Crash of the Polish Governmental Plane Tu-154M

Smolensk, Russia, on April 10, 2010

Numerical verifications of the official conclusions

Airplane Tu-154M Crash - Verifications

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Kyrgyzstan Jet Crash-Landing Injures 31

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Moscow TU-154 plane crash injuries reached to 83 on Dec 5, 2010

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Crash Tu154 into a Steel Structure

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Russian Final Report

Section 3.1.69

• The aircraft collided with the birch with a trunk diameter 30-40 cm, which led to the left outer wing portion of about 4.7 6.5 m long ripped off and intensive left bank.

Section 3.1.70

• In 5-6 more seconds, inverted the aircraft collided with the ground and was destroyed.

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Last seconds before the crash

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Question # 1

Is it possible that the Tu-154M airplane lost a major part of the wing as a result of hitting the Birch?

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Internal structure of the wing Tu-154M

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Spar Cross-sections

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230m

m

Inner wing structure Boeing 727

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Material parameters of the birch tree

Young’s Modulus (MPa) Poisson Ratio Shear Modulus (MPa) Density

(Kg/m3)

EL ER ET νLT νRL νRT GTL GLR GRT

Birch1 10300 803.4 515 0.451 0.043 0.697 700.4 762.2 175.1 700

Birch2 16000 1600 1100 0.451 0.043 0.697 700.4 762.2 175.1 1000

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Birch- elastic, cylindrically orthotropic;

Parameters of the Aluminum Tu-154

• Parameters of Aluminum D16, V95, AK6, etc.

http://www.splav.kharkov.com/en/

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Density(Kg/m3) Young’s

modulus, E(Pa) Yield Stress(Pa)

Tangent Modulus, Ec (Pa)

Poisson Ratio, ν

Failure Strain

2850 7.4E+10 4.44E+8 5.738E+8 0.33 0.14

Aluminum: isotropic, elasto-plastic hardened,

Strain Rate Dependence of Aluminum

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0

100

200

300

400

500

600

700

800

900

0 0.2 0.4 0.6 0.8 1 1.2

stre

ss (M

Pa)

Plastic strain

stress vs plastic strain

1500 1/s

5000 1/s

8000 1/s

9500 1/s

12000 1/s

Internal Structure of the Wing

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Validation of leading edge

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Leading edge Validation

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Wen Zhi Wang, Northwestern Polytech U.

Fuselage Validation

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Birch Three Point Bending Tests

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Density of the birch sample = 700 kg/m3

Methodology of Analysis

LsDyna3D Simulation

Parameters

• Velocity: 77-80 m/s horizontal, 0-19.2m/s vertical up • Plane mass: 78600 kg • Distance from the base to the tree cut : 6m - 6.5m • Birch diameter at the cut section: 40cm - 44 cm • Birch density: 550 - 1000 kg/m3

• Location of the impact on the wing from its tip: 3m - 7m • Several plane orientations:

– Horizontal, – Nose up: 5° – 20° – Roll -5° horizontal – Roll -5° and pitch 5° – 20°

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Math and Physics Background in CFX

• Ansys- CFX analysis conducted by UA Research Fluid Mechanics Laboratory.

• Full form of Navier-Stokes equations with continuity of the flow.

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Overall Pressure Contour

Wing Pressure Contours

23 Bottom Top

Widok z lewej strony samoloty

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Widok od Strony Samolotu

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Zblizenie 1

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Zbliżenie 2

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Naprężenia w brzozie i skrzydle

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Naprzenia w brzozie i skrzydle

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Conclusions # 1 • Based on the parameters provided in the

official reports, the model shows that the wing of the Tu-154M plane cuts through the birch for every analyzed scenario.

• The damage to the wing is localized on the edge, does not deteriorate the lift surface of the wing, thus should not significantly reduce the ability of the plane to fly. Above simulations have been consulted with and

positively evaluated by BOEING Principal Structural Engineer Dr. Waclaw Berczynski.

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Left Wing Reconstruction View From the Bottom Up – Front Edge(Part 9) not Damaged

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1 CENTROPŁAT LEWY 2 ODEJMOWANA CZĘŚĆ SKRZYDŁA LEWEGO (FRAGMENT POCZĄTKOWY

POSZYCIA SPODNIEGO Z SZACHOWNICĄ) 3 ODEJMOWANA CZĘŚĆ SKRZYDŁA (KOMPLETNA CZĘŚĆ KOŃCOWA) 4 DEFLEKTOR (FRAGMENT KOŃCOWY) 5 FRAGMENT KOŃCOWEJ CZĘŚCI KLAPY OCZS. 6 FRAGMENT ŚRODKOWEJ CZĘŚCI KLAPY OCZS. 7 REDUKTOR MECHANIZMU WYSUWANIA LOTKI-INTERCEPTORA 8 FRAGMENTY POSZYCIA ODEJMOWANEJ CZĘŚCI SKRZYDŁA 9 SLOT ŚRODKOWY, SEKCJA 2 (FRAGMENT KOŃCOWY)

10 SLOT ŚRODKOWY, SEKCJA 2 (FRAGMENT ŚRODKOWY) 11 SLOT ŚRODKOWY, SEKCJA 2 (FRAGMENT POCZĄTKOWY) 12 SLOT ŚRODKOWY, SEKCJA 1 (FRAGMENT KOŃCOWY) 13 SLOT WEWNĘTRZNY 14 WYRWANY DŹWIGAR NR 1 CENTROPŁATA Z FRAGMENTEM POSZYCIA 15 WYRWANY BLOK KLIMATYZACYJNY Z POSZYCIEM

Simulation of Fuselage with Explosion Sandia National Lab – CNN 2008

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Fuselage Walls Open Outside

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How to make a progress?

1. Get several samples of a Birch Tree, measure density, stress-strain in axial and transverse directions. Generate acceptable to all material properties and publish them.

2. Publish blue prints of the wing. Include thicknesses and other dimensions of the internal structure and outside components of the wing (slats, flaps, etc).

3. Encourage to conduct research based on the above data so researchers may be able to further develop simulation techniques and methodologies, help to establish realistic scenarios of the crash, while avoiding any political ramification.

4. Be friendly to your colleagues.

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