Steel Frame Buildings Research Articles

ISSUES OF DESIGNING INDUSTRIAL BUILDINGS CONSIDERING THE RISK OF LOCAL DESTRUCTION OF THEIR BEARING STRUCTURES

Problem statement. The present-day realities show that the design of buildings and structures with regard to possible local collapses of their bearing structures is becoming more and more realistic and thus an increasingly urgent challenge. The need to solve this issue is an important component in ensuring the safety of buildings and structures under operational and emergency loads. Local destruction is interpreted as a global result that can lead to the destruction of the entire frame or a significant part of it and cause loss of life. The peculiarity of calculations for progressive collapse of steel-framed buildings is that, unlike monolithic reinforced concrete, in a steel frame, the nodes of connection of elements are usually hinged, and this can lead to transformation of the structural scheme into a geometrically variable structural scheme. In this case, structural failure may occur not due to loss of material strength, but due to loss of load-bearing capacity of the structural connection joints. The purpose of the article is to analyse the main specific peculiarities occurring in the design (reinforcement) of industrial buildings with steel frames, considering the possibility of their local destruction. Conclusion. The article considers some problems that need to be solved during the designing or reconstructioning industrial buildings with a steel frame, the operation of which may be associated with some local destruction of the bearing structures. Prospective constructive ways of effectively solving these problems are presented.

H hybrid control and MRD in a steel frame building subjected to excessive vibrations caused by the dynamic action of wind and earthquake

The dynamic loads from earthquakes and winds can destroy lives, cause collapse in civil structures, and interrupt basic services provided to the population. In this scenario, structural designs must be developed to decrease the damage induced by these actions. The objective of this work is to design a hybrid controller based on the H¥ optimization via state feedback and the magneto-rheological damper (MRD) to mitigate the excessive vibrations of a three-story steel frame building, represented through the shear building model, subjected to the simultaneous dynamic action of wind and earthquake. All research is based on computational simulation, experimental research and results will not be addressed. In the numerical analysis, digital computer and MATLAB® software are used, and implemented codes generate the expected results based on the mathematical modeling. With the application of the H¥ control technique via state feedback, the displacements were reduced by 77%. With MRD this reduction was 79%. With the hybrid controller, this reduction was 100%. Thus, the verifications in relation to maximum displacements were met for NBR 15421:2006, NBR 8800:2008 and NBR 6118:2014. From the results, it is concluded that the hybrid controller proved to be more efficient and achieved the proposed objective. The exogenous inputs had zero influence on the behavior of the system output.

Utilisation of Reused Steel and Slag: Analysing the Circular Economy Benefits through Three Case Studies

This research explores sustainable construction practices focusing on material reuse, specifically reclaimed structural steel and slag. In general, the building stock is not designed for deconstruction, and material recovery for reuse at the end of life of buildings is complex and challenging. The study evaluates the benefits of content reuse through a thorough analysis of three case studies—BedZED eco-friendly housing, Angus Technopôle building, and the use of steel slag aggregate in road construction. It highlights the value of reclaimed structural steel and by-products like steel slag in waste reduction, energy conservation, and resource preservation. The BedZED case study showcases recycled steel’s cost-effectiveness and economic viability in construction, while the Angus Technopôle building exemplifies the adaptive reuse of an old steel frame building. Additionally, the third case study showcases the benefits of using Electric Arc Furnace C slag in asphalt-wearing courses, highlighting the reduction in greenhouse gas emissions and environmental impact. The versatility of reclaimed structural steel and slag is evident in integrating material reuse in building construction and road infrastructure. These case studies illustrate the potential for reusing steel and its by-products in various construction contexts, from eco-friendly housing to road development. Therefore, the study aims to demonstrate the feasibility and benefits of sustainable practices within the construction industry by showcasing the successful incorporation of reclaimed steel and slag in these projects. Considering the significant contributions of building construction to global greenhouse gas emissions, raw material extraction, and waste production, the study advocates for adopting circular economy (CE) principles within the construction industry. Finally, the analysis of case studies underscores the advantages of reclaimed structural steel and the valorisation of steel slag through the lens of CE and their contribution to sustainable development.

