International Journal of Steel Structures最新文献

The current study aims to investigate the effects of input factors on UTS (ultimate tensile strength), PE (percentage elongation), bead width and depth of penetration in TIG welding austenitic stainless steel 304L. Experiments were systematically designed using the Taguchi L9 orthogonal array technique, allowing efficient exploration of the parameter space using only nine experimental runs. X-rays radiography test was taken of the weld specimens to look for outer and inner surface defects. This study emphasizes the use of and TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method to find the ideal input parameters as well as significant outcome. Engineers and technicians may identify parametric parameters for better welding with the use of recent research and thorough study on connecting incompatible on those materials.

This study presents a novel method for developing a finite element (FE) model of partially encased composite (PEC) columns within the ABAQUS/Standard module, alongside a proposed compressive stress–strain relationship specifically for confined concrete. The proposed FE model’s accuracy was corroborated through comparison with existing experimental datasets from both monotonic and cyclic loading tests. Comparative assessments demonstrated that, in contrast to conventional concrete constitutive models, the FE model incorporating the proposed concrete constitutive relation achieved more accurate simulations of PEC column behavior. Additionally, a parametric investigation was performed on PEC columns subjected to cyclic loading to examine the effects of axial compression ratio and structural measures on their seismic performance. The results revealed that the inclusion of transverse links, longitudinal reinforcement, and stirrups effectively enhanced the load-bearing capacity and deformation capacity of the specimens. With an increase in the axial compression ratio, the distance from the most unfavorable section of the specimen to the bottom gradually increased. Under high axial compression ratios, special attention should be paid to the risk of the most unfavorable section shifting into the non-dense region of transverse links, where confinement effectiveness is compromised.

Corrugated steel web girder bridges offer significant advantages in terms of lightweight construction, cost-effectiveness, and enhanced durability, with their dynamic response being a critical factor influencing structural safety and performance under dynamic loading conditions. In this study, to investigate the impact of random road surface roughness on the dynamic response of corrugated steel web girder bridges, ANSYS finite element software and its APDL platform were used to establish a vehicle–bridge coupled model based on a corrugated steel web box girder bridge in China. A code is developed to implement a vehicle–bridge coupled vibration analysis method based on the contact constraint method. The analysis focuses on the dynamic response of the bridge under random excitation from road surface roughness, considering factors such as vehicle speed, vehicle configuration, and bridge surface roughness grade. The results show that the mean values of bridge displacement and bending moment responses are primarily controlled by the vehicle load on the bridge, with the maximum displacement and bending moment values occurring at a vehicle speed of 60 km/h. Moreover, increases in vehicle speed, vehicle load, and bridge surface roughness grade significantly amplify the dispersion of dynamic responses at the bridge mid-span.

Wire and Arc Additive Manufacturing (WAAM) is a recently developed metal additive manufacturing technology that enables the optimization of material properties and structural components according to specific construction requirements. In this study, austenitic stainless steel (308LSi) WAAM EHS (elliptical hollow section) stub column under axial compression has been developed using FE Abaqus software. The parametric study of the WAAM EHS have been done by covering various cross-sectional Classes 1–4, varying aspect ratio (a/b i.e. major axis/ minor axis) 1.2–2.77, length taken approximately twice to thrice the major axis diameter (2a) and thickness ranging 3.5–8 mm. Results indicate that ultimate load capacity (P_u) decreases with increasing aspect ratio, with reduction rates of 6.79–7.82%, 3.92–4.13%, and 5.58–9.62% for aspect ratio increases from 1.2 to 1.67, 1.67 to 2.0, and 2.0 to 2.77, respectively. The FE results were compared against existing stainless steel design standards: EN 1993-1-4 (2023), AISC 370 (2021), and the Continuous Strength Method (CSM) due to lack of design codes specifically for WAAM sections. The CSM demonstrated the highest reliability with a mean FE to capacity prediction ratio of 1.08, while EN 1993-1-4 and AISC 370 yielded conservative predictions with mean ratios of 1.44 and 1.43, respectively. Evaluation of cross-sectional classification systems revealed that EN 1993-1-4 classifications produce overly conservative results for WAAM EHS columns at the current slenderness limit of D_e/tε² = 90, prompting a recommendation for modification. Conversely, the classification criteria in AISC 370 and CSM were found to be satisfactory for WAAM EHS stub columns.

This study investigates smoke dispersion and toxic gas distribution in lower-deck vehicle fires on double-decker bridges through 27 sets of scaled experiments (1:8 model). Key findings reveal: windless conditions form stable ceiling jets, while crosswinds (> 3.3 m/s inward) disrupt stratification, creating hazardous turbulent smoke layers that reduce visibility to critical levels (e.g., 1.2 m thickness at 200 MW). CO₂ concentrations peak at 0.82% (16 × safe limit), CO reaches 13,352 ppm (267 × threshold), with vertical concentration gradients showing 3 × higher toxicity near upper decks. Gas concentrations scale proportionally with heat release rate (200 MW fires yield 1.5 × 100 MW levels). Most adverse conditions occur at 2 m/s outward and 4.4 m/s inward winds, where flame attachment to structural members exacerbates gas accumulation. The empirical evidence substantiates restricting tanker trucks from lower decks to mitigate catastrophic fire risks.

