Login
Register
Steel Construction Published the List of Highly Influential Articles of 2020
Current Issue
2026 Vol. 41, No. 3
Display Method:
2026, 41(3): 1-17.
doi: 10.13206/j.gjgS25082701
Abstract
PDF (6277KB)
Abstract:
To enhance the assembly efficiency and seismic performance of connections in modular steel structures，quasi-static low-cycle reversed loading tests and finite element simulations were employed to investigate the ultimate bearing capacity，failure mechanisms， hysteretic behavior，and energy dissipation of inter-module splicing joints under cyclic loading. The results indicated that：the inter⁃ nal partition plates installed in the column panel zone had a significant effect on the seismic performance of the joints and achieved a notable enhancement of the stiffness of the column walls；the cover plates installed on the upper and lower flanges of the modular beam effectively transferred the beam-end bending moments，promoted the outward relocation and full development of the beam-end plastic hinges，and thus significantly improved the seismic performance of the joints；the L-shaped connectors strongly enhanced the stiffness of the column walls in the joint core area and notably improved both the bearing capacity and ductility of the joints. Furthermore，para⁃ metric and stress-path analyses revealed that varying the thickness of horizontal connecting plates had no significant impact on bearing capacity or energy dissipation but notably improved joint ductility.
To enhance the assembly efficiency and seismic performance of connections in modular steel structures，quasi-static low-cycle reversed loading tests and finite element simulations were employed to investigate the ultimate bearing capacity，failure mechanisms， hysteretic behavior，and energy dissipation of inter-module splicing joints under cyclic loading. The results indicated that：the inter⁃ nal partition plates installed in the column panel zone had a significant effect on the seismic performance of the joints and achieved a notable enhancement of the stiffness of the column walls；the cover plates installed on the upper and lower flanges of the modular beam effectively transferred the beam-end bending moments，promoted the outward relocation and full development of the beam-end plastic hinges，and thus significantly improved the seismic performance of the joints；the L-shaped connectors strongly enhanced the stiffness of the column walls in the joint core area and notably improved both the bearing capacity and ductility of the joints. Furthermore，para⁃ metric and stress-path analyses revealed that varying the thickness of horizontal connecting plates had no significant impact on bearing capacity or energy dissipation but notably improved joint ductility.
2026, 41(3): 18-28.
doi: 10.13206/j.gjgS24121701
Abstract:
The flat single-axis photovoltaic （PV） tracker is a wind-sensitive structure， in which wind loads induce significant torsional moments in the main tubular beam. Current design codes， such as the AISC code， provide guidelines only for rectangular and circular tubular sections. However， they lack explicit calculation methods for polygonal tubular sections and offer no specific provisions for torsion design in steel structures （e.g.， in Chinese codes）. This study analyzed and compared the torsional capacity of thin-walled closed sections using shell buckling theory， standardized design principles， and numerical simulation. The results indicated that provided the width-to-thickness ratio requirements were satisfied， the theoretical predictions showed good agreement with the simulation results， based on which corresponding torsional capacity calculation formula was proposed. Accordingly， the cross-sectional optimization design strategies tailored to the characteristics of the flat single-axis tracker’s main tubular beam were explored.
The flat single-axis photovoltaic （PV） tracker is a wind-sensitive structure， in which wind loads induce significant torsional moments in the main tubular beam. Current design codes， such as the AISC code， provide guidelines only for rectangular and circular tubular sections. However， they lack explicit calculation methods for polygonal tubular sections and offer no specific provisions for torsion design in steel structures （e.g.， in Chinese codes）. This study analyzed and compared the torsional capacity of thin-walled closed sections using shell buckling theory， standardized design principles， and numerical simulation. The results indicated that provided the width-to-thickness ratio requirements were satisfied， the theoretical predictions showed good agreement with the simulation results， based on which corresponding torsional capacity calculation formula was proposed. Accordingly， the cross-sectional optimization design strategies tailored to the characteristics of the flat single-axis tracker’s main tubular beam were explored.
