Modelos de concepção para estruturas em concreto armado com comportamento não linear obtidos pelo método de bielas e tirantes e otimização topológica

Abstract

The actual tendency of more daring designs applied for structures leads to a complex sequel of analyses capable to modify structural parameters, initial conditions and boundary conditions. These modifications can make able the structural design suitable both for economical restrictions and for technical restrictions. Thus, the search for new structural systems capable to join performance and safety makes necessary a deeper knowledge regarding the mechanical behavior of structures subject to different loading conditions. The strut-and-tie model is used to the structural design for some reinforced concrete elements and to the regions where geometrical modifications and stress concentrations are observed, called regions D. This method allows a better structural behavior representation for strength mechanisms in the concrete structures. Nonetheless, the topological model choice depends on the designer experience regarding compatibility between internal flux of loads geometry and boundary/initial conditions. Thus, there is some difficulty on its applications, once the model conception presents some uncertainty. In this context, the present work aims the application of the strut-and-tie model to nonlinear structural elements together with an advanced topological optimization method. The topological optimization method adopted considers the progressive stiffness reduction of finite elements with low stress values. The performed analyses could help the structural designer to better understand structural conceptions, guaranteeing the safety and the reliability in the solution of complex problems involving structural concrete