To explore the dynamic response and failure mechanism of a Kiewitt-type cable dome structure under impact loads, a dynamic response analysis method was developed and failure criteria were established. Based on the positional relationship between the rod and the impact point, the cable dome structure is categorized into three distinct zones: the impact zone, non-impact zone 1, and non-impact zone 2. The dynamic response of the structure was analyzed using ANSYS/LS-DYNA software. Based on the analysis results, four failure modes of the structure under impact loads were identified and characterized, and the dynamic responses under each mode were analyzed. Energy absorption functions and corresponding thresholds for different failure modes were established. By analyzing the kinetic energy of the impactor and the energy absorbed by the cable dome structure, the impact failure mechanism was elucidated. Failure modes can be divided into four types: Mode 1 (non-failure), Mode 2 (local instability), Mode 3 (local failure), and Mode 4 (complete failure). In Modes 1, 2, and 3, the largest increases in internal force were observed in the inner diagonal cables, while the smallest increases were in the outer diagonal cables. In mode 4, the largest increases in internal force occurred in the outer loop cables. During the natural vibration process, the displacement of the nodes in the impact zone reached their maximized value and then gradually transferred to both non-impact zones. The transformation of kinetic energy into strain energy in the structure was related to the duration of the impact; a longer impact time resulted in more complete energy transformation. Finally, based on the analysis results, suggestions were made for the impact resistance design of a Kiewitt-type cable dome structure. The results demonstrate that the failure mode of the structure can be predicted from the amount of energy absorbed by the structure.

Energy dissipation capacity is a critical parameter in seismic design, reflecting a structure’s ability to absorb and dissipate energy under earthquake or dynamic loads. In steel structures, this parameter plays a vital role in maintaining structural integrity and ensuring safety. This study introduces a novel slotted steel plate shear wall (S-SPSW) system, comprising two inclined slotted infill plates (ISIPs) connected by high-strength steel bolts. The configuration of the infill plates is designed such that, under cyclic loading, one side of the wall experiences tensile forces while the opposite side undergoes compressive forces simultaneously. To evaluate the hysteretic performance of the proposed system, two one-third scale SPSW specimens were fabricated and subjected to quasi-static cyclic loading tests. Key performance indicators, including hysteretic behavior, shear capacity, and energy dissipation capacity, were experimentally assessed. The results demonstrate that the S-SPSW system enhances energy dissipation capacity by approximately 15.66% compared to conventional SPSW systems, highlighting its potential as a system that is capable of effectively resisting lateral loads in seismic applications.

Experimental tests can provide the most reliable and accurate results for any problem such as blast loading on structures But in some cases it is very costly, risky, and in some cases impossible. Using small-scale models is one of the best alternatives in such cases, but the dynamic response of scaled structures under blast loads often deviates from classical similarity laws, particularly for strain-rate-sensitive materials. To address these discrepancies, it is essential to modify scaling laws, ensuring that they accurately reflect the behavior of structure. In This study Based on classical nonlinear dynamic analysis method, a new formula has been proposed to solve the scaling deviation. By effectively modifying the applied impulse through an explicit formula, the approach significantly enhances the predictive accuracy of prototype model responses derived from scaled experiments. The results validate the importance of considering strain rate sensitivity and highlight the limitations of traditional scaling methods. Accuracy of the formula was verified by numerical simulation and investigated for maximum and permanent plate’s deflection. The new modification method gives better results for maximum deflection rather than permanent deflection. Results showed that the proposed formula can accurately predict the response of the prototype from the results of the scaled model.

Grouting defects in concrete-filled steel tube (CFST) columns with “inner tube-flange-grouting” vertical connections were investigated in this paper. To reveal the influence of grouting technology on grouting quality and of grouting defects on connection quality, visual grouting tests were first conducted to directly observe the flow patterns of grout and the formation of defects. The test results showed that a grout thickness of 20 mm minimized defects, while the double-sided outlet layout significantly improved grouting fullness through optimized air discharge. Then, numerical simulations of grout flow patterns were performed, and the results were in good agreement with the tests, thereby validating the correctness of the model establishment method. Furthermore, digital radiography testing was used to verify grouting integrity. The testing results of eight specimens showed that the simulated defect distribution was highly consistent with the actual, further confirming the defect distribution patterns. Based on the defect sizes derived from previous investigations, subsequent numerical simulations showed that minor grout defects had minimal impact on the stiffness and load-bearing capacity of vertical connections, demonstrating the connection's high tolerance to grout defects. These findings have laid a foundation for optimizing the construction design of “inner tube-flange-grouting” column-to-column connections, enhancing the overall mechanical performance, and guiding the practical engineering applications of prefabricated concrete-filled steel tube structures.

P110 Cr13S is a new high-performance casing steel, bridging the critical gap in engineering between conventional carbon steel and high-end stainless steel. To investigate the temperature-dependent cyclic plasticity of this material, standard monotonic tension tests and stress-controlled cyclic tests were conducted at various temperatures. The results of monotonic tension tests revealed that P110 Cr13S exhibits an advanced high tensile strength exceeding 800 MPa and its value gradually decreases with increasing temperature. In cyclic loading, the differences between two successive cycles decreased with increase in the number of cycles, and the retention behavior stabilized after approximately 50 cycles. After approximately 450 cycles, the final shakedown stage was reached. The Chaboche constitutive model was further modified based on experimental observations to accurately describe the cyclic plastic behavior of P110 Cr13S, taking into account the factor of temperature. The corresponding finite element formulations were implemented into ABAQUS via a user-defined material subroutine to perform numerical simulations. Comparisons between simulations and experimental results demonstrated excellent agreement, confirming that the proposed model can reliably predict the thermomechanical cyclic plasticity of P110 Cr13S. This study provides a validated constitutive framework for modeling the high-temperature cyclic response of high-strength casing steels, offering valuable insight for design and life prediction under varying thermal–mechanical conditions.