2026, 41(3): 29-35.
doi: 10.13206/j.gjgS24120401
Abstract:
Based on thin steel plate shear walls， domestic scholars have proposed a lateral force-resisting structural system composed of buckling-restrained braces at the four corners and a central shear steel plate. This system can concentrate the structure’s inelastic deformation within the central energy-dissipating element area， facilitating replacement and reducing post-earthquake repair costs. However， under horizontal loads， the shear steel plates in this system experience significant out-of-plane displacement， which hinders their capacity to fully and stably dissipate seismic energy. To address this issue， improvements have been made to the aforementioned buckling-restrained braces， proposing a casing-encased double-steel-tube buckling-restrained brace. Using the finite element analysis software， seven models of this brace design were subjected to unidirectional and cyclic loading simulations. This study compared the effects of varying parameters， such as inner tube length， outer sleeve length， and the stiffness ratio between the outer sleeve and the inner steel tube， on the numerical simulation results. The results showed that under tensile loading， the outer sleeve and the inner steel tube of the casing-encased double-steel-tube buckling-restrained brace cooperated in bearing the load， while under compressive loading， the outer sleeve separated from the inner steel tube， with only the inner tube providing compressive stiffness. Consequently， the brace’s tensile stiffness and tensile bearing capacity were greater than its compressive stiffness and compressive bearing capacity. This difference became more pronounced with a higher stiffness ratio between the outer sleeve and the inner steel tube. Furthermore， the proposed brace exhibited good ductility and energy dissipation capacity. This casing-encased double-steel-tube buckling-restrained brace can be arranged in a series of composite structural systems similar to cross bracing， which can fully utilize the capacity of the structural system to stably dissipate seismic energy through the lateral displacement of the plane of the self-restrained structure with different tensile and compressive stiffnesses.
Based on thin steel plate shear walls， domestic scholars have proposed a lateral force-resisting structural system composed of buckling-restrained braces at the four corners and a central shear steel plate. This system can concentrate the structure’s inelastic deformation within the central energy-dissipating element area， facilitating replacement and reducing post-earthquake repair costs. However， under horizontal loads， the shear steel plates in this system experience significant out-of-plane displacement， which hinders their capacity to fully and stably dissipate seismic energy. To address this issue， improvements have been made to the aforementioned buckling-restrained braces， proposing a casing-encased double-steel-tube buckling-restrained brace. Using the finite element analysis software， seven models of this brace design were subjected to unidirectional and cyclic loading simulations. This study compared the effects of varying parameters， such as inner tube length， outer sleeve length， and the stiffness ratio between the outer sleeve and the inner steel tube， on the numerical simulation results. The results showed that under tensile loading， the outer sleeve and the inner steel tube of the casing-encased double-steel-tube buckling-restrained brace cooperated in bearing the load， while under compressive loading， the outer sleeve separated from the inner steel tube， with only the inner tube providing compressive stiffness. Consequently， the brace’s tensile stiffness and tensile bearing capacity were greater than its compressive stiffness and compressive bearing capacity. This difference became more pronounced with a higher stiffness ratio between the outer sleeve and the inner steel tube. Furthermore， the proposed brace exhibited good ductility and energy dissipation capacity. This casing-encased double-steel-tube buckling-restrained brace can be arranged in a series of composite structural systems similar to cross bracing， which can fully utilize the capacity of the structural system to stably dissipate seismic energy through the lateral displacement of the plane of the self-restrained structure with different tensile and compressive stiffnesses.
2026, 41(3): 36-43.
doi: 10.13206/j.gjgS25043001
Abstract:
The cable elastic modulus conversion method is a technique that incorporates cable corrosion effects into the analysis of the overall cable-stayed bridge structure by converting the cable elastic modulus. However， its applicability in cases with complex corrosion pits on the cable wire surface is questionable， and scenarios involving significant stress concentration near the pits are not considered. In this paper， through the finite element simulation of corrosion pits on the surface of a cable wire， the relationship between the major-to-minor axis length ratio， depth， number， and spacing of the pits and the stress intensity factor of the wire was fitted binarily with consideration of the coupling effects between each pair of parameters. The applicability of the cable elastic modulus conversion method under various combinations of these parameters was then verified. Furthermore， the basic applicable conditions of the conversion method were defined by comparing cable stresses in the completed state of a specific cable-stayed bridge. The results showed that the stress concentration factors increased with the major-to-minor axis length ratio， pit depth， and pit number， and decreased with pit spacing. The elastic modulus conversion method is well applicable to combined scenarios of various corrosion pit parameters and meets the accuracy requirements of engineering calculations. However， it cannot be directly used when the local cable stress surpasses the ultimate strength of the steel wires.
