Design of a Scaled Bridge for Validation of Vehicle-Bridge Interaction Models

A gap exists between field experiments and laboratory scaled experimental set-ups, which hampers the validation of models and methods, and subsequently the application to practise. A similarity analysis is a useful tool in the design process of an experimental set-up to help bridging this gap for vehicle-bridge interaction systems. Expressing relevant quantities in dimensionless numbers allows for meaningful scaling, maintaining the desired dynamic behaviour of the scaled laboratory set-up while also maintaining the manufacturability. The relevant dynamic quantities are identified for the Boyne Viaduct in Ireland and the Diesel Multiple Unit trains passing this bridge, to design a scaled set-up of this bridge. The first experiments of the realised set-up show a deviation between the designed and actual values, which are mainly attributed to stiffness deviations of the bridge's lattice structure. However, it is also shown that the resonance frequency changes according to the theoretical expectation for a mass being positioned at different locations of the bridge. After mitigation of the stiffness issues with the lattice structure, dynamic measurements will be started to validate the numerical models and to further close the gap between theory and practise.