SME EM00-246

Coefficients of thermal and moisture expansion (CTE and CME) can be predicted for many composite laminates and sandwich panels. Core and adhesive properties, such as geometry and stiffness are important variables. Laminate theory is augmented with a modified model for anisotropic core properties to predict the CTE and CME of sandwich panels. Procedures to measure both CTE and CME are described. Since these are thermodynamic properties, methods to obtain equilibrium moisture strains are needed. Results are given for CFRP facesheets with A1 and NOMEX honeycomb cores, and for woven Kevlar facesheets with A1 cores. Tests with both sealed and unsealed edges are analyzed. Diffusion in unsealed sandwich panels, especially with moisture absorbing cores is non-Fickian and requires a three dimensional analysis to provide equilibrium data.

Product Details

Published:

11/01/2000

Number of Pages:

15

File Size:

1 file , 920 KB