Abstract：This paper proposed a functionally graded sandwich microbeam model considering size effects within the frameworks of the modified strain gradient theory and a refined high-order shear deformation theory. The material distributions were assumed to vary in the thickness direction and estimated through the Mori-Tanaka homogenization scheme. A two-node differential quadrature finite element with 18 degrees of freedom was established by combining the differential quadrature rule and Gauss-Lobatto quadrature rule to solve the high-order boundary value problems.The efficacy of our theoretical model and numerical method was validated by comparing the degenerated results with the reported ones. Finally, the effects of boundary conditions, material length scale parameters, functional gradient index, slenderness ratio, and thickness ratio on the static and dynamic characteristics of functionally graded sandwich microbeams were discussed. It was revealed that the introduction of strain gradients has significant impact on the static responses, vibration frequencies, buckling loads together with the related mode shapes of functionally graded sandwich microbeams. The results obtained were expected to provide data accumulation and methodological basis for the design of load-bearing devices in MEMS.
2022, Vol. 43 
