Reinforced plastic designing with

An incorporated technical organization founded in 1937 and serving the needs of the entire plastics industry in the U.S. It establishes standards for the properties and selection of materials and for product design and engineering. Its two major publications are the Plastics Engineering Handbook and the Reinforced Plastics Handbook. With it are associated the Plastics Pipe Institute and the Reinforced Plas-tics/Composites Institute. It is located at 1801 K ST NW, Suite 600K, Washington DC 20006. Website http //www.socplas.org. 

Old CF, Nicholas M, Paper No. 14, 2" International Carbon Fibres Conference, London, 1974. Old CF, Nicholas M, Paper No. 13, 2" International Carbon Fibres Conference, London, 1974. Pearce DG, Designing with carbon fibre reinforced plastics. Design Eng, Feb 1969. 

The ratio of 0.5 and 0.7 is not arbitrary, as it may appear, for small vehicles can normally be designed with W/D ratios of 0.5 or less, and vehicle displacements can become quite large as their W/D ratios approach 0.7. Using these values permits making meaningful comparisons of the depth potential of various hull materials. An examination of the data reveals that for all the metallic pressure-hull materials taken into consideration, the best results would permit operation to a depth of about 18,288 m (20,000 ft.) only at the expense of increased displacement. The nonmetallic materials of reinforced plastics (those with just glass-fiber-TS polyester) and glass would permit operation to 20,000 ft. or more with minimum-displacement vehicles. 

Mayer, R.M. (ed.) (1993) Design with Reinforced Plastics, Design Council, London. 

Whilst the book is self-contained, the accompanying volume on design principles (Mayer, R.M. (ed.) (1993) Design with Reinforced Plastics, Design Council, London) may need to be consulted if readers are not acquainted with the design process. 

Various methods have been developed for the production of GRC components. These methods have mostly been adapted from the glass fibre reinforced plastics industry, with proper modifications to adjust for the special nature of the cementitious matrix. To obtain a product of an adequate quality the mix composition should be carefully controlled, to be compatible with the production process, while at the same time providing the needed physical and mechanical properties in the hardened composite. Thus, the properties of GRC composites vary over a wide range, and are a function of a complex combination of the production process and the mix composition. A detailed discussion of the design and production of GRC components is beyond the scope of this chapter. These topics are covered in various publications and guidelines [31-37] and only some essential points will be discussed in Section 8.7 and Chapter 14. 

Some design factors, however, work against composites. For example, glass fiber-reinforced plastics generally have lower modulus (stiffness) than metals. Thickness and shape adjustments are requited where stiffness is a critical design requirement. With appropriate reinforcement, any modulus, even greater than that of metals, can be achieved. However, it may become expensive and uneconomical to do so. 

In this book no prior knowledge of plastics is assumed. Chapter 1 provides a brief introduction to the structure of plastics and it provides an insight to the way in which their unique structure affects their performance. There is a resume of the main types of plastics which are available. Chapter 2 deals with the mechanical properties of unreinforced and reinforced plastics under the general heading of deformation. The time dependent behaviour of the materials is introduced and simple design procedures are illustrated. Chapter 3 continues the discussion on properties but concentrates on fracture as caused by creep, fatigue and impact. The concepts of fracture mechanics are also introduced for reinforced and unreinforced plastics. 

The purpose of this subsection is to familiarize the reader with some of the basic characteristics and problems of composite laminate joints. The specific design of a joint is much too complex for an introductory textbook such as this. The published state-of-the-art of laminate joint design is summarized in the Structural Design Guide for Advanced Composite Applications [7-5] and Military Handbook 17A, Plastics for Aerospace Vehicles, Part 1, Reinforced Plastics [7-6]. Further developments can be found in the technical literature and revisions of the two preceding references. 

In structural applications for plastics, which generally include those in which the product has to resist substantial static and/or dynamic loads, it may appear that one of the problem design areas for many plastics is their low modulus of elasticity. The moduli of unfilled plastics are usually under 1 x 106 psi (6.9 x 103 MPa) as compared to materials such as metals and ceramics where the range is usually 10 to 40 x 106 psi (6.9 to 28 x 104 MPa). However with reinforced plastics (RPs) the high moduli of metals are reached and even surpassed as summarized in Fig. 2-6. 

Reinforced plastics (RPs) hold a special place in the design and manufacturing industry because they are unique materials (Figs. 6-11 and 6-12). During the 1940s, RPs (or low-pressure laminates, as they were then commonly known) was easy to identify. The basic definition then, as now, is simply that of a plastic reinforced with either a fibrous or nonfibrous material. TSs such as polyester (Table 6-19) and E-glass fiber dominated and still dominates the field. Also used are epoxies. 

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