scholarly journals Static Aeroelastic Beam Model Development for Folding Winglet Design

Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 106
Author(s):  
Bereket Sitotaw Kidane ◽  
Enrico Troiani
Keyword(s):  
Structural Integrity ◽  
Model Development ◽  
Computational Cost ◽  
Weighted Average ◽  
Element Model ◽  
Beam Model ◽  
Preliminary Design ◽  
Aerodynamic Loads ◽  
Aeroelastic Analysis ◽  
Aeroelastic Model

Wing shape adaptability during flight is the next step towards the greening of aviation. The shape of the wing is typically designed for one cruise point or a weighted average of several cruise points. However, a wing is subjected to a variety of flight conditions, which results in the aircraft flying sub-optimally during a portion of the flight. Shape adaptability can be achieved by tuning the shape of the winglet during flight. The design challenge is to combine a winglet structure that is able to allow the required adaptable shape while preserving the structural integrity to carry the aerodynamic loads. The shape changing actuators must work against the structural strains and the aerodynamic loads. Analyzing the full model in the preliminary design phase is computationally expensive; therefore, it is necessary to develop a model. The goal of this paper is to derive an aeroelastic model for a wing and winglet in order to reduce the computational cost and complexity of the system in designing a folding winglet. In this paper, the static aeroelastic analysis is performed for a regional aircraft wing at sea level and service ceiling conditions with three degree and eight degree angle of attack. MSC Nastran Aeroelastic tool is used to develop a Finite Element Model (FEM), i.e., beam model and the aerodynamic loads are calculated based on a doublet lattice panel method (DLM).

Assessment of Corner Failure Depths in the Deep Drawing of 3D Panels Using Simplified 2D Numerical and Analytical Models

2000 ◽  
Vol 123 (2) ◽  
pp. 248-257 ◽  
Author(s):  
Hong Yao ◽  
Jian Cao
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Analytical Models ◽  
Design Stage ◽  
Beam Model ◽  
Preliminary Design ◽  
Powerful Means ◽  
Preliminary Design Stage ◽  
Blank Size

Methodologies of rapidly assessing maximum possible forming heights are needed for three-dimensional 3D sheet metal forming processes at the preliminary design stage. In our previous work, we proposed to use an axisymmetric finite element model with an enlarged tooling and blank size to calculate the corner failure height in a 3D part forming. The amount of enlargement is called center offset, which provides a powerful means using 2D models for the prediction of 3D forming behaviors. In this work, an analytical beam model to calculate the center offset is developed. Starting from the study of a square cup forming, a simple analytical model is proposed and later generalized to problems with corners of an arbitrary geometry. The 2D axisymmetric models incorporated with calculated center offsets were compared to 3D finite element simulations for various cases. Good assessments of failure height were obtained.

scholarly journals Aeroelastic analysis of parachute deceleration systems with empirical aerodynamics

2019 ◽  
Vol 234 (3) ◽  
pp. 729-741
Author(s):  
Enrique Ortega ◽  
Roberto Flores
Keyword(s):  
Computational Cost ◽  
Structural Data ◽  
Element Model ◽  
Model Complexity ◽  
Inflation Model ◽  
Test Drop ◽  
Aeroelastic Analysis ◽  
Filling Time ◽  
Coupling Strategy ◽  
Mass Spring

A technique for the aeroelastic solution of parachute decelerators is presented in this work. The methodology uses empirical aerodynamics, based on a filling-time inflation model and Ludtke's area law, coupled to two explicit structural solution approaches. A mass-spring-damper technique allows solving the deployment of the system (when the grid is highly distorted) efficiently, and a finite element model is used for the accurate calculation of the structural loads and stresses during parachute opening and steady flight. The coupling strategy is staggered and the models share the same mesh. The methodology is intended for practical calculations of deceleration systems, and provides useful performance and structural data minimizing model complexity and computational cost. The suitability of the proposed technique is assessed by comparisons with reference test drop data.