The cable elastic modulus conversion method is a technique that incorporates cable corrosion effects into the analysis of the overall cable-stayed bridge structure by converting the cable elastic modulus. However， its applicability in cases with complex corrosion pits on the cable wire surface is questionable， and scenarios involving significant stress concentration near the pits are not considered. In this paper， through the finite element simulation of corrosion pits on the surface of a cable wire， the relationship between the major-to-minor axis length ratio， depth， number， and spacing of the pits and the stress intensity factor of the wire was fitted binarily with consideration of the coupling effects between each pair of parameters. The applicability of the cable elastic modulus conversion method under various combinations of these parameters was then verified. Furthermore， the basic applicable conditions of the conversion method were defined by comparing cable stresses in the completed state of a specific cable-stayed bridge. The results showed that the stress concentration factors increased with the major-to-minor axis length ratio， pit depth， and pit number， and decreased with pit spacing. The elastic modulus conversion method is well applicable to combined scenarios of various corrosion pit parameters and meets the accuracy requirements of engineering calculations. However， it cannot be directly used when the local cable stress surpasses the ultimate strength of the steel wires.
Calibration of Elastoplastic Constitutive Parameters for HRB400 Steel Based on Tension-Torsion Tests
2026, 41(3): 44-49.
doi: 10.13206/j.gjgS25080102
Abstract:
To obtain the elastoplastic constitutive parameters of HRB400 steel under tensile and shear stress states， smooth solid round bar and hollow thin-walled circular tube specimens were fabricated， and uniaxial tension and pure torsion tests were conducted respectively. The experimental data were processed using data processing software， where the nominal stress-strain curves in the uniform deformation stage were converted to true stress-equivalent plastic strain curves. Subsequently， the true stress-plastic strain curves after plastic instability were calibrated using the piecewise linear hardening method. A finite element model was established to simulate the experimental process. By repeatedly comparing the load-displacement curves obtained from simulations and experiments， as well as the deformation behaviors of the specimens， the calibrated curves were iteratively corrected to ensure the accuracy of the constitutive parameters. The results showed that when the calibrated hardening curves under tensile and shear states were applied in numerical simulations， the simulation results were in good agreement with the experimental curves and the deformation behaviors of the specimens. Comparative analysis revealed that there were differences in the hardening curves of HRB400 steel under tensile and shear stress states， specifically manifested as a stronger hardening effect under tensile stress than under shear stress. When the elastoplastic parameters obtained from tensile tests were used to simulate torsion tests， the simulated torque values were higher than the measured values， which further confirmed that the hardening of HRB400 steel exhibited directionality. The findings indicate that in practical engineering applications， a more conservative strength value should be adopted for HRB400 steel under shear stress states to ensure structural safety.
To obtain the elastoplastic constitutive parameters of HRB400 steel under tensile and shear stress states， smooth solid round bar and hollow thin-walled circular tube specimens were fabricated， and uniaxial tension and pure torsion tests were conducted respectively. The experimental data were processed using data processing software， where the nominal stress-strain curves in the uniform deformation stage were converted to true stress-equivalent plastic strain curves. Subsequently， the true stress-plastic strain curves after plastic instability were calibrated using the piecewise linear hardening method. A finite element model was established to simulate the experimental process. By repeatedly comparing the load-displacement curves obtained from simulations and experiments， as well as the deformation behaviors of the specimens， the calibrated curves were iteratively corrected to ensure the accuracy of the constitutive parameters. The results showed that when the calibrated hardening curves under tensile and shear states were applied in numerical simulations， the simulation results were in good agreement with the experimental curves and the deformation behaviors of the specimens. Comparative analysis revealed that there were differences in the hardening curves of HRB400 steel under tensile and shear stress states， specifically manifested as a stronger hardening effect under tensile stress than under shear stress. When the elastoplastic parameters obtained from tensile tests were used to simulate torsion tests， the simulated torque values were higher than the measured values， which further confirmed that the hardening of HRB400 steel exhibited directionality. The findings indicate that in practical engineering applications， a more conservative strength value should be adopted for HRB400 steel under shear stress states to ensure structural safety.