Sound transmission loss through steel-framed building partitions

Load-bearing steel-stud walls pose a unique acoustical challenge because both the spacing and the mil thickness of the studs can significantly affect the acoustical performance of these walls. A single wall type in a load-bearing steel building may actually include many acoustically distinct walls as the stud spacing and mil thickness change from floor to floor in the building due to the different loads. This can be especially challenging on delegated design projects where the final selection of the steel studs is left to the framing contractor and may not be included in the project documents supplied to the acoustical consultant, if there even is one on the project. In prior ASA presentations, Ben Shafer has clearly documented the effects of steel stud spacing and mil thickness on acoustical performance. This presentation adds to Ben’s prior work by investigating the effects of resilient sound isolation clips on wall performance. Clips are a unique application because the spacing of both the clips, and the hat channels does not change with changing stud spacing and because the low stiffness of the rubber isolators should reduce the effect of stud stiffness. This presentation will present the results of recent lab tests of walls with resilient sound isolation clips and compare the results to the data previously presented by Mr. Shafer.

Parametric study on seismic behavior of steel frame buildings subjected to different ground motions

Parametric study on seismic behavior of steel frame buildings subjected to different ground motions

Meta databases of steel frame buildings for surrogate modelling and machine learning-based feature importance analysis

Traditionally, nonlinear time history analysis (NLTHA) is used to assess the performance of structures under future hazards which is necessary to develop effective disaster risk management strategies. However, this method is computationally intensive and not suitable for analyzing a large number of structures on a city-wide scale. Surrogate models offer an efficient and reliable alternative and facilitate evaluating the performance of multiple structures under different hazard scenarios. However, creating a comprehensive database for surrogate modelling at the city level presents challenges. To overcome this, the present study proposes meta databases and a general framework for surrogate modelling of steel structures. The dataset includes 30,000 steel moment-resisting frame buildings, representing low-rise, mid-rise and high-rise buildings, with criteria for connections, beams, and columns. Pushover analysis is performed and structural parameters are extracted, and finally, incorporating two different machine learning algorithms, random forest and Shapley additive explanations, sensitivity and explainability analyses of the structural parameters are performed to identify the most significant factors in designing steel moment resisting frames. The framework and databases can be used as a validated source of surrogate modelling of steel frame structures in order for disaster risk management.

Performance assessment of steel frame buildings with hybrid self-centering braces under extremely rare far-field earthquakes

This paper investigates the seismic performance enhancement of steel frame buildings using a novel hybrid self-centering braces (HSBs) under extremely rare earthquake events. The hybrid self-centering brace consists of shape memory alloy (SMA) cables and viscoelastic (VE) dampers. A prototype bracing system is designed and fabricated to explore its basic mechanical behavior and working mechanism under cyclic loading, with a focus on its failure modes under large deformation loading condition. A multi-material mechanical model is developed to capture the mechanical behavior and failure of the HSB. Furthermore, five steel frame buildings with different parameterized HSBs are designed and modeled in OpenSees. Nonlinear dynamic analyses and incremental dynamic analyses are conducted on the five case-study frames using 44 far-field ground motions. The risk-based seismic performances of steel buildings with HSB are evaluated to assess the performance of HSB during extremely rare seismic events. The results show that the hybrid self-centering brace exhibits excellent self-centering and energy dissipation capabilities with the maximum equivalent viscous damping ratio reaching 9.4 %. Even under large deformations, VE dampers continue to work effectively after the failure of SMA cables, demonstrating remarkable redundancy. Numerical simulations further reveal that the redundancy of HSB can improve the structural seismic resilience in terms of inter-story drift ratio, residual drift, and floor absolute acceleration. The higher the redundancy of HSB in the case-study frames, the smaller the seismic response and mean annual frequency of exceedance of the engineering demand parameters, thereby indicating a significant improvement in seismic performance.

CNN‐based damage detection of buildings from wave propagation between two adjacent floors

AbstractStructural damages are expected to be detected from the changes in shear‐wave propagation in the vertical direction of the building. In the previous study, we constructed a convolutional neural network (CNN) model to recognize the changes in impulse responses at the inter‐floor with the virtual source at the top. However, it is difficult to tell the exact damaged stories, because it contains the information of all the stories between the virtual source and the receiver. In this study, to perform the story‐by‐story damage detection, wave propagation between two adjacent floors was proposed. The virtual source of the impulse response was changed from the top floor to the determined inter‐floor of the building. By recognizing the changes in the wavefield between the determined floor where the virtual source is located and its upper and lower adjacent floor, damages between two adjacent stories can be identified. The CNN model was used to automatically recognize the changes in the visualized impulse responses over time and validated using the data of a shake‐table test on a one‐third scaled 18‐story steel frame building.

