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Materials and Structures Branch

ONERA's Materials and Structures Branch (MAS) is composed of three scientific departments and one ONERA-CNRS mixed research unit. By the end of 2013, the MAS Branch personnel consisted of approximately 244 people, including 143 research engineers, 45 technical and administrative staff and 32 doctoral students and post-doctoral researchers.  The Branch is located in three different sites: Châtillon, Palaiseau, Lille.

The Branch's activities are concerned with experimental, theoretical and computational work and focus on materials and structures used in the aeronautical, space and defence industries.  They address phenomena at different scales, ranging from the level of the material microstructure to the dynamic response and vibration of structures in their service environments.   The research activities involve the development, processing and characterisation of metallic, ceramic and composite materials and structural components. 

Principal research axes of the MAS Branch

  • Microstructural studies – from the atomic to the macroscopic scales (LEM + DMSM + DMSC)
  • Material development and processing (DMSM + DMSC)
  • Development of numerical methods for modelling of actual 2D and 3D  microstructures (LEM + DMSM)
  • Characterisation and modelling of the constitutive behaviour of materials (LEM + DMSM +DMSC + DADS)
  • Structural optimisation and life predictions  (DMSM + DMSC + DADS)
  • Dynamic behaviour of structures (DADS)
  • Aeroelasticity (DADS)
  • Study and validation of new structural concepts (DMSC + DADS)

Contact


Esteban P. Busso

Scientific Director – MAS Branch

 

ONERA, Scientific General Directorate
Chemin de la Huniere
B.P. 80100
FR-91123 PALAISEAU CEDEX, France

Tel : +33 -1 80 38 67 80
E-Mail :
esteban.busso@onera.fr

The scientific departments

Aeroelasticity and Structural Dynamics (DADS)

Couplage statique aéro-élastique  du moteur de type open-rotorThe Department's activities cover five main themes. The design and mechanical optimisation of structures leading to the development of specific technologies (e.g. functional materials, actuators). The development of stochastic methods and tools to account for the effects of material and structural -related statistical variations leading to the development of new structural concepts.  In the area of structural vibrations, which includes hydro-elasticity, a broad spectrum is covered: low frequencies (modelling and identification of damping and non-linear effects in complex structures, hydrodynamic loads on deformable structures due to liquid-induced sloshing,  new modal identification methods), and medium and high frequencies (vibro-acoustic, new energetic approaches).  Dynamic studies  (transient, crash, impact) require the development of specific numerical methods, an account of design  variables and more generally of non-linear phenomena as well as the development of experimental methods for validation purposes.   

Modélisation d’un amerrissage

Finally, research on aeroelasticity is oriented towards the modelling and simulation of complex phenomena involving gas and liquid flows (shock, detachment), structures (gaps, contact) and systems (saturations, delays). 

Strong coupling between computational fluid and solid mechanics is required.  Alternative approaches (reduced models, linearised methods) and aeroelastic optimisation methods are developed and validated through tests. A strong effort is also devoted to the development of experimental aeroelastic control methods.

Composite Systems and Materials (DMSC)

The DMSC is involved in the evaluation and modelling of polymer and ceramic matrix composite behaviour at scales ranging from that of the microstructure up to the component or structure.  One of its main research themes concerns the study and modelling of composite damage and fracture, starting at the damage nucleation stage up to the life prediction of a composite structure subject to complex thermo-mechanical loadings.

Modélisation multi-échelle du comportement et de l’endommagement de composites interlocks

The development of specialised measuring techniques (e.g. field measurements by image correlation techniques or by acoustic emissions)  is also one of the areas in which the department is well known for.  Another of the Department's main research topic is health monitoring of materials using non-destructive tests based on ultrasound, thermography and fluorescence techniques.  It involves the quality control of bonded structures by Lamb waves and integrated health monitoring.  Furthermore, new ceramic, polymer and metallic matrix composites and functional materials are conceived and developed.  The modelling of processing methods and the measurement of thermo-physics and thermo-optical properties (e.g. conductivity, emissivity, thermal diffusivity) of high temperature materials are also important areas of activity within the DMSC.

Metallic Materials and Structures (DMSM)

The main objective of the DMSM is to improve the integration of physics and mechanics-based approaches to model the constitutive deformation behaviour of metallic materials and predict the life of components and structures under realistic operating conditions. Its activities are structured around three main axes: 

  • Development of new alloys and improvement of existing ones following a coupled physics based-mechanics approach
  • Study and modelling of the deformation and damage behaviour of metallic materials 
  • Development of computational solid mechanics approaches  

Materials are generally assumed to be either part of a system or sub-system or an element of a more complex structure. The department is also interested in joining processes and develops new microstructural and chemical analyses techniques adapted to that purpose. There is also a strong emphasis on the development of numerical and computational tools related to thermo-mechanical coupling, multi-physics, multi-scale and multi-code approaches, account of uncertainties, etc.  

