15.15: Dynamic Analysis of Steel‐Concrete Composite Building Floors Subjected to Human Rhythmic Activities

Abstract

This work aims is to investigate the structural dynamic response of steel-concrete composite floors, when subjected to rhythmic human activities, based on experimental tests and numerical modelling, from the point of view of human comfort. The main focus of this paper is to study the effect of the dynamic interaction between the occupants and the floors, representing these people by SDOF biodynamic models (mass-spring-damper systems), in order to better evaluate the dynamic response and the vibration serviceability states. This way, the investigated structural model is related to a steel-concrete composite building which is composed of three floors used for aerobics classes, with dimensions of 20m x 20m, a total area of 1200m² (3 x 400m²) and a ceiling height of 4m. The numerical modelling of the structure was performed by ANSYS program and was based on the finite element method (FEM). In order to evaluate the dynamic response of the investigated steelconcrete composite building, accelerations associated with 32 individuals practicing rhythmic activities were experimentally obtained to introduce them into the finite element model. Thus, the dynamic response of the building floors was evaluated in terms of the peak accelerations, RMS and VDV values, according to human comfort criteria and considering situations of the design practice.

Analysis of the Structure of Aerobics Complete Sets of Movements Based on Genetic Algorithm

“…It is a combination of continuous movements to show athletes "health, strength and beauty". Competitive aerobics originated from Traditional fitness aerobics is developed from a series of strict requirements on body flexibility, muscle strength, and endurance, as well as a perfect combination of complex arm movements and seven basic steps under the feet [3]. ey completed beautiful, changeable, and smooth sets of movements on a specified 5-squaremeter field within a specified time of 1.5 to 2 minutes.…”

Human Comfort Investigation of Steel‐Concrete Composite Floors Subjected to Rhythmic Dynamic Actions

“…2. The floor dynamic structural response assessment indicated that the "only force" loading models (AISC [5], SCI [6] and Faisca [7]) have induced higher levels of displacements and accelerations than the biodynamic systems [8]. This fact is associated to the difference between the mathematical models, especially the biodynamic systems that incorporate the dynamic characteristics of the people (mass; stiffness and damping).…”

“…On the other hand having in mind the most realistic representation of the human rhythmic activities, the biodynamic systems modelling is based on the dynamic properties of each individual. This way, Campista [8] formulated a biodynamic model considering a single degree of freedom (SDOF), consisting of a mass-spring-damper system (see Figure 5). The people dynamic properties were determined based on several experimental tests, considering the individuals jumping on a developed dynamic load platform.…”

“…The traditional models can be found in the guides AISC [5] and SCI [6] and the research work developed by Faisca [7]. On the other hand having in mind the most realistic representation of the human rhythmic activities, the biodynamic systems modelling is based on the dynamic properties of each individual [8].…”

“…Concerning the parameters in Eqs. ( 4) to (6); F i (t) is the dynamic force in (N); k i is the stiffness in (N/m); m i is the mass in (kg); c i is the damping in (Ns/m); x i (t) is the displacement in (m); v i (t) is the velocity in (m/s); a i (t) is the acceleration in (m/s 2 ); f i is the frequency in (Hz); ξ is the damping coefficient, considered equal to 0.25 [8] in this work.…”