Evaluation of Mode I Fracture Toughness Assisted by the Numerical Determination of K-Resistance
MetadataShow full item record
The fracture toughness of a rock often varies depending on the specimen shape and the loading type used to measure it. To investigate the mode I fracture toughness using semi-circular bend (SCB) specimens, we experimentally studied the fracture toughness using SCB and chevron bend (CB) specimens, the latter being one of the specimens used extensively as an International Society for Rock Mechanics (ISRM) suggested method, for comparison. The mode I fracture toughness measured using SCB specimens is lower than both the level I and level II fracture toughness values measured using CB specimens. A numerical study based on discontinuum mechanics was conducted using a two-dimensional distinct element method (DEM) for evaluating crack propagation in the SCB specimen during loading. The numerical results indicate subcritical crack growth as well as sudden crack propagation when the load reaches the maximum. A K-resistance curve is drawn using the crack extension and the load at the point of evaluation. The fracture toughness evaluated by the K-resistance curve is in agreement with the level II fracture toughness measured using CB specimens. Therefore, the SCB specimen yields an improved value for fracture toughness when the increase of K-resistance with stable crack propagation is considered.
This open access article is distributed under the Creative Commons license http://creativecommons.org/licenses/by/4.0/
Showing items related by title, author, creator and subject.
Kuruppu, Mahinda (2018)© 2018 ISRM International Symposium 2000, IS 2000. All rights reserved. Fracture mechanics is primarily used to predict the failure of structures made of engineering materials. Principles of fracture mechanics are applicable ...
Microstructural design and properties of high performance recycled cellulose fibre reinforced polymer eco-nanocompositesAlamri, Hatem Rashed (2012)In recent years, cellulose fibre-reinforced polymer composites have been gaining a great attention in several engineering applications due to their desirable properties, which include low density, low cost, renewability ...
Kuruppu, Mahinda; Obara, Y.; Ayatollahi, M.; Chong, K.; Funatsu, T (2014)A number of standard methods have been proposed to determine the Mode I fracture toughness of rock. They include those based on short rod (SR) specimen, chevron bend (CB) specimen and cracked chevron-notched Brazilian ...