Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials

Mahinda Kuruppu, Takahiro Funatsu

Research output: Contribution to conferencePaper

Abstract

A number of standard methods have been proposed to determine the Mode I fracture toughness of rock. They include those based on short rod specimen, chevron bend specimen and cracked chevon-notched Brazilian disk specimen. The semi-circular bend (SCB) specimen shown in Figure1 has been widely used for fracture toughness determination of geomaterials owing to inherent favourable properties such as its simplicity, minimal requirement for machining and the convenience of testing that can be accomplished by applying 3-point compressive loading using a laboratory load frame. It is made from typical rock cores. Despite the application of compressive loading the stresses at the crack tip are tensile and it causes tensile failure due to the opening mode (i.e. Mode I) of the crack propagation. The critical crack initiation parameter in linear elastic fracture mechanics is defined as the fracture toughness KIc and is considered as a material property. However unless the crack tip process zone where the micro cracks that generate due to the tensile stresses coalesces and form a macro crack is contained within a small volume of area in comparison to the specimen size, the resulting toughness value may not be equal to the fracture toughness. This paper discusses the minimum size requirements as appalicable to the determination of plane strain fracture toughness of rock materials using the SCB specimen.

Original languageEnglish
Pages432-439
Number of pages8
Publication statusPublished - Jan 1 2012
Event7th Asian Rock Mechanics Symposium, ARMS 2012 - Seoul, Korea, Republic of
Duration: Oct 15 2012Oct 19 2012

Other

Other7th Asian Rock Mechanics Symposium, ARMS 2012
CountryKorea, Republic of
CitySeoul
Period10/15/1210/19/12

Fingerprint

fracture toughness
fracture strength
Fracture toughness
crack
Rocks
Crack tips
crack tips
rocks
rock
Cracks
cracks
fracture mechanics
crack propagation
tensile stress
microcrack
plane strain
requirements
Crack initiation
Fracture mechanics
Tensile stress

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology

Cite this

Kuruppu, M., & Funatsu, T. (2012). Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials. 432-439. Paper presented at 7th Asian Rock Mechanics Symposium, ARMS 2012, Seoul, Korea, Republic of.

Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials. / Kuruppu, Mahinda; Funatsu, Takahiro.

2012. 432-439 Paper presented at 7th Asian Rock Mechanics Symposium, ARMS 2012, Seoul, Korea, Republic of.

Research output: Contribution to conferencePaper

Kuruppu, M & Funatsu, T 2012, 'Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials' Paper presented at 7th Asian Rock Mechanics Symposium, ARMS 2012, Seoul, Korea, Republic of, 10/15/12 - 10/19/12, pp. 432-439.
Kuruppu M, Funatsu T. Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials. 2012. Paper presented at 7th Asian Rock Mechanics Symposium, ARMS 2012, Seoul, Korea, Republic of.
Kuruppu, Mahinda ; Funatsu, Takahiro. / Feasibility of using semi-circular bend specimen to develop a standard method to determine Mode I fracture toughness of geomaterials. Paper presented at 7th Asian Rock Mechanics Symposium, ARMS 2012, Seoul, Korea, Republic of.8 p.
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