Disassembly and Reuse of Structural Members in Steel-Framed Buildings: State-of-the-Art Review of Connection Systems and Future Research Trends

Disassembly and Reuse of Structural Members in Steel-Framed Buildings: State-of-the-Art Review of Connection Systems and Future Research Trends

Optimum design of TMDs for reduction of floor vibration using evolutionary computation

Perceptible floor vibration can arise due to human activities such as walking, especially in steel-framed buildings. A general strategy to reduce floor vibration is to install tuned mass dampers (TMDs) between the floor slab and a raised OA floor. For the TMDs to act effectively, two parameters must be designed properly depending on the dynamic characteristics of the target floor: eigenfrequency and damping ratio. Conventionally, even when installing multiple TMDs in a floor, design has been carried out using fixed-point theory, which was originally used to design a single TMD. With the purpose of improving the performance of multiple-TMD installations, this paper describes the use of evolutionary computation (EC), a mathematical optimization method, to design the parameters for multiple TMDs. The new technique is first verified by implementing a numerical simulation using the spectral element method, a high-efficiency numerical analysis method. TMDs designed with EC are shown to suppress floor vibration more efficiently than those designed with fixed-point theory. Next, in experiments with an actual steel-framed building, sufficient vibration suppression performance is achieved with fewer EC-designed TMDs.

A Mathematical Approach for Predicting Sufficient Separation Gap between Adjacent Buildings to Avoid Earthquake-Induced Pounding

Studies on earthquake-related damage underscore that buildings are vulnerable to significant harm or even collapse during moderate to strong ground motions. Of particular concern is seismic-induced pounding, observed in numerous past and recent earthquakes, often resulting from inadequate separation gaps between neighboring structures. This study conducted an experimental and numerical investigation to develop a mathematical equation to calculate a sufficient separation gap in order to avoid the collision between adjacent mid-rise steel-frame buildings during seismic excitation. In this study, the coupled configuration of 15-storey & 10-storey, 15-storey & 5-storey, and 10-storey & 5-storey steel frame structures was considered in the investigation. The investigation concluded with a large number of data outputs. The outputs were used to predict structural behavior during earthquakes. The obtained data were categorized into three main categories according to the earthquake's Peak Ground Acceleration (PGA) levels. Also, the derived equations were divided into three different equations to estimate the required seismic gap between neighboring buildings accordingly. The derived equations are distilled to empower engineers to rigorously evaluate non-irregular mid-rise steel frame buildings. Doi: 10.28991/CEJ-2023-09-10-02 Full Text: PDF

Component Modeling for Fire Behavior of Shear Tab Connections

During a building fire scenario, the behavior and capacity of gravity connections can significantly contribute to the integrity of steel-framed building structures. Because gravity connections are subjected to axial and flexural force demands and have a limited rotational capacity due to large beam rotations during a fire scenario, a connection model is needed to simulate their behavior when using analytical models to simulate the behavior of a steel structure in fire. This study develops a component model for shear tab connections at ambient and elevated temperatures in the opensource finite element program, OpenSees, to further enable the use of OpenSees for simulating steel structures in fire. Although the developed component model is not limited to implementation within OpenSees. The developed component model is benchmarked against experimental tests of isolated connections and a structural assembly with shear tab connections subjected to mechanical and thermal loads. Through benchmarking, it is shown that (1) the developed component model could be used to simulate connection behavior during a fire scenario and (2) simulating the ductility of connections and connecting components due to damage is critical when simulating the behavior of shear tab connections exposed to fire.

Seismic risk-based optimization of tension-only shape-memory alloy device for steel moment-resisting frames

This study introduces the seismic risk-based design of SMA devices for steel moment-resisting frame buildings. The investigation begins with the numerical representation of the device which includes SMA wires exhibiting super-elastic stress–strain response, along with steel components. The model is then compared against an actual test result. Accordingly, several four-story steel-frame buildings are numerically characterized, all designed to withstand similar seismic loads. This includes a control frame building (Bare-SMF), a frame building with SMA devices using a traditional design approach (SMA-D), and a frame with buckling restrained braces (BRB-D) for comparison. As the traditional design method relies on the first modal shape and static loads, the pushover analysis results for all structures possessed similar amount of strength and deformation capacity. However, the nonlinear time history analysis revealed inconsistencies in the responses of the retrofitted buildings (SMA-D and BRB-D) when compared to Bare-SMF. To address this issue, a seismic risk-based design approach that combines nonlinear time history analysis on a steel moment-resisting frame and the particle swarm optimization algorithm is employed. By using this approach, the SMA brace quantities were determined such that the cost of SMA devices can be minimized while the life-cycle probability of collapse and demolition is smaller than that of Bare-SMF. As a result of the risk-based design approach, three brace quantities are determined according to a decision maker’s attitude against the seismic risk. As a result, the cost of SMA devices could be reduced by more than 40% while maintaining a significant reduction in the life-cycle probability of collapse and demolition.