2026, 41(3): 50-57.
doi: 10.13206/j.gjgS25060401
Abstract:
This paper conducts an in-depth study on the structural system selection for an irregular super high-rise building located in the Xuhui Waterfront Business District， Shanghai. The office tower features an irregular configuration characterized by a “bottom-tapered， top-enlarged” form， incorporating numerous discontinuous vertical members， bi-directional long-span structures， and multi-region cantilevers， presenting significant structural challenges. Leveraging the architectural plan characteristics， this study innovatively proposes a multi-stage load-transfer mechanism in plan layout. This system centers around a steel-braced core tube as the primary load-bearing element and integrates a “hybrid truss” system. It effectively utilizes the vierendeel truss action inherent in the steel frame to establish the primary structural skeleton. The conflict between MEP （Mechanical， Electrical， and Plumbing） service penetration and floor-to-ceiling height control is resolved through the implementation of “large-opening steel beams”. Furthermore， the application of Tuned Mass Damper （TMD） vibration control technology results in a 76% reduction in the peak vertical vibration acceleration within critical areas.
This paper conducts an in-depth study on the structural system selection for an irregular super high-rise building located in the Xuhui Waterfront Business District， Shanghai. The office tower features an irregular configuration characterized by a “bottom-tapered， top-enlarged” form， incorporating numerous discontinuous vertical members， bi-directional long-span structures， and multi-region cantilevers， presenting significant structural challenges. Leveraging the architectural plan characteristics， this study innovatively proposes a multi-stage load-transfer mechanism in plan layout. This system centers around a steel-braced core tube as the primary load-bearing element and integrates a “hybrid truss” system. It effectively utilizes the vierendeel truss action inherent in the steel frame to establish the primary structural skeleton. The conflict between MEP （Mechanical， Electrical， and Plumbing） service penetration and floor-to-ceiling height control is resolved through the implementation of “large-opening steel beams”. Furthermore， the application of Tuned Mass Damper （TMD） vibration control technology results in a 76% reduction in the peak vertical vibration acceleration within critical areas.
2026, 41(3): 58-64.
doi: 10.13206/j.gjgS24082201
Abstract:
As a load-bearing component， the lower flange plate and web plate serve as supporting structures for the vehicle’s running wheels and guide wheels. Since the track beam is a slender hollow channel structure with low rigidity and high requirements for production accuracy， deformation control is critical to the successful fabrication of track beams. Based on the first phase of the Optics Valley Tourism Line project， a systematic study was conducted on the factors affecting deformation during the suspended monorail track beam production process. In addition to determining appropriate welding parameters through welding test evaluations， welding methods that generate high heat input should be avoided during the welding design phase to minimize welding deformation. For key units where deformation must be strictly controlled， three production schemes were applied to the lower cover plate： separate cutting of the left and right panels， full-size cutting of the lower cover plate， and overall cutting with reserved cutting points. The deformation， assembly workload， and correction work of each process were measured to determine the optimal production process for the lower cover plate unit. Two welding schemes， namely tire frame welding and full-position welding within the tire frame， were developed and tested during the assembly and welding of track beam segments. The outer contour， box opening dimensions， linear accuracy， and rework workload were measured after removal from the tire frame to determine the optimal assembly and welding scheme. Additionally， based on research and analysis of thermal correction techniques applied to trial-produced components， the appropriate correction methods and positions for the track beam structure were identified. Practice has shown that welding materials， parameters， and methods determined through welding process experiments can reduce welding deformation. For the lower cover plate unit， the "overall cutting with reserved cutting points" scheme demonstrated effective control over both cutting and welding deformation. The full-position welding scheme also proved effective in reducing welding deformation and minimizing correction work after removal from the tire frame. Based on correction studies of trial components， applicable thermal correction procedures and three specific thermal correction positions for the track beam structure were proposed.
