Frame Structure Research Articles

Study of Panel Zone Behavior in Interior Beam–Column Joints with Reduced Beam Section (RBS)

Based on the post-earthquake investigation of the Beiling and Hanshen earthquakes, many welded rigid beam–column joints were found to exhibit brittle failure. The failure modes of the joint region and the overall steel frame structure under the action of the earthquake need to be studied. The seismic performance of different types of weakened beam-end interior joints was investigated. The finite element method was verified by high-strength steel beam–column joint tests conducted by our research team. Finite element modeling of weakened steel beam flanges and weakened steel beam web joints was carried out based on the validated finite element modeling method. The joints were studied and analyzed using seismic parameters such as joint stress clouds, equivalent story shear–inter-story displacement ratio curves, panel zone bending moment–shear ratio curves, ductility, stiffness, and energy dissipation. The results of this study showed that honeycomb open hole-type joints exhibit a better deformation and energy dissipation capacity compared to open circular web hole-type joints. However, their load carrying capacity is reduced, which is mainly due to the larger area of the web openings. Additionally, double reduced beam section (DRBS) joints exhibit superior seismic performance and plastic hinge outward movement characteristics compared to single reduced beam section (RBS) joints. It was also found that the deformation and energy dissipation of DRBS joints and steel beam honeycomb hole-type joints are mainly borne by the beams, with the panel zone’s participation in energy dissipation accounting for a smaller proportion of the energy.

Seismic vulnerability analysis of a high‐rise steel frame structure equipped with novel displacement‐amplified viscoelastic dampers

SummaryThe energy dissipation capacity of conventional viscoelastic dampers (VEDs) cannot be fully exerted due to the relatively small inter‐story displacement of building structures. Thus, a novel VED with a displacement amplification mechanism based on the lever principle is developed in this study to achieve small displacement but high energy dissipation ability. First, the structural layout of an amplified viscoelastic damper (AVED) system is briefly introduced, and then the displacement amplification effect is described in detail. According to the working principle of the AVED and the relationship of force and geometric displacement in an actual frame structure, the restoring force theoretical formula of the corresponding amplified damper is derived. Based on the restoring force of the AVED and in combination with the secondary development function of the ABAQUS unit, a VUEL subroutine suitable for the explicit algorithm is programmed with the FORTRAN language. Then, the correctness of the subroutine is verified through a comparative analysis of the ABAQUS simulation and theoretically calculated results. Consequently, the vulnerability analysis of a high‐rise steel frame structure is conducted by using the incremental dynamic analysis (IDA) method, and the influence of the AVED on the seismic performance of the steel frame structure is quantitatively analyzed from the perspective of probability statistics. The analysis results show that compared with the VED structure, the failure probability of the AVED‐2 and AVED‐3 structures reaching the ultimate failure state at all levels is reduced by approximately 43% and 57%, respectively, and the collapse margin ratio (CMR) of structures under large earthquakes is increased by approximately 35% and 68%, respectively. This indicates that the AVED structures with displacement‐amplified dampers have a better effect on the seismic stability of tall steel frame structures under random seismic excitations. This study aims to provide comprehensive information for the seismic‐resistant design of tall buildings in earthquake‐prone regions.

Study on the Anti-Progressive Collapse Behavior of Steel Frame Structures under Close-Range Blast Loading

The steel frame structure plays an important role in strategic deployments and is widely used in heavy machinery, metallurgy, military, and other important industries. To study the impact of explosive loads on the anti-progressive collapse performance of steel structures, this paper proposes to establish the vulnerability characteristics of steel frame structures and provides a method for calculating vulnerability characterization indicators. A finite element model is used to analyze the dynamic response of steel frame structures under the action of close-range explosive loads, and factors influencing the anti-progressive collapse of steel frame structures are proposed, including the number of stories and diagonal bracing. A comparison is made between the various column types of steel structures under explosive loads, such as corner columns, long-edge middle columns, short-edge middle columns, inner columns, also in various coupling conditions. The results show that the progressive collapse of steel frame structures is greatly influenced by the position of the explosion and less affected by the amount of explosive material. The simultaneous failure of corner columns and long-edge middle columns is more likely to cause overall structural failure. The addition of diagonal bracing significantly improves the anti-progressive collapse ability and prevents the lateral displacement of steel frame structures; increasing the number of stories provides more alternative load transfer paths for steel frame structures, thereby preventing their collapse.