Behavior of a Multi-Story Steel Structure with Eccentric X-Brace

Eccentrically Braced Frames (EBFs) outperform moment-resisting frames in seismically active regions because of their strength, stiffness, energy dissipation, and ductility. Conventional bracing systems, such as X, Y, V, or K types, are utilized to enhance structural integrity. This study employs computational modelling to analyze multi-story steel buildings featuring an eccentric X-brace system. In this investigation, 120 multi-story steel frame buildings were selected. These multi-story structures comprise six-, nine-, and twelve-story geometries. ETABS built a full-scale FE model of multi-story structures. The study's parametric variables are the X-brace eccentricity, steel X-brace section size, and X-braced placement. Steel X-braces may have an eccentricity of 500, 1000, or 1500 millimeters. The ETABS model was validated when its findings matched experimental data. According to the data, the eccentric X-brace increases top-story displacement more for 6-story multi-story structures than for 9- and 12-story ones. Eccentric X-braces reduced lateral stiffness, allowing more significant floor movement. Eccentric and diagonal braces offer less lateral rigidity than concentrically braced frames due to their flexibility. Eccentricity reduces stiffness, even if the X-braced component has a larger cross-section. EBFs may migrate horizontally. Since the EBF absorbs more energy, changing the X-brace section size and eccentricity affects its ductility.

Discrete sizing optimization method based on dividing rectangles algorithm and local response surface for steel frame structures

It has always been the goal of structural engineers to construct safe and stable buildings using the least amount of materials. Utilizing a quick and effective way to optimize the cross-section size is crucial because conventional building design methods are impacted by the designers' knowledge, and it is challenging to prevent material waste. Due to its implicit optimization function, discrete design variables, and expensive individual evaluation, sizing optimization of high-rise buildings is very challenging to achieve. In order to effectively handle this optimization problem, a two-stage discrete sizing optimization method for high-rise buildings based on the DIviding RECTangles (DIRECT) algorithm and local response surface is proposed in this paper. The optimization method suggested in this research consists of two key stages: the global search stage and the local search stage. In the global search stage, the entire design domain is divided using a modified DIRECT algorithm to swiftly identify potentially optimal subregions that may contain the best points. In the local search stage, the local response surface model is constructed to approximate the objective and constraint functions using the sampling points from the previous stage, and the discrete optimal solution is rapidly found through mathematical iterative solving. A sizing optimization calculation program for high-rise buildings was developed in Microsoft Visual Studio 2015 on the basis of C++ to achieve automatic optimization. The new method was applied to optimize three high-rise steel frame buildings with different heights and plan shapes. The results showed that the material cost could be successfully saved compared with the conventional design, and the over-limit constraints could be adjusted automatically, which demonstrated the viability and efficacy of the two-stage optimization method.

Variability in parameter estimation for a tall steel-frame building

The between-event variability in identified shear wave velocities of fitted four-layer beam models in the response of a 54-story steel-frame building during nine earthquakes over a period of 27 years (1992–2019) is investigated. Recorded response and simulated response by its digital twin (linear finite element model with fixed base) were used as input, that is, the real structure and its digital twin were identified. Two surrogate models were fitted, a Timoshenko beam and a shear beam. The waveform inversion of impulse response functions method, developed earlier by the authors, was used to fit the beam models. The coefficients of variation (C.V.) of the between-events variability in the wave velocity estimates of the four layers were analyzed and compared for the different cases of data (real structure versus digital twin), different surrogate models, and different locations on the floor where the motions were observed. The results showed that the variability of the digital twin was affected by the contamination of the response by torsion, which is not accounted for in the beam models, by the degree of geometric regularity of the structure and by how closely the beam model represented the nature of the building deformation (balance of shear and bending deformation). These effects were minor in comparison to the nonlinear effects (recoverable nonlinearity and permanent stiffness degradation), which were not present in the digital twin response. The C.V. for the real structure (about 3%–5%) was comparable for both beam models fitted.

