On the vibration of slab Floors subjected to vertical harmonic loading

The manufacturing buildings contain many vibrating sources such as pumps, compressors, air handling units and other equipment that all contribute to the excitation of the floors. The transmission of vibration throughout the building, which includes the transmission of vibration along the floor, is of concern to designers of these buildings. The civil engineering codes for the design of buildings are mainly related to the strength of the building to withstand static and seismic loads, and there are few codes available for the design of building with slab floors for vibration sensitive equipment. Due to the complexity of this vibration problem, designers use an empirical relationship that has been developed based on vibration measurements in many buildings. This paper treats the dynamic characteristics of a slab floors under dynamic loads, using finite element techniques. The vibrating response of floors is evaluated in terms of displacement and resonance frequency that depend on the damping and thickness of the floor, size of the bays and the stiffness of the columns. A comprehensive parametric study is conducted to investigate the effects of each factor on the response of slab floors under dynamic loading in the frequency range of interest. The results showed that the vibration response of the floor is due to the summation of a number of closely spaced vibration modes and the bay size has the greatest influence on the lowest resonance frequency of the floor. Also, it is concluded that the thickness of the slab is an important element in reducing floor vibrations where a slight increase in slab thickness can reduce floor vibrations considerably

Keywords:

Vibration , slab floors , dynamic load