Simultaneous size and topology optimization of 3D outrigger‐braced tall buildings with inclined belt truss using genetic algorithm

Abstract

To investigate the optimum location of the outrigger system, a metaheuristic-based size and topology optimization of the outrigger-braced tall buildings is carried out by various three-dimensional structural frames with different shapes of belt trusses. By considering the elastic behavior, the whole elements of the structural models such as beams, columns, core, and trusses are optimized simultaneously in conjunction with the location of the outrigger. Furthermore, to reach more optimality, several novel types of belt truss are proposed having inclined and inverse-inclined belt trusses with better structural and architectural features and optimum performance in comparison with the horizontal one. Different models with 25 to 40 stories having various span numbers are optimized using the genetic algorithm, and the results are compared with each other. In the modeling process, the exact wind load distribution is applied to the structure based on the ASCE7-16 rather than the uniform or triangular ones. According to the results, the optimum cross-sectional size and outrigger locations of different models are obtained, and it is indicated that the proposed novel belt trusses are optimal solution for the problem. K E Y W O R D S outrigger-braced building, size and topology optimization, inclined belt truss, genetic algorithm 1 | INTRODUCTION Tall buildings' development has been an important issue from recent centuries. The risk of vertical and horizontal load forces also increases by increasing the building height. Over certain height, an auxiliary system is needed for the moment-resisting frames with the braced core in order to become efficient to provide stiffness against seismic and wind loads. To achieve the considered strength and stiffness in the building, the lateral displacement should be controlled in the analysis and design of a tall building. One of the auxiliary systems which leads tall buildings to have sufficient stiffness is the outrigger system. Tall buildings with outriggers and belt trusses are a common solution for tall MRFs as they are easy to build and cheap in comparison with the other structural systems. Outriggers interact with peripheral columns through stiff arms. Under large lateral load, the core's rotation at the level of outriggers causes a tension-compression couple in the outer columns which reduces the core deflection utilizing the belt truss that distributes the force to whole peripheral columns. Optimization of tall buildings as a large-scale structure is essential due to a large amount of materials used in their construction. Reaching the optimum weight lowers the consumption of resources and saves a considerable amount of money. To achieve the optimal design, using metaheuristic algorithms in case of tall structures will be an arduous effort because of the high computational costs due to the massive modeling process. One of the crucial parameters that should be considered in the preliminary design steps is the optimum location of the outriggers. For the

Topology Optimisation in Structural Steel Design for Additive Manufacturing

“…Within the recent literature pertaining to optimisation programmes, exceptions to the former can be found in Tsavdaridis' optimisation of aluminium cross-sections [341], as well as in works of the Discrete Optimisation of trussed structures, including truss design to Eurocode 3 (EN1993-1-1 or, simply, EC3) with Differential Evolution Algorithms [267] and bracing systems optimisation with GA to the AISC-LRFD American standard [402,453].…”

A practical shear wall layout optimization framework for the design of high-rise buildings

“…A great deal of the existing literature in high-rise building optimization focuses on only the size optimization [22][23][24] and the topology optimization [25][26][27][28][29][30] of the beams and columns, while the more important layout optimization of shear walls is rarely addressed. Currently, a common approach to layout optimization of shear wall structures is to choose the best from several feasible schemes [31][32][33][34].…”