An investigation into size-dependent vibration damping characteristics of functionally graded viscoelastically damped sandwich microbeams

The size-dependent mathematical formulation of a functionally graded viscoelastically damped sandwich microbeam is developed on the basis of a modified couple stress theory called symmetric–deviatoric couple stress theory. All the physical and mechanical properties of the functionally graded layers are assumed to vary continuously through thickness according to a power law and also the sandwich core is modeled with a complex modulus. The newly developed model contains five material length scale parameters to interpret the size-dependent vibration damping characteristics of the sandwich microbeam. The natural frequency and loss factor of a functionally graded damped sandwich microbeam with sliding simply supported boundary conditions are analytically determined by using Navier solution procedure. Finally, the influence of size effect and functionally graded layers on the vibration damping characteristics of the damped sandwich microbeam is investigated.