Computerized Materials Selection

Abstract

Two analytical approaches are described for computer-aided selection of engineering materials. With given design or selection properties in mind, various materials within a given class may be rated by means of minimization procedures in conjunction with assignable engineering judgment factors. The first approach uses a geometric analogy in which two encompassing material parameters—“mean weighted characteristic” and “balance factor”—are used as a measure of the closeness of fit to a shape defined by desired material properties. The second approach is a variation on a familiar algebraic aid to decision making. In the latter approach materials are selected with the least total sum of property deviations from those desired. A number of examples dealing with plastics are given. Comparisons are made between the two approaches. Both approaches offer advantages over “hit and miss” procedures. By segmenting material classes and by limiting the number of material properties, an iterative and useful program has been proven on a minicomputer.