Virtual representation and analysis of structural systems, presented with a case study

Abstract

The main goal of this thesis is to establish and define the necessary procedures for a proposed method of analytical simulation for complex structural systems. In order to illustrate the required steps of the simulation procedure, a detailed example or case study was performed on dapped ended highway bridge girders. The physical properties and dimensions of the dapped ended girders, provided by existing construction documents, were used as an input to the simulation. Additionally, statistical traffic distributions of realistic traffic flows were identified to obtain accurate wheel load values. Once the geometry and loading conditions of the bridge were specified, finite element analysis was used to obtain localized load effects. This included, but was not limited to, stress and strain tensors in regions of fatigue susceptibility. This simulation was quasi-static in that each traffic configuration from the load history corresponded to a particular point in the stress history. The stress histories obtained from the simulation were used to define the parameters of an experimental program established to examine the behavior of dapped ended specimens under static and fatigue loading. Strain gauges and calibrated load cells were used to collect data, which were compared to the simulation predictions. Three main conclusions were drawn from this study. The first result of the detailed analysis was to highlight the ability of the simulation to provide multi-axial, and therefore, more realistic stress states in the girder. Simplified analysis of the girders would neglect several components of the stress tensor. Secondly, traffic histories with less frequent heavy truck loads produce a greater fatigue inclination for highway bridge girders. Finally, finite element analysis is most accurate at predicting experimental strains in regions of low stress concentration.