Steel Space Frames Research Articles

An optimal design approach for steel space frames with T-stub semi-rigid connections considering soil-structure interaction

An optimization technique for designing the steel space frame with T-stub semi-rigid connections and interaction between soil and structure is presented in this article. A three-parameter-based elastic foundation model is utilized to investigate soil-structure interactions (SSI). To enable two-way data transfer for all optimization methods, computer software was developed using C# version 17.8.6, which connects to SAP2000-OAPI version 22. Particle swarm optimization (PSO) and teaching-learning-based optimization (TLBO) are employed for optimal designs. These optimization techniques choose profile sections from a list, including 64W discrete sections from the American Institute of Steel Construction (AISC). The Load and Resistance Factor Design-American Institute of Steel Construction (LRFD-AISC) strength constraints, geometric constraints, inter-storey drift constraints, and displacement constraints are considered during optimization. The first phase entails creating optimal designs for two unique steel space frames that consider SSI but do not include T-stub semi-rigid connections. Following that, the same optimization procedures are carried out with T-stub semi-rigid connections. The parameters needed for the foundation model are obtained through soil surface displacements. Utilizing T-stub semi-rigid connections while considering the interaction between the structure and the soil produces increased structural weight.

Thermomechanical responses of steel frames under aftershock after fires

A novel advanced fiber beam-column element, which incorporates stability functions and the fiber distributed plasticity model to capture geometric and material nonlinearities, respectively, has been successfully developed to predict the nonlinear inelastic thermo-mechanical behaviors of steel frames subjected to aftershock after fires. To address the nonlinear dynamic problems resulting from aftershocks after fires, a sequential nonlinear thermal incremental-iterative solution scheme has been developed, which is based on the Newton-Raphson algorithm and Newmark-β method. In addition, a transcendental probability-based method is employed to express the statistical characteristics of aftershock intensity relative to the mainshock. The proposed method is applied to analyze three framed structures: a steel portal frame, a two-story plane steel frame, and a four-story asymmetric space steel frame. This analysis shows the accuracy, computational performance, and applicability of the proposed method. Remarkably, the results obtained from the code work, using just one or two elements per member, are in close agreement with all the results analyzed by Abaqus. This emphasizes that the proposed method effectively predicts the response of framed structures under aftershock after fires with excellent computational efficiency, significantly surpassing traditional finite element approaches in commercial software like Abaqus. The successful results of the dynamic analysis of the frames under aftershocks following fires underscore the importance of considering aftershocks after a fire incident. It is demonstrated that the occurrence of an aftershock accelerates the failure of the frame compared to the case when the frame is subjected to fire alone. This highlights the critical need to account for aftershocks when assessing the safety and structural integrity of framed structures after a fire event.

Seismic design optimization of space steel frame buildings equipped with triple friction pendulum base isolators

To increase the seismic resilience of structures, it is necessary to utilize seismic isolation to increase structural periods and reduce story drifts. When seismic isolation is implemented, structures are capable of deforming by remaining within safe limits. Thus, more seismically resilient designs are achieved compared to conventional fixed-based structures since lighter structural design weights are attained. The principal aim of this study is to achieve the comparative design optimization of space steel frame buildings equipped with seismic base isolation and to examine the effect of seismic base isolation on optimum structural design weight by comparing the same structures with conventional rigid-based ones. For seismic base isolation, triple friction pendulums are implemented into steel frame buildings. For this aim, four different space steel frame buildings with 4-, 6-, 8-, and 10-story are treated as design examples. A novel design optimization algorithm is encoded, which includes nature-inspired metaheuristic artificial bee colony, crow search, and Archimedes optimization algorithms to achieve design optimizations of triple friction pendulums equipped with seismic-isolated space steel frame buildings. The practice code provisions of load and resistance factor design specification for structural steel buildings have been applied to control the structural design constraints of inter-story drift, top-story drift, strength, displacement, and connections geometry of beams and columns. Eventually, it has been remarked that seismic base isolation significantly reduces the structural optimal design weight of space steel frame buildings.

