Characterization and Constitutive Model for Temperature and Strain-Rate Dependent Tensile Behavior of Short Carbon Fiber Reinforced PEEK Composites

Thermoplastic composites have important applications in medical, electronics, automotive, and aerospace industries due to their good mechanical properties, easy for processing, recyclability, and low cost. In this work, the mechanical failure behavior of short carbon fiber reinforced PEEK composites is studied systemically using experimental technologies of quasistatic tests and dynamic Hopkinson bar tests. The experimental characterization covers different loading rate from 0.001 s to 1,000 s and temperature ranges from -30 degrees C to 100 degrees C, which provides detailed illustration for the effects of strain rate and temperature on the mechanical failure of short carbon fiber reinforced PEEK composites. The experimental results provide fundamental understandings on the failure mechanism of this material, especially in identifying the main factors affecting the rate-dependent and temperature-dependent behavior, which can facilitate the material design and model development. Based on the experimental data, this paper proposes an improved phenomenological constitutive model to describe the constitutive behavior of PEEK composites under different strain rates and different temperatures conditions.