Design Of Steel Frame Structures Research Articles

Optimum sizing design of steel frame structures through maximum energy dissipation of friction dampers under seismic excitations

This paper focuses on optimum sizing design of steel frame structures equipped with friction dampers (FDs) in order to prevent the vulnerable effect of an earthquake. The fundamental concept is to maximize the energy dissipation of implemented FDs under different seismic excitations. The FDs utilized as passive energy dissipation devices in a steel structure increase the energy dissipation capacity of the structure by decreasing the seismic demand during an earthquake. In this context, the Pall friction dampers (PFDs) are implemented as diagonal damped brace members in investigated structures. Three different earthquake records (Kobe, Kocaeli-Duzce, Erzincan) are utilized to acquire nonlinear dynamic responses of the steel frame structures through time-history analyses. The open application programming interface (OAPI) functions are used to integrate a finite element modelling based structural analysis program, SAP2000, with a design optimization algorithm encoded in MATLAB for achieving the exact structural behaviours by synchronously data transferring. As an optimizer, one of the recent nature-inspired metaheuristic techniques, so-called Grey Wolf (GW) algorithm is used. Initially, under effect of seismic excitations, the steel frame structures are optimally sized for attaining minimum design weights without implementing the PFD elements by subjecting only strength, displacement, drift, and geometric structural design constraints taken from AISC-LRFD practice code provisions. Afterward, in order for optimally modelling the PFD elements, the frames are equipped with PFDs to calculate optimum yield strengths that is defined as slip load of a PFD. To do so, the GW algorithm ensures the maximizing of the dissipated energy and controls the yield strengths between the stories since the shear force due to the earthquake increases towards the base of the structure. Eventually, the provisions-based sizing design optimizations of the steel frame structures equipped with optimally modelled PFD elements are conducted under seismic excitations for conclusive evaluations.

Optimum Sizing Design of Steel Frame Structures Using Evaporation Rate-Based Water Cycle Algorithm with Greedy Selection

Optimum Sizing Design of Steel Frame Structures Using Evaporation Rate-Based Water Cycle Algorithm with Greedy Selection

Seismic loss optimum design of steel structures using learning‐based charged system search

SummaryOne of the structural engineers' challenges on a regular basis is balancing the expense of initial construction with the cost of future structural loss. At first appearance, employing the optimization method seems to be a viable option. However, since both the structure's analysis and design, as well as the computation of the cost of future loss, are time‐consuming and expensive, combining these processes with the costly optimization progression is prohibitively expensive. The purpose of this study is to present a methodology for the risk‐based optimum design of steel frame structures, as well as to enhance a previously published metaheuristic algorithm for a better optimization approach. The methodology given here allows structural designers to account for seismic risks in the design optimization process without incurring expensive computing expenditures. This approach may be appealing for practical work since it minimizes time‐consuming charges and provides designers with a structural impression. Furthermore, as compared to the standard version, the new optimization algorithm improves performance while decreasing computing costs. Bayesian linear regression is used in conjunction with a parameter identification challenge to derive probabilistic models for estimating structural analysis demand responses. The minimum amount of total initial cost and seismic loss cost is regarded as the objective function of the design of three chosen mid‐ to high‐rise moment frames for the optimization purpose. The results demonstrated enhanced optimization performance as well as a decreased loss cost for employed structures.

