Laminated composite materials types

Find another example or type of laminated composite material than those mentioned in Chapter 1 and describe it. 

Laminates ate a special form of composite material or reinforced plastic because the continuous reinforcing ply of fibrous material imparts significant strength in the x—j plane. The strength along the axis results from interlaminar bonding of resins. Very few fibers ate oriented in the direction, so it tends to be the weak link in this type of composite. 

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. 

When describing in more detail the characteristics and methods of manufacture of laminated sheet materials of different types it is helpful to use the classifications below, each of which is covered by a British Standard High-pressure laminates Decorative continuous laminates Direct-faced boards Composite boards. 

In addition, advanced polymer processing technology also provided for structural materials such as sheets and films, tubing, laminates, and other composite materials. Table I gives a general overview of the types of application for the various polymer systems. 

The laminates of tiK carbon-fiber composite were first characterized by acoustic NDI (C-scan) and optical microscopy to evaluate their quality. Scanning electron microsctqiy (SEM) was used to evaluate laminate quality and nanoparticle distributimi using a Philips XL30 ESEM TMP scanning electron microscope. Mechanical tests fm tiie carbon-fiber composite were selected to measure resin-dominated properties. These tests were transverse four-point flexure with a qian-to-deptii ratio of 32 1 and longitudinal four-point flexure with a qi>an-to-depdi ratio of 16 1 designed to induce mic lane shear failure. Ten qiecimens were tested for each material type and condition. 

Laminated plates form one of the basic structural elements for the use of composite materials. In this document laminated plates are defined as Plates Type I, II or III, depending on the degree of directional homogeneity of their material properties. 

The principle of additive strength can be applied equally, regardless of the type of composite material. Composite materials can be broadly classified as laminates, reinforced plastics, cermets, fabrics, and filled composites. Each class of composite materials has its own particular strengths and weaknesses and its own methods of production, although there is some crossover in the areas of application. 

The polymeric composite materials are frequently produced as 1) particle containing, whenever the matrix contains included powders or flakes 2) fibrous, when containing long or short fibres, with standard or high performance properties 3) laminates, especially representing layers of many materials and 4) hybrid materials, i.e. combinations of the first three types. 

Usually, the fibres are not unidirectional oriented in composite materials. Fibres orientation varies in function of the pieces thickness, processing method, and mould geometry. Accepting a random orientation of fibres, or a known and measured orientation, the laminates theory was appealed in order to describe the behaviour of this type of composites. The method allows the determination of the weakest layers, which will be firstly fractured [1285]. The Figure 3.456 illustrates a good agreement between the theory and practice, considering, for comparison, the data furnished by P.E. Chen [1285] and J.K. Lees [1286]. 

---