Active and semi-active control of structures – theory and applications: A review of recent advances

Abstract

It is internationally recognized that structural control was introduced in civil engineering through a pioneering article by Yao and through the implementations promoted by Kobori. The concepts of active and semi-active structural control in civil and infrastructure engineering date back 40 years and much progress has been recorded during these four decades. Periodically, state-of-the-art manuscripts have been published and technical books were also printed to testify the maturation of the topic. This article only covers the period from the second semester of 2009 to the first semester of 2011, emphasizing the developments in terms of theoretical, numerical and experimental studies, as well as the use of control algorithms and devices in actual implementations. It is observed that there are still several operational limitations to prevent from the expected growth of the applications in standard design. Nevertheless, some innovative concepts help to foresee future developments within special sectors of applications.

Vibroacoustic Response of an Annular Sandwich Electrorheological Disc

“…1), and θ and φ being the cone and azimuthal angles, respectively. The radiated acoustic pressure can be written in terms of the plate surface velocity through the well-known Rayleigh integral in the form [1,37]: (23) where k = ω / c 0 is the acoustic wave number, δw/δt is the transverse plate velocity amplitude at (r, ϕ), and is the length of the vector connecting a representative element of the plate (dr, rdϕ) to the field point "S," as shown in Fig. 1.…”

“…The above expression can be integrated into in a more simplified form as where ε 0 = 2π and ε n = π for n ≠ 0. Lastly, once the panel modal displacement coefficients are known, the transverse plate surface velocity, iωw(r, ϕ, t), can readily be substituted into the Rayleigh integral equation (23) to obtain the radiated far-field pressure.…”

“…Other valuable features of these materials include simplicity, compactness, low cost, low-energy loss, robustness and easy controllability by computers [22][23][24]. Several investigators have studied the use of the adaptive ER/MR materials for vibration and sound radiation/transmission control in various spheres of engineering.…”

Experimental Study on Robustness of an Eddy Current-Tuned Mass Damper

“…Vibration control is commonly used in civil engineering [1][2][3][4][5], and includes passive [6,7], semi-active [8][9][10] and active approaches [11][12][13]. In the passive approach, dampers, such as magneto-rheological dampers, fluid viscous dampers, particle dampers and tuned mass dampers (TMDs), have been utilized to suppress structural vibration and dissipate vibration energy of the controlled structures [14][15][16][17][18][19][20][21][22][23][24].…”

Modeling and Dynamics of a MDOF Isolation System

“…For different applications, different structures and control methods are carried out for different vibration suppression mechanisms, for example, energy transferring between different vibration modes [1][2], vibration suppressing with absorbers [3][4][5], or utilizing semi-active/active vibration control methods etc. [6][7][8]. In most cases in vibration isolation, better isolation effectiveness can be obtained by using elements with smaller restoring forces which result in smaller natural frequency of the system, especially for microgravity environment in aerospace engineering [9][10][11].…”