Epoxy carbon fiber composite laminate

Figure 2-21 The various changes in mechanical properties when the arrangement angle of carbon fibers in an epoxy/carbon fiber composite laminate is varied.

HDPE, composite materials such as epoxy-glass fiber and epoxy-carbon fiber, and laminate structures such as polymer films on bulk metal substrates. Thin-conductive film heaters were made of electrically conductive paints, electrically conductive polymer films, metal foils (stainless-steel, copper, titanium, and titanium alloys), and thin metal films sputtered on a ceramics or glass. The samples dimensions varied from a few centimeters to 5m. 

Fig. 3.4 Additional water uptake of unidirectional laminate measured at 70°C exhibiting two-equilibrium stages seemingly due to polymer swelling and physical relaxatirai (Suh et al. 2001) Credit Suh D, Ku M, Nam J, Kim B, Yoon S. Equilibrium wato uptake of epoxy/carbon fiber composites in hygrothermal environmental conditirais. 35(3) 264—278, copyright 2001 by Journal of Composite Materials. Reprinted by Permission of SAGE...

Carbon-Fiber Composites. Cured laminates of phenoHc resins and carbon-fiber reinforcement provide superior flammabiHty resistance and thermal resistance compared to unsaturated polyester and epoxy. Table 15 shows the dependence of flexural strength and modulus on phenoHc—carbon-fiber composites at 30—40% phenoHc resin (91). These composites also exhibit long-term elevated temperature stabiHty up to 230°C. 

The results presented below were obtained using a 2 mm thick carbon fiber reinforced epoxy composite laminate with 16 layers. The laminate was quasi isotropic with fiber orientations 0°, 90° and 45°. The laminate had an average porosity content of approximately 1.7%. The object was divided in a training area and an evaluation area. The model parameters were determined by data solely from the training area. Both ultrasound tranducers used in the experiment had a center frequency of 21 MHz and a 6 dB bandwidth of 70%. 

High performance composites may be laminates wherein veils of carbon fiber ate treated with an epoxy resin, stacked up to the desired final product thickness, and then laminated together under heat and pressure (see Composite materials Carbon and graphite fibers). Simply mixing together carbon or glass fibers and polymeric resins to form a reinforced plastic leads to a composite material, but this is not a laminate if not constmcted from discrete phes. 

Nanocarbon composites can be broadly divided into three kinds, each with some possible subdivisions. Examples of these composites and their schematic representations are presented in Fig. 8.1. The first type corresponds to composites where the nanocarbon is used as a filler added to a polymer matrix analogous, for example, to rubber reinforced with carbon black (CB). The second consists of hierarchical composites with both macroscopic fibers and nanocarbon in a polymer, such as a carbon fiber laminate with CNTs dispersed in the epoxy matrix. The third type is macroscopic fibers based... 

Fig. 8.15. Edge delaminalion and ultimate strength of [ 35°/0°/90°k AS4 carbon fiber-3501 epoxy matrix composite laminates with and without interleaves.

Figure 5.122 Strength chart for a (0, 9) unidirectional carbon-fiber-reinforced epoxy laminate composite. Reprinted, by permission, from N. G. McCrum, C. P. Buckley, and C. B. BucknaU, Principles of Polymer Engineering, 2nd ed., p. 408. Copyright 1997 by Oxford University Press.

Kusaka T, Hojo M, Ochiai S, Kurokawa T. Rate-dependent mode II interlaminar fracture behavior of carbon fiber/epoxy composite laminates. Mater Sci Res Int 1999 5 98-103. 

Trakas K, Kortschot MT. The relationship between critical strain energy release rate and fracture mode in multidirectional carbon-fiber/epoxy laminates. In Armanios EA, editor. Composite materials fatigue and fracture, vol. 1285. ASTM Special Technical Publication 1997. pp. 283—304. http //dx.doi.org/10.1520/ STP19933S. 

Soutis C, Measurement of the static compressive strength of carbon-fiber epoxy laminates, Composite Sci Technol, 42(4), 373-392, 1991. 

---