Preface

Structure vibration control is recognized as an effective method and possesses a promising prospect in reducing dynamic responses of structures by using additional vibration mitigation devices. It can be divided into two main categories: the passive control and the intelligent control. Passive control is a technology without external energy input. Some changes in structure dynamic property can be made by mounting shock absorptions or energy isolation devices, which dissipate, divert, or block the transmission of vibration energy. The control devices cannot change characteristic factors, therefore the passive control has many merits, such as simple construction, low cost, easy to maintain, not requiring external energy. Some passive control devices are quite mature and widely used in practical engineering, are even organized into the related codes. Passive control is mainly divided into two categories: vibration isolation and vibration mitigation. Intelligent control includes active control and semiactive control. Active control is a technology that needs for external energy, aiming at protecting structures or equipment. According to the modern control theory, it observes, tracks, and predicts the input of ground motion and structural responses on line, then analyzes the calculated results and imposes the opposite control force by a servomechanism to achieve selfregulating structure responses under dynamic loads. Semiactive control system has a great practical value and good engineering application, which combines the reliability of passive control and flexibility of active control. It can supersede the active control with improvements in some control laws and has a simple construction and stable performance. Thus, the semiactive control system can get over the constrained energy delivery in active control and narrow-band range in passive control. As a hot field, structural vibration control has developed rapidly and research achievements have been widely applied to engineering practice.

Intelligent vibration control has attracted a great deal of attention due to the precise vibration mitigation effect and the adaptability of control devices for different excitations. With particular emphasis on the alleviation of the dynamic responses of complex large-scale or important civil structures, intelligent vibration control will be implemented in accordance with different dynamic excitations. Obviously, an intelligent vibration control system consists of sensor system, control system, control device, and other components, therefore intelligent vibration control involves in some research topics including control devices, intelligent control strategies, intelligent controllers, and intelligent controlled structures. Not as mature as passive vibration control, many challenging topics of intelligent vibration control are still required to be studied further. At the same time, intelligent vibration control in civil engineering structures incorporates interdisciplinary technologies, including civil engineering, automation, mechanics, mechanical engineering, electronic engineering, etc. Therefore systematic books about intelligent vibration control are relatively rare. In view of this, the authors have written this book which provides a working knowledge of this exciting and fast expanding field and brings up-to-date current research and world-wide development of intelligent vibration control, and hope to help the relative researchers, teachers, and students in design, analysis, and application of intelligent vibration control.

The book is divided into eight chapters. In Chapter 1, the main dynamic excitations of civil engineering structures which refers to earthquake and wind excitations are introduced firstly, and then structural vibration control, especially for structural intelligent control, is classified and described. In Chapter 2, the equations of motion of intelligent control system are erected firstly, and then different intelligent control strategies for intelligent vibration control in civil engineering structures are introduced. In Chapter 3, active intelligent controls including principles and classification, active mass control system, active tension control system, and other active control systems are introduced. In Chapter 4, semiactive intelligent controls including principles and classification, magnetorheological damper, electrorheological damper, piezoelectricity friction damper, semiactive varied stiffness damper, semiactive varied damping damper, and magnetorheological elastomer device are introduced. In Chapter 5, taking magnetorheological damper, magnetorheological elastomer device, and active mass damper as examples, design and parameter optimization on intelligent control devices are presented. In Chapter 6, the intelligent controller is designed and experimented. In Chapter 7, dynamic response analysis methods of the intelligent control structure, including elastic, Elasto-plastic, and SIMULINK analysis method, are described. In Chapter 8, some intelligent control examples are introduced systematically, and the corresponding programs are compiled.

It is a great pleasure to acknowledge the contributions to the writing of this book by the researchers in my group, Xiang-Cheng Zhang, Jun Dai, Pan-Pan Gai, Ye-Shou Xu, Yang Yang, Si Suo, Yu-Liang Zhao, Meng Xu, Cheng Wang, Teng Ge, Qian-Wei Jiang, Chao Xu, Waseem Sarwar, Yan-Long Su, Da-Huan Jia, Ling-Feng Sha, Bing-Bing Chen, Tao Liu, Qian-Qiu Yang, Xing-Huai Huang, Jun-Jian Wang, and An-Nan Miao. Special thanks should be given to Prof. Jin-Ping Ou, Prof. Fu-Lin Zhou, Prof. B.F. Spencer, Prof. Fuh-Gwo Yuan, Prof. Ya-Peng Shen, Prof. Hong-Tie Zhao, Prof. Yong Lu, and Ms. Xiu-Fang Wu for their help and encourage. Financial supports for the research of our group described in this book are provided by National Science Fund for Distinguished Young Scholars, National High Technology Research and Development Program (863) with grants number 2009AA03Z106, National Natural Science Funds of China with granted numbers 11176008, 61004064, 11572088, Jiangsu Province Brace Program with granted number BE2010069, Jiangsu Natural Science Funds with grants numbers BK20140025, BK2005410, BK20141086, BE2015158. These supports are gratefully acknowledged.

Due to that the contents of the book are much involved in cutting-edge research technology, some errors maybe occur in the book. The authors appreciate any careful comment of experts and readers sincerely.

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Nanjing, China

Jan. 8, 2016