公开(公告)号：US20240280424A1

公开(公告)日：2024-08-22

申请号：US18581320

申请日：2024-02-19

Applicant: Southwest Research Institute

Inventor： Xin Chen ,  Adam C. Cobb ,  Douglas R. Earnest ,  Clint J. Thwing ,  Nikolay Akimov

IPC: G01L1/25 ,  G01N29/07 ,  G01N29/22 ,  G01N29/34 ,  G01N29/44

CPC classification number: G01L1/255 ,  G01N29/07 ,  G01N29/223 ,  G01N29/227 ,  G01N29/34 ,  G01N29/4436 ,  G01N2291/011 ,  G01N2291/0234 ,  G01N2291/02827 ,  G01N2291/0421 ,  G01N2291/105

Abstract: A method for detecting residual stress induced by cold expansion (Cx) (Cx stress) at a hole in a structure. Two transducer pairs transmit and receive ultrasonic waves into the structure in a pitch-catch configuration along two first paths parallel to a tangent of the hole. The two paths are at different distances from the hole. Both transducer pairs are arranged such that their incident angle into the structure provides longitudinal critically refracted (LCR) waves within the structure. Time-of-flight (ToF) measurements of the LCR waves along the first path and the second path are the basis of acoustoelasticity calculations that determine if Cx stress is present at the hole.

公开(公告)号：US20230393098A1

公开(公告)日：2023-12-07

申请号：US18326611

申请日：2023-05-31

Applicant: Southwest Research Institute

Inventor： Xin Chen ,  Adam C. Cobb ,  Douglas R. Earnest ,  Keith A. Bartels

IPC: G01N29/07 ,  G01N29/06

CPC classification number: G01N29/07 ,  G01N29/069 ,  G01N2291/02827 ,  G01N2291/2623

Abstract: A method of in situ measurement of an acoustoelastic constant (L) of a railway rail, using an ultrasonic wedge sensor to measure a stress-free (unloaded) time-of-flight (t0) in the vertical direction of the rail. Next, a vertical load of known load value is applied to the rail. While the vertical load is applied, the ultrasonic wedge sensor is used to measure a stressed time-of-flight value. The difference between the stress-free and the stressed time-of-flight is calculated to obtain a time-of-flight difference value (Δt). Based on the load value, the stress-free time-of-flight value, and the time-of-flight difference value, the acoustoelastic constant, L, may be calculated. The wedge sensor may be further used to measure the (stressed) horizontal time of flight, and a time-of-flight difference value in the horizontal direction may be used to measure longitudinal stress.