(Elsevier, 2018-01-01) Beato López, Juan Jesús; Vargas Silva, Gustavo Adolfo; Pérez de Landazábal Berganzo, José Ignacio; Gómez Polo, Cristina; Ingeniería; Ingeniaritza; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Gobierno de Navarra / Nafarroako Gobernua
In this work, a magnetoelastic sensor to detect the micrometer diameter variations of cylindrical
elements is analyzed. A nearly zero magnetostrictive amorphous ribbon with nominal composition
(Co₀.₉₃Fe₀․₀₇)₇₅Si₁₂․₅B₁₂․₅ was selected as sensor nucleus. The sensor, based on Giant Stress-Impedance
(GSI), is attached (glued) along the external perimeter of the cylindrical element. Changes in the cylindrical diameter, DM, induce effective tensile stresses, S, on the ribbon, giving rise to sensitive changes in
the high frequency impedance, Z. The sensor response is analyzed in terms of the relationship between
the induced strains and the diameter variations, where the effect of geometrical factors (cylinder diameter and sample length) is taken into account. The results indicate that although the maximum GSI ratio
depends on the pre-induced bending stresses associated to the cylindrical configuration, the sample
length plays the dominant role in the sensor sensitivity. The proposed device enables to monitor the
micrometric diameter variation in cylindrical elements, with a maximum strain gauge factor (GF≈-80)
for low induced strains.
