Optimum structural design of full-scale steel buildings using drift-tribe-charged system search

In this paper,the potential of utilizing improved metaheuristic approaches in optimal design of building structures is concerned.In this regard,the drift-tribe-charged system search algorithm is proposed that the position and velocity updating processes of the charged system search is developed by implementing the mathematical presentation of the free-electron model utilized for metal conductors.In addition,the searching phase of the developed algorithm is also divided into three separate phases in order to improve the convergence capability of the algorithm.By means of these modifications,the exploitation and exploration rates of the standard algorithm are enhanced.In order to determine the ability of the proposed improved metaheuristic method considering some complex optimization problems,a 10-story steel building structure with 1026 structural members alongside a 60-story structure with 8272 members are utilized as numerical examples.The overall capability of the developed metaheuristic approach is compared with other metaheuristics.A total number of 30 independent runs have been conducted for each of the standard and proposed methods while a statistical analysis is also conducted for comparative purposes.The obtained optimum results demonstrated that the proposed metaheuristic approach is capable of preparing better outcomes than other metaheuristics.

Beam Element Material Model for Rotary-Straightened Steel W-Shapes

An inelastic material model that was previously developed by the author for standard W-Shapes was adapted for use to model the behavior and strength of rotary-straightened hot rolled W-Shape sections.Using a published residual stress model for these W-Shapes,limit load analyses were conducted using the material model in MASTAN2 and were compared with published finite element results.The material model required an adjustment to the initial yield moment conditions and residual stress ratios.Comparisons with published results indicate that these minor modifications were sufficient to provide very good modeling agreement.The previously developed material model can be used effectively to model the limit load conditions of rotary-straightened hot rolled W-Shape beams and beam-columns in steel frames.The effect of rotary-straightening W-Shapes is more significant for minor axis bending conditions and this becomes more pronounced as the floor load magnitudes increase.

Static and Dynamic Analyses of Spliced Column

The analysis of spliced column has been carried out to detect optimum location of providing splices in the column.In the present work,static and dynamic(free vibration)analyses of spliced column have been done by randomising the location of splicing.A symmetrical four storey steel framed building has been modelled,analysed and designed for loads(dead,live and earthquake loads)recommended by Indian Codal provisions using Staad.Pro.The critical column at each floor level is identified based on axial force(AF),bending moment(BM)and shear force(SF).The total 16 models of spliced columns have been designed and then modelled in a 3D CAD Design tool(SOLIDWORKS)and then imported in the finite element tool(ANSYSWorkbench 14.0)for detailed analysis.The variation of stress,strain and deflection of the spliced column are shown in the form of contour.Further,the modal analysis is performed to determine the natural frequencies.The results of static and dynamic analyses are compared for each modelled spliced column to obtain the optimum location for providing splices in the column.The dynamic analysis of spliced column is of utmost importance in the region where dynamic loadings like earthquake,cyclones etc.are more frequent,and mere static analysis does not account for the safety of the structure.This study will help the engineers to select directly the optimum size and location of the splices in the column of a steel framed building.