Admissible geometrical domains and graphic statics to evaluate constitutive elements of structural robustness.

Zastavni, Denis [UCL] Deschuyteneer, Aurélie [UCL] Fivet, Corentin [UCL]

Structural robustness is a matter of insensitivity to local failure, which is linked to the ability of force redistribution. This paper explores how geometrical solution domains directly attached to form and force diagrams can characterize load path alternativeness and provide qualitative, yet relevant indicators of constitutive elements of structural robustness. Since most methods proposed today for assessing the robustness of structures are based on probabilistic approaches, they are of limited interest for the design phase. Of the few approaches based on a deterministic formulation, all provide a type of survey that is based on an in-depth analysis of the structure once it has been designed, according to specific scenarios. A central challenge is therefore to manage the issue of robustness earlier during the design process, or to be able to interact with a structural model in order to amend its robustness. Geometric solution domains are well suited for early design exploration since they only build on abstract load path networks. This paper explores how indicators linked to the area of these domains can summarize the ability of structures to redistribute forces. Based on case studies, this quantification is then compared with indices of deterministic and energetic criteria currently proposed in the literature.