Multi-modality strain estimation using a rapid near-field microwave imaging system for dielectric materials

• Published in: Measurement : journal of the International Measurement Confederation Vol. 151; p. 107243
• Main Authors: Shi, Xiaodong, Rathod, Vivek T., Mukherjee, Saptarshi, Udpa, Lalita, Deng, Yiming
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.02.2020; Elsevier Science Ltd
• Subjects: Crack initiation; Damage; Data integration; Deformation; Dielectric properties; Digital imaging; Elasto-plastic; Fracture mechanics; Image processing systems; Image resolution; Microwave heating; Microwave probes; Multi-modality data fusion; Multisensor fusion; Nondestructive evaluation; Plastic deformation; Polyamide resins; Strain; Strain and stress estimation; Strain distribution; Stress concentration; Multi-modality data fusion; Strain and stress estimation; Nondestructive evaluation; Elasto-plastic
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2019.107243

•Novel approach to detect and characterize elasto-plastic strain using near-field microwave.•High sensitivity measurement demonstrated through DIC data correlation residual strain.•Non-contact scanning methods developed that provides high resolution and subsurface penetration.•Very large strain (0.3–0.7) exhibited by dielectric materials is successfully measured electromagnetically. Strain distribution is an important indicator of stress concentration, damage initiation and evolution. Many dielectric materials sustain very large strain before failure. In this paper, a near-field microwave high-resolution imaging (NMHI) system is presented to estimate very large deformation. The sensitivity of the microwave imaging system to the dielectric property and geometric changes have been utilized in the present work. A multi-modality data fusion technique is applied to experimentally evaluate the strain in ASTM-D638 standard dog bone structure made of Polyamide 11 (PA-11) material. Plastic strain in the range of 0.3–0.7 has been successfully correlated to the microwave probe response in PA-11 materials. The comparison of strain distribution obtained from NMHI and digital image correlation (DIC) indicate the potential of NMHI as a fast, non-contact method to estimate large mechanical strain.