Abstract

Active microwave thermography (AMT) is a nondestructive testing and evaluation (NDT&E) technique that utilizes a radiating antenna to induce a thermal increase on or within a specimen under test (SUT). The radiated power density is spatially nonuniform and therefore results in a spatially nonuniform thermal excitation, which may result in missed or false indications of defects. To this end, this work proposes a novel image reconstruction technique for nonuniform excitation/heating and is referred to as Spatiotemporal Variance Reconstruction (STVR). STVR utilizes the spatial and temporal variance of the surface thermal profile. STVR is advantageous in that it does not require a reference measurement nor manipulation of the interrogating signal to mitigate the effect of the nonuniform thermal excitation. To illustrate the improvements offered by STVR, AMT measurements were completed on a set of carbon fiber reinforced polymer (CFRP) structures with an absorbing topcoat. Additional thermographic measurements were completed utilizing a halogen lamp source on a pressed high explosive (HE) SUT. In all cases, the STVR-processed results provide an indication of the defect, within 5% spatial error, without the need for a reference measurement or signal manipulation, which was not previously possible.

Department(s)

Mining Engineering

Second Department

Electrical and Computer Engineering

Publication Status

Open Access

Comments

Missouri University of Science and Technology, Grant None

Keywords and Phrases

Active Microwave Thermography (AMT); High Explosive (HE); Microwave Thermography (MT); Nondestructive Testing and Evaluation (NDT&E); Spatiotemporal Variance Reconstruction (STVR); Thermal Contrast (TC)

International Standard Serial Number (ISSN)

2768-7236

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2024 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Jan 2024

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