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Steel Construction Published the List of Highly Influential Articles of 2020
2024 Vol. 39, No. 8
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2024, 39(8): 1-10.
doi: 10.13206/j.gjgS23040301
Abstract
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Abstract:
During the period of waiting for repair in a damaged steel structure building, the material properties of the steel are significantly affected by static strain aging, resulting in a change in the overall mechanical properties of the repaired steel structure after restoration. In order to study the effect of strain aging on the mechanical properties of steel beams, three Q355B hot-rolled H-shaped steel beams were designed, and the strain aging effect of damaged steel beams was studied by two-stage loading test method. Based on the test results, the ABAQUS finite element model was established to analyze the mechanical properties of the damaged steel beams after strain aging. An ABAQUS finite element analysis model was established by importing a secondary model and redefining material properties to model the different material properties of the steel before and after strain aging, and subsequently, the finite element model of the damaged steel beam affected by strain aging was established and the parametric analysis was carried out. The results show that the mechanical properties of the damaged steel beam are determined by the residual deformation and the mechanical properties of the steel. When the damage degree of the steel beam is small, the mechanical properties of the steel beam do not change significantly, and the ultimate bearing capacity of the steel beam decreases due to the residual deformation. When the strain of part section reaches 4.5% or above due to the damage and deformation of steel beam, it is no longer suitable for further use after repair.
During the period of waiting for repair in a damaged steel structure building, the material properties of the steel are significantly affected by static strain aging, resulting in a change in the overall mechanical properties of the repaired steel structure after restoration. In order to study the effect of strain aging on the mechanical properties of steel beams, three Q355B hot-rolled H-shaped steel beams were designed, and the strain aging effect of damaged steel beams was studied by two-stage loading test method. Based on the test results, the ABAQUS finite element model was established to analyze the mechanical properties of the damaged steel beams after strain aging. An ABAQUS finite element analysis model was established by importing a secondary model and redefining material properties to model the different material properties of the steel before and after strain aging, and subsequently, the finite element model of the damaged steel beam affected by strain aging was established and the parametric analysis was carried out. The results show that the mechanical properties of the damaged steel beam are determined by the residual deformation and the mechanical properties of the steel. When the damage degree of the steel beam is small, the mechanical properties of the steel beam do not change significantly, and the ultimate bearing capacity of the steel beam decreases due to the residual deformation. When the strain of part section reaches 4.5% or above due to the damage and deformation of steel beam, it is no longer suitable for further use after repair.
2024, 39(8): 11-19.
doi: 10.13206/j.gjgS23053001
Abstract:
In order to investigate the effect of different height to thickness ratio of web and steel grade combinations on the static load carrying performance of steel beams, one same-grade steel beam and three Hybrid steel girders were designed and fabricated respectively, and four-point bending tests were conducted on the specimens to obtain the damage pattern, load-displacement curve, load-strain curve, corresponding load of web and flange yielding and ultimate load of each specimen, and the theoretical calculated values were compared with the experimental values. Buckling analysis was then performed by ABAQUS, and the calculated results were compared with the experimental results to verify the reasonableness of the finite element model. After that, parametric analysis was carried out to further investigate the effect of height to thickness ratio of web and steel grade combinations on the static load carrying performance of steel beams, and to analyze the economics of changing web height, web thickness and web strength with the variation of steel consumption. Finally, the flange yielding moment, plastic limit bending moment and critical moment of bending and torsional buckling obtained from the parametric analysis are compared with the results of the corresponding theoretical equations to provide some suggestions for the design of hybrid steel girders. The results show:1) The yield load of specimen M-1 flange is 8.7% larger than that of specimen S-1 flange, which indicates that the design capacity of Hybrid steel girders is slightly better than that of the same steel girders under the condition that the ratio of height to thickness ratio of web is the same as that of calculated value of the specification GB 50017—2017 Steel Structure Design Standard. Therefore, in the actual structure, when the web height to thickness ratio of web is large, the flange can use higher strength grade steel, while the web can use lower strength steel, forming Hybrid steel girders instead of the same steel girders, which can appropriately improve the static bearing capacity of steel girders and save the amount of steel at the same time; 2) When the height of the cross-section is increased, the yielding load of web of specimen is improved, and the yielding load of web of specimen M-3 is 12.7% higher than that of M-1, the effect of initial defects on the load carrying capacity of steel beams is mainly reflected in the late loading stage, because the web height to thickness ratio of web increases, the degree of its initial defects will increase, and at the same time, the load carrying capacity will be improved. Therefore, compared with specimen M-1, specimens M-2 and M-3 flank yielding corresponding to the load is not a big difference, and the destructive loads are reduced by 4.7% and 9.4%, respectively;3) By increasing the strength grade of the web, the steel consumption is increased by 7%, and the improvement of flange yielding moment is only 7%, which is ineffective; the improvement efficiency of flange yielding moment can reach 8 times of the improvement efficiency corresponding to the increase of the web thickness when increasing the height of the web; 4) The flange yielding moment, plastic limit moment and torsion critical moment can be determined by referring to the corresponding theoretical calculation formula.
