Laminate design other reinforcements

The effect of dispersoids on the mechanical properties of metals has already been described in Section 5.1.2.2. In effect, these materials are composites, since the dispersoids are a second phase relative to the primary, metallic matrix. There are, however, many other types of composite materials, as outlined in Section 1.4, including laminates, random-fiber composites, and oriented fiber composites. Since the chemical nature of the matrix and reinforcement phases, as well as the way in which the two are brought together (e.g., random versus oriented), vary tremendously, we shall deal with specific types of composites separately. We will not attempt to deal with all possible matrix-reinforcement combinations, but rather focus on the most common and industrially important composites from a mechanical design point of view. 

Characteristic material properties for fibre reinforced composites cannot be so rigorously defined as for most other structural materials. Standard data are either not generally available or cannot be relied upon except for preliminary design. Because of its nonhomogeneity and anisotropy, up to 21 elastic constants may, in theory, be required for a full analysis of a complex laminate. In practice though, due to symmetry, these reduce to ... 

In principle, every laminate structure is processable with a CCM machine so that the mechanical properties of profiles can be very different. Because of the working principle of the press, most profile designs will have no circumferential reinforcement fibers. For hollow profiles there is at least one joining zone, which has to transmit the load to the other part of the profile. The quahty and the performance of this joining zone are mainly determined by the process conditions and by the used matrix materials, which makes it difficult to give a general assessment. 

An unaccelerated, low viscosity, styrene free, corrosion resistant (to acidic and aikaline environments), flame retardant (<25 ASTM E-84 with 3% antimony trioxide) vinyl ester, offering high strength, excellent impact strength and toughness, designed to bond Hetron FR 992 resin laminates and meet the low odour requirements of the semiconductor and other industries. Since this resin does not contain styrene, the glass reinforcement must exhibit very little binder conventional CSM s do not wet-out well with this resin. 

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