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Reinforced composite materials
Published in Andrew Livesey, Motorcycle Engineering, 2021
Pre-preg has a limited shelf life, which is compounded by the fact that it must be stored at -18 °C. A deep freeze cabinet is therefore needed for storage. The pre-preg cannot be unrolled or cut when it is in the frozen state, so it must be removed from the freezer and brought up to normal room temperature. It is only possible to freeze and defrost the pre-preg a limited number of times, so the material must be managed carefully. The usual way to do this is by means of a control card. The dates and times of defrosting are recorded, as is the amount of material taken off the roll. That way the life of the roll and the amount of material left can be seen without removing the roll from the freezer.
Reinforced composite materials
Published in Andrew Livesey, Bicycle Engineering and Technology, 2020
Pre-preg has a limited shelf life which is compounded by the fact that it must be stored at −18°C. A deep freeze cabinet is, therefore, needed for storage. The Pre-preg cannot be unrolled nor cut when it is in the frozen state, so it must be removed from the freezer and brought up to normal room temperature. It is only possible to freeze and de-frost the Pre-preg a limited number of times, so the material must be managed carefully. The usual way to do this is by means of a control card. The dates and times of defrosting are recorded as is the amount of material taken off the roll. That way the life of the roll and the amount of material left can be seen without removing the roll from the freezer.
Reinforced composite materials
Published in Andrew Livesey, Alan Robinson, The Repair of Vehicle Bodies, 2018
Pre-preg has a limited shelf life which is compounded by the fact that it must be stored at −18°C. A deep-freeze cabinet is therefore needed for storage. The pre-preg cannot be unrolled nor cut when it is in the frozen state, so it must be removed from the freezer and brought up to normal room temperature. It is only possible to freeze and defrost the pre-preg a limited number of times, so the material must be managed carefully. The usual way to do this is by means of a control card. The dates and times of defrosting are recorded, as is the amount of material taken off the roll. That way the life of the roll and the amount of material left can be seen without removing the roll from the freezer.
First lamina hybridization of high performance CFRP with Kevlar fibers: Effect on impact behavior and nondestructive evaluation
Published in Mechanics of Advanced Materials and Structures, 2023
Carmelo Militello, Gabriella Epasto, Francesco Bongiorno, Bernardo Zuccarello
As above-mentioned, the hybrid C-KFRP composite material considered in study is a particular laminate widely used for sport automotive applications. It is generally manufactured by hand lay-up with subsequent vacuum bagging and autoclave curing processes with Tmax = 125 °C and Pmax = 5 bar for about two hours, by using pre-pregs laminae supplied by Delta-Preg S.p.a., in accordance with a defined stacking sequences reported in Table 1. These pre-preg laminae are made of epoxy thermosetting resin DT120, having a density equal to 1.22 g/cm3 and a range of curing temperature between 80 and 135 °C. Such resin has good impact strength. In more detail, the considered tri-component hybrid C-KFRP composite is constituted by a surface lamina reinforced by a twill type hybrid fabric (type GA210T, specific weight of 210 g/m2) consisting of alternating yarns made in carbon and Kevlar fibers, superimposed to two internal laminae reinforced by twill type carbon fabrics (type C630T, specific weight of 630 g/m2). The bi-component basic CFRP laminate, properly analyzed to highlight the hybridization effects, is constituted by three laminae reinforced by the same twill type carbon fabric C630T, with the lay-up reported in Table 1.
Numerical simulation of deployable ultra-thin composite shell structures for space applications and comparison with experiments
Published in Mechanics of Advanced Materials and Structures, 2023
Alfonso Pagani, Riccardo Augello, Erasmo Carrera
First analysis regards a typical TRAC boom employed in aerospace applications. Figure 5 describes the geometry and the stacking sequence of the structure where t represents the thickness of the curved flange and it is equal to 80 μm, r is its curvature radius equal to 12.7 mm, ϑ is the sweep angle equal to 90°, the flat vertical web h is 8 mm long and total length L of the TRAC is equal to 570 mm. The displayed stacking sequence reveals three layers for the curved flange and seven layers for the flat web, and the properties of the implemented material are reported in Table 1, where CF represents a unidirectional carbon fiber pre-preg tape with epoxy resin and GFPW stands for E-glass fabric glass fiber plain weave pre-preg with epoxy resin.
Optimized dynamic line scanning thermography for aircraft structures
Published in Quantitative InfraRed Thermography Journal, 2019
Jeroen Peeters, S. Verspeek, S. Sels, B. Bogaerts, G. Steenackers
The thermal model is built using the NX thermal solver. The thermal material properties are found in the CES material database [13] for unidirectional pre-preg CFRP with Epoxy matrix material and Rohacell foam. The heat source of 2000 W/m is approximated with a moving 2D mesh at a constant speed. The moving mesh contains a boundary heat source which emits Gaussian diffuse radiation. The view factors are computed using a Monte Carlo simulation in order to evaluate for each position of the moving heat source, the intensity received by the top layer mesh elements of the test sample. As the heat source moves over the test sample, the view factors variate over time.