Influence of Soil Structure Interaction on Seismic Performance of Steel Structure Interaction with Different Types of Foundations and Soil

Soil Structure Interaction is the reaction of soil that influence the motion of the structure. During serve seismic events, the dynamic response of the structure is affected not only by the behavior of the superstructure but also by the nature and behavior of the soil present in and around the substructure. The steel structure design process usually assumes the base of the foundation to be completely restrained in a fixed base condition. In the present project the influence of soil structure interaction on the seismic performance of a steel space frame on different soil has been investigated. The multi-story steel building (G+7) with column to column spacing distance 5m and six number of columns having both X and Y direction of the structure, is designed to withstand self-weight and seismic loads. The study also examined the impact of earthquake loading on the steel structure with soil structure interaction using Response Spectrum Method and Time History Method for seismic zone III, with forces determined using IS 1893 (Part-3):2015. The study measured the displacement of steel structure with influences of soil under seismic forces. Comparison of seismic performance like maximum storey displacement, maximum storey drift and base shear along with soil structure interaction under different types of soil are presented in this project. This paper discusses the influences of the soil structure interaction on steel structure with various configuration and different types of foundations and soil.

Numerical design optimization of real size complex steel space frame structures using a novel adaptive cuckoo search method

AbstractIn this study, real size complex steel space frame structures are numerically designed to achieve optimal design weight. For this aim, standard cuckoo search algorithm is rectified through a newly proposed adaptive method over two fundamental algorithmic parameters of alien egg probability detection (Pa) and step size control (α) to overcome incompetency of trapping into local optima. Besides, to strengthen exploitation phase of newly proposed algorithm, it is boosted with greedy selection (GS). So, novel algorithm has more promising exploration and exploitation capabilities. An 8‐story, 1024‐member and a 20‐story, 1860‐member real size complex steel space frame structures are selected as design examples. Also, initially to verify the supremacy of novel algorithm, a well‐known welded beam is optimized as a benchmark structural design problem. Afterwards, the steel space frame structures are optimally designed via novel algorithm. Since ready steel section lists are utilized as selection pool for design variables, discrete programming problem is come into existence. The dead, live, snow, and wind design loads acting on frame structures are calculated in direction of ASCE 7‐05 provisions. Furthermore, the structural design constraints are determined from LRFD‐AISC specifications. Eventually, the newly proposed adaptive cuckoo search algorithm boosted with GS presents outstanding algorithmic performance.

A guided evolution strategy for discrete sizing optimization of space steel frames

A guided evolution strategy for discrete sizing optimization of space steel frames

Application of steel frame viaduct for mountainous roads in Vietnam: Case studies in Quang Ngai Province and Lam Dong Province

Vietnam’s mountainous highways are increasingly affected by landslides each year, with climate change being a major cause. The government has allocated significant funds to repair, rehabilitate, and maintain these highways, but conventional methods like excavation and embankment are not always effective for roads that pass through unstable, large-angle slopes that have a high risk of landslides. This results in additional rehabilitation costs following natural disasters. To address this issue, JFE Civil Engineering & Construction Corporation has developed a new solution for constructing mountainous highways in Vietnam - a viaduct that functions as a space steel frame supported by steel pipe columns and beams. Prefabricated in a factory and transported to the construction site, the steel beams are then assembled, and steel piles are driven deep into the ground for a rigid pile-to-ground connection. These proposed structures offer sustainable and cost-effective solutions for mountainous highways with minimal impact on the surrounding environment. Two case studies in Quang Ngai Province and Lam Dong Province are presented as preliminary designs to demonstrate the feasibility of this solution.

Optimum design of steel frames with sizing and orientation design variables using a reformulated evolution strategy

Sizing optimization of steel frame structures has been traditionally conducted based on fixed orientations of structural members. However, it seems more expedient to search for an optimum design where orientations of column members are considered as design variables together with sizing of all members for the minimum weight design of a steel frame. In order to solve the resulting optimization problem effectively, a reformulated evolution strategy (ES) algorithm is proposed and employed in the present study. The numerical investigations are carried out using three test problems regarding the optimum design of steel space frames. In each test problem, a frame is first designed for the minimum weight considering sizing design variables only, where initial orientations of the column members are kept unchanged. Next, sizing and orientation design variables are considered simultaneously for minimizing the weight of the same frame. The results obtained in the foregoing two cases are compared and the associated optimal layouts for the column orientations are depicted. The study reveals that the optimal selection of column orientations has a significant influence on the minimum weight design of steel frames.

