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2 State of the art
phase where the problem is firstly identified, then the requirements in terms of inputs
and outputs are defined and lastly the physical mechanisms that govern the material
behavior are identified. Subsequently, the model precision or level of detail is targeted.
He stresses, that the model development should be an iterative process, where the first
model is of less detail enabling to predict the outputs within only a factor of 10 in order
to identify important variables. In the following model construction stage existing modeling approaches and material models are employed to generate the desired output.
Stages 6 and 7 correspond to the model implementation, which are followed by the interrogation and application of the model. The Ashby flowchart is unique in a sense that
it provides sequential steps, which may serve as general guide for developing physical
models. In addition, the described concepts are so universal that they are still up-to-date
three decades later.
Figure 21 Flowchart for constructing physical models of materials by Ashby [Ash92]