Reducing footfall-induced vibration in the timber floor system using a pre-stressed shape memory alloy-based tuned mass damper

The feasibility of utilising a shape memory alloy (SMA) in a tuneable mass damper to reduce the excessive vibration of a timber floor system was revealed in a pilot study. In real cases, the in-service excitations on a timber floor can be complex, and more frequencies and randomness can be involved. This paper aims to appraise the effectiveness of the SMA-based semi-active TMD in a real-scale timber floor by conducting OPENSEES numerical analysis. In this study, the human walking footfall-induced vibration is considered as inputs. When the floor-TMD system is subject to walking, which involves relatively low dominant frequencies, cooling the SMA is effective in reducing the off-tuning excessive vibration caused by increasing floor mass. Contrary to expectations, there is no increased vibration in the off-tuning condition caused by decreasing floor mass, because the response at the lower frequency range decreases.