scholarly journals The Study of Nonlinear Flutter Analysis Method for an Aircraft Full Composite Wing with High-aspect-ratio

2016 ◽  
Author(s):  
Sheng-Jun Qiao ◽  
Hang-Shan Gao ◽  
Jun-Ran Zhang
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Analysis Method ◽  
Nonlinear Flutter ◽  
Flutter Analysis ◽  
Composite Wing

The Effect of Structural Geometric Nonlinearities on the Flutter of the Straight and Swept Wing Configurations

2012 ◽  
Vol 189 ◽  
pp. 306-311 ◽  
Author(s):  
Qing Guo ◽  
Bi Feng Song
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Swept Wing ◽  
Geometric Nonlinearities ◽  
Air Vehicle ◽  
Structural Nonlinearity ◽  
Flutter Analysis ◽  
Long Endurance ◽  
The Impact ◽  
Straight Wing

High altitude and long endurance (HALE) vehicle always adopt straight or swept configuration, which leads to the problem that the wings of UAV have high aspect ratio and are very flexible. This kind of flexible wing exhibits large deformation when aerodynamic forces are loaded on them and the structural nonlinearity should be considered. So the dynamic and flutter characteristics will be changed. In the engineering applications, the effects of structural geometric nonlinearities on the air vehicle design are the most concerns of aeroelasticity before a systematic flutter analysis for the air vehicle. because the solution for nonlinear flutter speed based on the CFD-CSD method is complex and time consuming. In this paper, we propose a simple and efficient approach that can analyze the effect of structural geometric nonlinearities on the flutter characteristics of high aspect ratio wing quickly. And a straight wing and a straight-swept wing are analyzed to verify the feasibility and efficiency of the proposed method. It is found that the effect of structural geometric nonlinearities has a strong effect on the flutter characteristic of the straight wing, but is weak on the straight-swept wing. And finally the impact of swept angle on the dynamic and flutter characteristics of straight-swept wing is also discussed.

scholarly journals Geometrical Nonlinear Aeroelastic Stability Analysis of a Composite High-Aspect-Ratio Wing

2008 ◽  
Vol 15 (3-4) ◽  
pp. 325-333 ◽  
Author(s):  
Chang Chuan Xie ◽  
Jia Zhen Leng ◽  
Chao Yang
Keyword(s):  
Stability Analysis ◽  
Aspect Ratio ◽  
Equilibrium State ◽  
High Aspect Ratio ◽  
Unsteady Aerodynamics ◽  
Static Equilibrium ◽  
Beam Model ◽  
Aeroelastic Stability ◽  
Nonlinear Flutter ◽  
Static Equilibrium State

A composite high-aspect-ratio wing of a high-altitude long-endurance (HALE) aircraft was modeled with FEM by MSC/NASTRAN, and the nonlinear static equilibrium state is calculated under design load with follower force effect, but without load redistribution. Assuming the little vibration amplitude of the wing around the static equilibrium state, the system is linearized and the natural frequencies and mode shapes of the deformed structure are obtained. Planar doublet lattice method is used to calculate unsteady aerodynamics in frequency domain ignoring the bending effect of the deflected wing. And then, the aeroelastic stability analysis of the system under a given load condition is successively carried out. Comparing with the linear results, the nonlinear displacement of the wing tip is higher. The results indicate that the critical nonlinear flutter is of the flap/chordwise bending type because of the chordwise bending having quite a large torsion component, with low critical speed and slowly growing damping, which dose not appear in the linear analysis. Furthermore, it is shown that the variation of the nonlinear flutter speed depends on the scale of the load and on the chordwise bending frequency. The research work indicates that, for the very flexible HALE aircraft, the nonlinear aeroelastic stability is very important, and should be considered in the design progress. Using present FEM software as the structure solver (e.g. MSC/NASTRAN), and the unsteady aerodynamic code, the nonlinear aeroelastic stability margin of a complex system other than a simple beam model can be determined.

