Mathematical Model of Modified Classical Lamination Theory for Foam Core Sandwich Composites
Amith Kumar S.J., Ajith Kumar S.J.
Quarterly No. 4, 2023 pages 220-225
DOI: https://doi.org/10.62753/ctp.2023.06.4.4
keywords: honeycomb grid, syntactic foam, FRP, sandwich composite
abstract Elastic properties are important quantities in the modelling and analysis of sandwich composite structures. The stability of sandwich composites mainly depends on their elastic properties, which in turn depend on the elastic properties of its constituents namely, the core and face skin. Several models have been proposed to predict the elastic constants of core materials such as honeycomb and foam. A foam core may be open-cell foam or closed-cell foam. The present work is focused on the hexagonal cells of a honeycomb grid core and closed-cell polymer syntactic foam core. The honeycomb is considered to be orthotropic with nine independent elastic properties. However, the overall structural performance of the honeycomb core is mainly influenced only by out-of-plane elastic properties. On the other hand, the syntactic foam is considered to be isotropic with two independent elastic constants namely, the modulus of elasticity and Poisson’s ratio. The face skin material may be isotropic with two independent elastic constants or orthotropic with nine elastic constants under three-dimensional loading. The present work is focused on predicting the elastic properties of a honeycomb core, syntactic foam and a glass/epoxy composite using existing theoretical models. Thereafter, the elastic properties of the syntactic foam and glass/epoxy composite are later used to establish the elastic constants for syntactic foam core sandwich composites using modified classical lamination theory (MCLT). The results reveal that the reviewed theoretical models for the honeycomb core, syntactic foam, fiber-reinforced polymeric (FRP) glass/epoxy face skins and sandwich composites are validated by the experimental results.