scholarly journals Aeroelastic assessment of cracked composite plate by means of fully coupled finite element and Doublet Lattice Method

2018 ◽  
Vol 202 ◽  
pp. 151-161 ◽  
Author(s):  
Nur Azam Abdullah ◽  
Jose Luis Curiel-Sosa ◽  
Mahesa Akbar
Keyword(s):  
Finite Element ◽  
Composite Plate ◽  
Lattice Method ◽  
Doublet Lattice Method ◽  
Fully Coupled

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 Optimized Design for a Aircraft Horizontal Tail Base on Optimus Software

2014 ◽  
Vol 684 ◽  
pp. 58-63
Author(s):  
Da Qian Zhang ◽  
Xiao Dong Tan ◽  
Zi Lei Zhang ◽  
Xin Ping Fu
Keyword(s):  
Finite Element ◽  
Wind Tunnel ◽  
Similarity Theory ◽  
Dynamic Pressure ◽  
Unsteady Aerodynamics ◽  
Element Model ◽  
Scale Model ◽  
Optimized Design ◽  
Lattice Method ◽  
Doublet Lattice Method

Based on the similarity theory, the horizontal tail scale model is designed and manufactured. Subsonic doublet lattice method is used to calculate unsteady aerodynamics, V-g method is used to solve the flutter determinant. Optimus software is used to optimize the thickness of the skin. The constraint condition is the frequency, MAC value and flexibility, and the objective function is flutter dynamic pressure. Flutter velocity of horizontal tail model optimized decreased 6%,and flutter frequency increased greatly. Horizontal tail scale model was test in wind tunnel. The finite element calculate results was very close with wind tunnel results, which verify the correctness of the finite element model and optimization models.

Parametric Study of a Simply Supported Composite Plate Using Finite Element Method

2014 ◽  
Vol 4 (4) ◽  
pp. 26-33
Author(s):  
P.Deepak Kumar ◽  
◽  
Ishan Sharma ◽  
P.R. Maiti ◽  
◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parametric Study ◽  
Composite Plate ◽  
Simply Supported ◽  
Element Method

A Full-System Approach of the Elastohydrodynamic Line/Point Contact Problem

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
W. Habchi ◽  
D. Eyheramendy ◽  
P. Vergne ◽  
G. Morales-Espejel
Keyword(s):  
Finite Element ◽  
Nonlinear System ◽  
System Approach ◽  
Jacobian Matrix ◽  
Point Contact ◽  
System Of Equations ◽  
Nonlinear System Of Equations ◽  
Full System ◽  
Element Discretization ◽  
Fully Coupled

The solution of the elastohydrodynamic lubrication (EHL) problem involves the simultaneous resolution of the hydrodynamic (Reynolds equation) and elastic problems (elastic deformation of the contacting surfaces). Up to now, most of the numerical works dealing with the modeling of the isothermal EHL problem were based on a weak coupling resolution of the Reynolds and elasticity equations (semi-system approach). The latter were solved separately using iterative schemes and a finite difference discretization. Very few authors attempted to solve the problem in a fully coupled way, thus solving both equations simultaneously (full-system approach). These attempts suffered from a major drawback which is the almost full Jacobian matrix of the nonlinear system of equations. This work presents a new approach for solving the fully coupled isothermal elastohydrodynamic problem using a finite element discretization of the corresponding equations. The use of the finite element method allows the use of variable unstructured meshing and different types of elements within the same model which leads to a reduced size of the problem. The nonlinear system of equations is solved using a Newton procedure which provides faster convergence rates. Suitable stabilization techniques are used to extend the solution to the case of highly loaded contacts. The complexity is the same as for classical algorithms, but an improved convergence rate, a reduced size of the problem and a sparse Jacobian matrix are obtained. Thus, the computational effort, time and memory usage are considerably reduced.

Analysis of Nonlinear Flexural Behavior of Thick Composites With Fiber Waviness

1999 ◽  
Author(s):  
H.-J. Chun ◽  
S. W. Lee ◽  
I. M. Daniel
Keyword(s):  
Finite Element ◽  
Composite Plate ◽  
Current Model ◽  
Geometrical Nonlinearity ◽  
Mapping Method ◽  
Flexural Behavior ◽  
Analysis Model ◽  
Element Analysis ◽  
Fiber Waviness ◽  
Thick Composites

Abstract A finite element analysis model was developed to predict flexural behavior of thick composites with uniform, graded and localized fiber waviness. In the analyses, material and geometrical nonlinearties due to fiber waviness were incorporated into the model utilizing energy density and an incremental method. In the model, two kinds of geometrical nonlinearity were considered, one due to reorientation of fibers and the other due to difference of curvatures from one finite element to another during deformation. The finite element analyses utilize the iterative mapping method to incorporate these geometrical nonlinear factors. The model was used to predict not only the flexural behavior of a flat thick composite plate but also of a thick composite plate with initial curvature. Flat composite specimens with various degrees of fiber waviness were fabricated and four-point flexural tests were conducted. The predicted nonlinear behavior by the current model was compared with results from the thin slice model [7] and experiments. Good agreement was observed among them.

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