Weight optimization of stainless‐steel built‐up structural elements

AbstractThis paper describes the use of stainless‐steel as a structural material, discusses current structural design considerations, reviews recent research work, and highlights important findings and developments.Over the past 25 years, structural design codes for stainless‐steel have been introduced or substantially altered or are still being modified, while at the same time there is a growing interest in the use of stainless‐steel in construction. Realistic modeling of structural elements of stainless‐steel plays an important role in the analysis and design of steel framed structures. Structural element modeling and optimization using stainless‐steel, in case a built‐up column, can contribute to existing research on stainless‐steel. The object under consideration is a stainless‐steel built‐up column, which is classified as atypical structural elements. The purpose of this optimization problem is to perform the minimization of the weight of the selected built‐up column, when the height of the column and the load acting on it are known. The built‐up column is considered with two different types of cross‐sectional chords: at first with circular (CHS) cross‐sectional chords and then with elliptical (EHS) cross‐sectional chords.A genetic algorithm based optimum design is presented for such a built‐up column. The design algorithm obtains a built‐up column with the least weight by selecting appropriate sections from standard set of duplex stainless‐steel hollow elliptical cross‐sections. The optimization model accounts for the strength and stability constraints. The built‐up column is under action of compressive axial force, bending moment and combination compressive axial force and bending moment. The parameters under consideration include the height and width of the outer cross‐section of the column's chords, the ratio of the outer cross‐sectional dimensions to the thickness and the initial eccentricity of the load. The computation results showed that the chosen optimization model and genetic algorithm allow efficiently obtaining the column of minimum weight, where the variables are column chord cross‐section and diagonals cross‐section. The design algorithm used to solve the problem is described in detail in this work.Until today, there is known that the lack of information prevented the recommended methodology from being properly established. Because of this, the obtained results confirmed that these types of structural elements of the steel in question are needed to develop a more efficient design of stainless‐steel structures in the design method and thus contribute to its wider use in construction.

Elastic-Plastic Load-Carrying Capacity of Simple Frame Structures

The efficiency of plasticity for the design of steel frame structures is analysed in the paper. Technical theory of plasticity and standard assumptions and requirements for numerical study are applied. Two types of simple frames (double-sided pinned supporting and fixing) with different loading, geometrical dimensions of the frames and cross-sections of their columns and beams are considered. Some results of the numerical study and conclusions are also presented.

Assessment and Design of Steel frame Structure, consists Performance of Connection Joints with Tekla & Staad Pro

Steel offer the range of advantages to the structure Industry. The erudition of steel gives architects, and the freedom was to achieve the most ambitious visions. Steel is also one of the most sustainable construction materials, building owners naturally value the flexibility of steel buildings in addition the value of benefits they provide. Steel is ideal for modernization, reconfiguring, extending or adapting with minimal disruption. The conception of design analysis as well as modelling of steel structures is the most up-to-date edition in the civil engineering field. It is necessary to model a steel structure but if it is also analysed during its modelling then there will not be any chances of failure. Tekla structures are powerful and flexible software for all structural projects. Flurry up our construction work with an enormous of standard connections for all structural projects. In construction field, we create a evident, constructible 3D model of any steel structure from everyday industrial and commercial buildings to stadiums and high rise buildings. This project dealing with manual connection designing by using of Standards (ISO, AISC, AWS etc..). As well as considering of OSHA rules. Implemented manual designing and modelling by using of Tekla software. And the connections are an important part of steel structure like beam to column connections, moment connections. And are designed more conventionally than any individual members. The aim of this project work is to analyse a 7-storeyed commercial building for different load combinations using STAAD Pro software. And behaviour of connection of bolts.

ОПТИМАЛЬНОЕ ПРОЕКТИРОВАНИЕ СТАЛЬНЫХ РАМНЫХ КОНСТРУКЦИЙ С УЧЕТОМ УРОВНЯ МЕХАНИЧЕСКОЙ БЕЗОПАСНОСТИ

The approach to the design of steel frame structures is considered, taking into account the potential risk of occurrence of emergencies associated with their mechanical local damage, and possible material losses. It is proposed to classify these systems according to the safety level of the solution. In accordance with the introduced classification, methods for finding solutions are proposed based on the use of evolutionary modeling with subsequent risk assessment from the onset of an emergency. These methods include a combination of two-level stochastic optimization procedures. At the first level, a search is performed on discrete sets of design parameters of a design variant with a minimum cost. As constraints in the absence of emergencies, regulatory requirements of limit states are accepted, and the strength ratio is regulated. In a possible emergency for the construction is considered a limitation on survivability. At the second level, a heuristic search is performed for the design variant for which the risks of receiving material damage from an accident are minimal while ensuring a minimum of capital investments on the considered stages at building life cycle. Examples of the steel frame design with different levels of safety are given, which demonstrate the efficiency of the proposed approach.

