Quantitative measurements of lightweight timber floors using low-frequency impact source; analysis of the accuracy of 1/3 octave band heavy-hard impact prediction modelling in lightweight structures

This paper analyses heavy weight drops on lightweight structures such as timber frame and mass timber, with particular emphasis on the accuracy of the 1/3 octave band heavy-hard impact prediction modelling. With the increasing popularity of lightweight structures such as mass timber, timber frame and steel frame, this research investigates the behaviour of lightweight slabs when free weights such us kettlebells are dropped on fitness flooring. A comparison of the spectral shapes of various base structures has been carried out, focusing on the low-frequency range and resonance of various base structure types. Third-party laboratory data is utilised to derive design recommendations when free weights or heavy hard impacts are proposed in lightweight structure developments. Previously, the author carried out a case study in the UK which demonstrates the accuracy of the 1/3 octave band prediction model for concrete developments using force pulse data collected at the in-house drop tower. While the prediction method shows good agreement for concrete buildings up to 200 Hz, there is interest in extending the range for use in lightweight structures.