AVATAR

Additive Manufacturing (AM) and digital imaging are currently revolutionising the area of mechanics of materials. AM allows the fabrication of industrially-relevant cellular architected structures called lattices. However, AM generates non-negligible strut-level defects compared to the initial Computer-Aided Design (CAD). Volume imaging such as X-ray Computed Tomography opens the door for finely analysing such defects and, by means of data assimilation between measured fields obtain by Digital Volume Correlation (DVC) and simulated fields obtained by image-based modelling, for truly characterizing the behaviour of the lattice. Yet, three challenges need to be addressed: (i) the geometric description of the defect must be compatible with CAD to characterize the geometric variability, (ii) it is requested to measure kinematic fields at the sub-cellular scale while the texture is very weak at this scale, and (iii) the need of high-fidelity descriptions and the explosion of camera sensor definition require developing HPC tools at each step of the workflow. The goal of this project is to answer these issues to build a mechanical virtual twin of the lattice at the architecture scale by benefiting of massive image data. The proposed methodology relies on the construction and HPC of a dedicated spline-parametrized model. More precisely, we will (i) consider spline composition for the geometrical modelling which allows an explicit description of the geometric variability. Then, we will (ii) assist DVC with a physically-sound weak regularization using a simple linear-elastic image-based model and finally, we will (iii) develop specific isogeometric procedures for fast assembly as well as for scalable matrix-free solutions (based on domain decomposition) that benefit from the repetitiveness of the cell pattern. The consortium covers the interdisciplinary skills required for a successful completion of this project, namely applied mathematics, computer sciences and mechanics.