Analysis and development of efficient digital methods for the digital modelling by finite elements, analysis and optimization of linear and non-linear problems in solid mechanics with multi-physical couplings
Research axis : - Mechanical modelling by finite elements of damage and fissuration for creation of a virtual global chain of digital shaping simulations - Digital modelling, optimization and control of processes with electromagnetic couplings (continuous or alternative current) for heating and shaping applications - Reduction of calculation time, development of efficient multi grid methods, development of explicit methods for high speed process simulation - Biomechanical activity, mechanical comportment of living organs : hyper elastic comportment of soft tissue, elastic comportment of bones depending on bone density, implant and prosthesis modelling
The CEMEF research activities concern all types of material (metal, polymers, composites, glass, material for food products ...).
Coupling electromagnetism / thermal : - Heating and thermal treatment by induction with intervention of strong couplings between electromagnetism, thermal, mechanics and metallurgy. We developed a tool for the calculation of Maxwell equation for low frequencies
Thermal/mechanic coupling : - for hot forging, thermomechanical strong couplings and important differences concerning mechanical comportment of forged piece and - and comportment type " fluid viscoplastic " - and tool machines with comportment type " solid thermo set " - needs the development of specific algorithms to access the mechanical and thermal fields in a reasonable time frame.
Calculation of equations of all aspects of the field in a coupled way to assure the respect of the thermal and mechanical balances. The increase of the size of the calculation models as they now include different deformable domains, led us to the development of efficient equation solvers (based on the multi grid methods) and of procedures to alleviate the calculations for machine tools (priority for thermal calculation, partially uncoupled).
These developments aim to allow the determination of thermal and mechanical charges of the tool in order to forecast and increase the lifespan by decreasing the effects of wear for example.
Several damage models have been developed in finite element code FORGE2? and FORGE3?. The strong coupling comportment damage can also result in convergence problems that have to be resolved used advanced digital methods.
In the context of determination of rheological comportment of living tissue - immediately after ablation - , the Rheobiol clip has been developed and tested in cooperation with the functional group "Mesures Etudes Atelier Simulation" to allow identification near a theatre of operations. The experimental results are than verified by inverse analysis.
Biomechanical modelling for e.g. dental implants. Reconstruction of the geometry of a jawbone in 3D with the AMIRA 3D? software based on the scanner image, realization of a 3D grid of the geometry. In cooperation with dental surgeons we define the conditions of the representative limits of muscles and jaw joint and we insert a dental implant in the jawbone.
Parallel and sequential calculation capacities with about 10 parallel calculators with different architectures including one new cluster with 500 processors installed in 2008
Torsion with induction heating
Mini traction and mini torsion with heating (Joule effect) followed by resistivity
Tools for mechanical characterization of biological material (Rhéobiol clip, indentation)
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