Dynamic structural behaviour of steel-concrete composite floors subjected to rhythmic human activities

Resumo

Over the last few years, a lot of structural problems associated with excessive vibration of building floor
systems when induced by human rhythmic activities have occurred in places such as fitness centres, event halls
and offices. On the other hand, it’s well known that the resonance phenomenon can occur due to equality (or
proximity) between one of the excitation frequencies and the structure natural frequencies. Having this thought in
mind, this paper investigates the dynamic structural behaviour of a steel-concrete composite floor when subjected
to loadings induced by human rhythmic activities. This way, the studied structural system consists of a health club
that presents an area used for aerobics. The composite floor system presents dimensions of 22.5 m by 14 m and a
total area of 315 m2. In this study, the dynamic loadings were obtained through the use of several dynamic load

models (only force models) and also based on the modelling of biodynamic systems, to incorporate the human-
structure interaction dynamic effect to the analysis. The composite floor numerical model was generated based on

usual modelling techniques adopting the mesh refinement present in the Finite Element Method (FEM) and
implemented in the ANSYS program. The investigated floor dynamic structural response was calculated through
the consideration of 20 people practising rhythmic activities on the original area specified in the project and on the
other two possible areas of the structural system aiming to verify the occurrence of excessive vibration and also to
assess the human comfort having in mind the recommended limits proposed in the traditional international design
standards.