International Journal of Steel Structures最新文献

This study investigates and compares the relative cost-efficiency and seismic performance of two stability design approaches: the effective length method (ELM) and the direct analysis method (DM). Four steel special frames are first optimized for minimum weight under both design approaches using a recently developed design-driven optimization technique called capacity controlled search (CCS). The constraints governing each design, such as demand-to-capacity ratios and inter-story drift constraint ratios, are identified and presented. Subsequently, the seismic performance of the optimum designs is assessed by a nonlinear static procedure in compliance with ASCE/SEI 41-13. Finally, the results are compared to identify which stability design method leads to more economical and seismically resilient designs in general.

Compared to traditional steel plates, corrugated steel plates offered a lighter weight while providing higher strength, ensuring sufficient structural support. Corrugated steel plates effectively distributed stress, enhanced bending and shear resistance, and improve the overall bearing capacity of the infilled reinforced concrete (RC) frame. This study proposed analytical formulas for calculating the bearing capacity of infilled RC frames strengthened with corrugated steel plates. The proposed formulas were validated through experimental research, demonstrating good agreement between theoretical predictions and experimental results, with deviations of 3.97% and 9.67%. Furthermore, the influences of corrugated steel plate type, layout, and thickness on structural performance were investigated. The results indicated that greater wave heights reduced bearing capacity, while horizontal rib arrangements achieved the highest capacity, which decreased as the rib angle increased. Additionally, an increase in plate thickness enhanced bearing capacity. However, the improvement was marginal for plate types with higher ribs.

In complex structural analysis, dealing with uncertainty has become a critical aspect of engineering design and practice. While the finite element method (FEM) remains a fundamental numerical technique for analyzing such structures, deterministic FEM often fails to adequately address the inherent uncertainties in engineering problems. To overcome this limitation, stochastic finite element methods (SFEM) have been developed, integrating random analysis theory into traditional finite element methods. This paper proposes a reliability-based framework that combines finite element analysis, response surface modeling, and Monte Carlo simulation to calibrate structural resistance characteristic values under a predetermined target reliability index. This method provides a transparent and quantitative assessment of the effects of resistance uncertainty, representing an improvement over traditional deterministic or semi-probabilistic approaches. Our findings reveal a crucial aspect: when the coefficient of variation reaches a specific threshold, the variability of resistance characteristics is primarily influenced by material properties. However, beyond this threshold, the influence of material properties diminishes, while factors such as geometric deviations and discrepancies between actual and theoretical fundamental assumptions become more prominent. The insights gained from this study provide valuable guidance for addressing uncertainty in the design and implementation of multi-story steel frame structures in practical applications.

The performance of stiffened steel plate shear walls (SPSWs) with two different types of behavior is investigated. The SPSWs with aspect ratios ranging from 0.8 to 2.5 were designed according to AISC seismic provisions. Then the stiffeners with different arrangements were designed with two different methods. The first method is per codes and design guidelines, which usually lead to the low-stiffness stiffeners design, which does not prevent global buckling of the web plate. In the second method, stiffeners are designed in a way that prevents the global buckling of the web plate and converts the global buckling to the local buckling mode in each sub-panel. A group of SPSWs with 9 different aspect ratios and three types of stiffener arrangements, including horizontal, vertical, and horizontal-vertical, were designed with both design methods. A total of 54 numerical models of SPSWs were simulated and subjected to push-over and cyclic analysis. The strength, stiffness, and dissipated energy of the SPSWs were thoroughly investigated. The results show that the SPSWs with high-stiffness stiffeners have much better performance and concerning the amount of steel used for the stiffeners, the use of SPSWs with vertical or horizontal-vertical high-stiffness stiffeners is more appropriate and economic.

Based on existing triaxial plastic-damage constitutive models for concrete and elastic–plastic constitutive models for steel, a three-dimensional refined finite element (FE) model of rectangular concrete-filled steel tube (CFT) short columns under axial compression is developed. The FE analysis results, including damage morphology, load–displacement curves, and ultimate bearing capacity, are compared with experimental data. Following experimental validation, a parametric study is performed to evaluate the influence of steel tube strength, concrete strength, tube wall thickness, and length-to-width ratio on the load–displacement response. At ultimate bearing capacity, the confined and unconfined zones within the rectangular cross-section are identified, and the average von Mises stresses in these regions are quantified. A practical formula for predicting the axial load-carrying capacity, incorporating a confinement coefficient, is proposed. Comparisons of the ultimate bearing capacity obtained from the proposed formula with experimental results and FE predictions confirm its accuracy and validity. The proposed formula demonstrates superior performance compared with existing formulas presented in other studies and current design codes.

