D. Barpanda et Pr. Mantena, DYNAMIC-MECHANICAL ANALYSIS OF PULTRUDED GLASS-GRAPHITE EPOXY HYBRID COMPOSITES AT ELEVATED-TEMPERATURES/, Journal of reinforced plastics and composites, 15(5), 1996, pp. 497-532
In this paper the dynamic performance characteristics of pultruded gla
ss-graphite/epoxy hybrid samples at elevated temperatures are presente
d. In previous research the dynamic mechanical properties of the hybri
d composites have been characterized at room temperature but the wide
application range of these pultruded products necessitates their chara
cterization at high temperatures and over longer periods. The dynamic
mechanical analysis technique has been employed to characterize pultru
ded glass-graphite/epoxy hybrid composite materials over a wide temper
ature range. At elevated temperatures, the rate of degradation in flex
ural modulus and variation in loss factor were found to be dependent o
n the fiber lay-up sequence. Results indicate that the width of the gl
ass transition zone, an important design criterion, can be effectively
broadened by judicious incorporation of the glass fibers. Tests repea
ted on post-cured pultruded products demonstrate a significant shift i
n the glass transition temperature towards higher side along with an i
ncrease in the onset temperature of glass transition. The frequency mu
ltiplexing technique used in conjunction with the time-temperature sup
erposition principle proved to be an effective method for predicting t
he long-term behavior of these hybrids.