Phase I Benchmark Control Problem for Seismic Response of Cable-Stayed Bridges

Abstract

This paper presents the problem definition for the first generation of benchmark structural control problems for cable-stayed bridges. The benchmark problem is based on the Bill Emerson Memorial Bridge that is currently under construction in Cape Girardeau, Missouri. Construction of the bridge is expected to be completed in 2003. The goal of this study is to provide a testbed for the development of strategies for the control of cable-stayed bridges. Based on detailed drawings, a three-dimensional evaluation model has been developed to represent the complex behavior of the full scale benchmark bridge. The linear evaluation model is developed using the equations of motion generated around the deformed equilibrium position. Evaluation criteria are selected that are consistent with the goals of seismic response control of a cable-stayed bridge. Control constraints ensure that the results are representative of a control implementation on the physical structure. Each participant in this benchmark study is given the task of defining ͑including devices, sensors, and algorithms͒, evaluating, and reporting on their proposed control strategies. These strategies may be either passive, active, semiactive, or a combination thereof. A simulation program is provided to facilitate direct comparison of the capabilities and efficiency of the various control strategies. The problem is available through the internet in the form of a set of MATLAB ® programs and includes a sample control design to guide participants through the benchmark problem.

Phase II benchmark control problem for seismic response of cable‐stayed bridges

“…The 128 cables are made of high-strength, low-relaxation steel (ASTM A882 grade 270). The smallest cable area is 28.5 cm 2 (4.41 in 2 ) and the largest cable area is 76.3 cm 2 (11.83 in 2 ). The Hshaped towers have a height of 102.4 m (336 ft) at pier 2 and 108.5 (356 ft) at pier 3 ( Figure 3).…”

“…Additionally, the bridge is assumed to be attached to bedrock, and the effects of soil-structure interaction are neglected. A detailed description of the finite element model development is provided elsewhere [1]. The finite element model employs beam elements, cable elements and rigid links.…”

“…The nonlinear static analysis is performed in ABAQUS [13], and the element mass and stiffness matrices are output to MATLAB for assembly. Subsequently, the constraints are applied, and a reduction is performed to reduce the size of the model to something more manageable [1]. The first ten undamped frequencies of the evaluation model are 0.2899, 0.3699, 0.4683, 0.5158, 0.5812, 0.6490, 0.6687, 0.6970, 0.7102, and 0.7203 Hz.…”

“…In ABAQUS, the B31 beam element was used for the structural beam element, and the element T3D2 was used for the cable elements. Further details on this procedure can be found elsewhere [1].…”

Smart base-isolated benchmark building. Part I: problem definition

“…However, the relative merits of these active and semiactive controllers, as applied to base-isolated structures, has not been investigated by careful comparison on a well-defined benchmark problem. Recently well-defined analytical benchmark problems [16][17][18][19][20][21] have been developed for studying response control strategies for building and bridge structures subjected to seismic and wind excitation, by broad consensus effort of the ASCE structural control committee. The goal of this effort was to develop benchmark models to provide systematic and standardized means by which competing control strategies, including devices, algorithms, sensors, etc.…”