Categories of size effects

Size effects play an important role in up-or downscaling of processes and the transfer of knowledge to the processing in new geometric dimensions like micro- and nanotechnology. A definition of size effects and a systematic order for size effects is proposed. The main categories are density, shape and microstructure size effects, which can be subdivided into further subcategories. Using the example of size effects in the strength of materials it is shown that the systematic can be used to get the different effects unambiguous into an order, which helps to avoid apparent contradictions in experimental findings.