Background: Magnetorheological and electrorheological materials show variations in their rheological properties when subjected to magnetic and electric fields. We analyzed the vibration control behavior of a sandwich panel with elastic face sheets and an electrorheological or magnetorheological fluid core, using an improved higher-order theory. The theory was applied to the analysis of the structure's components as a combination of exponential, trigonometric, and polynomial functions. The core's flexibility was analyzed based on Frostig's second model, which has attracted material science researchers’ attention. Methods: Using the new theory, we analyzed the transverse shear and rotary inertia effects of the cover sheets. The governing equations and boundary conditions were derived by Hamilton's principle. The natural frequencies and loss factors were derived by solving the eigenvalue problem. The effects of changing the geometric parameters, the thickness of the magnetorheological or electrorheological layer, and thickness ratios on the vibration behavior of the panel were determined. Results: The panel's natural frequencies increased when the magnetic or electric field strength, and the panel's aspect ratio increased. It decreased when the core to panel thickness ratio increased. The magnetorheological material showed higher strength and lower sensitivity to external impurities than did the electrorheological material. Conclusions: We conclude that the magnetorheological materials minimize the structure's vibration at high-frequency operation, and the electrorheological materials are optimal for minimizing the structure's vibration at lower frequency operation. The findings of this study are useful to better understand the vibration behavior of sandwich panels with laminates under free vibration conditions.
