Patent · US Expired

Modified ring test

US4821577A · kind A · utility

3Cited by
5References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 22, 1987
Grant dateApr 18, 1989
Priority date
Expiry dateJun 22, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2203/0274
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A novel test specimen configuration and modified ring test method for determining the fracture toughness, K.sub.Ic, using rock core is disclosed. The use of a truncated hollow cylindrical specimen under compressive load avoids the development of a large process zone (microcracked region) during testing, thus allowing accurate fracture toughness measurements on subsized specimens. Results using soft sandstones and Indiana limestone validate the procedure.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.