Structural design and analysis of a composite wing with high aspect ratio

2019 ◽  
Vol 20 (10) ◽  
pp. 781-793 ◽  
Author(s):  
Yu-shan Meng ◽  
Li Yan ◽  
Wei Huang ◽  
Tian-tian Zhang ◽  
Zhao-bo Du
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Structural Design ◽  
Composite Wing

SOME ASPECTS OF MODELING A HIGH-ASPECT-RATIO COMPOSITE WING-BOX BY AN ANISOTROPIC BEAM

2015 ◽  
Vol 46 (3) ◽  
pp. 289-305 ◽  
Author(s):  
Sergei Aleksandrovich Tuktarov ◽  
Vasilii Vasil'evich Chedrik
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Composite Wing ◽  
Wing Box

Flutter analysis of an articulated high aspect ratio wing in subsonic airflow

2014 ◽  
Vol 351 (8) ◽  
pp. 4230-4250 ◽  
Author(s):  
A.V. Balakrishnan ◽  
Amjad M. Tuffaha ◽  
Iylene Patino ◽  
Oleg Melnikov
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Flutter Analysis

HALE UAV Composite Wing Structure Design

2010 ◽  
Vol 123-125 ◽  
pp. 105-108
Author(s):  
Myoung Keon Lee ◽  
Chang Min Cho ◽  
Se Yong Jang
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Composite Structure ◽  
Buckling Analysis ◽  
Design Parameters ◽  
Critical Design ◽  
Design Requirements ◽  
Wing Structure ◽  
Long Endurance ◽  
Composite Wing

HALE (High Altitude Long Endurance) UAVs are aircraft systems for surveillance and reconnaissance for over 25 hours. Most of UAVs consist of fuselage and high aspect ratio wing because of long-endurance flight mission. The structural weight of HALE UAV is one of the most critical design requirements. In addition, the structural stiffness for the high aspect ratio wing is another critical design requirement because the UAV has to keep the minimum clearance between wing tip and ground when the UAV is being towed. For above design requirements, the wing structure of the UAV has been designed by intermediate modulus Gr/Ep composite materials. The goal of this research is to present the optimized design concepts for the composite wing structure of the UAV. Although there are many design parameters for the composite structure of the aircraft, this research is focused on composite structure strength and buckling analysis for the plate type structures, such as cover panel skins and spar webs, which are loaded in in-plane shear and/or compression. This research presents that the wing structural weight can be reduced when the material allowables based on tape laminate are applied instead of unidirectional lamina allowables. For the buckling analysis, this report has a trade off study to find an optimized lay-up design and stacking sequence with 0°, ±45° and 90° plies. This research shows that the critical buckling load is a function of the number of ±45° plies and the position of the ±45° plies through the laminate thickness using a typical Gr/Ep composite tape material. The structural design of the UAV composite wing regarding buckling analysis is more effective when the laminates are stacked up with high percent of ±45° plies and the ±45° plies are located toward outside through the laminate.

scholarly journals Loads analysis and structural optimization of a high aspect ratio, composite wing aircraft

2021 ◽  
Author(s):  
Kautuk Sinha ◽  
Thomas Klimmek ◽  
Matthias Schulze ◽  
Vega Handojo
Keyword(s):  
Aspect Ratio ◽  
Structural Optimization ◽  
Design Process ◽  
High Aspect Ratio ◽  
Structural Design ◽  
Composite Structures ◽  
Selection Process ◽  
Weight Ratio ◽  
Bending Moment ◽  
Composite Wing

AbstractComposite structures have shown a prominent impact in the aircraft structural design. With an increasing shift towards incorporating more composite materials in the primary aircraft structure it is imperative to have corresponding design tools to simplify the design process. In the present work, a simplified implementation for composite optimization has been developed within the DLR-AE (German Aerospace Centre, Institute of Aeroelasticity) automated aeroelastic structural design framework cpacs-MONA. This paper presents the results of structural optimization of a high aspect ratio composite wing aircraft model developed in the DLR project ATLAs. The generation of almost all involved simulation models for this study is done using the in-house DLR tool ModGen. An aeroelastic trim analysis is conducted for various manoeuvre and gust conditions. A load selection process is used to determine the most relevant sizing load cases. A comparison is made between the optimization results of a composite wing and an aluminium wing to demonstrate the more favourable strength to weight ratio of the composite wing. A manoeuvre load alleviation procedure has been introduced in the load calculation process. The results show further weight savings in the design process when load alleviation is utilized due to reduction in the span wise bending moment.

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