MATERIALS SELECTION IN MECHANICAL DESIGN（机械设计中材料选择）.pdf

Troisieme Conference Europeenne sur les Materiaux et les Procedes Avances Euromat ‘93, Paris, June 8-10 1993 MATERIALS SELECTION IN MECHANICAL DESIGN M.F. Ashby and D. Cebon Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK ABSTRACT A novel materials–selection procedure has been developed and implemented in software. The procedure makes use of Materials Selection Charts : a new way of displaying material property data; and performance indices: combinations of material properties which govern performance. Optimisation methods are employed for simultaneous selection of both material and shape. INTRODUCTION The performance of an engineering component is limited by the properties of the material of which it is made, and by the shapes to which this material can be formed. Under some circumstances a material can be selected satisfactorily by specifying ranges for individual properties. More often, however, performance depends on a combination of properties, and then the best material is selected by maximising one or more ‘performance indices’. An example is the specific stiffness E/ρ (E is Young’s modulus and ρ is the density). Performance indices are governed by the design objectives. One is derived later in this paper and many others are tabulated elsewhere [1, 2]. Component shape is also an important consideration. Hollow tubular beams are lighter than solid ones for the same bending stiffness and I–section beams may be better still. Information about section shape can be included in the performance index to enable simultaneous selection of material and shape. THE PROCEDURE Performance Indices A performance index is a group of material properties which governs some aspect of the p