Calibration of the Modified Mohr–Coulomb Failure Criterion and Its Application in the Study of Collision Response of Ship Hull Plate Frame Structures

Calibration of the Modified Mohr–Coulomb Failure Criterion and Its Application in the Study of Collision Response of Ship Hull Plate Frame Structures

Vierendeel action in progressive collapse of three-storey RC structures under corner column removal scenario

Previous studies have found that the Vierendeel action (VA) is one of the main mechanisms against progressive collapse of multi-storey reinforcement concrete (RC) frame structures in the event of corner column failure. However, the knowledge remains inadequate in terms of the behavior, mechanism, and quantitative contribution of the VA to the collapse resistance. To fill this gap, quasi-static tests were performed on a 1/3 scale single-storey RC substructure and a three-storey RC substructure with identical geometry, material, reinforcements and boundary conditions under corner column removal scenario. Test results found that, compared with the single-storey substructure experiencing no VA, the three-storey substructure developed additional plastic hinges at the beam ends near the corner column and at the lower end of the corner column as a result of the VA. The ultimate resistance of the three-storey substructure was 10.6% more than the triple ultimate resistance of the single-storey substructure. Then, numerical analysis was conducted to cognize the formation sequence of the plastic hinges and the effect of slabs. Furthermore, two coefficients were defined to reveal the mechanism of the VA in the three-storey substructure, i.e., the displacement-related coefficient ed and the coefficient associated with ultimate resistance eu. Finally, a simplified analytical model was proposed to predict the ultimate resistance of the three-storey structures with consideration of the VA.

The engineering legacy of the FIFA World Cup Qatar 2022™: Stadium 974 – Reuse as driving force for sustainable stadium design

Stadium 974, located on the east shore of the Doha Bay in the municipality of Ras Abu Aboud, is the first fully demountable, transportable, and reusable stadium of its kind. Modular systems in construction have a long track record in the industry but developing and delivering an entire scheme for such a complex venue under the requirements of a FIFA World Cup Stadium was never achieved before. The basis of the innovative concept of a temporary venue is to create a highly repetitive grid of identical structural frames, supporting standardised components: bleachers, concourse slabs and modules carrying containers pre-equipped with all required functions. The venue can then be easily demounted after the event and completely re-installed in another location or repurposed into many small stadia at different locations. The structure consists of a series of steel frames resembling the appearance of a high-bay warehouse separated in different blocks, which e.g. include the stands, concourses, and sanitary fittings. All elements fit in specially modified and certified shipping containers. All individual elements can be dismantled and transported within the certified shipping containers to the next destination. This enables efficient reuse of the material and hence results in a reduced lifetime carbon dioxide footprint due to less construction material and reduced waste. This pioneering scheme posed significant challenges and constraints for the structural design, and required a comprehensive approach, from the development of suitable structural concepts to the implementation in the structural detailing. This paper describes some of those challenges and the design solutions adopted.

GPU-based parallel programming for FEM analysis in the optimization of steel frames

ABSTRACT Optimization of large-scale frame structures consumes a vast amount of time since the analysis of such complex systems contains several iterative processes. Mitigating computational burden and reducing this time to a reasonable level is possible by running GPU (Graphical Processing Unit) processors, which can be found on standard computers. This study presents an algorithm for the acceleration of size optimization of steel frames by using the BBO (Biogeography-Based Optimization) method that is suitable for GPU architecture. The GPU-based parallel algorithm, designed for FEM (Finite Element Method) analysis, is applied to three hypothetical steel-frame case structures with different numbers of members and nodes; and processed on four different computers which are available on the market. The presented case studies revealed that the proposed solution’s efficiency increases as the number of members increases and confirmed the ability of the acceleration algorithm for optimization of large-scale frame structures and provided time efficiency.

