Flutter analysis of composite lifting surfaces by the 1D Carrera Unified Formulation and the doublet lattice method

2013 ◽  
Vol 95 ◽  
pp. 539-546 ◽  
Author(s):  
M. Petrolo
Keyword(s):  
Lattice Method ◽  
Flutter Analysis ◽  
Carrera Unified Formulation ◽  
Doublet Lattice Method ◽  
Lifting Surfaces

scholarly journals MODAL AND FLUTTER ANALYSIS OF THE SAILPLANE LAK-17B USING NUMERICAL METHODS

Transport ◽  
2014 ◽  
Vol 29 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Marius Andrikaitis ◽  
Algimantas Fedaravičius
Keyword(s):  
Finite Element ◽  
Numerical Methods ◽  
Finite Element Model ◽  
Normal Modes ◽  
Element Model ◽  
Current Work ◽  
Lattice Method ◽  
Flutter Analysis ◽  
Doublet Lattice Method

The objective of current work is to determine the V–g and V–f diagrams for the sailplane’s LAK-17B empennage using numerical methods. The article considers the following problems: development of finite element model of the sailplane LAK-17B; normal modes calculation using created finite element model; flutter analysis of sailplane LAK-17B using doublet lattice method.

Flutter Analysis of Wing, Booster Fin and Vertical Tail

2011 ◽  
Vol 110-116 ◽  
pp. 3500-3505
Author(s):  
G. Vinayagamurthy ◽  
K.M. Parammasivam ◽  
S.Nadaraja Pillai
Keyword(s):  
Minimum Weight ◽  
Flexible Structures ◽  
Space Vehicle ◽  
Design Criterion ◽  
Lattice Method ◽  
Aerospace Vehicles ◽  
Flutter Analysis ◽  
Fixed Condition ◽  
Doublet Lattice Method ◽  
Theoretical Procedure

Aerospace vehicles are subjected to various types of severe environmental loads. The basic design criterion includes the minimum weight configuration that results in very flexible structures, which leads to various types of structural interaction problems like flutter, divergence etc. Hence every aerospace vehicle should be analysed for its aeroelastic instabilities. In the present work the flutter analysis of a typical space vehicle was carried out in substructure level with the interface fixed condition. The doublet lattice, zona51 and piston theories are used in the unsteady aerodynamic calculations for the subsonic, supersonic and hypersonic speed regimes. As there is no theoretical procedure for transonic speeds, doublet lattice method has been used in the present analysis. Frequency and damping versus velocity are presented to identify the flutter velocities and the flutter behavior.

Aeroelastic Behavior of Morphing Wing in Flutter Regions

2013 ◽  
Vol 284-287 ◽  
pp. 442-445
Author(s):  
Yoo Yeon Jung ◽  
Ji Hwan Kim
Keyword(s):  
Composite Laminates ◽  
Structural Characteristics ◽  
Dynamic Pressure ◽  
Aeroelastic Stability ◽  
Lattice Method ◽  
Stability Behavior ◽  
Flutter Analysis ◽  
Folding Wing ◽  
Doublet Lattice Method ◽  
Wing Structure

A morphing of a system is capable of changing the shape from the cruise to dash configurations. During the motion, the aerodynamic and structural characteristics can be varied tremendously, and the new shape will induce the different aeroelastic stability behavior. Thus, the purpose of this study is to investigate the flutter analysis of the folding wing structure including the effect of various parameters such as fold angles et al. of the composite laminates structures. For doing this these works, the aero-elastic analysis of folding wing is performed with respect to the parameters using PK method. Also, Finite Element Method is used in structural analysis, and Doublet Lattice Method is applied in aerodynamic analysis. Generally, the dynamic pressure and frequency during the flutter are sensitive to the structural characteristic, thus the flutter mode alteration is occurred by changed natural frequencies. Also, the alteration causes the flutter dynamic pressure variation. Therefore, results represent the aeroelastic stability variation due to the folding wing system including the effects of ply angles of composite laminates.

Comparison of flutter calculation methods based on ground vibration test result

2019 ◽  
Vol 91 (3) ◽  
pp. 466-476
Author(s):  
Wojciech Chajec
Keyword(s):  
Low Cost ◽  
Ground Vibration ◽  
Control Surface ◽  
Vibration Test ◽  
Problem Solution ◽  
Lattice Method ◽  
Mass Model ◽  
Content Type ◽  
Strip Theory ◽  
Flutter Analysis

PurposeA low-cost but credible method of low-subsonic flutter analysis based on ground vibration test (GVT) results is presented. The purpose of this paper is a comparison of two methods of immediate flutter problem solution: JG2 – low cost software based on the strip theory in aerodynamics (STA) and V-g method of the flutter problem solution and ZAERO I commercial software with doublet lattice method (DLM) aerodynamic model and G method of the flutter problem solution. In both cases, the same sets of measured normal modes are used. Design/methodology/approachBefore flutter computation, resonant modes are supplied by some non-measurable but existing modes and processed using the author’s own procedure. For flutter computation, the modes are normalized using the aircraft mass model. The measured mode orthogonalization is possible. The flutter calculation made by means of both methods are performed for the MP-02 Czajka UL aircraft and the Virus SW 121 aircraft of LSA category. FindingsIn most cases, both compared flutter computation results are similar, especially in the case of high aspect wing flutter. The Czajka T-tail flutter analysis using JG2 software is more conservative than the one made by ZAERO, especially in the case of rudder flutter. The differences can be reduced if the proposed rudder effectiveness coefficients are introduced. Practical implicationsThe low-cost methods are attractive for flutter analysis of UL and light aircraft. The paper presents the scope of the low-cost JG2 method and its limitations. Originality/valueIn comparison with other works, the measured generalized masses are not used. Additionally, the rudder effectiveness reduction was implemented into the STA. However, Niedbal (1997) introduced corrections of control surface hinge moments, but the present work contains results in comparison with the outcome obtained by means of the more credible software.

Further Refinement of the Subsonic Doublet-Lattice Method

1998 ◽  
Vol 35 (5) ◽  
pp. 720-727 ◽  
Author(s):  
William P. Rodden ◽  
Paul F. Taylor ◽  
Samuel C. McIntosh
Keyword(s):  
Lattice Method ◽  
Doublet Lattice Method
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