Micromechanical Analysis of Composite Corrugated-Core Sandwich Panels for Integral Thermal Protection Systems

摘要

A composite corrugated-core sandwich panel was investigated as a potential candidate for an integral thermal protection system. This multifunctional integral thermal protection system concept can protect the space vehicle from extreme reentry temperatures, and possess load-carrying capabilities. The corrugated core is composed of two, thin, flat sheets that are separated by two inclined plates. Advantages of this new integral thermal protection system concept are discussed. The sandwich structure is idealized as an equivalent orthotropic thick-plate continuum. The extensional stiffness matrix [A], coupling stiffness matrix [B], bending stiffness [D], and the transverse shear stiffness terms A_(44) and A_(55) were calculated using an energy approach. Using the shear-deformable plate theory, a closed-form solution of the plate response was derived. The variation of plate stiffness and maximum plate deflection due to changing the web angle are discussed. The calculated results, which require significantly less computational effort and tune, agree well with the three-dimensional finite element analysis. This study indicates that panels with rectangular webs resulted in a weak extensional, bending, and A55 stiffness and that the center plate deflection was minimum for a triangular corrugated core. The micromechanical analysis procedures developed in this study were used to determine the stresses in each component of the sandwich panel (face and web) due to a uniform pressure load.