Análise do comportamento estrutural de ligações com diferentes níveis de rigidez em pórticos de concreto prémoldado

Abstract

The precast concrete has stood for its construction efficiency, although concrete molded “in loco” still predominates in Brazil for cultural reasons. One of the greatest challenges lies in the characterization of structural connections, whose stiffness directly influences the overall behavior of the structure. Therefore, this work seeks to evaluate the structural behavior of precast concrete frames with different levels of stiffness, considering articulated, semirigid, and rigid connections, through modeling and parametric analyses in TQS software, correlating the variation in the rotational stiffness of the connections with displacement and internal forces. Initially, three models of the same building were analyzed, varying the stiffness levels of the connections by altering the type of support and the continuity reinforcement ratio. Subsequently, a second analysis was performed, comparing two models of the same building with two different types of connection, and altering the heights of the first and last floors. About the results, it was found that rigid connections provide greater stability, with an average reduction of 64% in horizontal displacements compared to articulated connections showed intermediate behavior. Geometric variations also showed a relevant influence, since increasing the heigh of the first floor caused a 63% increase in displacements, while changes in the height of the top floor had more discreet effects, less than 10%.