Thermomechanical free vibration buckling of FG graphene-reinforced doubly-curved sandwich shells

This study explores the thermomechanical free vibration and buckling behavior of doubly-curved sandwich shell structures with a core of FG graphene-reinforced foam and metal or ceramic face layers. Using Hamilton's principle and a Navier-type solution method, the governing equations and boundary conditions for simply supported, functionally graded doubly-curved shells are derived. The numerical results are validated through comparison with existing literature. The analysis focuses on the effects of the material grading index, foam void ratio, graphene volume fraction, side-to-thickness ratio, and temperature variations. Notably, it was observed that as R₁ increases from α to 10α, the buckling temperature significantly decreases, highlighting a reduction in thermal stability with increasing radii or inverse correlation between R₁ and R₂. These findings reveal unexpected thermal instability trends that could influence future design considerations for high-temperature applications. This study provides novel insights into the thermomechanical behavior of advanced sandwich structures, offering valuable contributions to the field in light of evolving technological needs.