In order to investigate the effect of different height to thickness ratio of web and steel grade combinations on the static load carrying performance of steel beams, one same-grade steel beam and three Hybrid steel girders were designed and fabricated respectively, and four-point bending tests were conducted on the specimens to obtain the damage pattern, load-displacement curve, load-strain curve, corresponding load of web and flange yielding and ultimate load of each specimen, and the theoretical calculated values were compared with the experimental values. Buckling analysis was then performed by ABAQUS, and the calculated results were compared with the experimental results to verify the reasonableness of the finite element model. After that, parametric analysis was carried out to further investigate the effect of height to thickness ratio of web and steel grade combinations on the static load carrying performance of steel beams, and to analyze the economics of changing web height, web thickness and web strength with the variation of steel consumption. Finally, the flange yielding moment, plastic limit bending moment and critical moment of bending and torsional buckling obtained from the parametric analysis are compared with the results of the corresponding theoretical equations to provide some suggestions for the design of hybrid steel girders. The results show:1) The yield load of specimen M-1 flange is 8.7% larger than that of specimen S-1 flange, which indicates that the design capacity of Hybrid steel girders is slightly better than that of the same steel girders under the condition that the ratio of height to thickness ratio of web is the same as that of calculated value of the specification GB 50017—2017 Steel Structure Design Standard. Therefore, in the actual structure, when the web height to thickness ratio of web is large, the flange can use higher strength grade steel, while the web can use lower strength steel, forming Hybrid steel girders instead of the same steel girders, which can appropriately improve the static bearing capacity of steel girders and save the amount of steel at the same time; 2) When the height of the cross-section is increased, the yielding load of web of specimen is improved, and the yielding load of web of specimen M-3 is 12.7% higher than that of M-1, the effect of initial defects on the load carrying capacity of steel beams is mainly reflected in the late loading stage, because the web height to thickness ratio of web increases, the degree of its initial defects will increase, and at the same time, the load carrying capacity will be improved. Therefore, compared with specimen M-1, specimens M-2 and M-3 flank yielding corresponding to the load is not a big difference, and the destructive loads are reduced by 4.7% and 9.4%, respectively;3) By increasing the strength grade of the web, the steel consumption is increased by 7%, and the improvement of flange yielding moment is only 7%, which is ineffective; the improvement efficiency of flange yielding moment can reach 8 times of the improvement efficiency corresponding to the increase of the web thickness when increasing the height of the web; 4) The flange yielding moment, plastic limit moment and torsion critical moment can be determined by referring to the corresponding theoretical calculation formula.
2024, 39(8): 20-28.
doi: 10.13206/j.gjgS23062701
Abstract:
Modular steel structure building is a new type of prefabricated building, which has a high level of industrialization and has been vigorously developed in China. The expansion project of Jiaguang Middle School in Rongcheng County of Xiong’an New Area adopts modular steel structure laminated box system. In order to facilitate the connection and installation between the modules of the upper and lower unit rooms, a new type of unit room socket connection column-column joint is proposed. The joint realizes the connection between the upper and lower columns through bolts and sleeves. The vertical connection between the units should not be separated vertically under wind load and frequent earthquakes. Tensile tests were carried out on three full-scale joint specimens to analyze their failure modes, bolt shear distribution and tensile bearing capacity. The influence of grouting and the number of bolts on the bearing capacity of the joints was discussed. Based on the calculation method of the design value of the shear capacity of high-strength bolts in the existing literature, the design formula of the tensile strength of the new joint is proposed. A reliable numerical model was established, and the number of bolts and the diameter of bolts were analyzed. The parametric analysis results were compared with the formula calculation results.
The results show that under the axial load, the shear failure of high-strength bolt group occurs in all specimens. At the same time, the inner sleeve hole wall buckling occurs in the non-slurry joint specimens, and the local crushing phenomenon of grouting material occurs in the grouting joint specimens, accompanied by the bond failure between steel and grouting material interface. In the early stage of test loading, the shearing force of high-strength bolt group is large at the end and small at the center. In the later stage of loading, the shear force difference of high-strength bolt group decreases gradually. When the ultimate bearing capacity is reached, the shearing force of high-strength bolt group tends to be evenly distributed. The new joint relies on the shear resistance of high-strength bolts to bear the axial tensile load. The average shear bearing capacity of a single bolt is 76.9% higher than the calculated value of GB 50017-2017 Steel Structure Design Standard; After the grouting material is injected into the joint, the grouting material and the high-strength bolt work together, and the tensile bearing capacity is 14.1% higher than that of the non-slurry joint. The number of bolts increased from 3 to 5, and the tensile bearing capacity of the joint increased by 80.9% due to the increase of friction force and the decrease of shearing force of single bolt. With the increase of bolt diameter, the bolt pre-tightening force in the elastic stage increases, the contact area between the screw and the hole wall in the plastic stage increases, and the tensile bearing capacity of the joint increases. The error between the finite element parametric analysis results and the theoretical calculation results is controlled within 10%. The proposed joint tensile strength design formula accurately predicts the tensile bearing capacity of the new joint under axial tension, which provides a theoretical reference for practical engineering applications.
