Experimental investigation of thermoforming carbon fibre-reinforced polyphenylene sulphide composites

Pre-consolidated carbon fibre-reinforced polyphenylene sulphide (CF/PPS) laminates were
thermoformed into V-shaped parts via designed out of autoclave thermoforming experiments.
The different processing conditions tested in the experiment have resulted in final
part angles whose differences ranged from 2.087 to 3.431 from the original mould angle.
The test results show that processing conditions influenced finished part dimensions as the
final sample angles were found to decrease relative to the tooling dimensions, as mould
temperature increases. Higher mould temperature conditions produce thinner parts due
to the thermal expansion of mould tools. The mould temperature of 170C, which can
produce parts with high degree of crystallinity as well as small size of crystal, has been
established as the optimal thermoforming condition for CF/PPS composites.

Finite Element Analysis of Drilling of Carbon Fibre Reinforced Composites

Despite the increased applications of the composite materials in aerospace due to their exceptional physical and mechanical properties, the machining of composites remains a challenge. Fibre reinforced laminated composites are prone to different damages during machining process such as delamination, fibre pull-out, microcracks, thermal damages. Optimization of the drilling process parameters can reduces the probability of these damages. In the current research, a 3D finite element (FE) model is developed of the process of drilling in the carbon fibre reinforced composite (CFC). The FE model is used to investigate the effects of cutting speed and feed rate on thrust force, torque and delamination in the drilling of carbon fiber reinforced laminated composite. A mesoscale FE model taking into account of the different oriented plies and interfaces has been proposed to predict different damage modes in the plies and delamination. For validation purposes, experimental drilling tests have been performed and compared to the results of the finite element analysis. Using Matlab a digital image analysis code has been developed to assess the delamination factor produced in CFC as a result of drilling. © Springer Science+Business Media B.V. 2011.