A few comments on what ends up as the material for a structure should also be made. First is a composition, essentially the basic chemistry of an alloy or the specific components of a composite. Producing the structure may require a few or many steps beyond this chemistry/components combination. | A few comments on what ends up as the material for a structure should also be made. First is a composition essentially the basic chemistry of an alloy or the specific components of a composite. Producing the structure may require a few or many steps beyond this chemistry components combination. Primary processing plays an important role. As examples an investment cast superalloy blade will have different characteristics depending on whether it is made using an equiaxed directionally solidified or single-crystal process and fiber-reinforced composites clearly have numerous wrap lay configurations that can influence their response. Subsequent thermal treatment for an alloy or curing conditions for a composite also contribute to the end product. Many metallic alloys far from being the uniform homogenous materials often envisioned are carefully orchestrated arrangements of microconstituents designed to provide specific property balances from these in situ composites. Effects of scale in the production of a material can have controlling effects. Examples are graphite size in gray iron transformation characteristics of steels or titanium alloys in heavy sections mechanical working in forgings and extrusions distributions of fibers in chopped-fiber reinforced polymer parts and phase and discontinuity distribution in ceramics. Further considerations might include machining processes plating shot-peening adhesive bonding welding and a myriad of other influences that confound what initially appears to be the desired rather straightforward association between the material content and structure. This is coupled with the geometric requirements of shape necessary to provide the geometry of the structure. Indeed it is equally true that the material defines the structure and the structure defines the material. A small shaft simply loaded in rotating bending may behave quite like specimens tested in a similar manner. On the other hand a composite wing built up from multiple parts .