NONLINEAR AEROELASTIC ANALYSIS OF A MORPHING FLAP

2012 ◽  
Vol 22 (05) ◽  
pp. 1250099 ◽  
Author(s):  
DAOCHUN LI ◽  
SHIJUN GUO ◽  
YUANYUAN HE ◽  
JINWU XIANG
Keyword(s):  
Element Model ◽  
Curved Beams ◽  
Reduced Order ◽  
Actuation Mechanism ◽  
Influence Coefficients ◽  
Aeroelastic Analysis ◽  
Aeroelastic Model ◽  
Freeplay Nonlinearity ◽  
Flutter Analysis ◽  
Structural Mass

A morphing flap integrated with an actuation mechanism was designed and investigated. Based on structure parameters from static experiments, a finite element model of the flap was created within MSC Patran software. Normal modal analysis and linear flutter analysis were carried out firstly. V–g and V–f curves were obtained to determine the critical flutter speeds with and without the actuation mechanism. Structural mass, damping, stiffness, and aerodynamic matrixes were printed with DMAP language to form an aeroelastic equation in modal coordinate. The freeplay nonlinearity between disks attached to the curved beams and wing skins was considered in the aeroelastic analysis. An unsteady aerodynamic influence coefficients matrix was calculated by Roger's approximation. The nonlinear aeroelastic equation in modal coordinate was solved by an iterative program written with MATLAB software. Based on the reduced-order aeroelastic model, the effect of freeplay on aeroelastic responses was investigated. Numerical results show that the freeplay nonlinearity may reduce critical flutter speed, leading to supercritical Hopf bifurcation.

Structural Optimization and Aeroelastic Analysis of a Composite T-Tail Configuration

2012 ◽  
Vol 466-467 ◽  
pp. 1125-1128
Author(s):  
Li Liang ◽  
Sun Qin
Keyword(s):  
Finite Element ◽  
Structural Optimization ◽  
Finite Element Model ◽  
Element Model ◽  
Aeroelastic Analysis ◽  
Aeroelastic Model

In this paper, a composite T-tail model is developed, including structural finite element model and aeroelastic model, and then structural optimization and aeroelastic analysis are made. Through two steps of structural optimization, and aeroelastic analysis, some valuable conclusions are achieved, which are useful for future composite T-tail design.

scholarly journals The ICON Single-Column Mode

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 906
Author(s):  
Ivan Bašták Ďurán ◽  
Martin Köhler ◽  
Astrid Eichhorn-Müller ◽  
Vera Maurer ◽  
Juerg Schmidli ◽  
...  
Keyword(s):  
Data Storage ◽  
Model Development ◽  
Computational Cost ◽  
Three Dimensional ◽  
Shallow Convection ◽  
Modeling Framework ◽  
Additional Tool ◽  
Eddy Simulation ◽  
Single Column ◽  
Stratocumulus Clouds

The single-column mode (SCM) of the ICON (ICOsahedral Nonhydrostatic) modeling framework is presented. The primary purpose of the ICON SCM is to use it as a tool for research, model evaluation and development. Thanks to the simplified geometry of the ICON SCM, various aspects of the ICON model, in particular the model physics, can be studied in a well-controlled environment. Additionally, the ICON SCM has a reduced computational cost and a low data storage demand. The ICON SCM can be utilized for idealized cases—several well-established cases are already included—or for semi-realistic cases based on analyses or model forecasts. As the case setup is defined by a single NetCDF file, new cases can be prepared easily by the modification of this file. We demonstrate the usage of the ICON SCM for different idealized cases such as shallow convection, stratocumulus clouds, and radiative transfer. Additionally, the ICON SCM is tested for a semi-realistic case together with an equivalent three-dimensional setup and the large eddy simulation mode of ICON. Such consistent comparisons across the hierarchy of ICON configurations are very helpful for model development. The ICON SCM will be implemented into the operational ICON model and will serve as an additional tool for advancing the development of the ICON model.

Determining the Rayleigh damping parameters of flexible pavements for finite element modeling

2021 ◽  
pp. 107754632110267
Author(s):  
Jiandong Huang ◽  
Xin Li ◽  
Jia Zhang ◽  
Yuantian Sun ◽  
Jiaolong Ren
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Natural Frequencies ◽  
Least Squares Method ◽  
Element Model ◽  
Beam Model ◽  
Element Modeling ◽  
Rayleigh Damping ◽  
Damping Matrix

The dynamic analysis has been successfully used to predict the pavement response based on the finite element modeling, during which the stiffness and mass matrices have been established well, whereas the method to determine the damping matrix based on Rayleigh damping is still under development. This article presents a novel method to determine the two parameters of the Rayleigh damping for dynamic modeling in pavement engineering. Based on the idealized shear beam model, a more reasonable method to calculate natural frequencies of different layers is proposed, by which the global damping matrix of the road pavement can be assembled. The least squares method is simplified and used to calculate the frequency-independent damping. The best-fit Rayleigh damping is obtained by only determining the natural frequencies of the two modal. Finite element model and in-situ field test subjected by the same falling weight deflectometer pulse loads are performed to validate the accuracy of this method. Good agreements are noted between simulation and field in-situ results demonstrating that this method can provide a more accurate approach for future finite element modeling and back-calculation.

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