Fracture Mechanics of Polymers

analysis approximation behaviour bending blunting Charpy cm/min computed condition constant load crack growth crack initiation crack length crack propagation crack speed crack tip craze stress criterion curves data for PMMA decrease deduced deformation density dependence determined displacement dissipation ductile tearing E₁ E₂ effects elastic energy release rate equation expression factor fatigue fracture mechanics Fracture toughness fully plastic function geometry give given HDPE homopolymer impact test increases K₁ Kc MPa√m kg/m³ kinetic energy kJ/m² ligament area line zone linear load-deflection material methanol microvoiding modulus MPa/m observed obtained occur parameter plane strain plane stress plasticisation plotted polymers range reference shear yielding shown in Fig shows slope solution specimen strain energy surface temperature tension thickness transition u₁ unstable values variation velocity versus visco-elastic viscosity Williams yield stress πα