impact simulation on the real part of aircraft … · bird strike fe fe simulationsimulation the...

IMPACT SIMULATION ON THE REALIMPACT SIMULATION ON THE REALPART OF AIRCRAFT STRUCTURESPART OF AIRCRAFT STRUCTURES

Radek Doubrava VZLU a.s., Czech Republic

Description of problemDescription of problem

AimAim:: predictionprediction ofof thethe impactimpact behaviorbehavior ofof hardhard andand softsoftbodybody immediatelyimmediately afterafter thethe impactimpact toto partpart ofof aircraftaircraftstructuresstructures..

Projectile Projectile impactimpact•• MeasurementMeasurement

NAFEMS NORDIC REGIONAL CONFERENCE 2010NAFEMS NORDIC REGIONAL CONFERENCE 2010

ConclusionsConclusions

Bird strikeBird strike

•• MeasurementMeasurement

•• FE simulation FE simulation

•• Comparison between measurement and FE simulation Comparison between measurement and FE simulation

•• MeasurementMeasurement

•• FE simulation FE simulation

•• Comparison between measurement and FE simulation Comparison between measurement and FE simulation

Description of problemDescription of problemIn the service of an aircraft has been possibility risk of emergency cases from point of In the service of an aircraft has been possibility risk of emergency cases from point of view unforeseeable circumstances (e.g. bird strike, sucked impurities to the engine view unforeseeable circumstances (e.g. bird strike, sucked impurities to the engine etc.), or owing to human factor (e.g. projectile, missiles etc).etc.), or owing to human factor (e.g. projectile, missiles etc).


http://en.wikipedia.org/wiki/File:Air_France_Flight_4590.jpghttp://en.wikipedia.org/wiki/File:Air_France_Flight_4590.jpghttp://en.wikipedia.org/wiki/Bird_strikehttp://en.wikipedia.org/wiki/Bird_strike

Aircraft surface scanningAircraft surface scanning

Projectile ImpactProjectile Impact


ATOS measurementATOS measurementResult of scanningResult of scanning

Comparison between real damage and nonComparison between real damage and non--damage (CAD) surfacedamage (CAD) surface

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Experimental [1]

material:E= 74000 MPan= 0,33r= 2,77E-09 t/mm3

A= 368,9 MPaB= 683,9 MPaC= 0,0083

m= 1,7n= 0,73

D1= 0,112D2= 0,123D3= 1,5D4= 0,007D5= 0

2024-T3

Elastic

Johnson-Cook constants

Johnson-Cook failure

Numerical simulationNumerical simulation

Model of real projectileModel of real projectileFE modelFE model



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Impact velocity [m/s]

Results of FE simulationResults of FE simulation 505

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Comparison between measurement and Comparison between measurement and FE FE simulationsimulation

MeasurementMeasurement



Leading edge resultsLeading edge results..Skin results between ribsSkin results between ribs..

FE simulationFE simulation

Diametr of muzzle [mm]

length of muzzle [m]

weight of birdvelocity of

bird [km/h]

125 25 2lb (0,91kg) 650125 25 4lb (1,81kg) 450

Bird strike Bird strike Test Method and FacilityTest Method and Facility


VELOCITY-PRESSURE

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PRESSURE [MPa]

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Bird strike Bird strike

FE FE simulationsimulation

The ABAQUS/Explicit has been used for impact simulation onto the part The ABAQUS/Explicit has been used for impact simulation onto the part of aircraft structureof aircraft structure

the bird for sharp parts such as the bird for sharp parts such as pitotpitot probe was modeled as a cylinder probe was modeled as a cylinder with refine mesh on the contact surface for point of view some numerical with refine mesh on the contact surface for point of view some numerical singularities elimination. For oblique parts has been used standard bird singularities elimination. For oblique parts has been used standard bird model (cylinder with spherical ends)model (cylinder with spherical ends)


In the simulation, the bird adopts an elasticIn the simulation, the bird adopts an elastic--plastic model with shear and plastic model with shear and tensile failuretensile failure

The bird nodes are charged with an initial velocityThe bird nodes are charged with an initial velocity

*TENSILE FAILURE*TENSILE FAILURE

*SHEAR FAILURE*SHEAR FAILURE

PitotPitot probeprobe



BirdBird massmass ==2lb 2lb (0,91kg(0,91kg))VelocityVelocity = 180 m/s (648km/h)= 180 m/s (648km/h)

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fragmented

Windshield glass of civil aircraftWindshield glass of civil aircraft


Bird mass =Bird mass = 4 lb (1,82 kg)4 lb (1,82 kg)


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Bird mass =Bird mass = 4 lb (1,82 kg)4 lb (1,82 kg)Velocity = 300 Velocity = 300 -- 450 km/h450 km/h

Windshield glass of military aircraftWindshield glass of military aircraftBird strike Bird strike


BirdBird massmass ==4 4 lb (lb (1,82 1,82 kg)kg)VelocityVelocity = 300 = 300 -- 450 km/h450 km/h

Future worksFuture works

development of the development of the new new synthetic model of bird with inner skeleton stiffness synthetic model of bird with inner skeleton stiffness simulationsimulation

simulations will be increased simulations will be increased about CEL (Coupled about CEL (Coupled EulerianEulerian ––LagrangianLagrangian) technique) technique


improve boundary conditions (frame, gasket etc.)improve boundary conditions (frame, gasket etc.)

improve material propertiesimprove material properties

ConclusionConclusionss

diagnostics of airframe damage diagnostics of airframe damage -- scanning of aircraft surface, photogrammetric scanning of aircraft surface, photogrammetric system application etc.system application etc.

application for structure repair evaluation application for structure repair evaluation –– damage of inner structure, composite damage of inner structure, composite

TheThe resultresult showsshows goodgood agreementagreement betweenbetween measurementmeasurement andand FEFE calculationcalculation..AlthoughAlthough thisthis workwork isis onlyonly aa firstfirst approximation,approximation, andand implementedimplemented inin relativelyrelativelysimplifiedsimplified terms,terms, thisthis methodmethod ofof findingfinding damagedamage propagationpropagation isis applicableapplicable forfor::


application for structure repair evaluation application for structure repair evaluation –– damage of inner structure, composite damage of inner structure, composite path application etc.path application etc.

service operations service operations –– visual inspectionvisual inspection

performance of airworthiness from point of view bird strikeperformance of airworthiness from point of view bird strike

impact simulation on the real part of aircraft … · bird strike fe fe simulationsimulation the...

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