The work carried out in WP 1 can be summarised by 3 subcategories:
Thermo-Mechanical testing: Experimental characterisation of the flow stress behaviour for selected alloys have been conducted.
Microstructure characterization: Focus has been to study recrystallization behaviour and the formation of adiabatic shear bands during the different test conditions.
Constitutive modelling: The framework for a physical-based constitutive model has been developed and implemented. The model account for many important microstructural features for the prediction of the material flow stress behaviour.
Scientific highlights and achievements for WP1:
R1.1: Physical-based constitutive model
R1.2: Microstructural features for the prediction of the material flow stress behaviour
R1.3: New experimental heated torsion device implemented
In the work carried out in WP 2, a multiscale approach has been developed to simulate strain localization phenomena in metallic alloys. Material and microstructure rotations play a crucial role in the development of shear bands during cutting or machining processes and can be adequately described by the Cosserat continuum model. This continuum approach was carried out. These meso and macro continuum models must then be used for High Performance Computing of complex material processes techniques.
Scientific highlights and achievements for WP2:
R2.1: New strain gradient crystal plasticity model
R2.2: Multiscale Cosserat approach to better simulate strain localization phenomena in the studied metallic alloys
R2.3: New portable implementation of the Cosserat media-based model on HPC system
Explanation of the work carried out in WP3:
In the WP3, 3 processes have been studied: Machining, Friction Stir Welding and Additive Manufacturing. The common objectives were the design of innovative experimental bench to identify material behaviour according process parameters, to explore capabilities of the process, parameters windows and material defects due to thermomechanical history, to characterise thermal & kinetic fields and produce realistic data (material flow, T°, Forces…)
Concerning machining, an experimental bench to test orthogonal cutting and to measure kinetic & thermal fields in-situ is today operational. A new methodology of digital image correlation analyses has been developed.
Concerning FSW, the thermal & kinetic fields have been characterised. Analyses permit the understanding of thermomechanical phenomena during welding and causes of defect generation. Microstructural changes have been characterised with UBx and UPV. Optimal operative conditions have been identified according to weld quality for aluminium alloys and on several equipment. A robust methodology to define operative conditions has been defined, based on previous results, and validated and a process monitoring solutions are proposed, based on forces and acoustic emission online measurements. A numerical simulation of FSW process is proposed, with a behaviour law considering a new damage criterion.
For AM process, a methodology to detect and identify the process anomalies in the SLM process using the commercial in-situ instrumentation is developed. Machine learning-based methodology is proposed to extract critical features at a global and local scale for photodiode-based Melt Pool Monitoring. The proposed methodology successfully identifies powder bedspread anomalies and their influence on the melt pool signal.
Scientific highlights and achievements for WP3:
R3.1: New experimental bench to test orthogonal cutting and to measure kinetic and thermal fields in-situ
R3.2: New methodology of digital image correlation (DIC) and realization of a coupled high-speed kinematic and temperature measurements system
R3.3: A better understanding of thermomechanical phenomena in FSW
R3.4: New numerical simulation using coupled Eulerian-Lagrangian formulation to develop a new damage evolution law
R3.5: A better understanding of the laser-material interaction in the Laser Powder Bed Fusion process and its influence from other process steps
