Search results

Bird strike and hail impact resistances are considered in relation to the fulfilment of airworthiness/crashworthiness regulations as specified by appropriate aviation authorities. Before aircraft are allowed to go into service, these regulations must be fulfilled. This includes the adaption of the wing leading edge (LE) structure to smart diagnostics and an easy repair. This paper aims to focus on the wing LE, although all forward-facing aircraft components are exposed to the impact of foreign object during the flight. The best practices based on credible simulations which may be appropriate means of establishing compliance with European Aviation safety Agency and Federal Aviation Administration regulations regarding bird strikes, together with the problem of collisions with hailstones, are overviewed in aspect of accuracy and computing cost.

The best means of evaluating worldwide certification standards so as to be more efficient for all stakeholders by reducing risk and costs (time and money consuming) of certification process are recommended. The very expensive physical tests may be replaced by adequate and credible computer simulations. The adequate credible simulation must be verified and validated. The statistical approaches for modelling the uncertainty are presented in aspect of computing cost.

The simulation models have simplifications and assumptions that generate an uncertainty. The uncertainty must be identified in benchmarking tests. Instead of using “in house” physical tests, there are scientific papers available in open literature thanks to the new trend in worldwide publication of the research results. These large databases can be efficiently transform into useful benchmark thanks to data mining and knowledge discovery methods and big data analyses. The physical test data are obtained from tests on the ground-based demonstrator by using high-speed cameras and a structural health monitoring system, and therefore, they should be applied at an early stage of the design process.

The sources of uncertainty in simulation models are expressed, and the way to their assessment is presented based on statistical approaches. A brief review of the current research shows that it widely uses efficient numerical analysis and computer simulations and is based on finite element methods, mesh structure as well as mesh free particle models. These methods and models are useful to analyse airworthiness requirements for damage tolerance regarding bird-strike and hail impact and haves been subjected to critical review in this paper. Many original papers were considered in this analysis, and some of them have been critically reviewed and commented upon.

Bird strike risk (BSR) evaluation is a significant part of the avian radar system worldwide installed and operated at airports. The paper aims to discuss these issues.

This paper proposed a method using the real-time avian radar data to evaluate BSR with the estimations of bird strike probability and severity. The probability estimation model considered the attributes of the relative positions of the flock and the runway, the altitude of the flock and the aircraft, the flight path of the aircraft, and the ability of the bird species to avoid collision. The severity was estimated by the combination of the Delphi method and the analytic hierarchy process (AHP), called DAHP, which took full advantage of the expert knowledge and quantitative calculation.

The model was tested successfully on the simulated data at Beijing Capital International Airport (BCIA) with three runways and real data at Beihai Fucheng Airport (BFA) with one runway.

The BSR evaluation model was specifically designed for the airports with avian radars. It enabled the airport managers to objectively evaluate the risk in real time and to take effective measures.

The proposed BSR evaluation model was constructed with the real-time features of birds and aircraft based on the DAHP framework, providing scientific guidance for aviation safety and environmental management at the airport.

Collisions between birds and aircraft are problems that have been with us since the early days of powered flight. The majority of such occurrences cause slight damage which does not affect airworthiness of the aircraft, but others have caused structural problems and loss of control with catastrophic results to the aircraft and occupants. The bird strike threat is significantly greater in military aviation since the normal operational environment is at a much lower altitude than in the civil sphere, and it is here that most birds are found.

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.

Explicit finite element analysis was used to numerically model bird strike events.

Structural performance charts related to materials and general design details were drawn to explore the design space dictated by the current applicable airworthiness requirements.

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.

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 selection.

An optimization method has been presented to simultaneously identify the bird’s constitutive model and its parameters automatically in the bird strike problems. The full contact‐impact coupling algorithm of finite element method (FEM) has been applied and the optimization objective is to minimize the square sum of percentage errors between testing results and FEM results. As an example, two bird’s material constitutive models, Plastic Kinematics model and hyper elastic Mooney‐Rivlin Rubber material model, have been used to testify the feasibility and reliability of the optimization method. The results show that the method presented in this paper can be used to study the bird strike problems.

The purpose of this paper is to analyze the bird impact damage of fuselage composite stiffened structures by numerical method and to evaluate the damage and the bird impact resistance of different structures.

The deformation and damage of composite stiffened plates during bird impact are numerically analyzed by the explicit finite element software LS-DYNA. A comparative study on the numerical calculation results was conducted by using SPH (Smoothed Particle Hydrodynamics)-FEM (Finite Element Method) modeling and simulation. First, the I-shaped, T-shaped, straight stiffened plates and unstiffened plate were designed. Second, the accuracy of the bird model was verified and further used to evaluate bird strikes on composite stiffened plate. Third, the results of damage modes as well as displacements of the stiffened plates were compared.

The stiffeners can increase the local stiffness of the composite panel, which can effectively inhibit the bird’s movement along the impact direction. Adding stiffeners can change the panel matrix tension damage from global distribution to local distribution mode; however, the impact damage distribution and the ability to inhibit damage propagation can differ for different stiffened panels. Especially, the I-stiffened panel exhibits a better anti-bird strike performance.

The analysis of geometric parameters of structural components by numerical methods can reduce the cost of the design phase and has been widely used in aircraft design. The present study evaluated the bird impact damage of composite stiffened plates with different structures, which provides a guideline for selecting the stiffened plate structure in the fuselage skin.

PUBLISHED by the CAA is an analysis of bird strikes reported world‐wide between 1976 and 1980 by European airlines from 14 countries. It includes civil aircraft of over 5,700kg (12,500lb) maximum weight, except that all executive jets including those of less than 5,700kg have been included. The birds involved were identified in 50% of the incidents, with gulls accounting for something under half of these with the next most frequently struck bird being the lapwing, followed by swallows and martins. The most frequently struck part of an aircraft was the nose and radome, followed by the fuselage and the engines, while the tail area was very rarely struck. It is noteworthy that the size of bird involved influences these percentages since small birds (below ¼lb) are rarely reported as striking the engines, wing or landing gear, but are more frequently reported on the nose and windshield.