As engineers seek practical techniques for analysis of complicated connections, researchers look to balance the simplicity and accuracy of joint models. Traditionally, the beam models are common computer simulations for structural analysis and design, while, there is a concern about the necessity of considering a more detailed structural configuration of complex connections, modeled by three-dimensional solid elements for performance assessment. An innovative gusset-less connection was designed for the newly reconstructed Memorial Bridge which connects Portsmouth, NH to Kittery, ME. Since for this connection gusset plates were removed, structural behavior of the joint may not be completely known. In this paper, a simplified beam model along with a more detailed three-dimensional solid model of the connection is used for structural parameter estimation of the gusset-less joint stiffness. For the simplified simulation, a SAP2000® beam model of the joint is developed whereas, for the detailed simulation, an ABAQUS® three-dimensional solid model of the connection is built. The three-dimensional solid model results are used as the input for a modal stiffness-based error function model updating procedure to estimate structural parameters of the gusset-less connection. The estimated parameters are then utilized for making appropriate modifications to the simplified model. Maintaining the simplicity, the updated beam model would then be a more reliable and representative analytical simulation of the real joint. As only a small part of the bridge truss is locally modeled, the results are a preliminary step towards a more developed system identification procedure that incorporates monitoring data of the instrumented Memorial Bridge for updating its global model.

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