Title: Detection and monitoring of changes in metallic structures using multimode acoustic signals

Abstract

Methods for detecting and monitoring changes in mechanical structures and in walls of pipes, vessels and storage tanks, using muitimode acoustic signal propagation and detection, are described. Acoustic signals having chosen amplitude-time-frequency characteristics excite multiple modes in the structure under investigation, are generated and received at a small number of accessible locations, such as the ends of pipes and the tops and bottoms of vessels and storage tanks, with the inspection region between transmit and receive transducers. Small mechanical changes lead to acoustic scattering and attenuation among the various modes, which are detectable as changes in received signal intensity. Such changes may include material loss, material conversion and material addition. Once the structure is characterized in a known condition, the present method may be used to monitor the structure at a later time to determine whether changes have taken place. Methods for effective temperature compensation are also described. In addition, various pipe geometries and complex pipe geometries involving elbows, flanges, and the like can be monitored.

Inventors:

Findikoglu, Alp T.; Sinha, Dipen N.; Chapman, Daniel R.

Issue Date:

2019-11-12

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1600273

Patent Number(s):

10473625

Application Number:

15/751,429

Assignee:

Chevron U.S.A. Inc. (San Ramon, CA); Triad National Security, LLC (Los Alamos, CA)

Patent Classifications (CPCs):

G - PHYSICS G01 - MEASURING G01F - MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL

G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES

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G - PHYSICS G01 - MEASURING G01F - MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL

G01F1/66 - by measuring frequency, phaseshift, or propagation time of electromagnetic or other waves, e.g. ultrasonic flowmeters
G01F1/708 - Measuring the time taken to traverse a fixed distance
G01F1/74 - Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid

G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES

G01N2291/011 - Velocity or travel time
G01N2291/0258 - Structural degradation, e.g. fatigue of composites, ageing of oils
G01N2291/2634 - cylindrical from outside
G01N29/043 - {in the interior, e.g. by shear waves}
G01N29/07 - by measuring propagation velocity or propagation time of acoustic waves
G01N29/326 - {compensating for temperature variations}
G01N29/343 - {pulse waves, e.g. particular sequence of pulses, bursts}
G01N29/348 - {with frequency characteristics, e.g. single frequency signals, chirp signals
G01N29/4409 - {by comparison}
G01N29/4463 - {Signal correction, e.g. distance amplitude correction [DAC], distance gain size [DGS], noise filtering}
G01N29/4472 - {Mathematical theories or simulation}
G01N29/449 - {Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation}
G01N29/46 - by spectral analysis, e.g. Fourier analysis {or wavelet analysis

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DOE Contract Number:  

AC52-06NA25396

Resource Type:

Patent

Resource Relation:

Patent File Date: 08/12/2016

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS