Flexible graphite (FG) with 1 - 1.2 g/cm3 density is employed as beam energy absorber material in the CERN's Large Hadron Collider (LHC) beam dumping system. However, the increase of energy deposited expected for new HL-LHC (High-Luminosity LHC) design demanded for an improvement in reliability and safety of beam dumping devices, and the need for a calibrated material model suitable for high-level FE simulations has been prioritized. This work sets the basic knowledge to develop a material model for FG suitable to this aim. A review of the FG properties available in literature is first given, followed by FIB-SEM (Focused Ion Beam - Scanning Electron Microscopy) microstructure investigation and monotonic and cyclic uniaxial compression tests. Similarities with other well-known groups of materials such as crushable foams, crumpled materials and compacted powders have been discussed. A simple 1D phenomenological model has been used to fit the experimental stress-strain curves and the accuracy of the result supports the assumptions that the graphite-like microstructure and the crumpled meso-structure play the major role under out-of-plane uniaxial compression.
@article{arxiv.2304.04021,
title = {FIB-SEM investigation and uniaxial compression of flexible graphite},
author = {Emanuele Solfiti and Di Wan and Ambra Celotto and Nicola Solieri and Pablo Andreu Munoz and Rui Franqueira Ximenes and Jorge Maestre Heredia and Claudio Leopoldo Torregrosa Martin and Antonio Perillo Marcone Francois-Xavier Nuiry and Antonio Alvaro and Filippo Berto and Marco Calviani},
journal= {arXiv preprint arXiv:2304.04021},
year = {2023}
}