Nonlinear tensile behavior of cotton fabric reinforced polypropylene composites

Abstract

Abstract From the perspectives of elastoplasticity (nontime‐dependent) and viscoelasticity (time‐dependent), the Ramberg–Osgood relation and time‐varying viscosity Maxwell (TVM) models were used to model and analyze the stress–strain behavior of cotton fabric‐reinforced polypropylene composites (CFRLs), respectively. The Ramberg–Osgood relation could well describe the tensile behavior of CFRLs as an elastoplastic behavior, while the tensile behavior could also be described as a nonlinear viscoelasticity behavior by Maxwell model. The fitting results showed that the Maxwell model accurately described the tensile behavior of different CFRLs samples under low strain, but there was a considerable gap between the test data and model values when the strain was greater than 5%. Therefore, a time‐varying viscosity fluid damper was used instead of a Newtonian fluid damper to modify the Maxwell model, namely the TVM model. The TVM model closely described the stress–strain behavior during the entire tensile process.