As a load-bearing component， the lower flange plate and web plate serve as supporting structures for the vehicle’s running wheels and guide wheels. Since the track beam is a slender hollow channel structure with low rigidity and high requirements for production accuracy， deformation control is critical to the successful fabrication of track beams. Based on the first phase of the Optics Valley Tourism Line project， a systematic study was conducted on the factors affecting deformation during the suspended monorail track beam production process. In addition to determining appropriate welding parameters through welding test evaluations， welding methods that generate high heat input should be avoided during the welding design phase to minimize welding deformation. For key units where deformation must be strictly controlled， three production schemes were applied to the lower cover plate： separate cutting of the left and right panels， full-size cutting of the lower cover plate， and overall cutting with reserved cutting points. The deformation， assembly workload， and correction work of each process were measured to determine the optimal production process for the lower cover plate unit. Two welding schemes， namely tire frame welding and full-position welding within the tire frame， were developed and tested during the assembly and welding of track beam segments. The outer contour， box opening dimensions， linear accuracy， and rework workload were measured after removal from the tire frame to determine the optimal assembly and welding scheme. Additionally， based on research and analysis of thermal correction techniques applied to trial-produced components， the appropriate correction methods and positions for the track beam structure were identified. Practice has shown that welding materials， parameters， and methods determined through welding process experiments can reduce welding deformation. For the lower cover plate unit， the "overall cutting with reserved cutting points" scheme demonstrated effective control over both cutting and welding deformation. The full-position welding scheme also proved effective in reducing welding deformation and minimizing correction work after removal from the tire frame. Based on correction studies of trial components， applicable thermal correction procedures and three specific thermal correction positions for the track beam structure were proposed.
2026, 41(3): 65-68.
doi: 10.13206/j.gjgS24082635
Abstract:
A second-order analysis was conducted for steel beams with initial deflection and twist. Assuming the initial deformations conform to the buckling mode shape， the second-order bending moment and bi-moment were derived. Subsequently， an expression for the stability coefficient of flexural-torsional buckling in steel beams was derived by applying the edge fiber yield criterion. This expression is identical in form to the Perry-Robertson formula used for compression member buckling， thereby providing a theoretical basis for unifying the stability coefficient expressions for compression members and steel beams. Although the expressions share an identical form， the imperfection factors for steel beams equal those for compression members multiplied by the square of a specific ratio. This ratio is defined as the normalized slenderness for lateral-torsional buckling of the steel beam divided by that for flexural buckling of the compression member about its weak axis. Given that this ratio is less than 1.0， the imperfection factor for beams is smaller. Consequently， at the same normalized slenderness， the stability coefficient for steel beams is higher than that for compression members. For uniformly loaded beams and beams under a mid-span concentrated force， similar derivations were carried out， incorporating the effect of load height. The results confirmed identical formulaic forms， with only minor differences in the definition of the imperfection factors. This consistency demonstrates the general applicability of the derivation.
A second-order analysis was conducted for steel beams with initial deflection and twist. Assuming the initial deformations conform to the buckling mode shape， the second-order bending moment and bi-moment were derived. Subsequently， an expression for the stability coefficient of flexural-torsional buckling in steel beams was derived by applying the edge fiber yield criterion. This expression is identical in form to the Perry-Robertson formula used for compression member buckling， thereby providing a theoretical basis for unifying the stability coefficient expressions for compression members and steel beams. Although the expressions share an identical form， the imperfection factors for steel beams equal those for compression members multiplied by the square of a specific ratio. This ratio is defined as the normalized slenderness for lateral-torsional buckling of the steel beam divided by that for flexural buckling of the compression member about its weak axis. Given that this ratio is less than 1.0， the imperfection factor for beams is smaller. Consequently， at the same normalized slenderness， the stability coefficient for steel beams is higher than that for compression members. For uniformly loaded beams and beams under a mid-span concentrated force， similar derivations were carried out， incorporating the effect of load height. The results confirmed identical formulaic forms， with only minor differences in the definition of the imperfection factors. This consistency demonstrates the general applicability of the derivation.
