Robustness of Structures

Robustness has become an important general requirement for both, design of new and evaluation of existing structures, to reduce the global risk caused by structures. Methods to achieve robustness are presented in a systematic order and illustrated by examples. Some important issues to get robust structures are addressed like strength, stiffness, ductility, strain hardening, and continuity. Different definitions of robustness are presented, showing that they slowly converge. Some proposed metrics are discussed, although they are not yet practically applicable. With a example of a bolted steel splice, it can be shown that even in a simple detail robustness as a design criterion may be ambiguous. Finally, the implicit and explicit treatment of robustness in former and actual codes is covered and developments for the future are sketched.