Moisture-uptake induced internal stresses in balsa core sandwich composite plate: Modeling and experimental

The present work investigates the internal stresses induced by moisture absorption in sandwich composite material. Moisture absorption effect was analyzed for balsa core specimens and sandwich structures composed of E-glass/polyester face sheets bonded to a balsa core. These materials were immersed in distilled water at 40 °C and the kinetic of moisture content absorption was identified. The hygroscopic strains were also determined and a new analytical model for the calculation of the effective diffusivities was proposed by solving the homogeneous problem.