Vibration and thermal buckling analyses of multi-span composite lattice sandwich beams

Abstract

Multi-span composite lattice sandwich beams have wide application prospects in the aerospace, high-speed trains and civil engineering fields because of the low specific weight, high specific strength and multifunctional potential. Moreover, the span number and the subspan length have a great influence on the vibration and thermal buckling properties of multi-span beams. Therefore, a simple and effective method is presented to investigate the vibration and thermal buckling behaviors of different multi-span sandwich beams with pyramidal truss core in this study. The first-order shear deformation theory is used to evaluate the strain–displacement relations in the structural modeling. The mode shapes modified by the interpolation function are used to evaluate the vibration modes of the multi-span lattice sandwich beam. The differential equation of motion is formulated by Hamilton’s principle. The natural frequencies of the multi-span sandwich beam with pyramidal truss core are validated through comparing the finite element method results. The parametrical investigations with respect to the ply angle of the composite laminated face sheets and the radius of trusses are conducted. Furthermore, the influences of the span number and subspan length on the vibration and thermal buckling behaviors of the composite lattice sandwich beams are also performed and discussed.