Finite-strip free-vibration analysis of wood floors

A complete design methodology for lightweight wooden floors must address the problem of annoying vibrations caused by occupant-induced footfalls. Recent proposed design methods against uncomfortable floor vibrations require knowledge of the dynamic characteristics of the floor structure. Generally, these approaches require that the fundamental frequency of the floor be located outside a "human-sensitive" frequency band. A means of accurately determining the fundamental frequency of lightweight wooden floors is thus required. This paper presents a finite strip solution procedure, adaptable to microcomputers, for the free-vibration analysis of wooden floors. The numerical model takes into account the various complexities in lightweight wooden-floor construction: orthotopic sheathing; variability in joist-to-joist stiffness; and semirigid sheathing-to-joist connections. A comparison against existing experimental results confirms the adequacy of this model. Using this numerical model as an analysis tool, the effects of changes in various floor parameters on the natural frequencies of wood floors is also investigated.