Features of the Design of Steel Frame Structures in India for Seismic Areas

This article is devoted to the analysis of one of the most common structural designs of the steel frame of small spans, currently used in India in construction and reconstruction for seismic areas. This scheme constructively involves the implementation of the main bearing elements - bolts and columns - in the form of a spatial truss box section. At the same time, rather simple rolling profiles from small-sized corners are used, as well as a round steel bar. The studies performed by the authors were carried out using the finite element method based on the national design computing complex SCAD for Windows. The loads, as well as the geometrical characteristics of the profiles, were taken according to the current building standards of India. Based on the results of the analysis, a number of recommendations were formulated to improve the efficiency of the considered design scheme for seismic effects of varying intensity.

Meta-heuristic design optimization of steel moment resisting frames subjected to natural frequency constraints

Natural frequencies of a structure play a key role for finding underlying structural properties. Therefore, structural design considering natural frequencies is a very important issue for engineers. While there are many studies on optimization of truss structures under multiple frequency constraints, just a few studies have been published on steel frames for which only gradient based methods were applied. In this paper, meta-heuristic algorithms are applied for the first time ever to optimal design of steel frame structures with frequency constraints. Several benchmark design examples are solved with five algorithms including particle swarm optimization (PSO), charged system search (CSS), teaching-learning based optimization (TLBO), grey wolf optimizer (GWO) and a recently developed improved grey wolf optimizer (IGWO). Optimization results of these algorithms are compared in terms of statistical indices, convergence and optimum solutions. Various types of planar and space steel frames ranging from small to large scale cases are considered for illustrating merits and applicability of meta-heuristic algorithms to these sizing optimization problems wherein the large scale cases are studied in both continuous and discrete forms.

Seismic response tests and analytical assessment of blind bolted assembly CFST frames with beam-connected SPSWs

This paper presents a series of experimental and analytical studies to investigate the seismic behavior of blind bolted assembly concrete filled steel tube (CFST) frames with infill steel plate shear walls (SPSWs) connected to beam only. Two specimens of single-bay, two-story blind bolted assembly CFST frames with beam-connected SPSWs were fabricated and tested under lateral cyclic load combined with a constant vertical axial load. The test parameters include the column section type, the beam-SPSW connection type and the SPSW setting. Typical failure modes of the specimens were summarized and discussed. The test results show that the presence of SPSWs can compensate effectively the relatively small lateral stiffness of bare blind bolted CFST frames, and the novel SPSW-frame system exhibited good hysteretic performance, ductility and energy dissipation capacity. Moreover, the moments at the beam ends of a CFST frame with semi-rigid joints under two partial vertical loads resulting from the beam-connected SPSWs are derived. A practical design method for semi-rigid CFST frames with beam-connected SPSWs is summarized for checking the strength of blind bolted end plate joints, steel beams and CFST columns. The accuracy of the design method is also verified by the test results. The study shows that the novel SPSW-frame has good potential for application in earthquake resistant design of steel frame structures.

A Comparison between different techniques for optimum design of steel frames subjected to blast

Abstract According to the conditions of today's world, design of resistant structures against blast loading is an important subject that requires special attention. Thus, given the benefits of optimization in engineering, development and assessment of optimization methods for optimum design of structures against blast is of great importance. In this research, the optimum design of steel frame structures against blast loading is investigated. For this purpose first an optimization methodology is proposed. In the proposed method the structural analysis is performed using nonlinear explicit finite element analysis. Based on the proposed method a framework is developed and three numerical examples are investigated using different numerical optimization techniques. Results of this study show that by using nonlinear explicit FE analysis as the structural analysis method and NLPQLP optimization technique as the optimization method, the current optimization problem can be performed effectively, because the procedure is relatively accurate and computationally inexpensive.