Experimental Study on Fire Performance of Polymer Foam Cavity Insulated Light Steel Framed Walls

AbstractLight steel frame (LSF) building systems are a fast, reliable and economical construction system for residential and non‐residential buildings. Since the thermal conductivity of steel significantly limits the effectiveness of such wall systems for use in modern energy‐efficient buildings, adequate thermal insulation is essential. For this reason, numerous research studies have been conducted on LSF structures with different types and positions of thermal insulation. Due to the combustible nature of polymer foam, LSF systems insulated with this type of insulation have not been the focus of this research. On the other hand, polymer foam is ideal for automated industrial production of prefabricated load‐bearing LSF walls, and research on such walls is mandatory. In this paper, the fire test results of two innovative LSF walls with polymer foam insulation and different gypsum fibreboards are presented. In the proposed configuration, spacers are also used to prevent direct contact between the wall panels and the steel studs. The study conducted shows that a suitable configuration of gypsum fibreboards can lead to satisfactory fire resistance of energy‐efficient LSF wall systems with polymer foam.

Experimental testing of liner tray walls subjected to near field blast

AbstractExplosions produced in urban or industrial areas due to accidental or intentional detonation of high energy explosives (e.g., improvised explosive devices IED) are low‐probability but high‐impact events. If standoff distance from buildings or other constructions is small, explosions can cause structural failures and serious injuries or deaths of people. Preventing buildings from collapse is essential to minimizing casualties among occupants. However, experience has shown that even if the collapse is prevented, high number of injuries can result from fragments and flying debris generated by the non‐structural components or building envelopes. This risk could be minimized through appropriate design and selection of construction materials for most exposed elements (i.e., building envelopes). Although heavy/stiff systems were long considered appropriate to protect buildings against explosive threats, lighter and flexible systems are increasingly used for modern buildings. By allowing damage (but not fragmentation), the envelope system can provide predictable response, with minimal injuries in case of an explosion.The study presents the results of full‐scale blast tests on liner tray walls attached to a steel frame building. Walls are tested against increasing blast charges until complete failure. The ultimate strength is given by the failure of the end fasteners, after large bolt hole elongations coupled with the pull‐through of the end fasteners.

Drift‐based risk‐oriented method for the explicit consideration of ground motion duration in seismic design

AbstractThis study proposes a method to explicitly account for ground motion duration in seismic design by modifying structural deformation capacity. An equation is presented to adjust the design drift limit prescribed in the New Zealand standard NZS 1170.5, based on the anticipated reduction in structural deformation capacity for ground motion durations longer than a critical value. The proposed relationship is used to derive designs corresponding to three duration targets each for two case‐study steel moment frame buildings ‐ a 4‐storey and a 12‐storey, located on a site in Nelson, New Zealand. Hazard‐consistent collapse risk assessment of the design versions is conducted using a structural reliability framework employing incremental dynamic analysis. Results indicate that buildings designed for lower drift limits have a lower mean annual frequency of collapse. The application of the proposed method is found to reduce the variation in the collapse risk of steel frame buildings designed for different duration targets, compared to the existing approach. The method proposed in this study is simple and easy for practical applications and can be modified for other design codes and a range of structural typologies.

Initial lateral stiffness of plate-type modular steel frame structure with semi-rigid corner connections

The plate-type modular steel frame buildings with semi-rigid corner connections are assembled structures, whose prefabricated plate-type modules are constructed in the factory and assembled on site. Owing to the assembly of different plate-type modules, this self-bearing building forms a double-beam and multi-column structure. To calculate the initial lateral stiffness of the plate-type modular steel frame structure with semi-rigid corner connections, based on the modified displacement method, the lateral amplification effect caused by semi-rigid connections between upper and lower modules was transferred to the lower beam of the upper module; according to the concept of superposed beam, the structure can be simplified into the form of single beam and multiple columns; in addition, by using the combination method of multiple columns with different corner connections, the theoretical formulas of the initial lateral stiffness of the semi-rigid connected plate-type modular frame structure were derived. Compared with the plate-type modular frame with rigid connections, the lateral amplification coefficients of regular plate-type modular frames with semi-rigid connections were derived and the influence of the number of spans and stories on the lateral amplification coefficient were investigated. The theoretical values of the initial lateral stiffness of the plate-type modular steel frame with semi-rigid connections were in good agreement with the experimental values and FEM evaluations.