The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 1981
Filed:
Mar. 19, 1979
Lynn M Barker, Salt Lake City, UT (US);
Terra Tek, Inc., Salt Lake City, UT (US);
Abstract
The present invention involves a new method for measuring plane strain fracture toughness (K.sub.Ic) of a somewhat non-elastic material uniquely suitable for use on specimens that are smaller than have formerly been required for performing valid K.sub.Ic tests. The present invention involves selecting a short-rod specimen configuration in which the specimen material at a crack front or tip therein would be constrained during loading to a plane strain state and, from the measurement and anelastic analysis of a load-displacement curve that includes at least two unloading slopes the energy per unit crack area that is required to slowly advance a steady state crack can be determined, which data, along with measurement of the critical load when the crack passes through a known location, and considering the specimen geometry, is used to determine the fracture toughness, K.sub.Ic, of the specimen.