Creep behavior of braided carbon fiber/epoxy composites

Braided structures hold a significant position in composite reinforcement due to their unique mechanical properties. However, a significant limitation in the application of fiber-reinforced composites is their susceptibility to creep. The use of a braided structure can significantly enhance creep resistance by maximizing fiber straightness (minimizing fiber waviness), thereby compensating for the excessive creep of the polymer matrix. This paper studies the tensile creep-recovery behavior of two-dimensional braided carbon/epoxy composites. An experimental study was conducted to examine the creep response of the braided composites in two directions of extension. The braided specimens were tested under four various load levels. A viscoelastic model is proposed to describe the tensile creep behavior. Using this model, the creep response is simulated and compared with the experimental data. The predicted tensile creep behavior shows good agreement with the test results. The proposed approach enables the creep prediction with reasonably acceptable accuracy. The obtained results contribute to optimal engineering design and the prediction of deformations in structures utilizing braided composites.