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It is planned that the high voltage electrical insulation on the ITER feeder busbars will consist of interleaved layers of epoxy resin pre-impregnated glass tapes (‘pre-preg’) and polyimide. In addition to its electrical insulation function, the busbar insulation must have adequate mechanical properties to sustain the loads imposed on it during ITER magnet operation. This paper reports an investigation into suitable materials to manufacture the high voltage insulation for the ITER superconducting busbars and pipework. An R&D programme was undertaken in order to identify suitable pre-preg and polyimide materials from a range of suppliers. Pre-preg materials were obtained from 3 suppliers and used with Kapton HN, to make mouldings using the desired insulation architecture. Two main processing routes for pre-pregs have been investigated, namely vacuum bag processing (out of autoclave processing) and processing using a material with a high coefficient of thermal expansion (silicone rubber), to apply the compaction pressure on the insulation. Insulation should have adequate mechanical properties to cope with the stresses induced by the operating environment and a low void content necessary in a high voltage application. The quality of the mouldings was assessed by mechanical testing at 77 K and by the measurement of the void content.

The mechanical and tribological performances of glass-epoxy (GE) and carbon-epoxy (CE) pre-peg composites are presented in this paper. Composites were prepared from their respective pre-pegs using compression molding technique. The mechanical and three body abrasive wear tests were conducted as per ASTM standards. Evaluation of mechanical properties indicated that carbon-epoxy composites had superior properties compared to glass-epoxy composites except the tensile modulus and percentage elongation. The three body wear study has shown the considerable influence of sliding distance on wear rate. The sliding velocity and normal load have shown lesser influence on wear rate. This study has shown that pre-peg composites can be successfully prepared using compression molding technique and can be tested as per ASTM standards.

This paper approaches the design, modeling, and manufacturing process of the multipurpose steering wheel for a formula-style race car. The Multipurpose steering wheel is a device for lateral control of the formula student and also for changing the formula’s parameters. Steering wheel’s parts are designed with an aim to comfort, usefulness, manufacturability, and cost of prototype. Subsequently, the main body modular mold design and manufacturing process is presented, taken into the account the technology of production and material with suitable attributes selection. For the steering wheel, it is utilized the technology of pre-impregnated carbon fiber fabric reinforced polymer (CFRP) cured in an autoclave. Design of layers of composite material is described in the detail, followed by the material’s bend test. Custom internal parts made by 3D printing technology with a purpose of mounting electrical components and mechanical control components are demonstrated. The final product is part of formula student electric racing car SGT-FE18.

A novel pre-preg coating method was used to improve the interlaminar fracture toughness in carbon fibre epoxy composite laminates, using reactive liquid rubber. The Epoxy Terminated Butadiene Nitrile (ETBN) liquid rubber incorporated between pre-pregs using automatic draw bar coating technique. Experimental test results reveal that by adding ETBN in small quantities in the range of 15.55–22.66 g/m2, inter laminar critical energy release rates (GIC and GIIC) can be improved up to 140% in mode-I loadings and 32% in mode-II loadings respectively. It was confirmed that the effect of ETBN rubber concentration in carbon epoxy pre-preg system on interlaminar fracture toughness under mode-I and mode-II loadings, was discussed by on the bases of fractographic observations and mechanism considerations using SEM.

This paper introduces an experimental and numerical investigation into hollow cylindrical thin-walled glass fibre reinforced epoxy matrix composite shafts produced by using both pre-preg wrapping and filament winding methods. The filament wound samples were manufactured with four different helix angles ([±30]FW, [±45]FW, [±60]FW, and [±75]FW ), whereas [0, 90]PP pre-pregs was utilised for producing the wrapped kind of samples. In order to assess the quasi-static failure responses, the samples were subjected to increasing amount of torsional load at a fixed angular rotation speed. The experimental findings of [±30]FW, [±45]FW, and [±60]FW samples were found to be very compatible with those obtained via Finite Element Analysis (FEA). Contrarily, the numerical model were not able to describe accurately the load—displacement behaviour of [±75]FW and [0, 90]PP with the exception of the initial loading phase. [±45]FW was found as the most favourable option for designers in terms of torsional stiffness. Whereas, those characterised by [±30]FW, and [±60]FW exhibited very close torsional resistances in a difference range of only 5%. [0, 90]PP exhibited the lowest average torsional failure resistant and stiffness but the highest average rotation angle before rupture.

