Bird impact poses serious threats to military and civilian aircrafts as they lead to fatal structural damage to critical aircraft components. The exposed aircraft components such as windshields, radomes, leading edges, engine structure, and blades are vulnerable to bird strikes. Windshield is the frontal part of cockpit and more susceptible to bird impact. In the present study, finite element (FE) simulations were performed to assess the dynamic response of windshield against high velocity bird impact. Numerical simulations were performed by developing nonlinear FE model in commercially available explicit FE solver AUTODYN. An elastic-plastic material model coupled with maximum principal strain failure criterion was implemented to model the impact response of windshield. Numerical model was validated with published experimental results and further employed to investigate the influence of various parameters on dynamic behavior of windshield. The parameters include the mass, shape, and velocity of bird, angle of impact, and impact location. On the basis of numerical results, the critical bird velocity and failure locations on windshield were also determined. The results show that these parameters have strong influence on impact response of windshield, and bird velocity and impact angle were amongst the most critical factors to be considered in windshield design. 1. Introduction High velocity bird impact is one of the most significant hazards to both civilian and military aircrafts [1]. When fighter military aircrafts are operated at lower altitude and higher speed, the probability of bird impact increases and proves lethal to the safety of pilot and critical aircraft components. Windshield is the exposed part of aircraft and prone to bird impact. In order to ensure the safety of aircraft, the windshield must be capable of withstanding high velocity impact threats. Design of an optimum impact resistant windshield is a challenge and requires extensive experimental testing. The advanced numerical techniques are being adopted as an effective tool to simulate the bird strike event and provide a substitute to excessive costly experimentations. Moreover, it allows analyzing the most stringent impact conditions that cannot be considered in the experiments and provides detailed insight to the impact process which is difficult to observe during experimental testing. Several researchers such as Zang et al. [2], Samuelson and Sornas [3], and Boroughs [4] carried out finite element analysis to investigate the impact response of windshield against bird strike. McCarty
References
[1]
J. Thorpe, “Fatalities and destroyed civil aircraft due to bird strikes, 1912–2002,” in Proceedings of the 26th Meeting of the International Bird Strike Committee, Warsaw, Poland, 2003.
[2]
S. G. Zang, C. H. Wu, R. Y. Wang, and J. R. Ma, “Bird impact dynamic response analysis for windshield,” Journal of Aeronautical Materials, vol. 20, no. 4, pp. 41–45, 2000.
[3]
A. Samuelson and L. Sornas, “Failure analysis of aircraft windshields subjected to bird impact,” in Proceedings of the 15th ICAS Congress, London, UK, 1986.
[4]
R. R. Boroughs, “High speed bird impact analysis of the Learjet 45 windshield using DYNA3D,” in Proceedings of the 39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference and Exhibit and AIAA/ASME/AHS Adaptive Structures Forum, pp. 49–59, Long Beach, Calif, USA, April 1998.
[5]
R. E. McCarty, “Finite element analysis of a bird-resistant monolithic stretched acrylic canopy design for the F-16A aircraft,” in Proceedings of the American Institute of Aeronautics and Astronautics, Aircraft Systems and Technology Conference, Dayton, Ohio, USA, 1981.
[6]
R. E. McCarty, M. G. Gran, and M. J. Baruch, “MAGNA nonlinear finite element analysis of T-46 aircraft windshield bird impact,” in Proceedings of the AIAA/AHS/ASEE Aircraft System Design and Technology Meeting, AIAA Paper 86-2732, Dayton, Ohio, USA, 1986.
[7]
F. S. Wang and Z. F. Yue, “Numerical simulation of damage and failure in aircraft windshield structure against bird strike,” Materials and Design, vol. 31, no. 2, pp. 687–695, 2010.
[8]
F. S. Wang, Z. F. Yue, and W. Z. Yan, “Factors study influencing on numerical simulation of aircraft windshield against bird strike,” Shock and Vibration, vol. 18, no. 3, pp. 407–424, 2011.
