tailieunhanh - Active Control in Bridge Engineering

Active Control in Bridge Engineering Introduction Typical Control Configurations and Systems Active Bracing Control • Active Tendon Control • Active Mass Damper • Base Isolated Bridge with Control Actuator • Base Isolated Bridge with Active Mass Damper • Friction-Controllable Sliding Bearing • Controllable Fluid Damper • Controllable Friction Damper 59 General Control Strategies and Typical Control Algorithms General Control Strategies • Single-Degree-ofFreedom Bridge System • Multi-Degree-of-Freedom Bridge System • Hybrid and Semiactive Control System • Practical Considerations Zaiguang Wu California Department of Transportation Case Studies Concrete Box-Girder Bridge • Cable-Stayed Bridge Remarks and Conclusions. | Wu Z. Active Control in Bridge Engineering. Bridge Engineering Handbook. Ed. Wai-Fah Chen and Lian Duan Boca Raton CRC Press 2000 59 Active Control in Bridge Engineering Zaiguang Wu California Department of Transportation Introduction Typical Control Configurations and Systems Active Bracing Control Active Tendon Control Active Mass Damper Base Isolated Bridge with Control Actuator Base Isolated Bridge with Active Mass Damper Friction-Controllable Sliding Bearing Controllable Fluid Damper Controllable Friction Damper General Control Strategies and Typical Control Algorithms General Control Strategies Single-Degree-of- Freedom Bridge System Multi-Degree-of-Freedom Bridge System Hybrid and Semiactive Control System Practical Considerations Case Studies Concrete Box-Girder Bridge Cable-Stayed Bridge Remarks and Conclusions Introduction In bridge engineering one of the constant challenges is to find new and better means to design new bridges or to strengthen existing ones against destructive natural effects. One avenue as a traditional way is to design bridges based on strength theory. This approach however can sometimes be untenable both economically and technologically. Other alternatives as shown in Chapter 41 include installing isolators to isolate seismic ground motions or adding passive energy dissipation devices to dissipate vibration energy and reduce dynamic responses. The successful application of these new design strategies in bridge structures has offered great promise 11 . In comparison with passive energy dissipation research development and implementation of active control technology has a more recent origin. Since an active control system can provide more control authority and adaptivity than a passive system the possibility of using active control systems in bridge engineering has received considerable attention in recent years. Structural control systems can be classified as the following four categories 6 Passive Control