Aircraft fuselage skin vibration in the field of pressure fluctuations

1997 ◽  
Author(s):  
B. Efimtsov ◽  
B. Efimtsov
Keyword(s):  
Pressure Fluctuations ◽  
Aircraft Fuselage ◽  
Fuselage Skin

FEM-BEM Modeling and Experimental Verification of the Vibro-Acoustic Behaviour of a Section of Aircraft Fuselage

2016 ◽  
Author(s):  
Viken N. Koukounian ◽  
Chris K. Mechefske
Keyword(s):  
Transmission Loss ◽  
Pressure Fluctuations ◽  
Experimental Methodology ◽  
Reverberation Chamber ◽  
Aircraft Fuselage ◽  
Ongoing Work ◽  
Damping Materials ◽  
Fuselage Skin ◽  
International Testing ◽  
Testing Standards

The aerodynamics of an aircraft in flight impose significant stresses upon the structure. Specifically, the mechanics of fluid flow are highly turbulent and, the layer around the aircraft, is referred to the turbulent boundary layer (TBL). The TBL incites a gradient of pressure fluctuations across the fuselage skin resulting in its vibration, and in turn, the generation of noise inside the passenger cabin. The investigation herein proposes a hybrid FEM-BEM modeling technique to predict the aforementioned vibro-acoustic response and an experimental methodology to verify the results (following ASTM and ANSI international testing standards). The described expectations required construction of an acoustic facility consisting of a reverberation chamber and a semi-anechoic room, the development of DAQ software using LabVIEW, an assembly of DAQ hardware using National Instruments products, and the post-processing of test data using Microsoft Excel. The principal quantity of interest is transmission loss (though insertion loss, absorption and other metrics are also calculated). Two panels (0.04in (40thou) and 0.09in (90thou) in thickness) were simulated and tested (0.01in = 1thou). The calculated error of the proposed methodology is within a maximum of 5dB, with an average of 1dB. Ongoing work is investigating complex constructions and the use of damping materials.

Case Studies of Aircraft Fuselage Cracking

2019 ◽  
Vol 33 ◽  
pp. 11-18 ◽  
Author(s):  
A.M. Al-Mukhtar
Keyword(s):  
Cyclic Loading ◽  
Corrosion Damage ◽  
Crack Size ◽  
Critical Crack ◽  
Aircraft Fuselage ◽  
Effective Role ◽  
Number Of Cycles ◽  
Fuselage Skin ◽  
Critical Crack Size ◽  
Cycles To Failure

Fatigue plays a significant role in the crack growth of the fuselage skin structures. In addition, the fuselage may suffer also from the corrosion damage, and the wear defects. The proper maintenance and scheduled test intervals can avoid the sudden skin failure. Therefore, the inspection interval has to be shortened. Nevertheless, the young machines may be also suffering from the unexpected skin rupture. The cracks are emanating from the rivets and the holes under cyclic loading. The stress concentration around the notch has an effective role under the effect of cyclic loading. The cracks propagate toward the high stressed area such as the notches or other crack locations. The propagation into a critical crack size is rather fast and causes a sudden aircraft fuselage cracking. Hence, the number of cycles to failure will be decreased dramatically. During the last decades, the fracture toughness, design, and the new alloying element have been enhanced. The previous fuselage failures show that the inspections against the cracking are recommended even after a few thousand of cycles. To prevent the crack extending, the crack arresting is recommended to use around the fuselage.

scholarly journals AFP mandrel development for composite aircraft fuselage skin

2014 ◽  
Vol 15 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Deepak Kumar ◽  
Myung-Gyun Ko ◽  
Rene Roy ◽  
Jin-Hwe Kweon ◽  
Jin-Ho Choi ◽  
...  
Keyword(s):  
Aircraft Fuselage ◽  
Fuselage Skin

Analytical-Experimental Evaluation of the Fatigue Resistance for Aircraft Fuselage Skin in the Case of Corrosion Damage

2021 ◽  
Vol 64 (2) ◽  
pp. 181-188
Author(s):  
V. S. Shapkin ◽  
A. V. Lapaev ◽  
K. A. Matveev ◽  
V. A. Gorshkov ◽  
A. A. Bogoyavlenskii
Keyword(s):  
Fatigue Resistance ◽  
Experimental Evaluation ◽  
Corrosion Damage ◽  
Aircraft Fuselage ◽  
Fuselage Skin

Passive Control of Transonic Cavity Aeroacoustics

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
David A. Roberts ◽  
David G. MacManus
Keyword(s):  
Passive Control ◽  
Pressure Fluctuations ◽  
Small Scale ◽  
Front Wall ◽  
Rear Wall ◽  
Aircraft Fuselage ◽  
Helmholtz Resonators ◽  
Target Individual ◽  
Large Pressure ◽  
Open Cavities

In recent years the continuing trend for the internalization of stores within an aircraft fuselage has led to a renewed interest in the field of cavity aeroacoustics. Open cavities exposed to transonic flow exhibit large pressure fluctuations which can result in damage to stores or components carried within the cavity. This study investigates the use of a passive resonant absorber based on Helmholtz resonators to attenuate the unsteady pressure fluctuations that arise in such cavity flows. The arrays are expected to remove energy from the high intensity cavity oscillations at the frequency to which they are tuned and therefore, to reduce the cavity noise. Six resonant arrays were designed to target individual Rossiter modes within a cavity. The arrays were tested in a small scale wind tunnel at both Mach 0.8 and Mach 0.9. The performance of the arrays were tested individually at both the front and rear wall of the cavity as well as in a combined arrangement. A peak attenuation of 14 dB was measured for an array at the front wall at Mach 0.9. A smaller attenuation of 8 dB was achieved when the same array was tested at Mach 0.8. Combined resonator installations at both the front and rear walls of the cavity further increased the peak sound pressure level (SPL) attenuation up to 18 dB at Mach 0.9. The investigation shows that passive resonant absorbers are a promising palliative method for the reduction of cavity acoustic modes at high subsonic speeds.

scholarly journals On the Global and Localised Corrosion Behaviour of the AA2524-T3 Aluminium Alloy Used as Aircraft Fuselage Skin

2019 ◽  
Vol 22 (2) ◽  
Author(s):  
Jéferson Aparecido Moreto ◽  
Luciana Sgarbi Rossino ◽  
Waldek Wladimir Bose Filho ◽  
Cláudia Eliana Bruno Marino ◽  
Miguel da Conceição Ferreira ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Corrosion Behaviour ◽  
Aircraft Fuselage ◽  
Fuselage Skin

Investigation on three-roller cylindrical bending of 2060-T8 Al-Li alloy plate for aircraft fuselage skin components

2017 ◽  
Vol 11 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Jingwen Peng ◽  
Weidong Li ◽  
Min Wan ◽  
Changsheng Zhang ◽  
Jian Li ◽  
...  
Keyword(s):  
Cylindrical Bending ◽  
Alloy Plate ◽  
Aircraft Fuselage ◽  
Fuselage Skin

PRESSURE FLUCTUATIONS OF LIQUID-LIQUID SLUG FLOW IN CROSS-JUNCTION SQUARE MICROCHANNELS

2018 ◽  
Author(s):  
Jin-yuan Qian ◽  
Min-rui Chen ◽  
Zan Wu ◽  
Zhen Cao ◽  
Bengt Sunden
Keyword(s):  
Slug Flow ◽  
Pressure Fluctuations ◽  
Liquid Slug
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