Relation between Fracture Toughness and Crack Growth Rate in PMMA

Abstract

The effect of temperature on the relation between fracture toughness and slow crack growth rate was investigated for PMMA in the temperature range -30°C to 80°C. Fracture toughness was measured by Gurney's sector method.
The results obtained are summarized as follows;
(1) A scaling law rather than an Arrhenius type equation holds between the crack growth rate and the fracture toughness. The exponent of the scaling law is nearly constant over the entire temperature range tested.
(2) The fracture surfaces associated with slow crack growth are classified into three typical types, i. e., mist surface with few radial lines, mist surface with many radial lines and mirror surface. These typical surfaces are closely related to the crack growth rate and testing temperature.