Análise numérica de dentes de concreto armado

Abstract

The dapped-end beams have the function of acting on the transmission of forces between the parts that make up the support arrangement of buildings, especially in precast concrete structures. With a specific geometry, the dapped-end beams have a reduction in height at the end, which causes high shear stresses, therefore, they are not fully well represented by a linear analysis, distancing it from the Bernoulli Hypothesis. Based on this, dapped-end beams are characterized as regions of discontinuities and need to be treated by more realistic models, such as strut- tie model, shear-friction model. Another alternative for examining the behavior of these elements, made possible by the progress of the processing capacity of the computational tools, is the use of finite elements associated with the non-linearity of the problem. In view of this, considering the evident importance of these connecting elements in supporting the structures, the verification and deepening of the study of their behavior are paramount. Therefore, this study aims, with the aid of the finite element computational tool ATENA, to contribute to this field of research by analyzing and comparing different models and types of dapped-end beams, previously tested experimentally in other studies obtained in the background literature and to evaluate the behavior of models dimensioned by the friction-shear and strut and tie models of national standards through this computer program. It was found in the validations that the shear support capacity of dapped-end beams grew with the decrease of the a/d ratio, being verified important compatibility with the data reported in the tests referring to loads, displacements, cracking panorama and failure modes. The hanger bars arranged inclined showed a more moderate cracking opening, showing a more adequate redistribution of stresses, and a greater bearing capacity than the vertical hanger bars. For the models studied considering the national regulations, it was observed that the lowest resistant capacities were manifested by the specimens of short dapped-end beams dimensioned by shear friction.