Name: PRISCILLA IZABEL DOS SANTOS RIBEIRO
Type: MSc dissertation
Publication date: 02/05/2017
Advisor:
Name |
Role |
|---|---|
| ADENILCIA FERNANDA GROBÉRIO CALENZANI | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ADENILCIA FERNANDA GROBÉRIO CALENZANI | Advisor * |
| RODRIGO SILVEIRA CAMARGO | Internal Examiner * |
| WALNÓRIO GRAÇA FERREIRA | Internal Examiner * |
Summary: One of the contemporary architecture trends is the design of buildings with longer spans in order to provide flexibility to the internal arrangements. Concomitantly, technological and constructive evolutions have enabled the use of structural elements, such as columns and beams, increasingly slender and lighter. Consequently, the structures tend to have lower natural frequencies; therefore, closer to the frequency bands associated to dynamic excitations due to human activities, such as walking. In addition, the dry construction technique characterized by the reduction of water usage at its projects and the application of prefabricated elements in the building, including dry floors, has been used in residential and commercial constructions. These types of slabs are usually lighter than conventional slabs, thus they are more susceptible to vibrations and they are not much appropriated to occupation types such as gyms and sport gymnasiums. Currently, one can find in the literature studies on the dynamic behaviour of floor systems composed of steel beams and steel deck slabs under human rhythmic loading. However, systems with steel beams and dry floors are still under-researched. For this reason, this project aimed to study the dynamic behaviour of a steel floor system with dry floors that belongs to a building, which works as an office, located in Araucária in the Brazilian state of Paraná (PR). The dynamic load applied on the structure was from the human activity of walking. Using the finite element software ANSYS® Academic Research, Release 17.0, a numeric model was developed to simulate the actual structure as realistic as possible. Initially, a static analysis was performed considering only the static loads in order to verify the finite element model. Afterward, outputs of modal, harmonic and transient analysis were generated, WHEREin the last one used three different walking load patterns in its analysis. The load patterns 1 and 2 were the human walking in-situ. The first pattern was a force-time history given by the resonant harmonic of a Fourier series and the second used the four harmonics of this series. The pattern 3 represented both the force-time history (using a Fourier series) and the movement of a human walk. The dynamic responses were measured at the point of maximum static deflection of the floor system. Then, a parametric analysis was performed to evaluate the influence of the damping ratio and the number of people walking on the floor. A study on the propagation of vibrations throughout the panels of the floor system was also presented.
Thus, the serviceability limit state for vibration floors was verified according to the standards ABNT NBR 8800:2008, ABNT NBR 6118:2014 and ISO 10137:2007 and to the design guides of Murray et al. (2016) and Smith, Hicks and Devine (2009). The dynamic responses were all measured in terms of peak acceleration and r.m.s. acceleration. Regarding to human comfort criteria, the floor system met the requirements of ABNT NBR 8800:2008 and ABNT NBR 6118:2014 related to the minimum fundamental frequency. On the other hand, all the numerical acceleration determined in this research exceeded the limits recommended by ISO 10137:2007, by Smith, Hicks and Devine (2009) and by Murray et al. (2016). Therefore, the floor system studied would require interventions to meet the limit state for excessive vibrations.
Keywords: Steel Floor System with Dry Floor. Dynamic Behaviour. Human Activity of Walking. Human Comfort.
