame. The digital high speed camera is mounted on the roof of the impact chamber and records through a mirror the object surface with the projected fringe pattern on it. Numerical routines based on Local Fourier Transform were developed to process the digital images, to extract the phase and the out-of-plane displacements. The phase evaluation is possible due to the carrier frequency nature of the projected moire pattern. This carrier frequency allows separation of the unwanted additive and multiplicative fringe pattern components in the frequency domain via the application of a proper mask. The numerical calculations were calibrated for the Bird Strike of an aluminium plate, where the plastic deformation could be checked after the test.
Giannopoulos, Ioannis K. - One of the best experts on this subject based on the ideXlab platform.
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Bird Strike virtual testing for preliminary airframe design
'Emerald', 2021Co-Authors: Perdikoulis Petros, Giannopoulos, Ioannis K., Theotokoglou, Efstathios E.Abstract:Abstract Purpose – The purpose of this paper is to use numerical methods early in the airframe design process and access the structural performance of wing leading edge devices made of different materials and design details, under Bird Strike events. Design/methodology/approach – Explicit finite element analysis was used to numerically model Bird Strike events. Findings – Structural performance charts related to materials and general design details were drawn to explore the design space dictated by the current applicable airworthiness requirements. Practical implications – This paper makes use of the current capability in the numerical tools available for structural simulations and exposes the existing limitations in the terms of material modelling, material properties and fracture simulation using continuum damage mechanics. Such results will always be in the need of fine-tuning with experimental testing, yet the tools can shed some light very early in the design process in a relative inexpensive manner, especially for design details down selection like materials to use, structural thicknesses and even design arrangements. Originality/value – Bird Strike simulations have been successfully used on aircraft design, mainly at the manufactured articles design validation, testing and certification. This paper presents a hypothetical early design case study of leading edge devices for appropriate material and skin thickness down selectio
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Bird Strike virtual testing simulations and results, for preliminary airframe design structural optimization
International Centre for Numerical Methods in Engineering (CIMNE), 2021Co-Authors: Perdikoulis P., Theotokoglou, Efstathios E., Giannopoulos, Ioannis K.Abstract:External airframe structural components facing the aircraft flight direction, are prone to Bird collisions. Aircraft manufacturers meet the Bird Strike airworthiness requirements through physical Bird Strike testing. Mainly due to the high costs involved in the certification process, recent studies have highlighted the capabilities and benefits of hybrid simulation-experiment techniques that reduce certification costs. The numerical investigation presented herein, studied the Bird-Strike simulation methodologies implemented to support airframe manufacturers to partially fulfill the current certification airworthiness requirements. The methodology can be also applied during preliminary aircraft parametric design stages. In the current study, the method was applied onto an aircraft wing leading edge preliminary design, which led to design exploration by correlating the leading edge skin materials and thicknesses with the rib pitch positioning. The Bird-Strike impact model was simulated using the Smoothed Particle Hydrodynamics numerical method using ABAQUS® Explicit finite element package. The materials benchmarked were aluminum alloy 2024-T3, carbon fiber reinforced epoxy IM7/8552 and S2 glass Fiber Metal Laminate GLARE®. The design goal of the case study was to provide with preliminary evidence for impact resistance, quantified as residual permanent structural deformation of the critical structural components for which design charts were drawn and presented herei
Jun Liu - One of the best experts on this subject based on the ideXlab platform.
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design of aircraft structures against threat of Bird Strikes
Chinese Journal of Aeronautics, 2018Co-Authors: Jun Liu, Xiaosheng Gao, Li Yulong, Y U Xiancheng, Zongxing LiuAbstract:Abstract In this paper, a method to design Bird-Strike-resistant aircraft structures is presented and illustrated through examples. The focus is on Bird Strike experiments and simulations. The explicit finite element software PAM-CRASH is employed to conduct Bird Strike simulations, and a coupled Smooth Particles Hydrodynamic (SPH) and Finite Element (FE) method is used to simulate the interaction between a Bird and a target structure. The SPH method is explained, and an SPH Bird model is established. Constitutive models for various structural materials, such as aluminum alloys, composite materials, honeycomb, and foam materials that are used in aircraft structures, are presented, and model parameters are identified by conducting various material tests. Good agreements between simulation results and experimental data suggest that the numerical model is capable of predicting the dynamic responses of various aircraft structures under a Bird Strike, and numerical simulation can be used as a tool to design Bird-Strike-resistant aircraft structures.
