Table of Contents
ISRN Mechanical Engineering
Volume 2011 (2011), Article ID 251219, 7 pages
Research Article

Estimation of Long-Term Stiffness of Storage Aged GFRP Composite Samples Immersed in HCl Acid by TTSP Method

1Department of Materials Engineering, Islamic Azad University, Najafabad Branch, 851414313, Isfahan, Iran
2Department of Chemical Engineering, Isfahan University of Technology, 84156, Isfahan, Iran
3Department of Materials Engineering, Isfahan University of Technology, 84156, Isfahan, Iran

Received 13 January 2011; Accepted 15 February 2011

Academic Editors: K. Y. Lee and L. Ma

Copyright © 2011 Salar Bagherpour et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The 15-year storage aged GFRP composite dumbbell-shaped specimens were immersed in concentrated HCl at different temperatures and times. The Young modulus, which is a yardstick of stiffness of the samples, was measured. The long-term stiffness at any time and temperature was predicted by using the master curve of stiffness obtained based on our accelerated testing results. In the first, second, third, and fourth years of the prediction the stiffness was  6800, 6400, 5550, and 5150 MPa, respectively. SEM micrographs of typical samples showed failure mode at the interface. The strength showed reduction due to degradation of fiber/matrix interfacial bond. The best match of our prediction obtained by using error function was between the first and the third years.