Detection of damage in offshore jacket structure using artificial neural network

With industrial growth over the years, geologists have begun to search for offshore sources of oil and natural gas. Most offshore oil-production platforms are jacket type. Offshore jacket structures consist of welded steel space frame. Tubular pipes are opted as they reduce hydrodynamic loads making them highly durable structures. However due to natural phenomenon like cyclones, earthquakes, etc. these structures can get adversely damaged. Apart from that the structure also degrades due to corrosion and fatigue due to the severe conditions it is always exposed to. In many cases physical inspection of the structure for checking damages is not possible due to unfavourable onsite conditions or lack of trained professionals. Hence there is a need to develop alternatives solutions. In recent years much research has been done in the application of Artificial Neural Networks (ANN) in Civil Engineering. ANN are computation systems that are inspired by biological neural systems. This paper aims at creating an ANN to identify damage in an offshore jacket structure using the modal parameters. The training set for the ANN is obtained by using a finite element software. The ANN is then tested using a test set and then it will be used to predict the structural damage in an offshore jacket structure.

Performance comparison of five regression-based machine learning techniques for estimating load-carrying capacity of steel frame using direct analysis

The development of computer science has promoted the application of scientific and technological achievements to construction engineering in general and steel structure design in particular. Recently, the steel frame structure design has applied advanced analytical methods to take into account the inelastic behavior of the material and the geometric nonlinear properties of the structure, leading to the results obtained close to the real structure. In addition, to reduce computational time and effort, it has been applied advanced machine learning (ML) algorithms to predict behavior, helping to accelerate decision-making, improve efficiency, and reduce errors. In this paper, 5 popular machine learning algorithms are currently being conducted for the regression-based to estimate the ultimate load capacity of steel frames, including Linear Regression, Deep Learning, Support Vector Machine, Random Forest, and XGBoost. The effectiveness of applying these methods is tested through a numerical example surveying a 20-story space steel frame. The performance of ML algorithms is evaluated by comparing the mean-squared error (MSE) and computational efforts. The results show that among the 5 selected methods, the XGBoost has obvious advantages and is superior in terms of both MSE and calculation time.

Reliability-based layout optimization of concentrically braced in 3D steel frames

For an economical and safe design of building systems with concentrically braced frames, the layout of the braces should be done by considering all limitations. The current study proposes an approach for a reliability-based optimal design of concentric bracing layouts in 3D steel frames. The objective function was considered to be a reduction in the total weight. The layout of the braces was considered as the variable of the optimization problem. The deterministic design constraints of limitations of strength, drift and torsional irregularities were considered according to AISC 360-16 and ASCE 7-16. The distance between the center of mass and the center of rigidity was defined as the probability constraint. The probabilistic variables were the intensity of the distributed loads and the cross-sectional area of the braces and columns. The reliability index was evaluated using the Monte Carlo simulation method. The reliability-based design optimization (RBDO) problem was solved for 4-, 5- and 9-story steel space frames using the EVPS algorithm. To investigate the effect of the probabilistic constraint on the optimal design, numerical examples were solved without applying this constraint and the solutions to the RBDO and deterministic design optimization problems were compared.

Topology and size optimization for X-bracing system of nonlinear inelastic space steel frames

In this article, a Python-programmed advanced design paradigm is firstly introduced to topology and size optimization of the X-bracing system of nonlinear inelastic space steel frames. For that purpose, an advanced analysis method considering both geometric and material nonlinearities is utilized as an effective finite element analysis (FEA) solver. In which, X-bracing members are modeled by truss elements, while the beam and column members are simulated by beam-column ones. The bracing members’ cross-sectional area and their position are respectively treated as discrete size and topology design variables. The problem aims to minimize the weight of X-bracing system so that the constraints on the strength, inter-story drift and maximum displacement are satisfied. An adaptive hybrid evolutionary firefly algorithm (AHEFA) is employed as an optimizer. Numerical examples are exhibited to illustrate the powerful ability of the present methodology.

Optimum design of space steel frames based on decomposition and reconstruction of plane frames using reinforcement learning

In practical design of building structure, the cross-sectional dimensions of the members are selected from a prescribed standard list. Machine learning (ML) is potentially effective for this problem; however, preparing a large dataset in advance is difficult. Even in this situation, Reinforcement Learning (RL) is applicable, can assist to find a better solution, and is expected to reduce computational cost when compared without the RL agents. We propose a new minimum volume design of a building steel frame based on a decomposition and reconstruction framework using a RL agent. In the method, i) the design problem of a space frame is decomposed into that of plane frames, ii) the plane frames are optimized by standard nonlinear programming, iii) and the plane frames are assembled to a space frame by the RL agent. The advantages of the methods are presented through a numerical example.

