Prior Thermal Spikes and Thermal Shocks on Mechanical Behavior of Glass Fiber-Epoxy Composites

Abstract

Fiber-reinforced glass-epoxy composites with and without prior thermal history are subjected to hygrothermal conditioning for different exposure times. The prior thermal history is given in the form of thermal shocks and thermal spikes at three different temperatures. The effects of exposure time and prior thermal history on the moisture absorption kinetics are studied. The effects of prior conditioning parameters are also investigated. The variation of mechanical properties as a function of exposure time and prior conditioning parameters are assessed by the three-point short beam shear bend test. It has been observed that there is an initial improvement in the mechanical properties followed by a steady deterioration. Mechanical tests performed at different crosshead velocities show increasing brittleness of the composites and that is found to be a function of cross-head velocity.