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Lightweight fibre-reinforced thermoplastic (FRTP) driveshafts are ideal for automotive applications. In this work, material and buckling failures of FRTP driveshafts subjected to torsion at elevated temperature are analysed by finite element modelling. Critical speed at increasing temperature is also quantified. The driveshafts comprise unidirectional carbon/polyetheretherketone (PEEK) layers with/without an inner layer of aluminium or unreinforced plastic. Temperature-dependent material properties are considered. The results demonstrate achievable performance of the fully carbon/PEEK and hybrid driveshafts, which are compared with traditional alloy counterparts. The carbon/PEEK shaft exhibits marked temperature sensitivity but satisfies the design requirements at high temperature with significant weight reduction. A hybrid shaft composed of carbon/PEEK layers over-wrapped onto an aluminium tube provides a compromise in terms of superior buckling resistance and critical speed but reduced material failure safety factor. Utilising a thick layer of unreinforced plastic to reduce fibre volume may only be suitable for low-temperature, low-speed applications. [ABSTRACT FROM AUTHOR]

Spoolable thermoplastic composite pipe (TCP) consisting of fibre-reinforced laminate with inner and outer liners is an ideal candidate to replace steel counterparts in deepwater. In this paper, a 3D finite element (FE) model is developed to analyse stresses in TCP under combined bending and uniform temperature change illustrative of spooling in different environments. Thermal load causes deviation from the stress symmetry expected at the top/bottom of the pipe in simple bending. Maximum stress, Tsai–Hill and Hashin failure responses are analysed for [±55]4, [±42.5]4, [±30]4 and [(±55)2/(±30)2] laminates at low and high temperatures. The [±42.5]4 configuration displays superior spooling capacity as layers orientated at ±55° and ±30° exhibit high utilisation of relatively weak transverse tensile and fibre compressive strengths, respectively. The failure criteria are in closest agreement at the top of the pipe (under axial tension) but differ more significantly at the bottom (axial compression). [ABSTRACT FROM AUTHOR]

The paper reviews practical applications of composite materials in oil and gas industry. A special consideration has been paid to possible future opportunities in offshore and onshore usage; in particular, to long fibre-reinforced composite pipes. The problem of thick-walled filament-wound multi-layered composite pipes subjected to outer pressure is considered as an example. An analytical method is used for failure analysis for different lay-ups and loading conditions. The stress distributions through the pipe thickness for various lay-ups are computed for fibre-reinforced pipes under different outer pressure magnitudes. [ABSTRACT FROM AUTHOR]

Metal-ceramic composites offer many advantages over monolithic metals and their alloys such as high specific stiffness and strength, better creep, fatigue and wear resistance, and good thermal properties. One of the recent advances in this area has been made possible thanks to innovative ceramic preforms, fabricated by freezing a water-alumina suspension and subsequent freeze-drying and sintering. As a result these metal/ceramic composites possess a hierarchical lamellar microstructure, with randomly orientated individual regions (domains), in which all ceramic and metallic lamellae are parallel to each other. Metal-ceramic composites with hierarchical lamellar microstructure exhibit pronounced elastic and plastic anisotropy at the domain level. In this paper, stress fields in a single-domain sample of metal-ceramic composite containing multiple cracks in the ceramic layer are investigated. The cracked microstructure for different stage of damage is modeled by analytical and computational approaches. The stress field is determined using a modified 2-D shear lag approach and a finite element method. The result obtained by finite elements analysis is consistent with experimental results. According to the obtained result, the average axial stress between two cracks is decreasing with decreasing the distance between the cracks. [ABSTRACT FROM AUTHOR]