Advances in the Creep Behavior of Continuous Synthetic Fiber‐Reinforced Thermoplastic Polymer Composites

ABSTRACT Thermoplastic polymers are gaining more attention nowadays because of their natures like easier recycling and secondary processing. The present study systematically summarized the creep test methods and the effects of material property, test parameter, and external environment on the creep behavior of continuous synthetic fiber‐reinforced thermoplastic polymer (C‐FRTP) composites. In addition, 11 prediction models regarding the creep strain and creep failure time were introduced. The results indicated that the increase of fibers not only utilizes their low deformation characteristic but also could change the crystallization conditions of C‐FRTP composites to resist the creep deformation. The crystalline regions of C‐FRTP composites could act as a stiff resistance to the creep deformation, and the crystallinity formation process influences the fiber impregnation by temperature change. Higher temperatures not only increase the molecular regrouping frequency of the matrix but also weaken the fiber‐matrix interface, resulting in a higher creep strain in C‐FRTP. Water absorption accelerates the creep deformation of C‐FRTP composites through the plasticization and swelling of the matrix, lowering their glass transition temperature, and reducing the interfacial bond between fiber and matrix. The Time‐Temperature‐Superposition‐Principle method is preferred regarding the creep strain prediction because of its validation at 10,000 h but the physical aging should also be considered to avoid overestimation of the long‐term creep deformation, while for the creep failure time prediction, the power law model is suitable for creep design purposes, considering its simple procedures. Finally, the future directions regarding the creep studies of C‐FRTP composites were recommended.