Fracture Study on Key-Hole Notches Under Tension: Two Brittle Fracture Criteria and Notch Fracture Toughness Measurement by the Disk Test

摘要

Notch fracture toughness expressions were developed for predicting tensile fracture in members containing key-hole notches based on the point stress and the mean stress criteria. The criteria were verified by using the experimental results obtained from new fracture tests on the key-hole notched Brazilian disk specimens, made of PMMA. It was found that the mean stress criterion predicts the experimental results very well. Also, found in this research was that while the point stress model provides generally satisfactory estimations, except for a special case, the accuracy of this criterion enhances as the notch radius increases.