Vibration Performance Of Cold-Formed Steel-Italian Poplar Structure Plywood Composite Floor System

As a new floor system，Cold-Formed Steel-Italian Poplar Structure Plywood CompositeFloor System takes full advantage of poplar trees in northern Jiangsu，which can bring economicbenefits to the local. Besides that，it also effectively reduces the weight of the floor system andthe cost，which can help to withstand earthquake.In recent years, with the pursuit of more living space, more freedom, the modern residentialstructure becomes lighter, more supple and have a greater span. This trend causes people becomemore sensitive to smaller loads such as walking. Therefore, floor design should also take fullaccount of people’s comfortableness besides the strength and deformation requirements. In thispaper, investigations are carried out on the vibration performance of the composite floor systemsafter they are designed. The research results provide a basis for the design and application of thecomposite floor according to the requirements of serviceability.Based on extensive literature, pedestrian excitation vibration theory and the model ofpedestrian load are discussed, through which the incentive time-history curve of pedestrian loadsare chosen. Floor vibration comfort evaluation criteria caused by crowd loads at home and broadare summarized and analyzed. The frequency, the maximum acceleration and RMS accelerationare discussed. According to the information，the evaluation criterion of the composite floorsystems are raised.Experimental investigations are carried out on the vibration performance of thirteen models.The fundamental frequency, damping ratio and the dynamic response under the differentfrequency of human walking of the composite floors are measured through the different walkcondition and different experimental method. The influence of walking frequency, boardthickness, span of floor, section form, and connectors spacing on the vibration performances ofthe composite floors are evaluated. It is shown that span of floor and section form has significanteffect.Based on the experiments，dynamical analysis for the composite floors is carried by usingANSYS. Comparing finite element analysis with the experiments，it is shown that the finiteelement models are sensible. On the premise of satisfying serviceability and bearing capacity,several slab spans from2.1meters to4.8meters common in residence and office building arechosen to be analyzed by ANSYS. Variation of natural frequency of the composite floor systemand acceleration are discussed through considering the influence of slab span and section form.Ideas about the design of the composite floor system are suggested in this paper.