The most common commercial processes for manufacturing pre-pregs for electronic applications use solvent-based epoxy systems. Solvents are environmentally unfriendly and contribute to voids in the pre-preg and laminate. Voids cause product variability, which is a major source of scrap in board shops. In this paper, we use chemo-rheological and kinetic measurements to identify a potential epoxy-based resin system for a solventless process that is based on injection pultrusion. Differential scanning calorimetry and rheological data show that the candidate system does not react appreciably without catalyst up to temperatures of 170 °C or with catalyst at temperatures

Shape memory alloys (SMA) exhibit functional properties associated with the shape memory effect, responsible of the SMA shape recovery after a cycle of deforming-heating and of a simultaneous generation of mechanical work. Composite systems incorporating SMA wires have the ability to actively change shape and other structural characteristics. The functional properties of such adaptive composites are related to the martensitic transformation in the SMA elements and to the constraining behaviour that the composite matrix has on the SMA wires. In this work the behaviour of a shape memory alloy hybrid composite (SMAHC) is numerically and experimentally investigated. A plate was fabricated using prestrained SMA wires embedded in an epoxy resin pre preg glass fibres composite system. Upon calorimetric and mechanical material characterization, a finite element model was used in order to predict the structural behaviour of the SMAHC. In the experimental tests, the plate was clamped at one side and actuated via electrical heating. Temperature and displacement data were collected and compared with the prediction of the finite element model. The results show that the model is able to capture the shape change in the actuation region, although a thorough description of the SMAHC behaviour requires further modelling work, including the simulation of the SMA loading history during composite manufacturing.

A new pre‐impregnated (pre‐preg) ceramic‐based electrical insulation system capable of surviving high superconductor reaction temperatures has been developed for use in superconducting magnets. The use of Nb3Sn superconductors holds great promise for increased magnet performance for high energy physics, fusion, and other applications. A robust, cost‐effective manufacturing process is critical to the successful implementation of these coils. Due to its embrittlement after the high temperature reaction cycle, Nb3Sn cable is usually insulated and wound into the coil prior to heat treatment. An earlier ceramic‐based insulation system, applied using wet‐winding or vacuum impregnation, has been successfully used in the “wind and react” fabrication process. Use of the new pre‐preg system will further simplify the manufacturing process while improving control over the insulation properties. Pre‐preg insulation offers several advantages including improved dimensional control of the insulation, controllable and uni...

Insulation is one of the critical components for high‐field Nb3Sn magnets that follow wind‐and‐react approach. The insulation material has to withstand high bending stresses while winding the coil and high heat‐treatment temperatures under pressure during coil reaction. At Fermilab we have developed a procedure and tested successfully the dry ceramic insulation tape with inorganic liquid binder to wind and cure the coils. Recently we have extended this to a pre‐preg ceramic insulation tape, which would minimize and control the amount of binder in the coil. Several coils with various insulation patterns have been fabricated and tested at Fermilab. This paper discusses the fabrication issues of the coils with different types of cable insulation including the pre‐preg ceramic insulation.

Polymeric matrix composites are the standard materials used in the construction of Formula 1 racing cars. The transition to these from metallic types for primary load-bearing structures began in 1980 and progressed rapidly thereafter. The original reason for the change was a perceived lack of stiffness in the main semi-monocoque chassis relative to that required for the increased aerodynamic loading being generated from that time onwards; vehicle performance, meanwhile, is also strongly affected by mass. Composites, therefore, provided an improvement in stiffness for no weight penalty. Stiffness design, however, was only one consideration as, in an activity where there is substantial inertial loading – and high probability of collision with barriers or other cars – strength is a parallel consideration. The range of design criteria for composites within the assembly is broader, however, also covering impact energy absorption, damage resistance, fatigue durability, and environmental tolerance. Manufacturing methods are largely confined to the use of carbon/epoxy prepregs, composite tooling, and autoclave curing. In this fast-moving industry, evolution of design thinking is rapid and component complexity is extreme but unit numbers of parts are low; intricacy in designs is, therefore, tolerable.