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The carbon fiber orientation distribution (FOD) of carbon fiber-reinforced polyamide 6 was estimated using wide-angle X-ray diffraction (WAXRD) images of the composites. In the diffraction image of the aligned carbon fibers, the straight line connecting the pair of diffraction spots caused by the graphite crystal is orthogonal to the fiber axis. This property was employed to investigate the FOD. In this study, we attempt to express WAXRD images, that is, the intensity distribution ( I (2 θ i , φ j ) ) by the linear combination of the radial basis functions arranged in the diffraction angle ( 2 θ i ) and azimuth angle ( φ j ). Consequently, FOD corresponds to the weight vector derived through serial waveform separation. Based on this concept, we attempted to identify the laminated composition of the composites, such as unidirectional, cross-ply, and quasi-isotropic composites. The analysis results were in good agreement with the ideal laminated composition. [ABSTRACT FROM AUTHOR]

The Dyneema fiber reinforced plastic (DFRP) that has a high thermal conduction property is used as a heat drain material for conduction cooled magnet. The experiments conducted on DFRP indicate that the effects depend on the fiber directions in the plastic.

The study is conducted to discuss a technique in order to reduce mechanical losses under AC operation by use of Zylon fiber reinforced plastic (ZFRP) bobbin in superconducting coils. The test results indicate that the coils whose winding tension at cryogenic temperature are strong make the reduction of mechanical losses possible.

A study is conducted to examine the influence of mechanical losses in AC superconducting coils having composite materials reinforced with Dyneema and glass fibers. The effect of the reduction of the mechanical losses in the coils having the DGFRP bobbins and the comparison with the coils whose bobbins are the DFRP and the GFRP are presented.

It is shown that plastics with high thermal conductivity can be used as spacers in conduction-cooled HTS coils.

Frictional losses caused by the periodic vibration of superconducting wires in AC superconducting coils are investigated and discussed.

Frictional properties are investigated, using an experimental simulation, to determine mechanical losses occurring in AC superconducting coils.

Coils that use Dyneema fiber reinforced plastic (DFRP) bobbin and stainless steel (SUS) bobbin are configured , and induced voltages between the ends of the coils are measured in a backup magnetic field. The coil with SUS bobbin showed sharp peaks in tap voltage induced by quick wire motions, but those using DFRP bobbin showed only a few small peaks, suggesting that motions were constrained by DFRP bobbin.

Two types of superconducting coils having the same specifications have been developed. One of the coils was manufactured from Dyneema fiber reinforced plastic bobbins that expands during the cooling process from room temperature levels to liquid helium temperature levels. The other coil is made of glass fiber reinforced plastic bobbins that contract during the same cooling process. A study of the effect of quench currents on the behavior of the materials has been conducted.

The fabrication of cable-in-conduit conductors (CICCs) with two kinds of nonmetallic conduit materials and the mechanical losses are measured. The results show that the losses decrease with the decrease of the void ratios in the cable-in-conduit conductors.

The fiber length distribution (FLD) is one of the factors that determine the mechanical properties of discontinuous carbon fiber reinforced plastic (CFRP). However, accurate sampling for FLD evaluation of CFRP is difficult because the homogeneity of CFRP for sufficient and measurable sample sizes is not always guaranteed and the carbon fibers in the evaluation specimens are easily broken. In this study, we presented a sampling method that extracts a sub-milligram-scale sample from the gram-scale quantity of carbon fibers. Based on the proposed method, filtration and a multi-stage sampling procedure were employed to prepare the sample. This method showed better precision compared to the sampling method of pulling the carbon fibers from the target with tweezers. Furthermore, our developed sampling method for FLD evaluation enabled the preparation of the sample representing a gram-scale quantity of the discontinuous carbon fibers. [ABSTRACT FROM AUTHOR]