Laboratory for Microstructural Investigations (LEM)

The LEM is a joint ONERA-CNRS research unit made up of personnel from both ONERA and the CNRS.  The LEM research activities are aimed at the study of microstructures and their development from a crystallographic, chemical, thermodynamical and lattice defect point of view. This includes the way they form and evolve and the role they play in shaping the physical properties and behaviour of the material.   The general philosophy is to combine experiments, theory and numerical simulations at different scales so as to identify the relationship between microstructures and properties.    The LEM activities can be identified around three main axes:    

  • Materials with small physical dimensions (nanotubes, graphene ...)
  • Atomic structures and transport properties
  • Microstructures with phase changes and which deform plastically

The LEM is interested in topics which address the understanding and optimisation of materials for aeronautic and space applications.  It carries out its own studies in these areas and participates in a broad range of external collaborations.  Emphasis is placed on gaining an understanding of complex physical phenomena and on developing the required experimental and computational tools.   It possesses a state-of-the-art electronic microscope platform which is also available to external users.  The LEM accounts for the needs of the MAS Branch and ONERA at large in its policy to replace and update its scientific instruments.

micrographie superalliage AM1 & prédiction numérique par champs de phase

Read more about the LEM

Materials, Systems and Processes

The type of materials studied within the Branch is very diverse but they all shared stringent property requirements (high temperature tolerance, noise and vibration damping capabilities, high strength-density ratios, etc. ).    They include superalloy / bond coat / thermal barrier systems for gas turbine blades, intermetallic alloys, structural materials able to tolerate very high temperatures, functional materials (shape memory alloys, ..), oxide-oxide based ceramic matrix composites, eutectic and ultra-refractory ceramics, felt and cellular materials,  non-linear optical materials (e.g. chalcoprites), SiC-Ti metal matrix composites, amongst others.   

Specific problems that are addressed on polymer matrix composites are:  statistical variations, robust design, complex (3D) structural loading, multiscale and multi-level approaches to study failure modes, constitutive material models for deformation and damage in inter-woven polymer matrix composites,  durability (physico-chemical aspects, long-term degradation, …), and kinetics of crack nucleation and growth.  For the more conventional materials, studies are sometime carried out at the structural level and concern aero-space applications:  disc and blades in turbo-engines, deformable wings, helicopter propellers, tubular structures to cool rocket engine nozzles (e.g.  Ariane 5's flight 517).  In most such cases, coupled aero-thermo-mechanical approaches are required to be developed.   In processing, only the methods required for the development of new materials are of interest.  

Experimental Resources

The MAS Branch and its departments dispose of a great deal of experimental and computational resources, including supercomputer clusters, and can also access ONERA's central resources, if needed. 

Aeroelasticity and Structural Dynamics (DADS)

  • Tour de crashMobile laboratory for the modal identification of large structures (448 large band channels with excitations by 12 electrodynamic pots of 200 to 1000 Newtons)
  • Data acquisition chains (64, 128, 320 bands simultaneously)
  • Photogrammetry measuring system for static deformations
  • Electro-hydraulic dynamic excitation system  (adapted to wind tunnels)
  • Laser vibrometers capable of operating in fixed and scanning modes
  • Real time control systems
  • Static and dynamic testing systems  (tension,  compression, impact machines, fast hydraulic jack, Hopkinson bars, crash tower, compressed air jets, lower caliber ballistic tests) 
  • Optical and video systems to record the evolution of dynamic and impact tests

Composite Systems and Materials (DMSC)

  • Mechanical testing (tension/compression, impact, high temperature micro-indentation, fatigue with a ± 50 tonnes machine)
  • Processing: 150 tons die-forging press, ceramic press, four polymer matrix composite presses and furnaces, four Bridgman furnaces…
  • Piezospectroscopic laser, ultra-sound NDT by immersion, Lamb waves, metrology by electromagnetic fields, infra-red thermography …
  • Thermal diffusimeters (5), thermal emissivity measuring equipments (2) conductimeters (2), laser oxidation bench, fast thermo-gravimetric analysis device

Contrôle santé : détection de dommages du radôme du RAFALE

Metallic Materials and Structures (DMSM)

  • Means for the development of new alloys (by conventional methods, production of metallic powders, including reactive and refractory materials, thermo-mechanical processing, deposition techniques, etc.)
  • Environmental characterisation and testing (corrosion bench, complex corrosion, saline spray, oxidation)
  • Mechanical testing machines (30 creep machines, fatigue) and a laboratory of experimental mechanics with four instrumented  servo-hydraulic testing machines for complex loading conditions
  • Laboratory of microscopy and micro-analysis

    Micro-indentation à chaud

Laboratory for Microstructural Investigations (LEM)

  • Microscope électronique  à transmission LIBRA200 haute résolution  avec une source FEG  Transmission electro-microscope CM20 FEI, nanosonde, with a LaB6 wire and a new Tecnai cannon  (August 2012) (HV = 80 - 200 kV, Spatial resolution < 2.5 Å).  Camera Gatan Orius and X-ray difraction
  • High resolution transmission electro-microscope LIBRA 200 MC Zeiss with a FEG Schottky source and a monochromatic and energy filter in its column (HV = 200 kV et 80 kV, Spatial resolution < 1.4 Å and energy from 150 meV to 200 kV and 95 meV to 80 kV). Camera Gatan Ultrascan
  • X-ray diffraction with a high resolution diffractometer (common laboratory between LEM + DMSM)

Diffractomètre des rayons X haute résolution

PDF Materials and Structures full presentation [April 2014]

Other scientific branches