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Steel Construction Published the List of Highly Influential Articles of 2020
2025 Vol. 40, No. 11
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2025, 40(11): 1-7.
doi: 10.13206/j.gjgS25101701
Abstract
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Abstract:
This paper investigates the effect of different tempering temperatures on the microstructure and properties of Q550qENH weathering bridge steel using optical microscopy， scanning electron microscopy， tensile testing， and impact testing. The corrosion behavior of the experimental steel in a simulated industrial atmosphere was also studied through cyclic immersion corrosion tests.The results showed that the microstructure of the experimental steel primarily consisted of granular bainite， polygonal ferrite， and a minor amount of acicular ferrite. As the tempering temperature increased， the strength of the experimental steel initially increased and then decreased. Specifically， the yield strength and tensile strength of the steel tempered at 500 ℃ were 690 MPa and 772 MPa， respectively， with an elongation of 21%. The tempering treatment promoted the decomposition of the M/A island structure in the matrix， resulting in an increased proportion of high-angle grain boundaries. This contributed to the excellent low-temperature impact toughness of the experimental steel， with impact energies of 291 J， 276 J， and 237 J at temperatures of -40 ℃， -60 ℃， and -80 ℃， respectively. Furthermore， cross-sectional analysis of the rust layer revealed the enrichment of Cr and Ni elements， and α-FeOOH was identified as the primary component， indicating excellent corrosion resistance.
This paper investigates the effect of different tempering temperatures on the microstructure and properties of Q550qENH weathering bridge steel using optical microscopy， scanning electron microscopy， tensile testing， and impact testing. The corrosion behavior of the experimental steel in a simulated industrial atmosphere was also studied through cyclic immersion corrosion tests.The results showed that the microstructure of the experimental steel primarily consisted of granular bainite， polygonal ferrite， and a minor amount of acicular ferrite. As the tempering temperature increased， the strength of the experimental steel initially increased and then decreased. Specifically， the yield strength and tensile strength of the steel tempered at 500 ℃ were 690 MPa and 772 MPa， respectively， with an elongation of 21%. The tempering treatment promoted the decomposition of the M/A island structure in the matrix， resulting in an increased proportion of high-angle grain boundaries. This contributed to the excellent low-temperature impact toughness of the experimental steel， with impact energies of 291 J， 276 J， and 237 J at temperatures of -40 ℃， -60 ℃， and -80 ℃， respectively. Furthermore， cross-sectional analysis of the rust layer revealed the enrichment of Cr and Ni elements， and α-FeOOH was identified as the primary component， indicating excellent corrosion resistance.
2025, 40(11): 8-12.
doi: 10.13206/j.gjgS25070301
Abstract:
Stainless steel clad plates for weathering bridges were developed using thermo-mechanical control processing（TMCP） along with relaxation and tempering processes. The effects of three different water cooling processes on the microstructure and properties of clad plates were studied. The results showed that the microstructure of the carbon steel substrate consisted of granular bainite， quasi-polygonal ferrite， and pearlite under all tested water cooling conditions. As the water entry temperature decreased， the decarburized layer at the carbon steel substrate at the clad interface became wider， and the volume fraction of proeutectoid ferrite in the substrate increased， resulting in a decrease in strength， especially a reduction in yield strength from 572 MPa to 527 MPa， and then a reduction in yield ratio from 0.87 to 0.83. At a constant water entry temperature， a lower self-tempering temperature promoted a more complete bainitic transformation. This increased the tensile strength from 658 MPa to 710 MPa， while the yield strength remained largely unchanged， thereby reducing the yield ratio and meeting the performance requirements for the 316L+Q500qENH composite system.
Stainless steel clad plates for weathering bridges were developed using thermo-mechanical control processing（TMCP） along with relaxation and tempering processes. The effects of three different water cooling processes on the microstructure and properties of clad plates were studied. The results showed that the microstructure of the carbon steel substrate consisted of granular bainite， quasi-polygonal ferrite， and pearlite under all tested water cooling conditions. As the water entry temperature decreased， the decarburized layer at the carbon steel substrate at the clad interface became wider， and the volume fraction of proeutectoid ferrite in the substrate increased， resulting in a decrease in strength， especially a reduction in yield strength from 572 MPa to 527 MPa， and then a reduction in yield ratio from 0.87 to 0.83. At a constant water entry temperature， a lower self-tempering temperature promoted a more complete bainitic transformation. This increased the tensile strength from 658 MPa to 710 MPa， while the yield strength remained largely unchanged， thereby reducing the yield ratio and meeting the performance requirements for the 316L+Q500qENH composite system.
