Abstract: This paper proposed a method based on multiscale mechanics to predict the impact mechanical response and failure mechanism of plain weave CF/PEEK composite materials under high-temperature and high strain rate conditions. Firstly, finite element models at micro, meso, and macro scales were established based on the real geometric structure and spatial distribution of fibers, fiber bundles, and matrix in the composite materials. A micro-mechanical model was developed based on the typical spatial distribution of fibers within the solidified fiber bundles, and extended to the meso scale to predict the failure modes of fiber bundles under different loading conditions using periodic boundary conditions. Secondly, a meso scale plain weave structure unit cell model was established to obtain the mechanical properties of single-layer plates in the composite materials, and an equivalent connection between microstructure and macro scale performance was established. Finally, temperature field and dynamic compression performance parameters are tested, and a homogeneous model similar to macro specimens is created to verify the effectiveness of the model by comparing with experimental results. Meanwhile, the impact mechanical response and failure modes of the pre-tested specimens were analyzed to reveal the dynamic compression effects of plain weave CF/PEEK thermoplastic composite materials under coupled temperature field conditions. This study provides valuable reference for the safe service of thermoplastic composite materials in extreme environments.

Key words: thermoplastic composite materials, compression, strain rate effect, temperature effect, multi-scale modeling