Effect of biological shells aggregate on the mechanical properties and sustainability of concrete

The recycling bio-waste shells problem has grown more and more serious in recent years and many efforts have been made to solve this problem. One possible solution is to put these bio-shells into concrete and recycle them as building materials using the aggregate matrix concrete approach. To verify the engineering feasibility, the mechanical properties of bio-shells aggregated concrete were invested via gradient substitution rates at 10%, 30%, and 50% with a total of 78 groups of specimens in this paper. Our results show that the mechanical properties of the concrete were enhanced in maximum flexural strength and maximum compressive. Economic performance was also analyzed and found that the costs of frame-shear structure, frame structure, and tube-in-tube structure were reduced by 10.2%, 10%, and 10.3%. The carbon environmental assessment also shows superiority in the carbon reduction of a single specimen with various rates of the shell. In summary, compared with ordinary concrete materials, it is very possible to use waste bio-shells as a substitute for aggregates to develop the sustainable recycling development of concrete materials.

Experimental investigation on seismic behavior of damaged self-centering friction beam-column joints after repair

Self-centering beam-column joints are an effective strategy to improve the seismic resilience of frame structures. Extensive research has been conducted on the seismic performance of newly constructed self-centering joints, involving experiments, theoretical analyses, and simulations. Nevertheless, less attention has been paid to evaluating the seismic resilience of self-centering joints after repair. To address this gap, this paper presents a series of experiments to investigate the mechanical properties of damaged self-centering friction beam-column joints (SCFJ) after repair. Three SCFJs damaged by cyclic loading are repaired using epoxy injection, CFRP wrapping, and replacement concrete. The repaired joints are then subjected to cyclic loading under the same conditions as the original loading. A comprehensive analysis is conducted of the hysteretic curve, skeleton curve, energy dissipation, stiffness degradation, and residual displacement of both the original and repaired SCFJs. The results show that the repaired SCFJs maintain their commendable self-centering capacity. Specifically, the replacement concrete method is the most effective in restoring the initial seismic performance of the SCFJs. The epoxy injection method is the fastest repair method and successfully restore the SCFJ to approximately its original ultimate strength and approximately 85% of its energy dissipation and self-centering capacity. The CFRP wrapping method is able to largely restore the self-centering capacity of the SCFJ to its original level, but with a notable decrease in stiffness.

Comparative analysis of track damping effect of structure jointly constructed by subway tunnels and high-rise buildings

The joint construction of subways and other public buildings is a relatively newer type of construction. There is little research experience in the vibration characteristics and track damping design for this type of structure. In this study, a field test was adopted to conduct site measurement analysis on the vibration response of the joint construction project consisting of a subway tunnel and a building with typical frame structures. Numerical simulation methods were also adopted to, respectively, assume the use of ordinary tracks and steel-spring floating slab tracks for the subway for the situation where the Cologne-egg high-elastic fasteners were used on the track for damping purposes. Comparisons were performed to analyze the difference in the system vibration response between three different types of track. The results showed that the high-elastic fastener track and floating slab track both have a certain degree of damping effect compared with an ordinary track. Specifically speaking, the former has a damping advantage for frequency bands below 20 Hz, while the latter has the advantage for frequency bands above 20 Hz under the impact of the structural vibration characteristics for this joint construction. For this jointly construction structure, affected by the natural vibration characteristics of the structure, the natural frequency of the floating slab track is within 4 ∼ 10 Hz, and the similar vibration reduction effect can be achieved. This indicates that the structural vibration characteristic of the jointly constructed structure is an important factor determining the appropriate natural frequency of the floating slab track.