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A novel design for reinforcing the aircraft tail leading edge structure against Bird Strike
International Journal of Impact Engineering, 2017Co-Authors: Jun Liu, Xiancheng Yu, Zhongbin Tang, Xiaosheng Gao, Yu Long Li, Jun Lv, Zhengli ZhangAbstract:This paper presents the work performed to design a novel tail leading edge structure by employing the finite element method coupled with the SPH method to simulate the Bird Strike process. The Bird is simulated by the SPH model while the structure is modeled with the traditional Lagrangian elements. Bird Strike experiments are conducted to validate the numerical model. Good agreements between simulation and experimental results showed that the coupled SPH-FE method provides a valid and effective means to predict the deformation and damage behavior of aircraft structures subjected to Bird Strike. Thus, it can be used as a tool to design Bird Strike-resistant structures. It is found that the novel design, which introduces a triangular reinforcement component to the leading edge structure, greatly enhances the anti-Bird Strike performance. Finally Bird Strike simulations and experiments are conducted for the Horizontal tail leading edge of a commercial aircraft with the above mentioned novel design. No penetration on the frontal beam is observed, suggesting that the novel design meet the certification requirement of CCAR part 25.
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a numerical model for Bird Strike on sidewall structure of an aircraft nose
Chinese Journal of Aeronautics, 2014Co-Authors: Jun Liu, Xiaosheng GaoAbstract:Abstract In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH) and finite element (FE) method to predict the dynamic responses of aircraft structures in Bird Strike events, Bird-Strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The Bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the Bird-Strike tests and a numerical model is established using a commercial software PAM-CRASH. The Bird model shows no signs of instability and correctly modeled the break-up of the Bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of Bird Strike.
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dynamic response of Bird Strike on aluminum honeycomb based sandwich panels
Journal of Aerospace Engineering, 2014Co-Authors: Jun Liu, Xiaopeng Shi, Wenzhi WangAbstract:Numerical simulation is often used in the design of aircraft structural components subjected to Bird-Strike loads. To verify the numerical method, a test of Bird striking was performed on honeycomb-based sandwich panels made from 3003 aluminum honeycomb and 2024-T3 aluminum skin. The dynamic responses of displacement and strain on the rear skin of the sandwich panel during Bird striking were measured using strain gauges and a laser sensor, respectively. A numerical model of Bird striking was developed with a nonlinear, finite-element program. A coupling smooth particle hydrodynamics–finite-element analysis algorithm was used to simulate the interaction of the impacting contact between the Bird and the target. The numerical simulation results were compared with the tests, and they are in good agreement, which validated the reasonableness of the numerical model established in the present paper. This shows the potential of using the FEM in simulating the dynamic response of aircraft structural components in Bird-Strike events.
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Bird Strike on a Flat Plate: Experiments and Numerical Simulations
International Journal of Impact Engineering, 2014Co-Authors: Jun Liu, Xiaosheng GaoAbstract:Abstract In this study, experiments of Bird impact with a flat plate are conducted at different striking velocities and simulated using an explicit finite element software PAM-CRASH with three Bird material models. The predicted displacement and strain in the plate and impact reaction force on the clamping fixture are compared with experimental measurements. The results suggest that the elastic–plastic material model with a defined failure strain is best suited for Bird Strike simulation at low impact velocities, the isotropic elastic–plastic hydrodynamic solid model is best suited for Bird Strike simulation at intermediate impact velocities, and the SPH (smooth particle hydrodynamic) method with the Murnaghan EOS (equation of state) for solid element is best suited for Bird Strike simulation at high impact velocities. Using the appropriate Bird material model, the simulation results agree very well with experimental data.
Xiaosheng Gao - One of the best experts on this subject based on the ideXlab platform.
