Vibrations in Steel-Frame Floors due to Human Activities
Architectural new tendencies along with current market demands are taking engineering design towards the use of flooring systems which can span great distances with a minimum number of columns allowing, thus, more architectural flexibility. This design philosophy has conducted to ever more slender structural elements, with ever lower natural frequencies that are, therefore, closer to the frequency bands of dynamic excitations associated to human activities, such as walking. Within this context, this paper studies the behaviour of the following flooring systems: (a) reinforced concrete slabs supported by steel beams, and (b) steel floor plates supported by steel beams. The evaluation of the natural frequencies of the structure and its responses (floor displacements and accelerations) to the walking activity were analyzed by the simplified analytical method of AISC 360-10 code. The flooring systems were modeled using the finite element software ANSYS 14.0™ and the numerical results for natural frequencies and floor accelerations were compared with those obtained by the simplified procedure of the AISC 360-10 code. This way, it was possible to draw conclusions about the dynamic behaviour of the analyzed flooring systems.
