Patent · US Expired

Method for measuring plane strain fracture toughness

US4116049A · kind A · utility

11Cited by
1References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 10, 1977
Grant dateSep 26, 1978
Priority date
Expiry dateJun 10, 1997

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2203/0066
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The present invention consists of a method for accurately measuring the plane strain fracture toughness of ductile and brittle materials, the method to be practiced on a specimen formed such that, when the specimen is appropriately loaded, a crack will initiate at a predetermined point or line, with such crack formed thereat being intrinsically stable such that the load executed on the specimen must be continually increased in order to further advance the crack along a predetermined path through the specimen, until, at some critical location along the predetermined crack path, the load necessary to further advance the crack reaches a maximum, thereafter decrasing as the crack advances beyond the critical location along the remainder of its predetermined path through the specimen, that critical location being essentially independent of the specimen material, it being determined by the specimen geometry alone as long as elastic plane strain conditions prevail in the specimen sufficiently close to the crack tip. The method of the present invention involves taking the specimen through an appropriate loading sequence and determining the critical (or maximum) load that occurs when the cr…

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