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Recent CEMEF achievements


Bio-aerogels


A new generation of fully biomass-based aerogels were prepared. They are based on cellulose ("aerocellulose") et pectin ("aeropectin")


Density: 0.05 - 0.25 g/cm³
Specific surface area: 200-400 m²/g
Young modulus: 5-50 MPa


Aeropectin is the first bio-aerogel having thermal superinsolating properties: thermal conductivity is 0.02 W/(m.K)

  aerogel biosourcÚ
       

Mechanisms of cellulosic fibre breakage under compounding


Fibres Tencel
Tencel fibres

Fibres de lin
Flax fibres


Natural fibres break under mechanical stress during compounding. Using unique counter-rotating rheo-optical set-up developed in Cemef, we studied the mechanisms of breakage of natural fibres. We demonstrated that contrary to glass fibres that break above a given stress, cellulosic fibres break after a cumulation of fatigue/strain due to numerous bending under shear.



Stretch-blow moulding

Stretch-blow moulding:


The stretch-blow moulding prototype reproduces the pre-blowing phase in the forming of a bottle. Heating is undertaken in a standard infrared furnace. Process parameters can be measured and deformations in the pre-forming can be observed. Using industrial preforms, it enables the scientific study of the industrial process.

taboo.jpg

"Totem-Taboo", CEMEF made device



Torsion- and traction-testing machines with rapid servo-control heating that allow in-laboratory reproduction of the rapid thermal and mechanical cycles of industrial operations and access to the kinetics of dynamic metallurgic changes when major deformations take place.

Forge software package:


Forge is a finite element software programme that makes it possible to simulate cold, warm and hot forging of 2D and 3D objects from ferrous metals (steel) and non-ferrous metals (aluminium alloys, copper alloys, titanium, nickel). Forge covers practically all of the solid-state forming utilisations of thick or fairly thick materials. The programme is today’s leading reference in forging simulation and is currently used by over 350 customers worldwide, including most of the major automobile and aeronautical manufacturers.

the Maybach piece the Maybach simulation
simulation and true piece of the Maybach (steering knuckle)


       

TherCast software package:


The THERCAST® programme is designed for analysing solidification in casting and smelting processes. It makes it possible to create a complete three-dimensional numerical simulation, including a solver, pre- and post-processors and a database. The pre-processor allows conversion into data and automatic mesh generation of the various domains (cast or moulded pieces, ingot moulds, mould parts). The solver includes two different modules: filling and solidification.
Big ingot filling simulation of the
Big ingot filling


with Rem3D software



Rem3D software package:


Rem3D® is a programme based on the CIMLib library for simulating the 3D injection of viscous, visco-elastic, fibrous or reactive (elastomer or thermoset) materials. It can predict polymer behaviour from the filling stage to the object’s ejection, and its end-used behaviour. Advanced techniques of interface capture (level-set approach, adapted anisotropic dynamic mesh generation) have enabled injection of hollow objects by introducing water or gas.

with Ximex software

XimeX software package:


XimeX is a 3D computational code for extrusion and mixing processes. Based on the CIMLib parallel library, the programme brings together numerical techniques for fluid-structure interaction for the consideration of mobile tools, level-set techniques for describing free surfaces, and kinetic theory resolutions for treating multi-scale particle dispersion.


with DigiMicro software

DigiMicro software package:


This programme, which is currently under development, focuses on the numerical construction of metallurgic microstructures. The digital microstructure obtained can be characterised, modified and optimised. When the necessary local properties are associated to it, the microstructure can also be converted into a finite element mesh for digital experiments. The latter necessitate appropriate local behaviour and/or kinetic laws of topological evolutions

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