2025, 40(11): 13-21.
doi: 10.13206/j.gjgS24022601
Abstract:
Through a two-stage field test involving ash storage and discharge in a coal-fired power plant's ash hopper， the test data and phenomena including stress in the hopper's stiffeners and wall， as well as wall displacement， were analyzed. Field measurements were compared with finite element simulations. Subsequently， the stress state of the ash hopper under both the test load and the full ash load conditions was analyzed using numerical simulations and Design Code of Steel Structures for ESP （JB/T 12127-2015） calculations. The calculation method for the stiffeners was also discussed. The results showed that the maximum dynamic stress at the test point was 147 MPa， and the test load was only 37% of the full ash load. During stable operation of the dust collector， the temperature of the ash hopper was mainly affected by the ambient environment.The thermal stress generated in the structure under temperature effects was non-negligible and should be considered in engineering design. According to the JB/T 12127-2015， the design method for stiffeners exhibited significant errors and did not align with reality. Calculation based on a closed-frame model was demonstrated to be more rational.
Through a two-stage field test involving ash storage and discharge in a coal-fired power plant's ash hopper， the test data and phenomena including stress in the hopper's stiffeners and wall， as well as wall displacement， were analyzed. Field measurements were compared with finite element simulations. Subsequently， the stress state of the ash hopper under both the test load and the full ash load conditions was analyzed using numerical simulations and Design Code of Steel Structures for ESP （JB/T 12127-2015） calculations. The calculation method for the stiffeners was also discussed. The results showed that the maximum dynamic stress at the test point was 147 MPa， and the test load was only 37% of the full ash load. During stable operation of the dust collector， the temperature of the ash hopper was mainly affected by the ambient environment.The thermal stress generated in the structure under temperature effects was non-negligible and should be considered in engineering design. According to the JB/T 12127-2015， the design method for stiffeners exhibited significant errors and did not align with reality. Calculation based on a closed-frame model was demonstrated to be more rational.
2025, 40(11): 22-31.
doi: 10.13206/j.gjgS24092403
Abstract:
The RSM integrated wall， consisting of a steel frame encased by double-sided thin steel plates and filled with rigid polyurethane foam， represents a novel type of shear wall. However， current literature lacks comprehensive research on the shear performance of RSM integrated walls， especially concerning the impact of self-tapping screw spacing on performance. This paper aims to investigate the influence of self-tapping screw spacing on the shear performance of RSM integrated walls through experimental testing and numerical simulation， providing scientific insights and design guidance for practical engineering applications. To thoroughly examine the shear performance of RSM integrated walls， a finite element model was developed using ABAQUS software. To validate this model， two RSM wall specimens with different self-tapping screw spacings （75 mm and 150 mm） were subjected to monotonic loading and quasi-static loading tests. Experimental data， including load-displacement curves and load-lateral hysteresis curves， were collected to evaluate the walls’ behavior. By comparing finite element simulation results with experimental data， the model’s accuracy was preliminarily validated. Subsequently， this study was extended to include five different self-tapping screw spacings （50 mm， 75 mm， 100 mm， 125 mm， and 150 mm） to explore their influence on the shear performance of RSM walls. Findings from both experiments and simulations showed that reducing the self-tapping screw spacing significantly improved the initial stiffness， shear capacity， and energy dissipation capability of RSM walls. Comparative analysis revealed that smaller screw spacing strengthened the connection between thin metal plates and the steel frame， delaying tearing at self-tapping screws and allowing better performance of the thin metal plates. As the screw spacing decreased， the bearing capacity degradation coefficient increased， and the stiffness degradation curve became more gradual， indicating enhanced ductility. However， when the steel plates were damaged， the frame could not fully bear horizontal loads， leading to a rapid decrease in wall bearing capacity. Additionally， energy dissipation capacity was negatively correlated with screw spacing， while the equivalent viscous damping coefficient increased initially and then decreased as displacement grew， indicating minimal impact from changes in screw spacing. The findings suggest that reduced self-tapping screw spacing enhances the connectivity between thin metal plates and the steel frame， effectively delaying the rupture of the thin metal plates. This significantly improves the shear strength and initial stiffness of the wall. These results establish a theoretical foundation for optimizing the design of RSM integrated walls and hold significant value for engineering applications.
