Design of lightweight wooden floors to avoid human discomfort

Abstract

This paper gives "designer usable" methods for predicting the dynamical behaviour of lightweight wood-joist floors covered with semirigidly attached wood-based sheathings of materials such as plywood or waferboard. Included are methods for predicting natural frequencies and root-mean-square (rms) acceleration under a defined forcing function. It is proposed that this rms acceleration be the criterion for estimating user perception based tolerance of a projected design solution in the domestic setting. Case studies suggest that the economic cost of producing more rational designs is small. Consideration is, at this stage, limited to floors that are rectangular in plan and contain no openings nor intermediate support partitions. Suggestions are made as to methods of building floors with acceptable vibrational performances, together with recommendations for further research. Key words: floors, wood, vibrations, human tolerance, design method.

Field Testing and Investigation of the Dynamic Performance and Comfort of Timber Floors

“…Many other studies (Erik, 2008, Smith and Chui, 1988, Onysko, 1985, Hu, 2000 have focused on the damping ratio of the timber floors: the values recommended in these studies range from 2% to 3.6%.…”

Dynamic response of low frequency Profiled Steel Sheet Dry Board with Concrete infill (PSSDBC) floor system under human walking load

“…Experimental serviceability criteria were also reported to minimise the vibration of the floors. Smith and Chui [31] presented a usable method for designers based on a flow chart to evaluate the dynamic response of lightweight wood-joist floor by determination of natural frequency and RMS acceleration of the system under the heel-drop impact load. Howard and Hansen [21] studied the vibration analysis of waffle floors based on a mathematical method for several manufacturing buildings which was also verified by finite element and experimental results.…”

Vibration serviceability of timber floors in residential construction

“…Work by Smith & Chui led to other vibration serviceability design criteria for timber floors [20,35]. These criteria are based on guidelines for evaluating building vibrations given in British Standard 6472 [36], which suggests that, for the purpose of predicting human response, vibration in buildings should be evaluated by calculating the frequency-weighted rms acceleration.…”

“…where n is the number of joists; m s the mass per unit area of floor sheathing; m J the mass per unit length of joists; b the floor width; and K is a parameter determined from f(0), fundamental modal damping ratio , and duration of a heel impact t 1 using the equation in [20,35].…”