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design of aircraft structures against threat of Bird Strikes
Chinese Journal of Aeronautics, 2018Co-Authors: Jun Liu, Xiaosheng Gao, Li Yulong, Y U Xiancheng, Zongxing LiuAbstract:Abstract In this paper, a method to design Bird-Strike-resistant aircraft structures is presented and illustrated through examples. The focus is on Bird Strike experiments and simulations. The explicit finite element software PAM-CRASH is employed to conduct Bird Strike simulations, and a coupled Smooth Particles Hydrodynamic (SPH) and Finite Element (FE) method is used to simulate the interaction between a Bird and a target structure. The SPH method is explained, and an SPH Bird model is established. Constitutive models for various structural materials, such as aluminum alloys, composite materials, honeycomb, and foam materials that are used in aircraft structures, are presented, and model parameters are identified by conducting various material tests. Good agreements between simulation results and experimental data suggest that the numerical model is capable of predicting the dynamic responses of various aircraft structures under a Bird Strike, and numerical simulation can be used as a tool to design Bird-Strike-resistant aircraft structures.
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A novel design for reinforcing the aircraft tail leading edge structure against Bird Strike
International Journal of Impact Engineering, 2017Co-Authors: Jun Liu, Xiancheng Yu, Zhongbin Tang, Xiaosheng Gao, Yu Long Li, Jun Lv, Zhengli ZhangAbstract:This paper presents the work performed to design a novel tail leading edge structure by employing the finite element method coupled with the SPH method to simulate the Bird Strike process. The Bird is simulated by the SPH model while the structure is modeled with the traditional Lagrangian elements. Bird Strike experiments are conducted to validate the numerical model. Good agreements between simulation and experimental results showed that the coupled SPH-FE method provides a valid and effective means to predict the deformation and damage behavior of aircraft structures subjected to Bird Strike. Thus, it can be used as a tool to design Bird Strike-resistant structures. It is found that the novel design, which introduces a triangular reinforcement component to the leading edge structure, greatly enhances the anti-Bird Strike performance. Finally Bird Strike simulations and experiments are conducted for the Horizontal tail leading edge of a commercial aircraft with the above mentioned novel design. No penetration on the frontal beam is observed, suggesting that the novel design meet the certification requirement of CCAR part 25.
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Dynamic response of Bird Strike on aluminium foam-based sandwich panels
International Journal of Crashworthiness, 2015Co-Authors: Juhua Liu, Xiaosheng Gao, Pengpeng Liu, Lingyong KongAbstract:This study attempts to establish an experimental–numerical framework to simulate the dynamic response of aluminium foam-based sandwich panels subjected to Bird Strike. The numerical model is developed with the non-linear dynamic finite element code PAM-CRASH, where the smooth particle hydrodynamics (SPH) algorithm is used to model the Bird, an elastic–plastic material model with isotropic damage is used to describe aluminium skin and the Deshpande–Fleck foam model is used to describe the foam core. Mechanical tests of the skin and foam materials as well as Bird-Strike tests of a double sandwich panel are conducted and the experimental results are used to calibrate the model parameters. The Bird-Strike simulation results show reasonably good agreement with test data, indicating the simulation method is capable of predicting the dynamic response of aluminium foam-based sandwich panels in the event of Bird Strike. Finally a series of parametric studies are conducted to examine the effects of foam thickness a...
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a numerical model for Bird Strike on sidewall structure of an aircraft nose
Chinese Journal of Aeronautics, 2014Co-Authors: Jun Liu, Xiaosheng GaoAbstract:Abstract In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH) and finite element (FE) method to predict the dynamic responses of aircraft structures in Bird Strike events, Bird-Strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The Bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the Bird-Strike tests and a numerical model is established using a commercial software PAM-CRASH. The Bird model shows no signs of instability and correctly modeled the break-up of the Bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of Bird Strike.
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Bird Strike on a Flat Plate: Experiments and Numerical Simulations
International Journal of Impact Engineering, 2014Co-Authors: Jun Liu, Xiaosheng GaoAbstract:Abstract In this study, experiments of Bird impact with a flat plate are conducted at different striking velocities and simulated using an explicit finite element software PAM-CRASH with three Bird material models. The predicted displacement and strain in the plate and impact reaction force on the clamping fixture are compared with experimental measurements. The results suggest that the elastic–plastic material model with a defined failure strain is best suited for Bird Strike simulation at low impact velocities, the isotropic elastic–plastic hydrodynamic solid model is best suited for Bird Strike simulation at intermediate impact velocities, and the SPH (smooth particle hydrodynamic) method with the Murnaghan EOS (equation of state) for solid element is best suited for Bird Strike simulation at high impact velocities. Using the appropriate Bird material model, the simulation results agree very well with experimental data.
