Composite steel-concrete bridge: analysis with finite element method

Rebeca Jéssica Schmitz¹; Inácio Benvegnu Morsch¹

¹ Universidade Federal do Rio Grande do Sul

doi:10.20906/CPS/CILAMCE2017-0093

Resumo

Composite steel-concrete elements can be used in any structural elements: in this research an application in bridge structures is studied. The goal of this work is to analyze the behavior of a bridge structure designed by a normative code. The bridge´s design was done using a simplify model in software ANSYS to analyze the actions and normative references, like NBR8800, Eurocode 4 and AASTHO was applied to elements design. The bridge consists in only one span composed by eight composite beams and five lines of steel "I" section diaphragms along the span. The applied connectors are studs bolt. In this research, it is used a more complex model developed in ANSYS, using the software customization for include the concrete behavior. The finite element model adopted four different types of finite elements: solid186 for the concrete slab, reinf264 for the reinforced steel represented as an incorporated element in the solid element, shell181 for the steel "I" beam, combin39 for the studs. The stud behavior is represented by the curve of push out experiments. The structural steel is considered an elastoplastic material with nonlinear hardening, and the reinforcement steel is considered elastoplastic with a small linear hardening. The concrete is modeled considering two types of analysis: instantaneous behavior for short-term loads, and its deferred behavior for long-term loads. From this bridge model some analysis were made. In the first analysis was verify the effects of the environmental conditions on concrete creep and shrinkage along ten years, it were considered nine different situations, combining temperature and air humidity. Another analysis was about the level of stress on the structure components considering all actions combined on two cases for the permanent load: young structure (without time effects) and considering the predicted time effects, which were verified on the earlier analysis. Then it was possible verifying the neutral axis and the effective width, which are the basis of the design. Comparing these

Palavras-chave: steel-concrete bridges; finite element method; ANSYS customization