Modeling of physical wear assessment of zinc coating of space steel frame road structures for road safety information systems

The article developed an improved physical and mathematical model of the corrosive wear of zinc coating of steel structures in a city. The research is based on full-scale experimental data for determining the wear of a zinc coating of full-scale metal spatial structures of frame road structures for informational safety systems on roads after 10 years of operation in the conditions of Kyiv. The frame structure consists of metal columns and a steel crossbar frame. The crossbar frame is a spatial block of two steel trusses. The block of trusses is assembled from unified spatial sections united by vertical and horizontal ties, and which are connected by flange nodes of a special design. All structural elements are made of rolled tubes. Based on the research results, an approach to assessing the physical wear of the zinc coating of the spatial structural system is proposed.
 
 According to the peculiarities of the arrangement of elements in frame structures, and, accordingly, to different conditions and operations, an approach is proposed to assess the corrosive wear of a zinc coating for various groups of elements: columns, spatial block of two steel trusses, flange nodes.
 The physical and mathematical model is based on the working hypothesis of uneven wear of the zinc coating over time. It was found that for each group of structural elements, the conditions of the gaseous environment, the effects of atmospheric precipitation, wind speed, temperature changes individually affect the reduction of the zinc coating. The obtained experimental data were used to determine the parameter of the rate of decrease in the zinc coating of the physical and mathematical model. The results of the research and the development of the methodology helped to establish the operating conditions of the zinc coating according to the criterion of the rate of wear of the zinc coating, to classify the category of aggressiveness of the environment for each group of structural elements. Also, studies allow predicting the service life by reducing the thickness of the zinc coating, as well as the wear of the zinc coating in time in the subsequent period of operation.
 
 The methodology is universal and can be extended to other types of galvanized metal structures.

Rao algorithm-based method for optimisation of steel frames using nonlinear inelastic analysis

Metaheuristic optimisation algorithms have been increasingly used because of their superior ability to find globally optimal solutions. Theoretically, these algorithms are very powerful and can be applied in all types of optimisation problems. However, in reality, their performance depends on the characteristics of each optimisation problem class. In addition, the complexity of an algorithm is an important factor affecting its application in specific design problems. In this paper, the Rao optimisation algorithm, one of the newest metaheuristic algorithms, is presented for the optimisation algorithm of steel frame structures. The advantage of the Rao algorithm is that it is quite simple with few parameters, so engineers can easily apply it in daily design tasks. A nonlinear inelastic analysis is used to consider the nonlinear behaviors of the steel structure. A two-story space steel frame is studied. The results show that Rao-1 is more stable and converged more quickly but easily trapped in local solutions than Rao-2 and Rao-4. Rao-4 is more efficient in global search but its stability is less than other algorithms. Keywords:nonlinear inelastic analysis, optimisation, Rao algorithm, steel frame.

Auto-Regressive Integrated Moving-Average Machine Learning for Damage Identification of Steel Frames

Auto-regressive (AR) time series (TS) models are useful for structural damage detection in vibration-based structural health monitoring (SHM). However, certain limitations, e.g., non-stationarity and subjective feature selection, have reduced its wide-spread use. With increasing trends in machine learning (ML) technologies, automated structural damage recognition is becoming popular and attracting many researchers. In this paper, we combined TS modeling and ML classification to automatically extract damage features and overcome the limitation of non-stationarity. We propose a two-stage framework, namely auto-regressive integrated moving-average machine learning (ARIMA-ML) with modules for pre-processing, model parameter determination, feature extraction, and classification. Based on shaking table tests of a space steel frame, floor acceleration data were collected and labeled according to experimental observations and records. Subsequently, we designed three damage classification tasks for: (1) global damage detection, (2) local damage detection, and (3) local damage pattern recognition. The results from these three tasks indicated the robustness and accuracy of the proposed framework where 97%, 98%, and 80% average segment accuracy were achieved, respectively. The confusion matrix results showed the unbiased model performance even under an imbalanced-class distribution. In summary, the presented study revealed the high potential of the proposed ARIMA-ML framework in vibration-based SHM.