V Melito - One of the best experts on this subject based on the ideXlab platform.
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modelling Bird impacts on an aircraft wing part 2 modelling the impact with an sph Bird model
International Journal of Crashworthiness, 2005Co-Authors: M A Mccarthy, J R Xiao, A Kamoulakos, Conor T. Mccarthy, J. Ramos, J. P. Gallard, V MelitoAbstract:Abstract In a collaborative research project, aircraft wing leading edge structures with a glass-based Fibre Metal Laminate (FML) skin have been designed, built, and subjected to Bird Strike tests that have been modelled with finite element analysis. In this second part of a two-part paper, a finite element model is developed for simulating the Bird Strike tests, using Smooth Particle Hydrodynamics (SPH) for modelling the Bird and the material model developed in Part 1 of the paper for modelling the leading edge skin. The Bird parameters are obtained from a system identification analysis of Strikes on flat plates. Pre-test simulations correctly predicted that the Bird did no penetrate the leading edge skin, and correctly forecast that one FML lay-up would deform more than the other. The SPH Bird model showed no signs of instability and correctly modelled the break-up of the Bird into particles. The rivets connecting the skin to the ribs were found to have a profound effect on the performance of the structure.
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modelling of Bird Strike on an aircraft wing leading edge made from fibre metal laminates part 1 material modelling
Applied Composite Materials, 2004Co-Authors: M A Mccarthy, J R Xiao, Nik Petrinic, A Kamoulakos, V MelitoAbstract:Fibre Metal Laminates with layers of aluminium alloy and high strength glass fibre composite have been reported to possess excellent impact properties and be suitable for aircraft parts likely to be subjected to impacts from objects such as runway debris or Birds. In a collaborative research project, aircraft wing leading edge structures with a glass-based FML skin have been designed, built, and subjected to Bird Strike tests that have been modelled with finite element analysis. In this first part of a two-part paper, a material model developed for FML suitable for use in impact modelling with explicit finite element analysis is presented. The material model is based on a recent implementation in the commercial finite element code PAM-CRASH/SHOCK of a Continuum Damage Mechanics (CDM) model for composites, incorporating anisotropic strain rate effects. Results from the model are compared with experimental results on FML at variable strain rates and the model is shown to be capable of capturing most of the complex strain rate dependent behaviour exhibited by these materials.
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modelling of Bird Strike on an aircraft wing leading edge made from fibre metal laminates part 2 modelling of impact with sph Bird model
Applied Composite Materials, 2004Co-Authors: M A Mccarthy, J R Xiao, A Kamoulakos, Conor T. Mccarthy, J. Ramos, J. P. Gallard, V MelitoAbstract:Fibre Metal Laminates with layers of aluminium alloy and high strength glass fibre composite have been reported to possess excellent impact properties and be suitable for aircraft parts likely to be subjected to impacts such as runway debris or Bird Strikes. In a collaborative research project, aircraft wing leading edge structures with a glass-based FML skin have been designed, built, and subjected to Bird Strike tests that have been modelled with finite element analysis. In this second part of a two-part paper, a finite element model is developed for simulating the Bird Strike tests, using Smooth Particle Hydrodynamics (SPH) for modelling the Bird and the material model developed in Part 1 of the paper for modelling the leading edge skin. The Bird parameters are obtained from a system identification analysis of Strikes on flat plates. Pre-test simulations correctly predicted that the Bird did not penetrate the leading edge skin, and correctly forecast that one FML lay-up would deform more than the other. Post test simulations included a model of the structure supporting the test article, and the predicted loads transferred to the supporting structure were in good agreement with the experimental values. The SPH Bird model showed no signs of instability and correctly modelled the break-up of the Bird into particles. The rivets connecting the skin to the ribs were found to have a profound effect on the performance of the structure.