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Abstract Fused filament fabrication is considered one of the most used processes in additive manufacturing rapid prototypes out of polymeric material. Poor strength of the deposited layers is still one [...]

In this article, the overall mechanical properties of a short glass fiber-reinforced polyphenylene sulfide (PPS) composite were tested after oxidation at different temperatures (140, 160, 180, and 200[degrees]C), with a maximum oxidation time of approximately 5,300 h. In aspect of thermal aging process, the oxidation rates in 200 and 180[degrees]C are considerably harsher and faster than the case in 160 and 140[degrees]C, according to the concentration evolution of [C=O]. In aspect of mechanical properties, for virgin samples, due to an excellent fiber-matrix adhesion, no progressive damage is developed. Moreover, the fatigue results of aged samples show that the fatigue lifetime of PPS composites decreases more and more obviously with the oxidation time increasing while no significant loss of stiffness is observed. In addition, both monotonie and cyclic loadings are basically driven by the PPS matrix deformation. In the end, the relationship between fatigue lifetime and concentration of [CO] is built and discussed., INTRODUCTION In the past several decades, glass fiber-reinforced polyphenylene sulfide (PPS) composites are widely used to lighten automotive parts and other application sections [1-15]. The main reason to use this [...]

The design of 700‐bar composite tanks considering the safety factor imposes resistance to a bursting pressure greater than 1645 bars remains difficult which leads to the addition of carbon fibers. On the other hand, the specifications in terms of mass storage capacity and cost require the quantity of this same fiber to be limited. Thus, the optimal sizing of the composite remains one of the major challenges in the development of 700‐bar tanks. This study is focused on an optimum design of dome contours for 700 bar hydrogen tank type IV considering the geometrical limitations, winding condition, and the feasible direction. The study is centered on the composite part and is separated into two parts: a study of the manufacturing process (filament winding) in its fundamental aspects and a structural calculation under HyperWorks to check the mechanical strength of the composite layers and optimize their stacking and the number to ensure the holding while minimizing the mass and therefore the cost of the tank. [ABSTRACT FROM AUTHOR]

Influence of loading temperature on the damage mechanism of polyphenylene sulfide (PPS) reinforced by glass fiber (PPS/GF30) under tension was experimentally studied from quasi-static (QS) to high strain rates. Two kinds of PPS/GF30 samples were prepared: PPS-0° and PPS-90° (correspond to fibers oriented parallel and perpendicular to the injection direction, respectively). After microscopic observation and thermomechanical characterizations by dynamic mechanical analysis, tensile tests up to failure with strain rates varying from 10−3 s−1 to 100 s−1 have been carried out at 25°C and 120°C with regard to PPS/GF30 glass transition temperature. To achieve the coupling effect of high strain rate and high temperature, a special chamber was designed to install on the servo-hydraulic machine. The results of QS tensile tests confirm the significant effect of fiber orientation and temperature on the Young's modulus, the ultimate stress, and strain. High strain tensile test results showed that the PPS/GF30 composite is strain rate dependent at both temperatures. The results indicated that Young's modulus remains constant by strain rate increasing at both temperatures while ultimate stress and strain are increased. No significant damage has been observed at 25°C in QS loading, whereas the macroscopic damage variable is increased to 20% at 120°C. Debonding at the fiber–matrix interface is the main damage mechanism at 120°C. [ABSTRACT FROM AUTHOR]

Shape-memory polymers (SMPs) and their composites (SMPCs), as a kind of smart materials, can respond to particular external stimulus and recover the original shape. They present outstanding features encompassing shape-memory effect, deformability, biocompatibility, variable stiffness, lightweight, and so on. They have attracted considerable research interest in recent years. Several stimulation methods to actuate the deformation of SMPs and SMPCs, of which the thermal stimulation is the common one, and many types of reinforcements have been developed over the past few years. It is revealed that the SMPC thermal and mechanical properties can be improved by introducing a number of reinforcements. Therefore, to well investigate the SMPC characteristics upon exposure to a specific external stimulus, a deep knowledge and understanding of the potential reinforcements as well as the available stimulation methods are crucial. In this review, reinforcements such as fibers, ceramics, and nanocarbons are first concisely presented. Next, numerous novel stimulation methods used to trigger the memory effect of the SMPCs are introduced, where the mechanisms of electrical, magnetic, thermal, light, and solution stimulations are briefly discussed. Finally, considering the increase of the number of interesting reinforcements as well as the efficient stimulation methods, SMPCs are expected to have great potential applications in different fields. [ABSTRACT FROM AUTHOR]