Short-term creep behavior of multi-axial warp knitted fabric-reinforced polyethylene matrix composites

Short-term creep experiments of composites of polyethylene reinforced with polyester fiber multi-axial warp knitted (MWK) fabrics were carried out for tensile and shear modes in three directions. This work primarily focuses on using the Burgers and Findley models to obtain parameters associated with stress level, temperature, and structure of MWK fabrics. Specifically, the material parameter A of the Findley model has higher values at elevated temperatures, which is contrary to the impact of fiber content along the loading direction. The material parameter n rises with an increasing temperature and is not affected by the fiber content. In terms of the Burger parameters, material parameters E ₁ , E ₂ , and η ₁ have a downside as temperature increases. The relationship of these parameters with fiber content is contrary to their relationship with temperature. There is no significant effect of temperature and fiber content on relaxation time, whereas there is an upward trend of relaxation time with increases in stress.