Abstract The strain rate dependency of the initial modulus ( E i ), secant modulus at yield (E o ), and of the yield stress, ( y ), of glass fiber reinforced polypropylene (GF-PP) were investigated and modeled along with the stress strain relationship. The GF-PP had a density of 1940 kg/cm 3 . The tensile test specimens were directly machined out of the pipe insulation system. The strain rate, , of loading was varied from 0.30%/min to 35%/min. The stress strain relationship of the composite polymer in tension was elasto plastic with hardening and a stress strain model was used to predict the behavior
