THE RELIABILITY LEVEL IN DETERMINING THE YIELD STRENGTH OF GLASS FIBRE-SIC REINFORCED EPOXY RESIN BASED ON INPUT VOLUME FRACTIONS OF GLASS FIBRE AND SIC

Abstract

The reliability level in determining the yield strength of glass fibre-SiC reinforced epoxy resin based on input volume fractions of glass fibre and SiC has been established. The yield strength of the composite was predicted, using a derived empirical model; ϒ =  Ϧɤs  - ẞɤg  + N. Analyses of generated results indicate that the validity of the derived model is strongly rooted on the core model structure; ϒ + ẞɤg ≈ Ϧɤs  + N, where both sides of the structure are correspondingly near equal. The model-predicted results are in agreement with previous research, considering the direct and inverse relationships between yield strength of the composite and input volume fractions of SiC and glass fibre respectively. The correlations evaluated using experimental and model-predicted results, between the yield strength and volume fractions of glass fibre & SiC were all > 0.99. The standard error involving model-predicted yield strength, relative to the experimental results was 1.89%. This translates to over 98% model confidence levels.  The yield strengths of the composite per unit volume fractions of glass fibre & SiC were -5.1571, -4.8435 and -4.8509 MPa (%)-1 and 2.79, 2.6203 and 2.6243 MPa (%)-1, using experimental, derived model-predicted and regression model-predicted results respectively. The overall maximum deviation of the model-predicted tensile strength from experimental results was < 7%. The derived model will evaluate the yield strength of the glass fibre-SiC reinforced polyester, within the experimental results range, on substituting into the model, volume fractions of glass fibre and SiC, providing the boundary conditions are considered.

 

KEYWORDS: Yield strength, Glass Fibre-SiC, Epoxy Resin, Hand Lay-Up, Input Volume Fraction.