Well-known design codes employ different lateral load patterns for the Equivalent Lateral Force (ELF) procedure. however, the effect of designing with these different lateral load patterns on the structural collapse capacity has rarely been studied. Different lateral load patterns employed in design result in distinct distributions of stiffness and strength along the height of the structure and consequently in non-uniform distribution of damage in building stories. As a result, the damage may be very severe in some stories such that exceeds the collapse criteria, while the capacity of other stories is not fully used. Therefore, different lateral load patterns induce variations in the distributions of stiffness and strength along the building height, thereby affecting the structural collapse capacity. The influence of employing varying lateral load patterns on the collapse capacity of structures is evaluated in this study. For this purpose, steel moment-resisting frames (SMRFs) were designed using four distinct load patterns, such that all structures designed with different load patterns have the same total weight. Subsequently, by performing incremental dynamic analysis (IDA) and fragility analyses for designed models, the median collapse intensities were compared. The results clarify that the lateral load pattern can affect the collapse capacity of the structure by up to 20%.

Considering that research on the mechanical properties, configuration design, mass design, and applications of regular prismatic units has become relatively mature, this paper innovatively investigates their internal space. First, the topological patterns of regular prismatic units are analyzed, including structural parameters, connectivity matrix, and complexity. Second, the space utilization ratio is defined to characterize the internal space, along with its computational methodology. Through formulaic analysis, it is demonstrated that complexity and connectivity are the primary factors influencing the space utilization ratio. Finally, the variation patterns of space utilization ratio are analyzed by changing complexity and connectivity. The results demonstrate that the space utilization ratio reaches its maximum value under either the first or the final connection configuration, while exhibiting a monotonically increasing trend with rising complexity. The space utilization ratio exhibits a symmetric distribution. The 3-bar tensegrity prismatic unit exhibits the minimum space utilization ratio. This research provides inspiration for the exploitation of internal spaces.

This study investigates the seismic performance of fluid storage tanks constructed using functionally graded materials (FGMs) and compares their behavior with conventional isotropic steel tanks. The motivation for adopting FGM lies in its ability to achieve a continuous variation of material properties through thickness, enabling improved stiffness distribution, reduced stress concentration, and enhanced dynamic performance. A finite element model incorporating fluid–structure interaction is developed to evaluate hydrodynamic pressure, base shear, displacement response, and stress distribution under seismic excitation. Radiation damping at the soil boundary is modeled using viscous dashpots, while structural damping is represented through Rayleigh proportional damping. The results demonstrate that the FGM tank exhibits higher natural frequency, reduced maximum displacement, lower peak stresses at critical regions, and improved stress redistribution compared to the conventional steel configuration. Significant reduction in shell–bottom junction stresses and sloshing response is observed, indicating enhanced structural reliability under earthquake loading. The findings confirm that stiffness tailoring through functional gradation provides a promising alternative to traditional homogeneous materials for improving the seismic safety and durability of liquid storage tanks.

This study focuses on the seismic responses of Multi-span Suspension Bridge (MSB) under Multi-Support Excitation (MSE), taking into account incoherence and wave-passage effects. The study conducts a time history analysis of “Cheon-Sa Bridge” to investigate the responses of girder and pylons under three different types of homogenous soil conditions: soft, medium, and firm, with three different apparent wave velocities of 600 m/s, 900 m/s, and 1200 m/s. The responses obtained for different MSE cases are compared with a uniform seismic excitation of recorded earthquake ground motion of El-Centro 1940, Imperial Valley: 180 deg. Results show that MSE significantly affects the longitudinal and vertical responses of MSB. The girder exhibits 3.3 times higher deflections under soft and medium soil MSE cases. The MSE cases significantly increase the girder axial force by about 6 times that of the uniform excitation case. The side pylons exhibit a 30%–38% increase in transverse responses and approximately 10–12 times higher longitudinal responses. It is elucidated that the local site conditions and corresponding acceleration spectral density of bedrock motion significantly influence the response of MSB. Merely considering the wave-passage effect may underestimate the actual response.

Bolted endplate connections are widely employed in steel structures to connect beams to columns, since they are easy to fabricate and provide efficient structural performance. The T-stub connection model is commonly used to represent the tension zone components in the bolted endplate connections. Prying action is a crucial factor influencing the overall behavior of the T-stub connection model. Existing design equations consider the effect of prying force on the behavior of the steel T-stub connection model at ambient temperature. However, the material properties, such as the yield strength, ultimate strength, or elastic modulus, decrease, leading to the remarkable loss of stiffness, strength, and potential failure modes of steel connections at high temperatures. Therefore, accurate modelling of T-sub connections, including the prying effect, at elevated temperatures, is crucial to ensure the integrity of the steel structures in a fire. This study investigates the overall behaviors of the steel T-stub connection model affected by prying action at elevated temperatures via the finite element (FE) method, strictly considering nonlinear material, geometric, contact, and friction in modelling. The FE model is validated using the experimental results conducted by others, in which the failure modes are determined by comparing the stress and equivalent strain at the monitor point in the FE models. The prying forces exerted by the endplate are numerically calculated based on the bolt’s forces and the applied load. Finally, a parametric analysis is performed thoroughly to investigate the effect of temperature, bolt diameter, and T-stub section on the behavior of the steel T-stub connection model at elevated temperatures. The results show that temperature and bolt diameter are the most influential parameters in the behavior of the steel T-stub connection model with prying action at elevated temperatures.