Topology optimization of steel frame structures with constraints on overall and individual member instabilities

A computationally efficient structural topology optimization framework is proposed for design of steel frame structures with user-defined factors of safety against overall structure (global) and individual member instabilities. The objective function is minimization of either compliance or the maximum of von Mises stresses within the frame structure. Within optimization, overall structure buckling modes are found via an eigenvalue analysis, a subset of “pseudo modes” are identified using a newly proposed methodology and are discarded to obtain a set of real eigenvalues. Moreover, individual member buckling loads are estimated with Euler buckling analysis and are aggregated into a single constraint. The minimum of each instability constraint is then estimated with separate differentiable negative p-norm functions. Sensitivities of these newly developed constraints are explicitly derived for application of gradient-based optimizers. The topology of four frame structures featuring moment-resisting connections and member cross-sectional properties mapped from the American Institute of Steel Construction design manual are optimized with the proposed algorithm to verify its effectiveness in optimizing structural performance while maintaining factors of safety against overall and individual member instabilities. The interaction effects of preventing instabilities at different safety levels and the choice of objective function on the final designs and their performances are investigated.

Evolutionary Optimization of Frame Structures Taking into Account the Project Reliability and Possibility of Emergency Actions

The article describes methods of optimal design of steel frame structures of buildings considering impacts not provided for standard operation conditions. In particular fast removal of support braces is analyzed. The frame optimization methodology based on evolutionary simulation is used for solving this task considering plastic deformation of the damaged structure in the genetic algorithm.

Optimal shakedown design of steel framed structures according to standards

The paper considers the relationships between the optimization of perfectly elastic–plastic structures under repeated variable load and the valid structural design standards. The physical and geometrical properties of a structure are known in advance. The quasi-static cyclic loading is characterized by time-independent upper and lower bounds. The mathematical model for determining the optimal internal limiting force distribution of a structure at shakedown with strength, stiffness and stability constraints according to EC3 standard is presented. The model takes into account the ultimate and serviceability limit states of EC3 with corresponding reliability levels. The evaluation of the stability of the elements under compression takes into account plastic deformations in the shakedown process. The proposed methodology allows a more precise interpretation of the stability constraints in continuous optimization problems of mathematical programming. The results are valid for the assumption of small displacements. Numerical examples of the optimization of a portal and three storey steel frames are presented.

Optimum design of steel frame structures by a modified dolphin echolocation algorithm

Dolphin echolocation (DE) optimization algorithm is a recently developed meta-heuristic in which echolocation behavior of Dolphins is utilized for seeking a design space. The computational performance of meta-heuristic algorithms is highly dependent to its internal parameters. But the computational time of adjusting these parameters is usually extensive. The DE is an efficient optimization algorithm as it includes few internal parameters compared with other meta-heuristics. In the present paper a modified Dolphin echolocation (MDE) algorithm is proposed for optimization of steel frame structures. In the MDE the step locations are determined using one-dimensional chaotic maps and this improves the convergence behavior of the algorithm. The effectiveness of the proposed MDE algorithm is illustrated in three benchmark steel frame optimization test examples. Results demonstrate the efficiency of the proposed MDE algorithm in finding better solutions compared to standard DE and other existing algorithms.

Optimum design of steel frame structures considering construction cost and seismic damage

Minimizing construction cost and reducing seismic damage are two conflicting objectives in the design of any new structure. In the present work, we try to develop a framework in order to solve the optimum performance-based design problem considering the construction cost and the seismic damage of steel moment-frame structures. The Park-Ang damage index is selected as the seismic damage measure because it is one of the most realistic measures of structural damage. The non-dominated sorting genetic algorithm (NSGA-II) is employed as the optimization algorithm to search the Pareto optimal solutions. To improve the time efficiency of the proposed framework, three simplifying strategies are adopted: first, simplified nonlinear modeling investigating minimum level of structural modeling sophistication; second, fitness approximation decreasing the number of fitness function evaluations; third, wavelet decomposition of earthquake record decreasing the number of acceleration points involved in time-history loading. The constraints of the optimization problem are considered in accordance with Federal Emergency Management Agency\'s (FEMA) recommended seismic design specifications. The results from numerical application of the proposed framework demonstrate the efficiency of the framework in solving the present multi-objective optimization problem.