Performance of Jaya algorithm in optimum design of cold-formed steel frames

This paper presents a research on optimum design of cold-formed steel space frames using a new algorithm method named Jaya, which has been developed in recent years. The most obvious difference of Jaya algorithm from other algorithms is that it does not need any control parameters for updating. However, Jaya algorithm is able to successfully reach the optimum solutions without any delay. In this study, in order to test the robustness and practicality of this novel algorithm technique, different steel space frame problems that have been studied with other algorithms in literature are examined. The minimum weight designs of the problems are carried out by selecting suitable C-section from a prepared list including 85 C-sections with lips taken from American Iron and Steel Institute (AISI 2008). A program is coded in MATLAB interacting with SAP2000 OAPI (Open Application Programming Interface) in order to obtain optimum solutions. The strength constraints according to AISI-LRFD (Load and Resistance Factor Design), lateral displacement constraints, inter-story drift constraints and geometrical constraints are taken into account in the analyses. Two different cold-formed steel space frames are taken from literature to research optimum solutions by using Jaya algorithm. The first steel space frame is 379-member and the second steel space frame is 1211-member. The results obtained using Jaya algorithm are compared with those in reference studies. The results prove that Jaya algorithm technique is quite successful and practical optimum design of cold-formed steel space frames.

Performance evaluation of artificial bee colony algorithm and its variants in the optimum design of steel skeletal structures

Artificial bee colony algorithm (ABC) has been efficiently used to obtain the optimum design of structures under design code limitations. There are several enhancements suggested to improve the performance of ABC even further in the literature. In this chapter, the performance of enhanced ABC variants in the optimum design of steel skeletal frames is studied. The mathematical model of such design problem when based on the provisions of design code requirements results in a discrete nonlinear programming problem. Seven variants of ABC is selected from the literature. These are standard artificial bee colony algorithm (sABC), artificial bee colony algorithm with orthogonal learning (OCABC), quick artificial bee colony algorithm (qABC), noel chaotic artificial bee colony algorithm (STOC-BC), directed artificial bee colony algorithm (dABC), improved artificial bee colony algorithm (NSABC) and artificial bee colony algorithm with Levy flight distribution (ABC_Levy). Seven optimum design algorithms are developed to obtain the solution of the design problem formulated considering design code provisions. Two steel space frames, one ten story and the other fifteen story are optimized using each of the seven optimum design techniques. The performance of each variant is observed and the optimum designs are compared. It is noticed after carrying out the statistical analysis that ABC_Levy and qABC algorithms outperform the other algorithms.

Seismic design of space steel frames using advanced static inelastic (pushover) analysis

A rational and efficient seismic design method for regular space steel frames using inelastic (pushover) analysis (PA) is presented. This method employs an advanced static finite element analysis that takes into account geometrical and material non-linearities and member and frame imperfections. Resistances (strengths) are computed according to Eurocodes 3. The PA is employed with multimodal lateral loads along the height of the building combining the first few modes. The design starts with assumed member sections, continues with deformation and damage check at three performance levels with the aid of PAs and ends with the adjustment of member sizes. Thus, it can sufficiently capture the limit states of displacements, strength, stability and damage of the structure and its individual members so that separate member capacity checks through the interaction equations of Eurocode 3 or the use of the behavior factor q suggested in Eurocode 8 are not required. One numerical example dealing with the seismic design of a one bay in both horizontal directions and three storey steel moment resisting frame is presented to illustrate the method and demonstrate its advantages.

Nonlinear 3D finite element modelling of conventional and composite steel spaceframes structures

Spaceframes steel structures are a common worldwide technique for roofing wide areas. In this study, after validating one of the models experimentally, nonlinear 3d finite element modelling were performed to analyze failure mechanism of space frames models with the help of Abaqus program. Additionally, this study attempts to convert such common roofing structure to a composite structure using ultra high strength concrete slab to withstand various floor loads. Various space frames shaft angles were tested, namely, 30, 45, and 60. Tests results were evaluated and compared in term of ultimate load, load at maximum displacement, toughness, and stiffness. Tests results have shown that spaceframes models with angle 60 have the highest load capacity compared to other angles, and highest toughness compared to various techniques. Also, compositing 40 mm of ultra-high-performance concrete slab method has approved its efficiency to withstand loads and showed comparable results with the conventional spaceframes. the composite systems with sufficient concrete slab thickness and strength have reflected an efficient technique for flooring wide span structures.