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:
Jul. 08, 2025
Filed:
Feb. 13, 2023
Harbin Institute of Technology, Harbin, CN;
Xiaolei Cui, Harbin, CN;
Shijian Yuan, Harbin, CN;
HARBIN INSTITUTE OF TECHNOLOGY, Harbin, CN;
Abstract
A method for measuring an r-value of a tube in a circumferential direction: determine a size of an annular sample, and cutting the sample from a to-be-measured tube; making speckles or circular grids on an outer surface of the sample; sleeving the annular sample in a middle of an outside of a ring segmented rigid die; filling a liquid bag with a fluid medium and controlling an internal pressure, and driving the ring segmented rigid die to move outward uniformly in a radial direction using a uniformly distributed load generated by pressurizing the liquid bag, so as to cause equal diameter bulging of the annular sample; measuring strain in width and circumferential directions in a speckle or circular grid region on the annular sample; and determining the plastic strain ratio of the tube in the circumferential direction according to the strain in the width and circumferential directions.