Login
Register
Steel Construction Published the List of Highly Influential Articles of 2020
2025 Vol. 40, No. 5
Display Method:
2025, 40(5): 1-17.
doi: 10.13206/j.gjgSS23080601
Abstract
PDF (2716KB)
Abstract:
With the continuous advancement of modern social economy， industry， culture， transportation， and sports， the functions of buildings have become increasingly diverse. Consequently， there is a growing demand for expansive internal spaces in contemporary architecture， particularly in terms of floor spans. However， there is currently a lack of systematic review and summary regarding long-span floor structures. This has led to confusion in selecting suitable structure during practical engineering design processes and has caused inconvenience to such designs. Therefore， it is crucial to summarize the appropriate structural forms for long-span floors and compile existing research status to provide valuable references for engineering practices. Thus， this paper systematically summarized the research and application status of long-span floors by categorizing them into six types： prestressed concrete floors， steel-concrete composite floors，steel grid composite floors，hollow floors，string-supported floors and prefabricated floors. The research status of these six types was further summarized based on their structural concepts and forms， static and dynamic performance evaluations， construction process analysis as well as human-induced vibration laws and control measures. Additionally， representative projects pertaining to each type were elaborately introduced.Finally，this paper discussesd the main challenges faced by long-span floor structure systems along with their development directions.These included limited options for floor structures suitable for spans exceeding 30 meters， insufficient experimental data on long-span floor structures as well as complex human-induced vibration control technologies applicable to such structures.This paper provides a comprehensive summary of existing forms of long-span floor structures while also presenting their research status and engineering applications in detail， which has a certain value in engineering applications.
With the continuous advancement of modern social economy， industry， culture， transportation， and sports， the functions of buildings have become increasingly diverse. Consequently， there is a growing demand for expansive internal spaces in contemporary architecture， particularly in terms of floor spans. However， there is currently a lack of systematic review and summary regarding long-span floor structures. This has led to confusion in selecting suitable structure during practical engineering design processes and has caused inconvenience to such designs. Therefore， it is crucial to summarize the appropriate structural forms for long-span floors and compile existing research status to provide valuable references for engineering practices. Thus， this paper systematically summarized the research and application status of long-span floors by categorizing them into six types： prestressed concrete floors， steel-concrete composite floors，steel grid composite floors，hollow floors，string-supported floors and prefabricated floors. The research status of these six types was further summarized based on their structural concepts and forms， static and dynamic performance evaluations， construction process analysis as well as human-induced vibration laws and control measures. Additionally， representative projects pertaining to each type were elaborately introduced.Finally，this paper discussesd the main challenges faced by long-span floor structure systems along with their development directions.These included limited options for floor structures suitable for spans exceeding 30 meters， insufficient experimental data on long-span floor structures as well as complex human-induced vibration control technologies applicable to such structures.This paper provides a comprehensive summary of existing forms of long-span floor structures while also presenting their research status and engineering applications in detail， which has a certain value in engineering applications.
2025, 40(5): 18-26.
doi: 10.13206/j.gjgSS24031901
Abstract:
V-notched round bar specimens with five different notch angles were fabricated and tested for Q355D steel and its welds. Ductile fracture occurred in monotonic tensile tests on all these specimens. The fracture displacements of the specimens increased with the V-notch angle. The welded specimens exhibited slightly smaller fracture displacements than their corresponding base metal counterparts. Observations of the fracture surfaces showed that ductile fracture initiated at the notch tip for specimens V60， V75 and V90， while at the notch section center for specimens V105 and V120. Monotonic tensile tests on V-notched round bar specimens were simulated using the finite element method. The load-displacement curves obtained by numerical simulations agreed well with test results. The void expansion models were calibrated for the Q355D steel and its welds based on the tests and numerical simulations. The parameters in the void expansion model for the base metal and its welds were almost identical， indicating that the welds exhibited comparable superior ductility to the base metal. The fracture locations predicted by the void expansion model were consistent with the test observations for all V-notched round bar specimens. The predicted fracture displacements for all V-notched specimens differed from test results by less than 15%， validating the rationality of the calibrated void expansion model. This also confirmed the applicability of the void expansion model for the analysis of ductile fracture of V-notched round bar specimens initiating at different locations.
