Affiliations: [a] Non-destructive Evaluation Division, Metallurgy and
Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam,
India
Correspondence:
[*]
Corresponding author: B. Purna Chandra Rao, Non-destructive
Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for
Atomic Research, Kalpakkam, TN-603 102, India. Tel.: +91 44 2748 0232; Fax: +91
44 2748 0356; E-mail: [email protected]
Abstract: This paper discusses finite element modeling of spiral coil
electromagnetic acoustic transducer (EMAT) to generate bulk waves. First, a 2D
electromagnetic model is developed for calculating the Lorentz force density,
which is the driving force for sound wave generation within the material.
Second, the calculated force at each point in the material is used as the
driving force for generating sound wave modes. This model is used to predict
the ultrasonic A-scan signals of bulk (longitudinal and shear) waves in
isotropic homogeneous material. Spiral coil EMATs of two different coil
spacings are developed for experimental studies. The model predicted results
are validated by experimental results and for this, the ratio of amplitude of shear
wave to longitudinal wave is used.
Keywords: Spiral coil EMAT, lorentz force density, finite element modeling, bulk waves