The RSM integrated wall， consisting of a steel frame encased by double-sided thin steel plates and filled with rigid polyurethane foam， represents a novel type of shear wall. However， current literature lacks comprehensive research on the shear performance of RSM integrated walls， especially concerning the impact of self-tapping screw spacing on performance. This paper aims to investigate the influence of self-tapping screw spacing on the shear performance of RSM integrated walls through experimental testing and numerical simulation， providing scientific insights and design guidance for practical engineering applications. To thoroughly examine the shear performance of RSM integrated walls， a finite element model was developed using ABAQUS software. To validate this model， two RSM wall specimens with different self-tapping screw spacings （75 mm and 150 mm） were subjected to monotonic loading and quasi-static loading tests. Experimental data， including load-displacement curves and load-lateral hysteresis curves， were collected to evaluate the walls’ behavior. By comparing finite element simulation results with experimental data， the model’s accuracy was preliminarily validated. Subsequently， this study was extended to include five different self-tapping screw spacings （50 mm， 75 mm， 100 mm， 125 mm， and 150 mm） to explore their influence on the shear performance of RSM walls. Findings from both experiments and simulations showed that reducing the self-tapping screw spacing significantly improved the initial stiffness， shear capacity， and energy dissipation capability of RSM walls. Comparative analysis revealed that smaller screw spacing strengthened the connection between thin metal plates and the steel frame， delaying tearing at self-tapping screws and allowing better performance of the thin metal plates. As the screw spacing decreased， the bearing capacity degradation coefficient increased， and the stiffness degradation curve became more gradual， indicating enhanced ductility. However， when the steel plates were damaged， the frame could not fully bear horizontal loads， leading to a rapid decrease in wall bearing capacity. Additionally， energy dissipation capacity was negatively correlated with screw spacing， while the equivalent viscous damping coefficient increased initially and then decreased as displacement grew， indicating minimal impact from changes in screw spacing. The findings suggest that reduced self-tapping screw spacing enhances the connectivity between thin metal plates and the steel frame， effectively delaying the rupture of the thin metal plates. This significantly improves the shear strength and initial stiffness of the wall. These results establish a theoretical foundation for optimizing the design of RSM integrated walls and hold significant value for engineering applications.
2025, 40(11): 32-39.
doi: 10.13206/j.gjgS24111401
Abstract:
The stiffening ribs of steel plate shear walls （SPSWs） are typically welded， which may result in the ribs bearing vertical frame loads， thereby complicating the stress distribution and affecting the seismic performance of the SPSWs. This study proposes a novel insert-stiffened steel plate shear wall that not only effectively mitigates these issues but also improves the wall's ease of assembly. Using finite element analysis via ABAQUS software， finite element models for five different types of SPSWs， including the insert-stiffened steel plate shear wall， were developed to conduct a comparative analysis of their hysteretic behaviors， bearing capacities， energy dissipation capacities， stiffnesses， and deformation characteristics. The results indicated that， compared to unstiffened steel plate shear walls， both welded-stiffener and insert-stiffened steel plate shear walls exhibited a significant increase in ultimate load， with improvements of 13.93% and 18.91%， respectively， demonstrating superior bearing capacity. Furthermore， due to the friction between contact surfaces， the insert-stiffened steel plate shear wall showed a 54.1% increase in total energy dissipation and a 23.7% improvement in its equivalent viscous damping coefficient， indicating exceptional energy dissipation and seismic performance. Although the stiffness of the insert-stiffened steel plate shear wall decreased significantly during the initial loading phase， its initial stiffness remained the highest among all models， with an 11.6% increase compared to the unstiffened steel plate shear wall. This indicated that the inserted stiffening ribs effectively restricted out-of-plane deformations of the steel plate， contributing to its superior seismic performance. As the density of the stiffening rib combination increased， the performance of the insert-stiffened steel plate shear wall was enhanced； however， when the density became excessively high， the rate of performance enhancement slowed. Thus， it is crucial to balance economic considerations and select an optimal stiffening rib combination density in the design.
