MECHANICAL CHARACTERIZATION OF THIN-WALLED GFRP MEMBERS BASED ON EXPERIMENTAL DYNAMIC TESTING

Resumo

The use of composite materials such as pultruded members of glass-fiber reinforced polymer
(GFRP) has increased in recent years, with important applications for footbridges, bridge decks, cooling
towers, stair towers, industrial structures, and rapid-assembly kits for temporary accommodation. The
mechanical characterization of GFRP in terms of elastic properties is often carried out by means of
destructive tests as specified by international standards. On the other hand, recent studies have proposed
the use of non-destructive techniques based on dynamic testing also known as experimental modal
analysis (EMA). In this sense, this work aims to identify the dynamic properties of thin-walled GFRP
members regarding their natural frequencies, mode shapes and damping ratios. These experimental
dynamic characteristics obtained for a C-channel beam are, then, used to determine specific material
elastic properties back-calculated from numerical optimization process. Finally, the properties
determined from proposed approach are compared to those obtained from classical destructive tests.
Therefore, the non-destructive procedure presented in this paper gives an alternative approach for the
mechanical characterization of GFRP members, which is especially important for low cost in situ quality
control.