Dynamic Properties of a Sawn Timber Floor Element with High Transverse Bending Stiffness

Abstract

A novel wooden floor system for blocks of flats, schools and office buildings where long spans are required is investigated. The floor system aims at high stiffness and good vibration performance. In the longitudinal, main load-bearing direction the floor system works as a truss with flanges of longitudinally oriented timber members and web diagonals of transversely oriented members. In the transverse direction the web diagonals work as beams. A 2.4 × 4.8 m floor element with a total height of 260 mm is examined. Laboratory tests as well as static FE calculations show that the bending stiffness in the transverse direction is of the order of one fourth of the bending stiffness in the main direction. The torsional stiffness is however low. The dynamic properties, i.e. natural frequencies and modes of vibration were evaluated using laboratory tests and FE calculations. In general, laboratory tests and FE calculations were in good agreement. As the study shows promising results, further development and testing are proposed. A test floor is planned in which the transversely oriented wooden members will be replaced by thinwebbed beams of wood and hardboard. In future, the floor will be examined with respect to acoustic properties.