Nonlinear bending of sandwich beams composed of FG-GPLRC faces and FG-TPMS core: Effect of initial deformation due to temperature rise

This study presents a new procedure and assumption for predicting the thermal bending behavior of a novel class of sandwich beams under various distributed loads. The sandwich beams are made of functionally graded graphene platelet reinforced composites at their faces and functionally graded triply periodic minimal surface materials at their core layer. The modified formulations are also provided to estimate the material properties of such advanced composites in each layer. The potential and practical applications of this study involve the construction of sandwich structures with advanced composite materials for enhancing lightweight and stiffness properties, designing beam-like nanocomposite structures in thermal environments where the temperature exceeds the critical buckling temperature, taking into account the effects of thermal initial deformation and geometrically nonlinear strain in the structural design of beams under various kinds of distributed loads. The governing equations for such a problem are formulated using the higher-order shear deformation theory with the von Kármán nonlinear strain component, and they can be solved numerically using a newly developed computational procedure. Based on our analysis, we observe that when straight beams are curved due to initial thermal deflection, their performance in resisting deformation improves in accordance with characteristics of curved beams. Consequently, beams subjected to mechanical loads in a high temperature environment exhibit less deflection than those in an ambient environment.