Shape factors and material indices for dimensionally constrained structures Part 2: Shafts

Abstract Shape factors and material indices have been recently developed for the optimal design of load-bearing beams and shafts. These shape factors and material indices are generally only applicable where there are no dimensional constraints. However, dimensional constraints are very common in mechanical design because of the integrated nature of modern machinery and equipment. This paper extends the methodology of a previous paper by Ashby by developing the shape factors and material indices for the case of constrained diameter in shafts. The paper also shows that dimensional constraints can have a very significant effect on the optimal selection of material and shape.