▎ 摘　　要

In this study, dynamic instability of a sandwich beam made of an isotropic core and functionally graded (FG) graphene platelets-reinforced composite (GPLRC) face sheets is investigated for the first time. A Frostig theory for soft core and third-order shear deformation theory (TSDT) for sheets are used. Hamilton's principle is used to derive the governing equations of motion, and by applying Bolotin's approach, the dynamic instability regions (DIRs) are investigated. A comprehensive investigation is conducted to assess the effects of different weight fractions of nanofiller, various GPL patterns, boundary conditions, slenderness ratio, the thickness of face sheet and static load factors on the DIRs of the beam.