Dynamic Response Equivalence of a Scaled Bridge Model Due to Vehicular Movement

Abstract

The design of scaled testing is important for establishing equivalence with a full-scale structure but if difficult since the geometry and the material both need to be scaled. For a good, scaled testing, it is important to demonstrate the results of the scaled original structure and the designed scaled testing behave similarly, so that there is control over experimentation. Despite existing guidance around this topic, such equivalence is sometimes not checked appropriately, leading to uncertainties and variations in scaled testing which significantly compromises the usefulness of such experiments. This paper addresses this topic for a bridge-vehicle interaction problem and demonstrates how a scaled testing can show equivalence with respect to its full-scale counterpart. A Buckingham-Pi approach has been taken for scaling and the assumptions around the models and the responses are defined to establish the boundaries of the responses that are intended to be replicated. The non-dimensional parameters are defined and guide the design of future experiments. The conversion of a complex cross-sectional profile to an equivalent beam with made of a different material is dictated by the matching of modelled responses of the scaled responses of the original structure versus the unscaled responses of the experimental structure. The match indicates that establishment of such equivalence is particularly relevant for carrying out future experiments within the laboratory and subsequently linking it to full-scale structures for implementing sensors or carrying our intervention aspects such as repairs. The work also emphasizes on how a well-designed scaled testing should have a numerical benchmark for future interpretation and understanding assumptions around such interpretations when comparing full-scale experiments with controlled laboratory-based experiments, reducing uncertainty around such comparisons. The presented work is expected to be of interest for both researchers and practicing engineers.