SchwallBe

The vibration analysis is usually relevant to the design of wide-span timber ceilings. This leads to large cross-section values and material consumption. Alternatively, the vibration amplitudes can be reduced using large masses. This method also leads to more material consumption. The aim of the research project is to optimize the design of timber and timber-concrete composite ceilings with large spans by measuring and analysing the vibration and sound insulation properties of completed objects.

Do the measured data on the vibration behavior of wide-span timber beam ceilings in completed buildings match the predicted data? Can the normatively required values for the vibration protection of timber ceilings also be met with slimmer / lighter constructions?

Although the first resonances, which are decisive for the vibration protection of wide-span ceilings, are not in the audible range, the question arises as to what extent the associated harmonics influence the low-frequency sound transmission?

As all empirical values indicate that particularly wide-span wooden ceilings behave better in reality in terms of vibration protection than predicted, this project examines objects that have been constructed in order to determine the actual vibration and sound insulation behavior. The data measured in this way is then compared with the predicted data. A new, optimized design method for long-span timber ceilings is derived from the comparison of measured and calculated data. This gives planners certainty about the verification procedure and the limit values to be complied with.

To bridge the frequency gap between vibration and sound insulation properties (5 Hz - 100 Hz), the extended low frequency range is also considered in airborne and impact sound measurements. Modal analysis is also performed using pulse excitation. Thanks to the cooperation between HBC and HFT, this correlation can be further researched. The recorded values are summarized in a database and made available to all interested planners.

A new, optimized design method for wide-span timber ceilings is derived from the comparison of measured and calculated values. This method is intended to make it possible to plan slimmer ceilings. Through the associated material savings, the project contributes to the resource-conserving use of raw materials and to reducing construction costs.