Temperature effects on mechanical properties of woven thermoplastic composites for secondary aircraft structure applications

Abstract

The effect of temperature on the mechanical behavior of 8-H satin woven glass fabric/polyethylene sulfide (GF/PPS) was investigated in this paper. Static-Tensile tests were both conducted on notched and unnotched specimens at typical temperatures (ambient, 95oC and 125oC) based on the glass transition temperatures (Tg) of the neat resin and composite, their strength and moduli were obtained and compared. The damage patterns of failed specimens of notched and unnotched were examined with the aid of high-definition camera and stereomicroscope. The results of stress-strain relationships showed that the slight nonlinearity of the curves were observed for these two specimens, which was associated with the plastic deformation of localized resin. The damage patterns of notched and unnotched specimens at different temperatures proved that damage and plastic deformation were two simultaneous mechanisms and it was prominent in the notched. It was the overstress accommodation mechanism that led to a relative high strength rentention for the notched and a reduction of the hole sensitivity. The results obtained in this paper indicated that GF/PPS can be used as secondary aircraft structures at elevated temperatures higher than its Tg.