Improved Mechanical Performance in FDM Cellular Frame Structures through Partial Incorporation of Faces

The utilization of lattice-type cellular architectures has seen a significant increase, owing to their predictable shape and the ability to fabricate templated porous materials through low-cost 3D-printing methods. Frames based on atomic lattice structures such as face-centered cubic (FCC), body-centered cubic (BCC), or simple cubic (SC) have been utilized. In FDM, the mechanical performance has been impeded by stress concentration at the nodes and melt-solidification interfaces arising from layer-by-layer deposition. Adding plates to the frames has resulted in improvements with a concurrent increase in weight and hot-pocket-induced dimensional impact in the closed cells formed. In this paper, we explore compressive performance from the partial addition of plates to the frames of a SC-BCC lattice. Compression testing of both single unit cells and 4 × 4 × 4 lattices in all three axial directions is conducted to examine stress transfer to the nearest neighbor and assess scale-up stress transfer. Our findings reveal that hybrid lattice structure unit cells exhibit significantly improved modulus in the range of 125% to 393%, specific modulus in the range of 13% to 120%, and energy absorption in the range of 17% to 395% over the open lattice. The scaled-up lattice modulus increased by 8% to 400%, specific modulus by 2% to 107%, and energy absorption by 37% to 553% over the lattice frame. Parameters that emerged as key to improved lightweighting.

Seismic Performance of Full-Scale Autoclaved Aerated Concrete Panel-Assembled Walls: Experimental Study and Numerical Modeling

Prefabricated panel-assembled wall systems, comprising a confining frame and infill lightweight panels of autoclaved aerated concrete (AAC), are widely employed in framed structures. Different from studies on a main frame with infill walls, this study aimed to explore the seismic performance of partition walls, which were fabricated with AAC panel-assembled walls and located outside of the main frames. Two full-scale specimens, one with a door opening and the other without, were constructed and cyclic loading tests were executed to examine the failure modes, hysteresis characteristics, envelope curves, ductility, strength and stiffness degradation, as well as energy dissipation capacity of the AAC panel-assembled walls. Additionally, a restoring-force model for the panel-assembled walls was developed and a method for predicting the lateral load-bearing capacity of the AAC panel-assembled walls was proposed. The findings indicated that the panels enhanced the system’s lateral resistance, energy dissipation capacity, and deformation capability. The door frame increased the initial stiffness, peak lateral load and energy dissipation capacity of the AAC panel-assembled wall compared to the wall without a door frame. Compared to the specimen without a door frame, the peak lateral load of the specimen with a door frame increased by 19.7–30.1%. The deformation capacity of the panel-assembled walls aligned with the requirements for concrete framed structures.

The stacking sequence optimisation of a filament wound composite bicycle frame using the data-driven evolutionary algorithm EvoDN2

ABSTRACT This work focusses on identifying the optimal stacking sequence for composite tubes in mountain bike frames using a data-driven model combined with evolutionary algorithms. The objective is to find a frame that is sufficiently stiff while meeting the requirements of weight, strength, and minimum tube wall thickness. The decision variables are the ply winding angles and the ply thicknesses of each tube. The study performs designs for two load cases – Starting and Uphill – and explores two types of winding: the gradual winding of individual layers (1ply) and the winding of layers between predefined inner and outer layers with variable thicknesses (TW). Additionally, the design process is applied to frames made of isotropic materials, such as steel, aluminium, and titanium, using the same methodology to allow for comparison of results. The article demonstrates the successful application of this methodology to common sports equipment, suggesting its potential for beneficial use in other common composite frame structures.

