Estimating in-situ Material Properties of a Wood Joist Floor: Part 1 — Measurements of the Real Part of Bending Wavenumber

This paper outlines and evaluates a non-destructive experimental technique used to obtain in-situ measures of the real part of the bending wavenumber in the two principal directions of a wood joist floor. In-situ measured wavenumbers are compared to those obtained from beam samples cut from the floor sheathing to identify the frequency range when the joists significantly affect vibration response in the floor sheathing. Wavenumber measurements confirm the highly orthotropic nature. Measurements indicate that the wavenumbers in the direction parallel to the joists are a function of location between the joists. Lower wavenumbers in this direction can be expected closer to the joists. Some discussion is given regarding the rates of attenuation with distance that can be expected parallel and perpendicular to the joists given the variation in wavenumbers, however this will be the topic of a separate paper, Part 2.

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