Plastics Design Toolbox

Here are examples in the selection of the many resources available to the plastics designer and other plastics users also review references 3, 6, 10,14, 20, 29, 31, 36, 37, 39, 43 to 125. 

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This book will not provide extensive engineering equations since they are readily available from industry that are reviewed in Appendix A PLASTICS DESIGN TOOLBOX and references (3, 6,10,14, 20, 29, 31, 36, 37, 39, 43 to 125). Equations will be reviewed throughout this book where they are required to understand the behavior of plastics in order to meet different load requirements (static to dynamic). What this book provides is information on the behavior of... 

As these problems were encountered in the past, it became evident that we did not have at hand the physical or mathematical description of the behavior of materials necessary to produce realistic solutions. Thus, during the past half century, there has been considerable effort expended toward the generation of both experimental data on the static and dynamic mechanical response of materials (steel, plastic, etc.) as well as the formulation of realistic constitutive theories (Appendix A PLASTICS DESIGN TOOLBOX). 

The first step in applying FEA is the construction of a model that breaks a component into simple standardized shapes or (usual term) elements located in space by a common coordinate grid system. The coordinate points of the element corners, or nodes, are the locations in the model where output data are provided. In some cases, special elements can also be used that provide additional nodes along their length or sides. Nodal stiffness properties are identified, arranged into matrices, and loaded into a computer where they are processed with certain applied loads and boundary conditions to calculate displacements and strains imposed by the loads (Appendix A PLASTICS DESIGN TOOLBOX). 

A common pressure vessel application for pipe is with internal pressure. In selecting the wall thickness of the tube, it is convenient to use the usual engineered thin-wall-tube hoop-stress equation (top view of Fig. 4-1). It is useful in determining an approximate wall thickness, even when condition (t < d/10) is not met. After the thin-wall stress equation is applied, the thick-wall stress equation given in Fig. 4-1 (bottom view) can be used to verify the design (Appendix A PLASTICS DESIGN TOOLBOX). 

Designing has never been easy in any material, particularly plastics, because there are so many. Plastics practically provide more types with the many variations that are available than any other material. Of the more than 35,000 different plastics worldwide, only a few hundred are used in large quantities. Unfortunately, some designers view plastics as a single material because they are not aware of all the types available (Appendix A, PLASTICS DESIGN TOOLBOX). 

The problem of acquiring complete knowledge of candidate material grades should be resolved in cooperation with the raw material suppliers. It should be recognized that selection of the favorable materials is one of the basic elements in a successful product-configuration design, material selection, and conversion into a finished product (Appendix A PLASTICS DESIGN TOOLBOX). 

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