A New Way for Polymer Characterisation Using a Combined Approach LEFM – Plastic Zone Corrected LEFM

摘要: ABSTRACT Toughness quantification of polymers is still an open issue, since no unique fracture mechanics method able to provide intrinsic crack propagation resistance values over the whole range material behaviours from brittle ductile. A sensitive way characterise mechanical performance these materials, exemplified with rubber modified isotactic polypropylenes, determine their ductile-brittle transitions as key-factor for ranking. conventional Linear Elastic Fracture Mechanics (LEFM) often used data reduction. Although being strictly reserved assessment, it constitutes a guaranty continuity analysis several decades test speeds. Nevertheless, descriptors such K, stress intensity factor, provided by this are geometry dependent in ductile range. To overcome difficulty, original approach, which takes into account high amount plasticity tough polymers, proposed. It consists determining experimentally size plastic zone developed at tip using specimens different ligament lengths. was shown large conditions, except near transitions. combined approach “conventional LEFM-plastic corrected LEFM” therefore necessary apprehend accurately behaviour studied blends.