A Smart Tower Crane to Mitigate Turbulent Wind Loads

Abstract

Tower cranes have, in general, low structural damping, leading to challenges with respect to vibrations induced by natural hazards. Crane failures due to wind excitations are very common around the world. In the present research work, a smart tower crane equipped with pairs of collocated sensors and actuators is proposed to mitigate turbulent wind. A three-dimensional finite element model of the crane is created using MATLAB^®/Structural Dynamics Toolbox. Modal analysis is performed to calculate natural frequencies and corresponding mode shapes. Dynamic analysis of the crane is carried out under turbulent wind excitation. A decentralized active vibration control method is then used to prevent collapse of the crane. Active damping is added to the tower crane using pairs of force actuators–displacement sensors collocated on selected elements. A robust control strategy based on decentralized direct velocity feedback is implemented. The vibrations of the tower crane in all directions are significantly damped. It is concluded that the proposed smart tower crane model is highly efficient in mitigating the turbulent wind loads.

Keywords:

• smart tower crane
• wind turbulence
• modal analysis
• crane active control
• direct velocity feedback

Acknowledgements

The authors gratefully acknowledge the project support (G.R.P-82-39) provided by the Deanship of Scientific Research, King Khalid University, Abha, Kingdom of Saudi Arabia, and also thank them for providing the facilities required for the successful completion of the project. The authors would like to thank Dr Etienne Cheynet, from the University of Stavanger (Norway), for his fruitful discussions about the wind modeling.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by King Khalid University [grant number G.R.P-82-39].