US 12,411,113 B2
Multilayer bolthole nondestructive inspection (NDI)
John Nagel, Austin, TX (US); Mark Warchol, Austin, TX (US); David Forsyth, Austin, TX (US); and Ajay Shah, Austin, TX (US)
Assigned to TEXAS RESEARCH INTERNATIONAL, INC., Austin, TX (US)
Filed by Texas Research International, Inc., Austin, TX (US)
Filed on Oct. 16, 2022, as Appl. No. 17/966,872.
Claims priority of provisional application 63/257,089, filed on Oct. 18, 2021.
Prior Publication US 2023/0123998 A1, Apr. 20, 2023
Int. Cl. G01N 29/265 (2006.01); G01N 29/06 (2006.01); G01N 29/22 (2006.01); G01N 29/24 (2006.01)
CPC G01N 29/265 (2013.01) [G01N 29/06 (2013.01); G01N 29/226 (2013.01); G01N 29/2487 (2013.01); G01N 2291/0289 (2013.01); G01N 2291/2691 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for detecting fatigue cracks extending from fastener holes in multilayer metallic structures without removing the fasteners, wherein the fasteners have fastener heads, comprising the steps of:
a) providing a probe guide to be used by a human inspector;
b) wherein the probe guide includes an ultrasonic testing (UT) sensor;
c) wherein the probe guide can be used by the human inspector to locate the ultrasonic testing sensor at specific selected locations on the surface of the multilayer metallic structures;
d) wherein the probe guide can be positioned against selected fastener heads and rotated around the selected fastener head by the human inspector; and
e) wherein the probe guide contains an inertial measurement unit (IMU) or a rotary encoder that provides the human inspector with information or displays of the rotational position and angle of the probe as well as the ultrasonic signal as the probe is rotated around the fastener head.