V-notched round bar specimens with five different notch angles were fabricated and tested for Q355D steel and its welds. Ductile fracture occurred in monotonic tensile tests on all these specimens. The fracture displacements of the specimens increased with the V-notch angle. The welded specimens exhibited slightly smaller fracture displacements than their corresponding base metal counterparts. Observations of the fracture surfaces showed that ductile fracture initiated at the notch tip for specimens V60， V75 and V90， while at the notch section center for specimens V105 and V120. Monotonic tensile tests on V-notched round bar specimens were simulated using the finite element method. The load-displacement curves obtained by numerical simulations agreed well with test results. The void expansion models were calibrated for the Q355D steel and its welds based on the tests and numerical simulations. The parameters in the void expansion model for the base metal and its welds were almost identical， indicating that the welds exhibited comparable superior ductility to the base metal. The fracture locations predicted by the void expansion model were consistent with the test observations for all V-notched round bar specimens. The predicted fracture displacements for all V-notched specimens differed from test results by less than 15%， validating the rationality of the calibrated void expansion model. This also confirmed the applicability of the void expansion model for the analysis of ductile fracture of V-notched round bar specimens initiating at different locations.
2025, 40(5): 27-32.
doi: 10.13206/j.gjgS24030103
Abstract:
The frame structural system consists of a supporting system formed by columns and beams. Its assembly follows a "piece-by-piece to whole" lifting process. The installation accuracy of the steel frame structure’s columns and beams is closely related to both the stiffness of its own support structure system and the lifting scheme. This paper， in combination with an actual steel frame structure project， conducted lifting construction error monitoring and observed that the deviation direction was mainly in the axial connection direction of the columns and beams， indicating a cumulative error. Different benchmark support units and bolt tightening degrees were set as working conditions， and the stiffness of the structural system was calculated based on the finite element software ABAQUS. The results showed that the welding at the steel column base had little effect on the stiffness of the structural system， while the number of column-beam assemblies and the tightness of their bolted connections significantly influence the stiffness of the structural system. The benchmark support units promoted the transformation of the steel frame structure’s column-beam system from a frame structureal system with lateral displacement into one without lateral displacement， which fully exerted the benchmark control effect and benchmarking effect of the benchmark support units， eliminated error accumulation during the lifting of the steel frame structure’s columns and beams， and guaranted its lifting accuracy.
The frame structural system consists of a supporting system formed by columns and beams. Its assembly follows a "piece-by-piece to whole" lifting process. The installation accuracy of the steel frame structure’s columns and beams is closely related to both the stiffness of its own support structure system and the lifting scheme. This paper， in combination with an actual steel frame structure project， conducted lifting construction error monitoring and observed that the deviation direction was mainly in the axial connection direction of the columns and beams， indicating a cumulative error. Different benchmark support units and bolt tightening degrees were set as working conditions， and the stiffness of the structural system was calculated based on the finite element software ABAQUS. The results showed that the welding at the steel column base had little effect on the stiffness of the structural system， while the number of column-beam assemblies and the tightness of their bolted connections significantly influence the stiffness of the structural system. The benchmark support units promoted the transformation of the steel frame structure’s column-beam system from a frame structureal system with lateral displacement into one without lateral displacement， which fully exerted the benchmark control effect and benchmarking effect of the benchmark support units， eliminated error accumulation during the lifting of the steel frame structure’s columns and beams， and guaranted its lifting accuracy.
