公开(公告)号：US20240344909A1

公开(公告)日：2024-10-17

申请号：US18412648

申请日：2024-01-15

Applicant: IIDA Co., Ltd.

Inventor： Shigeo MIYAKE ,  Shuichi NOWATARI ,  Hidemi HANADA

IPC: G01L1/24 ,  G01N21/3581

CPC classification number: G01L1/248 ,  G01N21/3581 ,  G01N2201/061

Abstract: An objective of the present invention is to quantitatively estimate the residual stress of an object. The present invention provides a method for estimating the residual stress of an object, the method comprising: irradiating an object with terahertz waves; measuring polarization intensity of the terahertz waves transmitted through or reflected by the object; and calculating tensile stress of the object based on the measured polarization intensity. In one embodiment, calculating the tensile stress includes calculating the tensile stress based on a relationship between polarization intensity and tensile stress derived from: a relationship between polarization intensity and tensile distance; and a relationship between tensile distance and tensile stress.

公开(公告)号：US20220146257A1

公开(公告)日：2022-05-12

申请号：US17270856

申请日：2020-02-27

Applicant: IIDA Co., Ltd. ,  THE UNIVERSITY OF TOKYO

Inventor： Shigeo MIYAKE ,  Yusuke KAJIHARA ,  Shuichi NOWATARI ,  Seiichiro IWASAKI ,  Junya NOWATARI

IPC: G01B15/06

Abstract: An objective of the present invention is to provide a method, or the like, for estimating the convergence of dimensional changes in a molded article over time, by utilizing the polarization intensity of terahertz waves. The present invention provides a method for estimating the convergence of changes in the dimensions of a molded article over time, the method comprising: irradiating a molded article with terahertz waves at multiple positions thereon, wherein the molded article is irradiated with the terahertz waves at each position thereon in multiple orientations about the optical axis; measuring polarization intensities of the terahertz waves transmitted through or reflected from the molded article; and determining whether the polarization intensities at the multiple positions are in a given relationship with each other.