Displacement-Based Seismic Design Method of Steel Moment Frame

According to lots of documents previously studied, a seismic design method is put forward based on displacement for steel moment frame. This method is established in condition that the yield displacement of steel frame can be determined by its geometrical dimension; then the objective displacement (ultimate displacement) can be determined in light of performance level of the structure, and the corresponding coefficient of ductility can be obtained. Thereafter, the design base shear of steel frame structure can be calculated by the use of reduced elastic spectrum. Thus, the design of stiffness and capacity can be conducted on steel frame structure. The analysis of case study indicates that the displacement-based seismic design method addressed herein is of reasonable safety and reliability, and of operational convenience, which can still realize the seismic design of steel frame structure at different performance levels.

The Practical Application of Structural Fire Engineering on a Retail Development in the UK

The British Building Regulations allow the application of performance based design methods to ensure the fire resistance of buildings. This has led to significant amounts of research and testing on the fire performance of structures. This research generated the understanding that steel framed buildings have an inherent fire resistance, which has in turn resulted in the development of specialist numerical calculation tools as well as simplified design methods for the fire design of steel-framed structures. The paper describes the practical application of these structural fire engineering methods using a large retail and cinema complex in the UK as a case study. The finite element software Vulcan has been used to analyse the behaviour of large parts of this multi-storey building during a number of likely design fire scenarios in order to optimise the amount of applied passive fire protection to the structure. The building is constructed as a steel composite structure with normal down-stand composite beams supporting a composite floor on trapezoidal metal deck. This type of structure is ideal to utilise the benefits of tensile membrane action during a fire which can be used to omit fire protection from off grid secondary beams. Due to the size and the multiple usage and changing floor construction of the buildings five different sub-frames haven been analysed. In the UK a number of simplified methods are currently applied to justify partially protected steel structures. These methods are based on individual bays only and therefore do not consider the effects of the surrounding structure. In order to investigate the differences further, the behaviour of the large sub-frame models has been compared with the results of individual bay analysis methods.

Multiple cardinality constraints and automatic member grouping in the optimal design of steel framed structures

For structural optimization problems, such as the weight minimization of steel framed structures, the sizing design variables are often defined as the cross-sectional areas of the members, which are to be chosen from commercially available tables such as those provided by the American Institute of Steel Construction. Alternatively, the cross-section dimensions, bf, tf, d and tw (which may be discrete or continuous) can be defined independently for each profile. This paper discusses the structural optimization problem of framed structures involving sizing design variables where a special genetic algorithm encoding is proposed in order to establish a strategy to discover ideal member grouping of members. Advantages in fabrication, checking, assembling, and welding, which are usually not explicitly included in the cost function, are thus expected. The adaptive penalty method (APM) previously developed by the authors is applied to enforce all other mechanical constraints considered in the structural optimization problems discussed in this paper.

SUPPORTING SCHEME FOR STRUCTURAL DESIGN OF STEEL FRAME STRUCTURES BY USING MULTI-OBJECTIVE OPTIMIZATION METHOD

Present paper proposes a supporting system for structural design of steel frame structures by using multi-objective genetic algorithm. Most of steel structures are composed of the standardized members produced at the factory. In order to take such situation into the process of structural optimization, the structural optimization scheme through the usage of genetic algorithm which can easily deal with discrete variables is presented. Furthermore, multi-objective optimal design method to obtain the Pareto solutions considering both structure's safety and its economy by using multi-objective genetic algorithm is proposed. Through the numerical examples, present design system is shown to be useful for designers as a valuable proposal tool especially in the beginning stage of the structural design.