2025, 40(5): 33-44.
doi: 10.13206/j.gjgS24080602
Abstract:
Modular integrated construction（MIC） is an innovative prefabricated building， but current modular structural systems fail to satisfy the requirements of high-rise buildings with large storey height and long span. To improve the applicable height and the building performance， a new structure based on a sparse-component frame （SCF） filled with two stories of modules is proposed， however， traditional design methods will be adverse to steel reduction and cost efficiency. Therefore， the lateral performance of the global structure filled by modules remains to be investigated， and the module stiffness contribution can be obtained to improve the design economy for the new MIC.In this paper， a numerical analysis on two-storey stacked modules， SCF， and the frame-module structure combing the modules and SCF was conducted using nonlinear FE software（ABAQUS）， the numerical results were compared to differentiate the intrinsic stiffness of stacked modules from their real stiffness contribution to the frame-module structure. Moreover， the effects of the member section sizes of modules and frames， the module-to-frame connection（M2FC） stiffness， and the row number of modules were studied；to illustrate the specific influencing factors， the lateral stiffness augmented factor α， module stiffness correction factor βM， M2FC-related correction factor βRF， and the space-frame-related correction factor βSP were all proposed.The results indicated that the contribution of modules to the overall lateral resistance was non-negligible（i.e.， α>0）. However， the real lateral stiffness contribution of stacked modules was slightly lower than the intrinsic values when the M2FC was designed with bolted connections， where the factor βM averaged 0.937 for the structure filled with one single row of modules； when the M2FC turned to welded type， the module stiffness contribution increased， with the factor βRF ranging from 1.340 to 1.352. Besides， the space frame effect should be considered to reduce the stiffness contribution for modules outside the loading plane of the SCF， with the factor βSP ranging from 0.799 to 0.907.
Modular integrated construction（MIC） is an innovative prefabricated building， but current modular structural systems fail to satisfy the requirements of high-rise buildings with large storey height and long span. To improve the applicable height and the building performance， a new structure based on a sparse-component frame （SCF） filled with two stories of modules is proposed， however， traditional design methods will be adverse to steel reduction and cost efficiency. Therefore， the lateral performance of the global structure filled by modules remains to be investigated， and the module stiffness contribution can be obtained to improve the design economy for the new MIC.In this paper， a numerical analysis on two-storey stacked modules， SCF， and the frame-module structure combing the modules and SCF was conducted using nonlinear FE software（ABAQUS）， the numerical results were compared to differentiate the intrinsic stiffness of stacked modules from their real stiffness contribution to the frame-module structure. Moreover， the effects of the member section sizes of modules and frames， the module-to-frame connection（M2FC） stiffness， and the row number of modules were studied；to illustrate the specific influencing factors， the lateral stiffness augmented factor α， module stiffness correction factor βM， M2FC-related correction factor βRF， and the space-frame-related correction factor βSP were all proposed.The results indicated that the contribution of modules to the overall lateral resistance was non-negligible（i.e.， α>0）. However， the real lateral stiffness contribution of stacked modules was slightly lower than the intrinsic values when the M2FC was designed with bolted connections， where the factor βM averaged 0.937 for the structure filled with one single row of modules； when the M2FC turned to welded type， the module stiffness contribution increased， with the factor βRF ranging from 1.340 to 1.352. Besides， the space frame effect should be considered to reduce the stiffness contribution for modules outside the loading plane of the SCF， with the factor βSP ranging from 0.799 to 0.907.
2025, 40(5): 45-50.
doi: 10.13206/j.gjgS24011002
Abstract:
The traditional reinforcement method for long-span steel box girders has disadvantages， such as poor recovery of initial deflection deformation and insufficient bearing capacity. In order to solve these problems， a construction method for strengthening existing long-span steel box girders using the string beam stress system is proposed in this paper. Specifically， the method involves arranging the vertical supports reasonably beneath the steel box girder according to a certain distance， and connecting them to the steel box girder using prestressed cables， thereby forming a string beam stress system. The working principle of the reinforcement system is to generate a negative bending moment on the steel box girder through the pre-tension of the cable， so as to realize the structural deflection deformation recovery and the bearing capacity improvement. This self-balancing feature ensures that the steel box girder does not produce horizontal forces during the reinforcement process. It minimizes little impact on the original support， eliminates the require for special adjustments， and improves the convenience and safety of construction. Using MIDAS Gen， an analysis model of the strengthened structure with a string beam was established. The construction steps were set reasonably， so that the strengthening effect of the string beam began to appear after the steel box beam had produced a certain deflection. The inverse iteration method was used to determine the shape of the string beam structure and optimize the cable pretension. The structural stresses and deflections of steel box girders under different working conditions were calculated， and the changes of structural bearing capacity as well as reinforcement effects were analyzed. In addition， the calculation models of beam elements and shell elements were respectively employed in the finite element simulation analysis process， and a comparative analysis was conducted on the differences in bearing capacity and deformation between the two models for the string beam-reinforced structure. The simulation results showed a linear relation between cable pretension and structure deflection. When the cable pretension was 4000 kN， the deflection of the structure under the set working condition was 0 mm； under the full load condition， the deflection of the beam-reinforced structure system was 63.39 mm， and the maximum stress was 227.9 MPa， both of which met the specification requirements of GB 50017—2017. Compared with the beam element model， the deflection calculation results of the shell element model were smaller， and the stress calculation results were larger. The main reason was that the shell element model provided a more comprehensive consideration of the overall stiffness of the structure， and the mesh refinement accurately reflected the local stress situation in the structure. After conducting structural finite element analysis， the section design， optimization， and local stability analysis of structural members were further analyzed to ensure the safety and economy of the structure. The comprehensive research results showed that reinforcing the existing long-span steel box girders using the string beam stress system could effectively restore the initial deformation of the structure， improve its bearing capacity， and ensure construction safety and convenience.