Cost optimization of tall buildings having tube composite columns using social spider algorithm

SummaryThis study aims to develop an algorithmic approach to obtain optimum designs for tall buildings having composite columns and investigate the material cost advantages of these buildings over steel structures. The social spider optimization (SSO) algorithm, a new meta‐heuristic optimization method that has shown promising results in optimizing frame structures, was used to obtain the optimum designs. Concrete‐filled steel tube sections were chosen for composite columns. To define the optimization problem, we considered the material cost of the structure as the objective function, the size of columns (strength, deflection, drift, and geometric limitations) as the constraint functions, and ready steel sections as the design variables. We tested eight different frame structures of varying heights and irregularities to analyze how cost varied according to these parameters. Our results demonstrate that composite columns are a more cost‐effective option than steel structures, even for buildings that are not considered high rises. We found that the difference in cost between the two types of structures increases with building height and irregularity. Additionally, our optimization algorithm was unable to find feasible designs for steel structures taller than 180 m using ready steel profiles.

Building pose detection for the characterization of reinforced concrete buildings

SummaryThe automated identification of building characteristics for seismic vulnerability remains a challenge for governments due to the high number of buildings in cities. The diverse architectural styles of these buildings complicate the automated identification of building information (e.g., number of stories, structural system, and material type). Deep learning techniques lose accuracy as they generalize information, while the visual contents of a building exhibit a considerable range and diversity. This study leverages the pose detection technique to tackle such issues by focusing on a common construction style: reinforced concrete buildings representing columns, beams, or floors on the façade. With an aim to enable the assessment of seismic vulnerability, the technique developed herein is conceived for buildings with up to six stories that are more likely to be moment‐frame buildings. The AI‐enabled proposed framework starts with collecting building images and categorizing those containing this specific building type. A bounding box detector is then used to isolate building facades, for the subsequent identification of the structural frame with the High‐Resolution Network (HR‐Net). For demonstration, we illustrate this technique by identifying the structural frame on concrete buildings with a sample dataset developed based on buildings found in Mexico City in a pre‐earthquake event state.

A two-loop RBDO approach for steel frame structures using EVPS, GWO, and Monte Carlo simulation

This paper evaluates Enhanced Vibrating Particle System (EVPS) and Grey Wolf Optimizer (GWO) algorithms for Reliability-based Design Optimization (RBDO) of steel frames. The two-loop RBDO method minimizes frame weight while satisfying strength, drift, and reliability constraints, considering uncertainties in material properties and loads. Both EVPS and GWO effectively reduce structure weight and ensure required reliability levels, demonstrating their applicability in sustainable steel frame design.

Experimental studies of the impact of fluid sloshing in the tank on the dynamic characteristics of the “wing model – fuel tank” system

Flexible response of the airframe structural elements under operational loads are one of the main sources of fatigue damage accumulation. It is known that fuel sloshing in tanks can change the dynamic (frequencies and shapes of natural oscillations) and dissipative properties (oscillation damping decrements) of an elastic system, including partially or completely fuelfilled tanks. It is specified that fuel sloshing in tanks due to the additional oscillation energy dissipation of the elastic system can have a significant impact on both the fatigue and aeroelastic characteristics of aircraft structural elements. Theoretical and experimental studies, applicably to the majority of currently operating transport aircraft, have shown that when modeling dynamic phenomena and solving aeroelasticity problems, fuel can be considered conditionally solidified, which actually does not affect the resultant effect. The advent of modern heavy transport aircraft with a high aspect ratio wing and four engines on pylons under the wing has led to a considerable change in the dynamic picture of the aircraft interaction with the environment. The main feature is that, under this arrangement, the first horizontal bending mode of the wing is embedded in the main flexible modes that determine the dynamic response to external effects. In this case, the model of solidified fuel can have a significant impact on the accuracy of predicting dynamic loads and, as a consequence, on the quantitative characteristics of durability and aeroelasticity. The article presents the results of experimental studies of the impact of fluid sloshing in the tank on the dynamic characteristics (frequencies of natural oscillations and amplitudes of forced oscillations) of the “wing model – fuel tank” system. The design of the experimental installation and the methodology of conducting experiments are described. During the experiment, the tank was partially filled with liquid or full, and horizontal bending modes of the wing model, for which considering liquid sloshing in the tank is the most relevant, were studied. The tank refueling levels are determined at which the maximum effect of the system oscillation damping is achieved due to energy dissipation under liquid sloshing. The effect of various factors (presence of a top cover, internal structural frame, perforation in the structural frame) on the amplitudes and frequencies of forced oscillations is analyzed.