[9]
X. Wang, Z. Feng, F. Wang, and Z. Yue, “Dynamic response analysis of bird strike on aircraft windshield based on damage-modified nonlinear viscoelastic constitutive relation,” Chinese Journal of Aeronautics, vol. 20, no. 6, pp. 511–517, 2007.
[10]
M. Guida, A. Grimaldi, F. Marulo, and A. Sollo, “FE study of windshield subjected to high speed bird impact,” in Proceedings of the 26th International Congress of the Aeronautical Sciences (ICAS '08), 2008.
[11]
J. Liu, Y. L. Li, and F. Xu, “The numerical simulation of a bird-impact on an aircraft windshield by using the SPH method,” Advanced Materials Research, vol. 33–37, pp. 851–856, 2008.
[12]
S. Zhu, M. Tong, and Y. Wang, “Experiment and numerical simulation of a full-scale aircraft windshield subjected to bird impact,” in Proceedings of the 50th AIAA/ASME/ASCE/AHS/ ASC Structures, Structural Dynamics, and Materials Conference, Palm Springs, Calif, USA, 2009.
[13]
J. Yang, X. Cai, and C. Wu, “Experimental and FEM study of windshield subjected to high speed bird impact,” Acta Mechanica Sinica, vol. 19, no. 6, pp. 543–550, 2003.
[14]
W. Lili, Z. Xixiong, S. Shaoqiu, G. Su, and B. Hesheng, “Impact dynamics investigation on some problems in bird strike on windshields of high speed aircrafts,” Acta Aeronautica et Astronautica Sinica, vol. 12, no. 2, pp. B27–B33, 1991.
[15]
F. Zhou, L. Wang, and S. Hu, “A damage-modified nonlinear visco-elastic constitutive relation and failure criterion of PMMA at high strain-rates,” Explosion and Shock Waves, vol. 12, no. 4, pp. 333–342, 1992.
[16]
A. Wang, X. Qiao, and L. Li, “Finite element method numerical simulation of bird striking multilayer windshield,” Acta Aeronautica et Astronautica Sinica, Series A and B, vol. 19, pp. 446–450, 1998.
[17]
Z. Zhi-lin, Z. Qi-qiao, and L. Ming-xing, “Bird impact dynamic response analysis for aircraft arc windshield,” Acta Aeronautica et Astronautica Sinica, vol. 9, article 018, 1992.
[18]
R. Doubrava and V. Strnad, “Bird strike analyses on the parts of aircraft structure,” in Proceedings of the 27th Congress of the International Council of the Aeronautical Sciences, France, 2010.
[19]
J. Bai and Q. Sun, “On the integrated design technique of windshield against bird strike,” Mechanics and Engineering, vol. 27, no. 1, pp. 14–18, 2005.
[20]
Y. Zhang and Y. Li, “Analysis of the anti-bird impact performance of typical beam-edge structure based on ANSYS/LS-DYNA,” Advanced Materials Research, vol. 33–37, pp. 395–400, 2008.
[21]
A. F. Johnson and M. Holzapfel, “Modelling soft body impact on composite structures,” Composite Structures, vol. 61, no. 1-2, pp. 103–113, 2003.
[22]
J. Cheng and W. K. Binienda, “Simulation of soft projectiles impacting composite targets using an arbitrary Lagrangian-Eulerian formulation,” Journal of Aircraft, vol. 43, no. 6, pp. 1726–1731, 2006.
[23]
F. Stoll and R. A. Brockman, “Finite element simulation of high-speed soft-body impacts,” in Proceedings of the 38th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, pp. 334–344, April 1997.
[24]
R. Hedayati and S. Ziaei-Rad, “A new bird model and the effect of bird geometry in impacts from various orientations,” Aerospace Science and Technology, 2012.
[25]
AUTODYN Theory manual Rev. 4.3. Century Dynamics, a subsidiary of ANSYS Inc, 2005.
[26]
J. Wilbeck, “Impact behavior of low strength projectiles,” Report AFML-TR- 77-134, Air Force Materials Laboratory, 1977.
[27]
C. J. Welsh and V. Centonze, “Aircraft transparency testing artificial birds,” Report AEDC-TR-86-2, US Air Force, 1986.
