EFFECTS OF CURVATURE OF LOADING SURFACE ON MECHANICAL PROPERTIES OF PIEZOMAGNETIC MATERIAL SHEETS

In measurement of interlayer stress between cylindrical or spherical contact convex-concave interfaces with related big curvature,the flat sensitive element will be curved to the form of the measured contact surfaces,which can cause measurement errors. This issue must be considered in developing sensors applied to measuring such kind of contact interfaces stress. For this application background and taking the cylindrical contact interfaces issue as an example,a finite element model consisting of a loading part with a convex cylindrical surface,a soft piezomagnetic sensitive material sheet,and a fixed part with a concave cylindrical surface is developed by using the approximate numerical method for analyzing combined structure with soft foam parts suggested previously by the author. Through numerical computation and related experiment,the axial compressive stress-strain curves of the sheets are obtained for several different curvatures of the loading surfaces and the effects of curvature on mechanical behaviors of piezomagnetic material sheets were analyzed. It is indicated that the bigger the curvature radius of the loading surface is,the bigger the slope of the approximate linear segment of the axial stress-strain curve is. The result is useful for development of sensors for measurement of interlayer pressurized force between cylindrical or spherical contact interfaces with related big curvature.