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:
Oct. 30, 2001
Filed:
Jul. 21, 2000
Subra Suresh, Wellesley, MA (US);
Antonios Giannakopoulos, Somerville, MA (US);
Inventium LLC, Wellesley, MA (US);
Abstract
Provided are methods and apparatus for determining from indentation testing the preexisting stress and/or effective strain in a section of a material. The invention also provides methods and apparatus for determining the variation of the stress with depth in the material (e.g. the gradient). According to the invention, first data are provided from an indentation test of the stressed (or strained) section. The stress (or effective strain) can then be determined from the first data and from second data characteristic of the material, such as a stress-strain curve. Second data can also be obtained from an additional indentation test of a section having a known stress. The methods provided herein are suitable for programming on a general purpose computer or calculator.