Structural design with polymorphic uncertainty models

Structural design should be robust with respect to the polymorphic characteristics of the available data and information. Generally, the availability of data and information in engineering practice is limited. Incomplete, fragmentary, diffuse and frequently expert‐specified knowledge leads to imprecision in data. In addition, engineers have to cope with the objective variability and fluctuations in material, geometry and loading. The objective of numerical structural design is the computation of reliable and economic structures. The design task is to find the best parameter combination, with respect to a design objective, inside a permissible design space, defined by constraints. In this contribution, strategies for the solution of an optimisation task with polymorphic uncertain design variables and further uncertain a priori parameters are proposed. The active and the passive optimisation strategies are mathematically formulated and numerical implementations are shown. Two engineering examples show the capability of the approaches.