Experimental and theoretical investigations of the viscoelastic behaviour of short carbon fiber reinforced polyetherimide composites

The dimensional stability of fiber reinforced composite-based engineering components is crucial to guaranteeing their structure-safe services. The viscoelastic response of fiber reinforced composites is a critical factor for dimensional stability but the viscoelastic behavior of short carbon fiber reinforced polymer composites is rarely reported. In this work, the viscoelastic behaviour of short carbon fiber reinforced polyetherimide (SCF/PEI) composites is investigated by a series of short-term creep-recovery tests in an extensive applied stress range. Experimental results reveal that the ∼ 32% ultimate strength is the applied stress as an indicator for the start of the nonlinear viscoelastic behavior of the SCF/PEI composites. Meanwhile, an empirical constitutive model is established by using Schapery’s model to elaborate the viscoelastic behaviour of the SCF/PEI composite. It is found by validation that the predictions agree with the experimental results of the SCF/PEI composites.