Performance evaluation and FRP strengthening of concrete-filled steel tubular columns subjected to vehicle impact

Concrete-filled steel tubular (CFST) columns have been widely used in multi-story and high-rise frame structures. During the service period, they may suffer vehicle impact due to traffic accidents or terrorist attacks. This paper numerically evaluates the performance of CFST columns under vehicle impact and investigates the effects of carbon FRP (CFRP) wrapping arrangements on performance improvement of the columns. Before that, a numerical model was developed to simulate the responses of CFST columns without and with FRP wrapping under vehicle impact and post-impact axial compression, and then calibrated by reported tests. Evaluation results show that the performance of CSFT columns under vehicle impact is divided into five levels, i.e., no repair required, rapid repair required, minor repair needed, major repair needed, and replacement needed. The performance level decreases with the increase in the vehicle weight or speed and increases with the increase in the column diameter or steel tube thickness. The column height has little effects on the performance level. A higher axial load ratio, e.g., 0.5, might reduce the performance level. Besides, a CFST column tends to fail in flexure mode when hit by F800 medium truck, while it may fail in flexure & shear mode when hit by C2500 pickup truck. Investigation results indicate that FRP wrapping with each layer orientation of 90° (i.e., in the longitudinal direction) and 0° (i.e., in the hoop direction) present the best performance improvement for a CFST column possibly undergoing flexure & shear and flexure failure, respectively. The increase of the number of FRP layers effectively improves the performance levels of CFST columns but the excessive demand may be not economical. It is not necessary to employ an FRP wrapping range of 100% for improving the vehicular impact performance level of a CFST column to the expected one.

Structure of Spread Spectrum Telemetry Radio Link for LEO Small Satellite

The paper considers the design of telemetry radio link for low Earth orbit (LEO) satellites, particularly based on CubeSat format. A significant limitation of such spacecrafts are the available dimensions for antennas and the transmitting power, which leads to low energy level at the ground receiving point of transmitted signal. The article presents the physical level structure for data frame based on direct sequence spread spectrum technique, which allows for additional signal gain to achieve the required level of link performance. Using such principle also make possible to implement adaptive data rate control depending on dynamics in signal-to-noise ratio when the distance from the satellite to the ground point changes. For proposed data frame structure, an analysis of received information size during a communication session was carried out, which is parameterized on the maximum observable elevation angle of the satellite. The issue of datalink layer interaction between devices is also considered.

Hybrid origami-linkage vaulted deployable structures: parametric development and form-finding

AbstractThe demand for adaptable structures is steadily increasing in contemporary architectural practice. Deployable structures, characterized by their flexibility and versatility, offer innovative solutions across demanding engineering and architectural contexts. Among the various types of deployable structures, two main categories emerge: lattice deployable structures and continuous surface deployable structures. This paper explores the creation of hybrid deployable vaulted structures by incorporating kinetic elements from both deployable structure categories. A combination of rigid thick origami surfaces and retractable structural frames composed of four-bar and scissor-hinged linkages is examined, while both direct and inverse design methodologies are explored. To facilitate the parameterization and kinematic study of the proposed structures, an algorithm is developed within the Rhino Grasshopper visual programming environment, which is then utilized for form-finding and design optimization of the generated deployable vaults. The present study aims to contribute to the evolution of lightweight, kinetic elements for versatile architectural applications. The proposed hybrid deployable structures are designed to adjust to evolving spatial and functional requirements while maintaining structural integrity.