In the vibration reduction technology of building structures, bridge engineering and large mechanical equipment, pendulum dampers are widely used because of their flexible structure and stable response. Different from common linear damping devices, pendulum dampers can absorb and dissipate vibration energy through swinging mechanism, which can effectively reduce the dynamic response of structures caused by wind, earthquake or equipment operation. However, the actual vibration control effect of pendulum damper is not static, but is influenced by many factors.

1. Influence of structural parameters on control effect

Swing length and swing angle

The swing length determines the natural period of the damper, and the swing angle affects its displacement amplitude in the working state. A reasonable pendulum length can match the vibration period of the controlled structure, thus improving the resonance control effect; Too small or too large swing angle will cause insufficient energy absorption or unstable motion of the damper.

damping factor

Damping coefficient is the key index of energy absorption efficiency of pendulum damper. The damping coefficient is too low and the energy consumption capacity is insufficient; If it is too high, it may cause the damper to dissipate energy prematurely and reduce the adjustment space. Scientific determination of damping coefficient can restrain structural vibration and maintain system stability.

Mass block configuration

The mass size and distribution of pendulum damper affect its inertia characteristics. Reasonable mass distribution can enhance the energy dissipation ability and improve the response of the system to multi-frequency excitation.

Second, the degree of matching between installation and structure

Installation position

Pendulum dampers are mostly installed at the top of the structure or at nodes with strong vibration. If the installation position deviates from the vibration main control point, the control effect will be obviously weakened.

Connection stiffness

The connection stiffness between the damper and the main structure needs to be moderate. Too flexible will lead to insufficient force transmission, and too rigid may introduce new stress concentration points.

Debugging and calibration

After the installation of pendulum damper, dynamic test and parameter calibration must be carried out. Improper debugging will lead to the deviation between theory and actual effect.

Iii. Environmental conditions and external factors

Temperature and humidity

Extreme temperature or humidity changes may affect the performance of swing bearings or damping media, and then change the damping coefficient and swing flexibility.

Vibration source characteristics

Vibration amplitude, frequency and randomness have direct influence on the working state of the damper. For multi-frequency mixed vibration, pendulum damper needs more detailed parameter design and test.

Wear and aging of long-term operation

Bearings, connectors and damping media may be worn, aged or degraded in long-term operation, which will lead to the decline of vibration control effect.

Fourth, the synergy between design and maintenance

The design of pendulum damper lies not only in the initial parameter matching, but also in the later maintenance and management. It is helpful to maintain the long-term control effect of the damper by regularly detecting its swing flexibility, mass stability and connection state. By collecting data and adjusting parameters through the monitoring system, its vibration reduction performance can also be gradually optimized.

V. Industry Significance

As a mature vibration control equipment, pendulum damper's effect depends not only on a single technical parameter, but also on the coordination of the whole system. Reasonable structural design, accurate installation and debugging and continuous maintenance and management can make it play a stable role in the ever-changing vibration environment.

VI. Conclusion

The vibration control effect of pendulum damper is influenced by many factors, including structural parameters, installation location, environmental conditions and long-term maintenance. Only by scientific control in all aspects of design, construction and operation and maintenance can the technical value of pendulum dampers be truly brought into play and more reliable vibration safety guarantee be provided for engineering projects.