The J-Integral as a fracture toughness criterion for ductile polymer films

The utility of using the J-Integral as a fracture toughness criterion for ductile polymer films was investigated. To perform this work, a simple yet definitive technique was developed to accurately determine flaw position. Accurate detection of flaw position is needed to enable construction of a J-Integral tear resistance curve so that the critical value of the J-Integral can be determined. The critical value of the J-Integral and the initial slope of the J-Integral resistance curve were found to be well correlated with observed phenomena. A strong correlation between the critical value of the J-Integral and the initial slope of the J-Integral tear resistance curve was found. Techniques relying on physically marking film material to measure flaw position were found to be ineffective. Material processing conditions and testing temperature were found to influence fracture toughness measurements.