Numerical Simulation on the Dynamic Response of a Suspension Bridge with Mass Eccentricity under Wind Action

摘要

A numerical method is developed to predict the dynamic behavior of a suspension bridge with a trapezoidal cross-section having mass eccentricity as well as its surrounding flow field in a two-dimensional sense. The simulations contain the computations of the dynamic behaviors of flow and structure, which are performed alternatively during the calculation process. Wind tunnel measurements are conducted in parallel to confirm the numerical predictions and to examine the instability of the bridge model. Results show that the numerical predictions are in good agreement with those from the measurements. Generally, the fluctuating response increases as the approaching flow speed increases except when resonances occur, resulting in two local peak values. Among all the test cases, the largest fluctuating responses are detected when the approaching-flow attack angle is zero. On the other hand, the existence of mass eccentricity tends to promote the fluctuating responses. For a bridge deck with a trapezoidal cross-section, this effect is more significant as the mass center moves upstream.