Virtual hybrid simulation is a computationally-efficient method that enables coupling of two or more finite element analysis programs. In this study, benefits of this technique in predicting both cyclic and seismic response of a one-story one-bay frame equipped with a Triangular-plate Added Damping and Stiffness (TADAS) damper are evaluated. For this purpose, a detailed FE model of the damper is built in Abaqus to take into account precise modelling of its hysteretic behavior as well as a number of important features related to the geometric characteristics of the including parts of the device, while the remainder of the structure is modelled in OpenSees. Continuous exchange of the data between the coupled codes is conducted through the software framework, OpenFresco. Comparison of the results with experimental outcomes is presented, which proves the ability of the introduced technique in modelling the behavior of such structures in an efficient manner while preserving sufficient accuracy. At the end, a series of dynamic virtual hybrid simulations of the frame are performed which provide useful insights into design of TADAS frames.

Bridge structures nationwide across the United States are aging and in need of repair or, in some cases, full replacement. Repair decisions are common among bridge owners because of the economic feasibility when compared to the higher cost of full replacement of damaged or deteriorated bridge components such as girders. Using a proper repair approach, as a long-term or just a short-term solution, can lead to benefits that could not be achieved otherwise such as considerable savings in both time and cost. Additionally, an appropriate repair approach can help avoid adverse environmental impacts, interruptions to service, overburdening of nearby infrastructure, and local opposition to construction. The main objective of this paper is to provide a synthesis of the repair methods and materials for reinforced concrete bridge girders proposed in research studies, i.e., state-of-the-art as well as state-of-the-practice established methods. Different steps in the general repair procedure are explained first. Next, a detailed description of three common bridge girder deficiencies, i.e., shear, flexural, and fire damage, is provided. For each damage type, the main causes and common solutions found in the literature are presented. The authors then provide specific recommendations to each repair procedure. This is intended to enable researchers, engineers, and decision makers to compare the available repair methods more conveniently to find the optimal repair approach for specific projects based on economic and environmental requirements as well as structural and construction conditions.

Summary Magnetorheological (MR) dampers have gained significant attention in seismic mitigation of structural systems due to their distinguished characteristics such as inherent stability and minimum power requirements. Their performance in control of nonlinear structural response, however, has not been widely investigated. This paper provides comprehensive nonlinear seismic performance assessment of a three‐story benchmark structure equipped with a large‐scale MR damper using virtual real‐time hybrid simulation to efficiently capture the nonlinear behavior of the damper. The framework is first verified by means of available experimental results of an actual RTHS on the same structural system. A set of 12 earthquake ground motions, each one scaled to have 12 different intensities are then utilized to perform nonlinear dynamic analyses. An energy‐based adaptive passive‐on control strategy is proposed, and its performance is compared with passive‐on, passive‐off, and uncontrolled response of the structure in terms of interstory drifts shown by fragility curves, residual drifts, MR damper control force, and the ability to maintain a uniform interstory drift along the height of the structure.

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