Reduction of bridge dynamic amplification through adjustment of vehicle suspension damping: Fid-Bau Portal

Reduction of bridge dynamic amplification through adjustment of vehicle suspension damping

Harris, N.K. / OBrien, E.J. / Gonzalez, A.

This paper presents a novel approach to the reduction of short-span bridge dynamic responses to heavy vehicle crossing events. The reductions are achieved through adjustment of the vehicle suspension damping coefficient just before the crossing. Given pre-calculations of the response of a vehicle-bridge system to a set of 'unit' road disturbances, it is shown that a single optimum damping coefficient may be determined for a given velocity and any specified road profile. This approach can facilitate implementation since the optimum damping is selected prior to the bridge and there is no need to continuously vary the damping coefficient during the crossing. The concept is numerically validated using a bridge-vehicle interaction model with several road profiles, both measured and artificially generated. The bridge-friendly damping control strategy is shown to reduce bridge dynamics across a typical range of vehicle velocities, proving most effective for road profiles that induce large vibrations in the vehicle-bridge system. The effect of the bridge-friendly control strategy is investigated for several measured and artificially generated road profiles. In all cases, maximum bridge DAF (Dynamic Amplification Factor) is reduced across a typical range of vehicle velocities due to the new approach. The effect is generally more pronounced for rougher profiles with reductions of up to 40% of the dynamic increment achieved. For relatively smooth profiles, the contribution of road roughness to overall DAF is lessened, and the achievable reductions tend to be smaller. It is also noted that RMS (Root Mean Square) tyre forces and RMS body accelerations are largely unaffected by the bridge-friendly suspension.