Influence of the flexibility of beams and slabs in static response and dynamic properties

Abstract

This article examines numerically the flexibility influence of support beams in static response and dynamic properties of a symmetric plate formed by massive slabs of reinforced concrete in elastic linear regime, using the Finite Element Method. In the static response the variation of bending mo-ments and displacements are evaluated, which depend on the relationship between the flexibility of the slab and the beam. The evaluation of dynamic properties is held in undamped free vibration, through which the vibration modes and the values of the natural frequencies is obtained, which are compared with the limits of the Brazilian standard code for design of concrete structures. Results show that the response may show great variation due to the change in the relationship between bending stiffness of the slabs and the beams.

Evaluation of limit state of stress and strain of free-fixed columns with variable geometry according to criteria from the Brazilian code for concrete structures

“…The use of Equation (1) as a valid shape function for a structure with variable geometry was validated by Wahrhaftig (2019a) in comparison to computational analyses using the finite-element method (FEM). The FEM is a technique to discretize the continuum that has been used recently in computer modeling to analyze buckling and vibration of reinforced concrete structures, as mentioned by Rodrigues et al (2014), who studied concrete columns eccentrically loaded, considering nonlinearities inherent in the system, including creep and shrinkage, for sections with reinforcement ratio of 1.98% and 3.95%, by Bueno and Loriggio (2016), who evaluated undamped free vibrations of reinforced concrete decks in relation to recommended limit states, and also by Rajasekaran and Khaniki (2018), who assessed buckling of beams with functional graded materials.…”