The traditional reinforcement method for long-span steel box girders has disadvantages， such as poor recovery of initial deflection deformation and insufficient bearing capacity. In order to solve these problems， a construction method for strengthening existing long-span steel box girders using the string beam stress system is proposed in this paper. Specifically， the method involves arranging the vertical supports reasonably beneath the steel box girder according to a certain distance， and connecting them to the steel box girder using prestressed cables， thereby forming a string beam stress system. The working principle of the reinforcement system is to generate a negative bending moment on the steel box girder through the pre-tension of the cable， so as to realize the structural deflection deformation recovery and the bearing capacity improvement. This self-balancing feature ensures that the steel box girder does not produce horizontal forces during the reinforcement process. It minimizes little impact on the original support， eliminates the require for special adjustments， and improves the convenience and safety of construction. Using MIDAS Gen， an analysis model of the strengthened structure with a string beam was established. The construction steps were set reasonably， so that the strengthening effect of the string beam began to appear after the steel box beam had produced a certain deflection. The inverse iteration method was used to determine the shape of the string beam structure and optimize the cable pretension. The structural stresses and deflections of steel box girders under different working conditions were calculated， and the changes of structural bearing capacity as well as reinforcement effects were analyzed. In addition， the calculation models of beam elements and shell elements were respectively employed in the finite element simulation analysis process， and a comparative analysis was conducted on the differences in bearing capacity and deformation between the two models for the string beam-reinforced structure. The simulation results showed a linear relation between cable pretension and structure deflection. When the cable pretension was 4000 kN， the deflection of the structure under the set working condition was 0 mm； under the full load condition， the deflection of the beam-reinforced structure system was 63.39 mm， and the maximum stress was 227.9 MPa， both of which met the specification requirements of GB 50017—2017. Compared with the beam element model， the deflection calculation results of the shell element model were smaller， and the stress calculation results were larger. The main reason was that the shell element model provided a more comprehensive consideration of the overall stiffness of the structure， and the mesh refinement accurately reflected the local stress situation in the structure. After conducting structural finite element analysis， the section design， optimization， and local stability analysis of structural members were further analyzed to ensure the safety and economy of the structure. The comprehensive research results showed that reinforcing the existing long-span steel box girders using the string beam stress system could effectively restore the initial deformation of the structure， improve its bearing capacity， and ensure construction safety and convenience.
