Dynamic analysis of composite beam and floors with deformable connection using plate, bar and interface elements.

Abstract

New architectural tendencies combined with more resistant materials and increasingly efficient structural systems, results in projects that are safe for ultimate load capacity, but with problems related to service loads, i.e., the structure doesn’t collapse, but causes discomfort to the user. Structures with deformable connection are formed by the association of two or more structural elements by means of a deformable shear connection. In construction the most common cases of this type of structures are steel-concrete composite structures. Among these, the composite beams and floors are more susceptible to be excited by dynamic loading induced by human rhythmic activities, as walking, dancing, jumping, among others. The objective of this work is, from the three dynamic finite element formulation (plate, bar and interface), to show the efficiency of these in simulation of composite floors and beams with deformable connection under dynamic loading, where the deformable shear connection is simulated by the interface element, being the main contribution of this work. The proposed analysis model is tested and validated by means of frequency analysis results and natural vibration modes of composite floors and beams, as well as the calculation of displacements and accelerations of those when subjected to dynamic loads due the rhythmic activities. Another contribution of the model proposed in this article is the verification of the influence of the “shear lag” effect in the determination of the natural frequencies and vibration modes of composite beams, which cannot be evaluated when analyzed only for bar and interface elements.