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In recent decades, many researchers have conducted research studies on structural control to improve the safety and serviceability of high-rise buildings against earthquakes and strong winds. On the other hand, applying active control systems and controlling strategies in buildings are costly process, and it is necessary to reduce the number of controllers.In this paper, a multiobjective genetic algorithm is proposed to optimize the placement of active tendons in a 2D shear frame and a 3D irregular building considering soil-structure interaction effect to reduce active control cost and response of structures at the same time. For multiobjective optimization, multiobjective genetic algorithm of the MATLAB toolbox is used to find a set of Pareto optimal solutions for a multiobjective minimization. The results indicate that the method is capable of finding the number and location of the required active tendons in both 2D shear frame and 3D irregular building with 10 and 20 stories while the base shear of structure is minimized. The specific advantage of the employed algorithms is to reduce the number of mounted active tendons approximately by 50%. KEYWORDS active control, active tendon, irregular multistory buildings, multiobjective optimal placement, soilstructure interaction 1 | INTRODUCTION In the last three decades, the response reduction of structures subjected to strong earthquake has become an important subject of research, and many structural control strategies such as active, passive, hybrid, and semiactive control systems have been used in theory and practice. The active vibration control methods are very effective for both the transient vibrations and those with a wide frequency range. One of the most reliable active control devices is active tendon controllers. [1] Some control strategies developed for civil engineering structures include modified linear quadratic regulator (LQR), modified linear quadratic Gaussian, neural network-based, fuzzy logic, sliding mode, and wavelet-based controllers. [2] In reality, most buildings have irregular plans inducing rotation around their vertical axis when subjected to lateral excitation that would naturally increase the structural response. The torsional effect cannot be considered in two-dimensional frame; thus, a three-dimensional (3D) structure model must be used. In the 3D model, there is a large torsion around z direction, simultaneously with the lateral displacement in both x and y directions. Yanik et al. [3] utilized a new performance index for a 3D fully controlled building structure where controllers situated only in one direction. A comparison was made between the performance of the proposed control algorithm and the classical linear optimal control algorithm on the structure under several earthquakes. Jiang and Adeli [4] utilized the effect of geometrical and material nonlinearities on the 3D building structures controlled by a dynamic fuzzy wavelet neuroemulator.The soil-structure interaction (SSI) effect is significant, especially in the buildings bui...

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This paper presents a stacking sequence optimization for maximizing the buckling load of rotationally restrained laminated composite rectangular plates with different boundary conditions resting on an elastic Pasternak foundation subjected to uniaxial and biaxial in-plane static loads. The Mindlin Plate Theory (MPT), which considers the first-order shear deformation effect, is used to extract the characteristic equations of the plates under in-plane loading, including platefoundation interaction. The buckling problem of the laminated plates is analyzed by the Rayleigh-Ritz method. The aim of optimization is to maximize the buckling load and post-buckling load capacity by using the Genetic Algorithm (GA) method, and the design variable is the ply orientation. The results showed that the optimal orientation, θ, of the laminated square plate under biaxial in-plane loading with various conditions is 45° approximately. The existence of a foundation, clamped boundary conditions, and high aspect ratio lead to increase the optimal orientation.