2025, 40(5): 51-62.
doi: 10.13206/j.gjgS24073001
Abstract:
To meet the functional requirements of steel structure modular buildings and improve the construction assembly ratio， a connection joint between modules of special-shaped steel tubular columns is proposed. This joint adopts a through-bolt assembly connection， with L-shaped special-shaped steel tubular columns used as the columns， and the designed column section has the same thickness as the wall， which avoids exposure of the column corners and meets the functional requirements of the building. The ABAQUS finite element software was used to establish a refined finite element model with varying joint parameters， and to perform monotonic and low-cycle cyclic loading on it. A comparative analysis was conducted on the bearing capacity and seismic performance indicators such as joint failure modes， hysteresis curves， skeleton curves， stress paths， and energy dissipation capabilities. The research results showed that the failure mode of the connection joint between the special-shaped steel tubular column modules was dominated by bending failure of the beam， which conformed to the design concept of "strong columns and weak beams." The hysteresis curve presented a full shuttle shape， with the ultimate inter-story rotation angle and ductility coefficient exceeding 0.03 rad and 5.0， respectively， meeting the seismic design requirements for the joint. Reinforcing the angle steel in the panel zone effectively improved the stress state near the bolt holes in the column wall. Increasing the thickness of the vertical cross-shaped connection keys enhanced the energy dissipation capacity of the joint. Based on the force transmission mechanism and deformation mechanism of the joint， the superposition method was used to calculate the shear deformation in the core area of the joint. A theoretical formula for the initial rotational stiffness was derived and verified with finite element numerical simulation results. The research results indicated that the theoretical calculation formula for the initial rotational stiffness achieved good consistency with the finite element calculation results.
To meet the functional requirements of steel structure modular buildings and improve the construction assembly ratio， a connection joint between modules of special-shaped steel tubular columns is proposed. This joint adopts a through-bolt assembly connection， with L-shaped special-shaped steel tubular columns used as the columns， and the designed column section has the same thickness as the wall， which avoids exposure of the column corners and meets the functional requirements of the building. The ABAQUS finite element software was used to establish a refined finite element model with varying joint parameters， and to perform monotonic and low-cycle cyclic loading on it. A comparative analysis was conducted on the bearing capacity and seismic performance indicators such as joint failure modes， hysteresis curves， skeleton curves， stress paths， and energy dissipation capabilities. The research results showed that the failure mode of the connection joint between the special-shaped steel tubular column modules was dominated by bending failure of the beam， which conformed to the design concept of "strong columns and weak beams." The hysteresis curve presented a full shuttle shape， with the ultimate inter-story rotation angle and ductility coefficient exceeding 0.03 rad and 5.0， respectively， meeting the seismic design requirements for the joint. Reinforcing the angle steel in the panel zone effectively improved the stress state near the bolt holes in the column wall. Increasing the thickness of the vertical cross-shaped connection keys enhanced the energy dissipation capacity of the joint. Based on the force transmission mechanism and deformation mechanism of the joint， the superposition method was used to calculate the shear deformation in the core area of the joint. A theoretical formula for the initial rotational stiffness was derived and verified with finite element numerical simulation results. The research results indicated that the theoretical calculation formula for the initial rotational stiffness achieved good consistency with the finite element calculation results.
2025, 40(5): 63-66.
doi: 10.13206/j.gjgS24070825
Abstract:
The theoretical analysis method was introduced by examining the design requirements for steel plate walls or multi-cellular composite walls. Analytical theory was presented to determine the buckling factors. Based on the calculated results， the concept of threshold stiffness for edge stiffeners was identified， at which the plate buckled as a four-side supported plate. The threshold stiffness was calculated， and approximate equations were proposed. For steel plate walls and stiffeners in the elastic-plastic phase， the design approach for frames with leaning columns was introduced， where the three-side supported steel plate wall was treated as a leaning column and the edge stiffeners as the framed column， requiring the effective length of the stiffeners to be amplified to account for their bracing effect on the steel plate. A formula for the amplification factor was presented.
The theoretical analysis method was introduced by examining the design requirements for steel plate walls or multi-cellular composite walls. Analytical theory was presented to determine the buckling factors. Based on the calculated results， the concept of threshold stiffness for edge stiffeners was identified， at which the plate buckled as a four-side supported plate. The threshold stiffness was calculated， and approximate equations were proposed. For steel plate walls and stiffeners in the elastic-plastic phase， the design approach for frames with leaning columns was introduced， where the three-side supported steel plate wall was treated as a leaning column and the edge stiffeners as the framed column， requiring the effective length of the stiffeners to be amplified to account for their bracing effect on the steel plate. A formula for the amplification factor was presented.
