Introduction to Mechanical Characteristics in Polymeric Solids: Lecture 4: Tensile Fracture Behavior of Polymer Solids

The tensile fracture behavior of polymeric solids was phenomenologically analyzed using high-density polyethylene (HDPE) and polypropylene (PP) with double-notched specimens to suppress neck propagation. The fracture points obtained under various temperatures and strain rates were found to lie on a single failure-envelope curve, suggesting the validity of the time–temperature equivalence law. Statistical analysis of more than 100 PP specimens revealed that both fracture time and strength follow Gaussian distributions, reflecting the stochastic nature of fracture events. The probabilistic characteristics were formulated through Itô-type stochastic differential equations, demonstrating that fracture proceeds as a diffusive random process.