Image-based numerical simulation of thermal expansion in C/C composites

One of the most important properties of dense C/C composites intended for ultra-high-temperature applications is their thermal expansion. This quantity is difficult to estimate by 'virtual material' models in the case of complex fibrous architectures involving weavings and needlings. We present here a technique based on the processing of medium-resolution X-ray CMT scans of '2.5D' C/C composites. The local orientation of the fiber bundles is detected throughout the sample; then, local thermal and mechanical properties are affected to every voxel accounting for this fiber orientation and to micro-scale models. A finite-element solver is used for a thermoelastic problem resolution in the image, in a 'voxel-element' approach. Preliminary results and validations are shown and discussed. (authors)