The stiffening ribs of steel plate shear walls （SPSWs） are typically welded， which may result in the ribs bearing vertical frame loads， thereby complicating the stress distribution and affecting the seismic performance of the SPSWs. This study proposes a novel insert-stiffened steel plate shear wall that not only effectively mitigates these issues but also improves the wall's ease of assembly. Using finite element analysis via ABAQUS software， finite element models for five different types of SPSWs， including the insert-stiffened steel plate shear wall， were developed to conduct a comparative analysis of their hysteretic behaviors， bearing capacities， energy dissipation capacities， stiffnesses， and deformation characteristics. The results indicated that， compared to unstiffened steel plate shear walls， both welded-stiffener and insert-stiffened steel plate shear walls exhibited a significant increase in ultimate load， with improvements of 13.93% and 18.91%， respectively， demonstrating superior bearing capacity. Furthermore， due to the friction between contact surfaces， the insert-stiffened steel plate shear wall showed a 54.1% increase in total energy dissipation and a 23.7% improvement in its equivalent viscous damping coefficient， indicating exceptional energy dissipation and seismic performance. Although the stiffness of the insert-stiffened steel plate shear wall decreased significantly during the initial loading phase， its initial stiffness remained the highest among all models， with an 11.6% increase compared to the unstiffened steel plate shear wall. This indicated that the inserted stiffening ribs effectively restricted out-of-plane deformations of the steel plate， contributing to its superior seismic performance. As the density of the stiffening rib combination increased， the performance of the insert-stiffened steel plate shear wall was enhanced； however， when the density became excessively high， the rate of performance enhancement slowed. Thus， it is crucial to balance economic considerations and select an optimal stiffening rib combination density in the design.
2025, 40(11): 40-46.
doi: 10.13206/j.gjgS25081801
Abstract:
An experimental study was conducted to evaluate the fire resistance of two full-scale precast-cast-in-place composite square concrete columns featuring a novel connection method under the ISO 834 standard fire curve. The investigation aimed to examine the differences in failure modes， axial deformation， and fire resistance limits when the core cast-in-place concrete strength was C30 （normal-strength concrete） versus C60 （high-strength concrete）. The results demonstrated that the use of high-strength core concrete led to more severe spalling. The precast square tubes provided effective thermal insulation， delaying heat transfer to the core concrete， thereby protecting it and resulting in a smaller loss of bearing capacity. Furthermore， the precast square tubes and the core concrete exhibited synergistic behavior， maintaining excellent structural integrity even at failure. The axial deformations at failure were -25.28 mm for C30 and -19.32 mm for C60， indicating an insignificant difference. However， the fire resistance limits were 121 minutes for C30 and 48 minutes for C60， revealing a significant degradation in fire resistance when high-strength concrete was used in the core. In conclusion， composite columns with normal-strength core concrete possess superior fire resistance compared to those with high-strength core concrete.
An experimental study was conducted to evaluate the fire resistance of two full-scale precast-cast-in-place composite square concrete columns featuring a novel connection method under the ISO 834 standard fire curve. The investigation aimed to examine the differences in failure modes， axial deformation， and fire resistance limits when the core cast-in-place concrete strength was C30 （normal-strength concrete） versus C60 （high-strength concrete）. The results demonstrated that the use of high-strength core concrete led to more severe spalling. The precast square tubes provided effective thermal insulation， delaying heat transfer to the core concrete， thereby protecting it and resulting in a smaller loss of bearing capacity. Furthermore， the precast square tubes and the core concrete exhibited synergistic behavior， maintaining excellent structural integrity even at failure. The axial deformations at failure were -25.28 mm for C30 and -19.32 mm for C60， indicating an insignificant difference. However， the fire resistance limits were 121 minutes for C30 and 48 minutes for C60， revealing a significant degradation in fire resistance when high-strength concrete was used in the core. In conclusion， composite columns with normal-strength core concrete possess superior fire resistance compared to those with high-strength core concrete.
2025, 40(11): 47-54.
doi: 10.13206/j.gjgS22061101
Abstract:
In recent years， with the development of prestressed spatial structures， Galfan-coated steel cables have been widely used in engineering applications due to their excellent corrosion resistance and fire performance. To gain an in-depth understanding of the mechanical behavior of cables under complex loading conditions and the interaction mechanisms among internal steel wires， this study establishes a three-dimensional refined finite element model of a 1×19 Galfan-coated steel cable to simulate and analyze its mechanical response under axial tension and tension-bending coupling. The model defines the constitutive relation of the Galfan-coated steel wires， considers the contact between wires， utilizes rigid body coupling for boundary condition setting， and validates the accuracy of the finite element model by comparing it with experimental data. Analysis of the finite element simulation results reveals that： under axial tension， the influence of the friction coefficient on the contact pressure between wires varies with location； the Poisson effect and mutual misalignment between wires lead to a decrease in contact pressure， and the influence of the friction coefficient subsequently diminishes； the stress development in the wires is significantly affected by the lay angle， with the center wire （having no lay angle） exhibiting the fastest stress growth， while the outer layer wires grow slower due to the circumferential grip-wrapping effect； under tension-bending coupling， the variation trend of contact pressure is noticeably influenced by position， with the area below the center wire showing rapid growth due to greater tensile force， while the area above the center wire first decreases in contact pressure due to compression and then increases as the transverse load becomes dominant； furthermore， the stress distribution during cable bending exhibits significant inhomogeneity， with stress concentration areas being particularly prominent at the fixed ends and transverse load application regions， where alternating tension and compression is evident. The results indicate that the internal stress and contact pressure distribution of the cable under complex loading exhibit complex patterns； during tension， the wire lay angle plays a dominant role in stress development， while the bending effect significantly alters the distribution patterns of contact pressure and stress in the cable wires.
