7/31/2019 Design Criteria for Birdstrike Damage on Windshield

1/2

Aerospace Structural Impact Dynamics International Conference 2012National Center for Aviation Training - November 6-9, 2012

http://www.niar.wichita.edu/impactconference

DESIGN CRITERIA FOR BIRDSTRIKE DAMAGE ON WINDSHIELD

A. Grimaldi *, A. Sollo *, F. Marulo #, M. Guida #

* Piaggio Aero Industries - ItalyDesign Office Structure Technology Dept.

Email: agrimaldi@piaggioaero.it

# Universit di Napoli Federico IIDepartment of Aerospace Engineering

Via Claudio, 2180125 Napoli, Italy

Keywords: SPH approach, High velocity impact, Birdstrike scenario, Glass compositematerial, Windshield component.

According to the aeronautical specifications, with the term birdstrike we mean the collisionbetween a bird and an aircraft front facing component (windshield, nacelles, wing, leading edge andcompressor blade).It plays an important role about the aircraft safety because of the high probability that it impactsagainst a foreign object (in particular a bird) during its life cycle.Each aircraft have to be certified for a proven level of impact resistance, assuring the capability of asafe flight and landing after the impact against a bird at cruise speed.The aim of this research work was to define a scientific and methodological approach to the study of

the birdstrike phenomenon.For this reason a series of numerical simulations were performed by using the explicit finite elementsolver code LS-Dyna, in order to obtain an evaluation of the windshield-surround structurecapability to absorb the impact energy, involving during a birdstrike event, in a safe and efficient wayand in according to the EASA Certification Specifications 25.631 on the Bird-strike Damage[CS25.631 (2003)].The research is divided into two different stages.Firstly the paper provides a parametric numerical analysis of a simplified, but realistic, square flatwindshield model subjected to impact by a 1.8 kg bird model at 155 m/s to estimate the influence ofthe target geometry, the impact angle, and the plate curvature on the impact response of thewindshield structure (figure 1).

The second stage is the development of a numerical simulation of a birdstrike event on a full-scaleaircraft windshield-surround model with an innovative configuration (figure 2).For both numerical analysis it was used a FE-SPH coupled approach to simulate the fluid-structureinteraction.The main achievement of this research was the collection of results and experiences, obtained byboth simplified realistic and full-scale FE model analysis, to define a design rule of thumbassessment with regard to the Birdstrike problem.It has permitted to trace the guidelines to perform a certification test simulation and finalize abirdstrike test article proposal, necessary for a design of an airplane windshield structure able to

7/31/2019 Design Criteria for Birdstrike Damage on Windshield

2/2

withstand to a birdstrike event in according with the conditions stated in the CS 25 standardrequirements.

Figure 1 Case suited as changed of curvature and impact angle

Figure 2 Geometry and FE model of the cockpit structure