Experimental investigation of dynamic characteristics of material applied to reduced scale physical models in the elastic state

Abstract

Dynamic and vibration difficulties have begun to play a major part in structural analysis as a result of the increasing complexity and slimness of bridges. Nonetheless, creating numerical models that accurately capture the true behaviour of structures remains a challenge. It can be caused by the lack of references that characterise the dynamic and vibration properties of the material. For that reason, the main goal of this work is to investigate experimental methods to characterise materials that are commonly used to build reduced scale physical models. We tested four types of materials in order to achieve this goal, as well as evaluating the major influence of reinforcement on the material’s elastic stiffness. That presents a novel approach to support engineers to suitably select scaled physical models materials. In addition to identifying the basic static properties of the studied materials, material damping and material relaxation were also characterised through the following: General logarithmic decrement method, Half-power band, modal damping and random decrement. In order to evaluate the material damping, we analysed the acceleration and displacement of cantilever specimens using a data acquisition module. As a result, the confidence level of each approach in contrast to the experimental data could be determined. Finally, the material behaviour of each material was examined in order to determine the best material for producing reduced scaled models of reinforced concrete bridges. As a result, it was easy to see that modal damping indicates higher confidence, whereas logarithmic decrement indicates lower confidence. It is also important to keep in mind that most methods for determining damping ratios are based on viscous damping. As a result, non-linear regression and modal damping were deemed the best methods for characterising vibration and dynamic responses of materials.