Strain rate effect on mechanical properties of 3D needle-punched C/C composites at different temperatures

Carbon/carbon (C/C) composites are considered as one of the most promising materials in structural applications owing to their excellent mechanical properties at room and high temperature. Considering their service environments, investigations on the quasi-static and dynamic mechanical properties of C/C composites at different temperatures are of great importance. In this work, the compressive strengths and failure modes of C/C composites under different strain rates and at different temperatures were studied in detail. The experiments were conducted at room temperature and 300 °C with the strain rate controlled over a wide span of 2.08 × 10⁻⁴ −1862.09 s⁻¹. Results showed that the failure modes of the C/C composites were obviously influenced by the strain rate and temperature, and the compressive strength of the C/C composites significantly increased with the increase of strain rate or temperature. In addition, relationships between the dimensionless compressive strength and strain rate were first established for C/C composites by using a bilinear fitting algorithm at different temperatures. The results can be conveniently used to predict the compressive strength of C/C composites in engineering applications.