In recent years， with the development of prestressed spatial structures， Galfan-coated steel cables have been widely used in engineering applications due to their excellent corrosion resistance and fire performance. To gain an in-depth understanding of the mechanical behavior of cables under complex loading conditions and the interaction mechanisms among internal steel wires， this study establishes a three-dimensional refined finite element model of a 1×19 Galfan-coated steel cable to simulate and analyze its mechanical response under axial tension and tension-bending coupling. The model defines the constitutive relation of the Galfan-coated steel wires， considers the contact between wires， utilizes rigid body coupling for boundary condition setting， and validates the accuracy of the finite element model by comparing it with experimental data. Analysis of the finite element simulation results reveals that： under axial tension， the influence of the friction coefficient on the contact pressure between wires varies with location； the Poisson effect and mutual misalignment between wires lead to a decrease in contact pressure， and the influence of the friction coefficient subsequently diminishes； the stress development in the wires is significantly affected by the lay angle， with the center wire （having no lay angle） exhibiting the fastest stress growth， while the outer layer wires grow slower due to the circumferential grip-wrapping effect； under tension-bending coupling， the variation trend of contact pressure is noticeably influenced by position， with the area below the center wire showing rapid growth due to greater tensile force， while the area above the center wire first decreases in contact pressure due to compression and then increases as the transverse load becomes dominant； furthermore， the stress distribution during cable bending exhibits significant inhomogeneity， with stress concentration areas being particularly prominent at the fixed ends and transverse load application regions， where alternating tension and compression is evident. The results indicate that the internal stress and contact pressure distribution of the cable under complex loading exhibit complex patterns； during tension， the wire lay angle plays a dominant role in stress development， while the bending effect significantly alters the distribution patterns of contact pressure and stress in the cable wires.
2025, 40(11): 55-59.
doi: 10.13206/j.gjgS24082625
Abstract:
The lateral bearing capacities corresponding to various failure modes of the chevron-braced frame were analyzed. The findings indicate that： 1） Chevron-braced frames exhibit four failure modes： absolute shear-weakened type with vertical shear yielding at the beam-brace intersection； relative shear-weakened type characterized by buckling of the compression brace preceding joint shear failure； flexural-weakened beam type where the tension brace remains elastic； and flexural-strengthened beam type where the tension brace yields. 2） The bending moment induced by the unbalanced force from the braces should be calculated based on simply-supported beam conditions， regardless of whether the beam-column connection is rigid. 3） For shear-weakened configurations， the joint panel zone must satisfy minimum requirements equivalent to those for beam-column connections and should be stiffened according to eccentrically braced frame （EBF） standards； if necessary， introducing openings in the panel zone can enhance deformation capacity. 4） For flexural-weakened beam cases， a minimum required unbalanced force is specified for design.
The lateral bearing capacities corresponding to various failure modes of the chevron-braced frame were analyzed. The findings indicate that： 1） Chevron-braced frames exhibit four failure modes： absolute shear-weakened type with vertical shear yielding at the beam-brace intersection； relative shear-weakened type characterized by buckling of the compression brace preceding joint shear failure； flexural-weakened beam type where the tension brace remains elastic； and flexural-strengthened beam type where the tension brace yields. 2） The bending moment induced by the unbalanced force from the braces should be calculated based on simply-supported beam conditions， regardless of whether the beam-column connection is rigid. 3） For shear-weakened configurations， the joint panel zone must satisfy minimum requirements equivalent to those for beam-column connections and should be stiffened according to eccentrically braced frame （EBF） standards； if necessary， introducing openings in the panel zone can enhance deformation capacity. 4） For flexural-weakened beam cases， a minimum required unbalanced force is specified for design.
