Buckling analysis of sandwich cylindrical micro shells with functionally graded porous core subjected to uniform magneto-electric fields based on couple stress theory

Abstract

This study examines the buckling behavior of sandwich cylindrical microshells made of functionally graded materials under uniform magneto-electric load. The analysis utilizes a high-order shear and normal deformation shell theory, incorporating a material length scale parameter from the couple stress theory. Hamilton's principle is used to derive the equations of motion and boundary conditions at both ends. The Navier procedure is employed to determine the dimensionless critical buckling load for three types of functionally graded sandwich cylindrical microshells, with a vector used to represent the uniform magneto-electric fields at both ends. Results indicate that angled functionally graded sandwich cylindrical microshells exhibit higher stiffness in couple stress theory than in normal FGS, resulting in an increased dimensionless critical buckling load. Moreover, the material length scale parameter has a significant impact on the dimensionless critical buckling load across various axial and circumferential wavenumbers. An increase in power-law index n for specific values of dimensionless length scale parameter (l/h) leads to a decrease in DCB load according to MCST.