Design criterion for wood floor vibrations via finite element and reliability analyses.

摘要

In this study, the vibration of wood floors and their behavior under normal human activities was studied in terms of serviceability design requirements. Detailed finite element modeling of wood floor systems was used to develop and verify measures of vibration that can be used to quantify the level of human perception. The measures investigated included static deflection, fundamental frequency, the criteria of Reiher-Meister, and root mean square accelerations {dollar}(asb{lcub}rms{rcub}).{dollar} The results obtained from the finite element analysis were first compared with the results obtained from experiments using three different techniques. Based upon these comparisons, it was found that results obtained from finite element analysis agree well with those obtained from experiments. Then, the finite element method was used to study the effect of several parameters affecting wood floors, such as floor damping, joist stiffness, floor mass density. support conditions, etc. The analyses showed that floor vibration is significantly affected by the location of human beings and system damping and only slightly affected by the weight of human beings.; A set of design curves for floor vibration was developed based on {dollar}asb{lcub}rms{rcub}{dollar} for a standard wood floor. The design curves were based upon detailed finite element analysis. Test results obtained from three different floor systems were used to verify the design curves. A design criterion, based on the design curves, was then defined in accordance with accepted limits on both fundamental natural frequency and {dollar}asb{lcub}rms{rcub}.{dollar}; A simplified finite element model of wood floor systems was developed on the basis of orthotropic plate behavior. This simplified model was implemented in a program written by the author called FLOVIB, and it was verified against existing software.; Finally, reliability analysis of wood floors was performed using both the design curves and the simplified finite element model. A number of vibrational criteria were studied. It was found that wood floors are most sensitive to joist stiffness. Also, it was found that relatively stiff floors will give better vibrational performance than those that are more flexible.