Influence of magnetic force and thermal effect on the stability of sandwich beam with different width tapered profiles

This paper presents an innovative Magnetic Constrained Layer Damping (MCLD) approach for improving the static and dynamic stability of sandwich beam structures. The proposed configuration introduces a novel arrangement of permanent magnet pairs placed on the upper and lower elastic layers, creating controllable magnetic attraction and repulsion forces that act as a non-contact stiffness mechanism. This magnetic interaction enhances the overall stability of the sandwich beam, enabling improved performance compared to conventional Passive Constrained Layer Damping (PCLD) systems. The non-dimensional governing equations and boundary conditions are derived using Hamilton’s principle. The non-dimensional mass and stiffness matrices are determined by the Galerkin method. A new formulation of the distributed magnetic interaction force is developed and incorporated directly into the beam’s stability model. The combined effects of width tapering, thermal gradient, pre-twist, rotation and magnetic stiffening are examined simultaneously. The results demonstrate that the proposed MCLD mechanism effectively suppresses resonance peaks, shifts unstable regions to higher excitation frequencies and enhances structural stiffness and stability. The findings establish a new framework for magnetically tunable sandwich beam and offer valuable insights for the development of lightweight vibration-resistant structures in aerospace, mechanical and precision engineering applications.