Thermomechanical EBM‐based modeling of time‐dependent creep behavior in semicrystalline polymers: Competitive viscoelastic impact of amorphous and crystalline sections

In this study, the creep behavior of semicrystalline polymers was investigated based on time‐dependent thermomechanical characteristics of the amorphous and crystalline sections. To this end, different equivalent box models (EBMs) with simple or complex structures were designed to interconnect the system components and cover all of their likely interactions. To induce time‐dependency to the model, a variety of viscoelastic models (e.g., Maxwell, Kelvin–Voigt, Maxwell representation of standard linear viscoelastic [SLV] model, Kelvin representation of SLV model, Burger and developed Bingham–Norton) were incorporated with the EBM structures as its crystalline/amorphous components. A specific strategy was devised in order to separately indicate the particular effects of crystalline and amorphous sections along with stress concentration on the temperature‐dependent creep behavior of the system. This approach combined with validating the theoretical data against the creep test results, performed at 20, 40, and 60°C, helped to indicate the most efficient structure for EBM and the best applicable viscoelastic model component. Accordingly, based on the findings of the present study, it was revealed that the series arrangement of the amorphous and crystalline model components, represented by the Burger viscoelastic model, could provide the best predictions regarding the temperature‐dependent creep in semicrystalline polymers.Highlights Creep behavior of semicrystalline polymers at different temperatures. Representing the crystalline and amorphous sections using viscoelastic models. Evaluating different interactions in the semicrystalline polymers using EBMs. Comparison of the efficiency of different viscoelastic model components in EBM. Distinct impact of crystalline and amorphous sections on the system properties.