Accumulation of submicroscopic damage in polymers under simple loading

The accumulation of microdamage in specimens of polystyrene, Ftorlon, and high-pressure polyethylene loaded continuously to failure has been investigated. It is shown that at small specimen lifetimes the residual damage accumulates primarily in the fracture zone. Outside the fracture zone appreciable damage accumulation is observed at specimen lifetimes close to the long-term strength. The ultimate strain at various lifetimes is determined. It is shown that the strain corresponding to failure depends on the fraction of irreversible damage accumulated and is largely determined by the resistance of the polymers to fracture.