| Summary: | An experimental study of two lightweight wooden floors’ dynamic response was per
formed. The objective of this study was to evaluate the applicability of the computer
programs, NAFFAP and DYFAP, for the case of lightweight wooden floor vibration. The
program NAFFAP solves for the floor system’s natural frequencies and mode shapes
while DYFAP performs a time domain integration of the equations of motion in response
to a specified loading on the floor. DYFAP also has the capacity to model the coupled
response of oscillators upon the floor system. These programs employ a T—beam finite
strip analysis. The test data of the floors’ dynamic response to various impacts were
compared with the programs’ simulations. One floor used 2x8 sawn lumber joists while
the other used composite wood I—Joists. The transient dynamic response of the two floors
to three types of excitation were recorded. The three types of excitation were created by
a hammer tap, releasing a sand filled bag and a standard human heel drop. The modelling of a human occupant with a single degree of freedom oscillator, the International
Standards Organization’s two degree of freedom oscillator model and a forcing function
were investigated with DYFAP. The oscillators were composed of lumped masses, springs
and viscous dashpots.
The program NAFFAP was sufficiently successful in predicting the floors’ natural
frequencies. The floor parameters that were used with NAFFAP were then used with
DYFAP to produce displacement time histories that compared well with the test data.
DYFAP’s modelling of occupants with simple oscillators rather than a forcing function
proved to be appropriate. === Applied Science, Faculty of === Civil Engineering, Department of === Graduate
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