Structures analysis

Metal structures are generally made up of bars – often straight – connected to each other to form the structure's geometry. Together with the definition of support conditions and connections between elements, they form the static diagram of the structure, which defines and characterizes its degrees of freedom, i.e. the way in which it registers displacements and deforms under the effect of applied loads.

In his day-to-day work, the engineer in charge of a structure's design must ensure its resistance and stability for the various phases of its life (erection, daily life, exceptional events...). In practice, this is usually done in two stages: an initial analysis phase, followed by a series of checks (see § 2 ).

The global analysis or structural analysis characterizes the influence of external actions (permanent, climatic, operating loads, etc.) on the various elements, sections and connections of the framework, and is most often carried out on the entire structure (or possibly on a substructure, cf. § 2.3.2 ) – This is why it is usually referred to as a global analysis.

Once the overall analysis has been carried out, the strength of the sections and connections, as well as the stability of the various structural components, can be verified.

The overall analysis can be carried out using either the elastic or plastic methods (§ 3.2). It should be noted, however, that while plastic analysis is generally more economical, it is subject to stricter conditions of application. Depending on the type of structure, the overall analysis can be carried out using 1 ^er order or 2nd order theory (§ 3.3.2). In the former case, reference is made to the initial, undeformed geometry of the structure, whereas in the case of a 2nd order analysis,...