Fracture Toughness Testing on Bars Under Opposite Cylinder Loading

摘要

Bars loaded by opposite concentrated forces via rollers are appropriate test specimens for the determination of the fracture toughness, K_(Ic), and the crack resistance curve (R-curve). of ceramic materials. In this paper stress solutions for the proposed test specimens are provided, as well as the stress intensity factor and the T-stress solutions. As practical applications, R-curves are determined for a soft PZT ceramic and several alumina ceramics.