Creep Crack Growth in Polypropylene Film with Various Crack Lengths at Diverse Stresses and Temperatures

Creep crack growth rates were measured using centrally cracked tension specimens of thin polypropylene film with different crack lengths at various stresses and temperatures. The creep crack growth rates were correlated with the stress intensity factor. There was the region of the minimum constant crack growth rate which occupied more than 70% of the total creep failure life. This constant creep crack growth rate characteristics were analyzed on the basis of the stress-dependent Arrhenius type thermally activated process.