Characterisation of the mechanical and thermal degradation behaviour of natural fibres for lightweight automotive applications

It is well established that light-weighting of automotive parts leads to reduced carbon emissions over vehicle lifetime. Mineral fibres and fillers have a relatively high density and may require high levels of energy in their production, resulting in a large carbon footprint. Natural fibres have been identified as a potential candidate to substitute mineral fillers in automotive application of thermoplastic matrix composites. This paper focuses on the characterisation of the mechanical and thermal degradation of two types of natural fibres (date palm and coir fibres) as part of an evaluation of their potential for the substitution of high density mineral fillers with more environmentally friendly lower density natural fibre reinforcements

Characterisation of the mechanial and interfacial adhesion performance of natural fibres in polyolefin compounds for lightweight automotive applications

This paper presents a study on the measurements of the interfacial adhesion of coir fibre with various polypropylene (PP) matrices along with the mechanical properties of their related injection moulded composites. The interfacial adhesion between coir fibres and homopolymer and copolymer polypropylene, including the effect of coupling agent, was investigated using the pull-out method. The addition of coupling agent significantly increased the interfacial shear strength of coir fibre polypropylene. Results are presented from tensile and impact testing for characterisation of tensile properties and notched and un-notched impact strength of coir reinforced polypropylene. Results showed a positive effect of the coupling agent on stress at yield, Young’s modulus and un-notched impact strength

Characterisation of the mechanical performance of natural fibres for lightweight automotive applications

It is well recognized that light weighting of automotive parts leads to reduced carbon emissions over vehicle lifetime. Mineral fibres and fillers have a relatively high weight and can require very high levels of energy in their production, resulting in a large carbon footprint. Natural fibres could be a potential candidate to substitute mineral fillers in automotive application of thermoplastic matrix composites. Results will be presented from single fibre testing for characterization of fibre modulus and strength. One of the unique aspects of natural fibres is their variable, non-circular cross-section which usually has larger dimensions than mineral fibres and fillers. This paper will further discuss the need for accurate determination of fibre cross-section in order to properly characterize the mechanical performance

Analysis of Geometry and Field Quality Along the Series Production of the 11 T Dipole for the High Luminosity LHC

The first series production of Nb3Sn Accelerator Magnets is approaching its end. The LHC dipole upgrade within the scope of the High Luminosity project consists of collared assemblies of 5.6 m-long coils targeted for a nominal field of 11 T at 11.85 kA and 60 mm aperture. As part of the quality control of the production, geometrical and magnetic measurements are performed at different steps. The experience gathered during manufacturing of 28 coils and 11 collared coils is summarized here. Using the available data, we analyzed the distributions of coil geometry, collared coil size, main field, and low order field errors in warm conditions. In some cases, the trends were traced back to displacements of the conductor with respect to the nominal layout. Three magneto-static conductor deformation models aim to explain the variability of field harmonics, confronted with measured data

Mechanical analysis of the collaring process of the 11 T dipole magnet

As part of the Large Hadron Collider (LHC) accelerator upgrades foreseen by the high luminosity-LHC project, the CERN 11 T program is aimed at replacing standard LHC Nb-Ti main dipole magnets, operating with a bore field of 8.3 T, with pairs of shorter Nb$_3$Sn dipole magnets with a bore field of 11 T and the same total integrated field, thus providing space for additional collimators in the dispersion suppressor region. At the time of the submission of this paper, six single-aperture and two double-aperture short models have been fabricated and tested. As a result of a degraded quench performance observed in some of the short models, attributed to excessive stress on the Nb$_3$Sn coil mid-planes, a thorough investigation of the room temperature loading procedure, and in particular of the collaring process, has been launched. A 150-mm-long collared coil mockup, instrumented with strain gauges and pressure sensitive films, has been used to study the peak stresses experienced by the brittle and strain sensitive Nb$_3$Sn cables in the different phases of the collaring and as a function of coils' size and collaring force. In this paper, the results of the test campaign are described