Finite element dynamic analysis of orthotropic sandwich plates with an electrorheological fluid core layer

The finite element dynamic analysis of an orthotropic rectangular sandwich plate with orthotropic base plate and constraining layer and an electrorheological (ER) fluid core is analyzed in the present paper. The orthotropic rectangular plate is covered an ER fluid core and a constraining layer to improve the vibrational behavior of the system. The finite element method and Hamilton’s principle are employed to derive the finite element equations of motion for the orthotropic sandwich plate. The effects of the natural frequencies and loss factors on the dynamic behavior of the orthotropic sandwich plate are studied. The rheological property of an ER material, such as viscosity, plasticity, and elasticity may be changed when applying an electric field. The ER fluid core is found to have a significant effect on the vibrational behaviors of the orthotropic sandwich plate. The modal dampings and the natural frequencies for the orthotropic sandwich plate are calculated for various electric fields. When an electric field is applied, the damping of the system is more effective. The effects of the thickness ratio of the base plate, ER fluid core, and the constraining layer on the natural frequencies and modal loss factors are also discussed.