al14

Understanding and Modeling Nonlinear Behaviors in Aerospace Structures using Sine-Sweep Testing

Auteurs: 

T. Dossogne, J. P. Noël, L. Masset, G. Kerschen (Aerospace and Mechanical
Engineering Department, University of Liège)
B. Peeters (Test Division, Siemens Industry Software NV)

During the design cycle of aircraft, the role played by the structural dynamicists consists in constructing a validated numerical model of the aircraft behavior under vibration. Model validation is performed experimentally, by correlating predicted and measured natural frequencies and mode shapes.

Highly-Nonlinear and Transient Structural Dynamics: a Review about Crashworthiness of Composite Aeronautical Structures

Auteurs: 

E. Deletombe, D. Delsart (ONERA)

This paper is a bibliographic review dealing with composite aircraft and rotorcraft crashworthiness. The paper focuses on structural aspects of large composite aircraft or rotorcraft parts (fuselage parts, barrels or larger parts). Material topics, such as the experimental characterization and numerical modelling of the dynamic behavior of composite materials, of composite joints (details) and of energyabsorbing components (elementary parts) are mentioned but not discussed in detail.

Study of Morphing Winglet Concepts Aimed at Improving Load Control and the Aeroelastic Behavior of Civil Transport Aircraft

Auteurs: 

C. Liauzun, D. Le Bihan, J.-M. David, D. Joly, B. Paluch (ONERA)

Morphing is today widely studied in order to improve aircraft performance and thereby decrease their environmental footprint. This paper deals with the preliminary study of several morphing winglet concepts aimed at improving load control and aeroelastic behavior. The first step consisted in building and validating low-CPU-time-consuming but accurate aeroelastic models able to take into account aerodynamics, structural dynamics and flight mechanics, in order to handle free flexible aircraft.

A Review of Industrial Aeroelasticity Practices at Dassault Aviation for Military Aircraft and Business Jets

Auteurs: 

E. Garrigues (Dassault Aviation)

Aircraft structure design is a complex industrial process that requires multidisciplinary analyzes and considerations in fields as diverse as aerodynamics, structure, materials and systems, as well as the right compromise between the constraints imposed by these different fields, in order to meet the overall performances required for aircraft.

Videos: 

Video 1: typical flutter displacement mechanism computed on the RAFALE in air-to-ground configuration, far away from the flight-domain envelope

Video 2: typical wind-tunnel flutter test on a MIRAGE F1 with a dynamically-similar flexible mock-up

Video 3: wind-tunnel flutter test on a military wing in complex configuration near the flutter point, before and after the flutter instability is detected and the automatic wind-tunnel security system activated

Video 4: typical CFD DES computation on a Falcon with interaction between wing and horizontal tail plane at a high angle of attack

Vibration Mitigation Based on Nonlinear Absorbers

Auteurs: 

C. Stephan, G. Pennisi (ONERA)
G. Michon (University of Toulouse - ICA, CNRS, ISAE)

The design of vibration absorbers is a challenging task for complex real-life structures. Although several technological solutions have now reached maturity, a need for better efficiency in terms of added mass, broadband frequency range and level of reduction requires the study of new ideas and concepts coming from nonlinear dynamics. In this paper an introduction to a class of absorbers called Nonlinear Energy Sinks (NES) is proposed to highlight their potential for vibration mitigation.

Advances in Parametric and Model-Form Uncertainty Quantification in Canonical Aeroelastic Systems

Auteurs: 

J.-C. Chassaing, C. T. Nitschke, A. Vincenti (Sorbonne Université)
P. Cinnella (Laboratoire DynFluid)
D. Lucor (LIMSI-CNRS)

Uncertainty quantification is going to play a crucial role in the aeroelastic design and optimization of aircraft. Stochastic aeroelastic models are currently being considered to account for manufacturing tolerance in material properties, variability in flight conditions or uncertainty in the aeroelastic model itself. In this paper, some challenging issues in the development of efficient and robust stochastic solvers are reported within the framework of canonical aeroelastic systems.

On the Validation and Use of High-Fidelity Numerical Simulations for Gust Response Analysis

Auteurs: 

F. Huvelin, S. Dequand, A. Lepage, C. Liauzun (ONERA)

Specific gust response is considered as one of the most important loads

Videos: 

Video 1 – Response of a NACA airfoil to a gust: Mach distributions for a gust period (URANS simulation with the gust amplitude equal to U/60)

 

Video 2 – Response of a NACA airfoil to a gust: Mach distributions for a gust period (URANS simulation with the gust amplitude equal to U/1500)

 

Descent Methods for Design Optimization under Uncertainty

Auteurs: 

F. Poirion, Q. Mercier (ONERA)

This paper is about optimization under uncertainty, when the uncertain parameters are modeled through random variables. Contrary to traditional robust approaches, which deal with a deterministic problem through a worst-case scenario formulation, the stochastic algorithms presented introduce the distribution of the random variables modeling the uncertainty. For single-objective problems such methods are currently classical, based on the Robbins-Monro algorithm.

Modelling the Damping at the Junction between Two Substructures by Non-Linear Meta-Models

Auteurs: 

V. Kehr-Candille (ONERA)

We are interested in the modelling of the damping at the junction between

Overview of the Aeroelastic Capabilities of the elsA Solver within the Context of Aeronautical Engines

Auteurs: 

A. Dugeai, Y. Mauffrey, A. Placzek, S. Verley (ONERA)

This paper presents the status of current development and research activities conducted at ONERA concerning the numerical modelling of aeroelastic phenomena of rotating machines. Three different topics are detailed after a short reminder of some features of ONERA’s CFD solver elsA. The first one addresses the development of methodologies for taking into account geometrical non-linear structural behavior in the modelling of the static aeroelasticity of large fan blades.