Modular steel structure building is a new type of prefabricated building, which has a high level of industrialization and has been vigorously developed in China. The expansion project of Jiaguang Middle School in Rongcheng County of Xiong’an New Area adopts modular steel structure laminated box system. In order to facilitate the connection and installation between the modules of the upper and lower unit rooms, a new type of unit room socket connection column-column joint is proposed. The joint realizes the connection between the upper and lower columns through bolts and sleeves. The vertical connection between the units should not be separated vertically under wind load and frequent earthquakes. Tensile tests were carried out on three full-scale joint specimens to analyze their failure modes, bolt shear distribution and tensile bearing capacity. The influence of grouting and the number of bolts on the bearing capacity of the joints was discussed. Based on the calculation method of the design value of the shear capacity of high-strength bolts in the existing literature, the design formula of the tensile strength of the new joint is proposed. A reliable numerical model was established, and the number of bolts and the diameter of bolts were analyzed. The parametric analysis results were compared with the formula calculation results.
The results show that under the axial load, the shear failure of high-strength bolt group occurs in all specimens. At the same time, the inner sleeve hole wall buckling occurs in the non-slurry joint specimens, and the local crushing phenomenon of grouting material occurs in the grouting joint specimens, accompanied by the bond failure between steel and grouting material interface. In the early stage of test loading, the shearing force of high-strength bolt group is large at the end and small at the center. In the later stage of loading, the shear force difference of high-strength bolt group decreases gradually. When the ultimate bearing capacity is reached, the shearing force of high-strength bolt group tends to be evenly distributed. The new joint relies on the shear resistance of high-strength bolts to bear the axial tensile load. The average shear bearing capacity of a single bolt is 76.9% higher than the calculated value of GB 50017-2017 Steel Structure Design Standard; After the grouting material is injected into the joint, the grouting material and the high-strength bolt work together, and the tensile bearing capacity is 14.1% higher than that of the non-slurry joint. The number of bolts increased from 3 to 5, and the tensile bearing capacity of the joint increased by 80.9% due to the increase of friction force and the decrease of shearing force of single bolt. With the increase of bolt diameter, the bolt pre-tightening force in the elastic stage increases, the contact area between the screw and the hole wall in the plastic stage increases, and the tensile bearing capacity of the joint increases. The error between the finite element parametric analysis results and the theoretical calculation results is controlled within 10%. The proposed joint tensile strength design formula accurately predicts the tensile bearing capacity of the new joint under axial tension, which provides a theoretical reference for practical engineering applications.
2024, 39(8): 29-36.
doi: 10.13206/j.gjgS23082701
Abstract:
The Shunde Desheng Sports Center Training Center is the largest elliptical closed double layered spoke cable network structure built in the South China region. The structure of the training center consists of vertical V-braces, external compression rings, internal tension rings, support rods, radial stress cables, and circumferential stability cables. The plane is elliptical, with a plane size of 97 m × 83 m, with the length of the long and short axes of the cable mesh being 89 m×75 m respectively, the height of the middle pressure ring is 8.3 meters. In response to the drawbacks of the complex force finding program and difficult optimization of the spoke type double-layer cable network structure system, this paper applies the improved particle swarm optimization algorithm for the first time to the above problems. Particle Swarm Optimization (PSO) is a biomimetic optimization algorithm inspired by the natural biological phenomenon of birds foraging. Although it has emerged in various optimization fields, its application in the field of large-span prestressed structures is relatively limited. Given the above situation, based on the advantages and disadvantages of PSO optimization algorithm, an improved PSO algorithm is proposed. The improved algorithm avoids the disadvantage of the original method’s inertia coefficient w not being able to be updated according to the optimization process, which leads to low optimization efficiency in the later stage of the algorithm, significantly improving the optimization efficiency of the algorithm. An improved PSO algorithm program was developed using the programming software Matlab. Through the collaborative working mechanism between Matlab and ANSYS finite element software, the improved PSO was applied to the prestressed optimization of the double-layer spoke cable network structure system. The results showed that the optimized algorithm resulted in a maximum vertical displacement of only 33 mm in the prestressed state of the double-layer cable network structure, and the optimization effect was significant, meeting the regulatory requirements of GB 50017-2017 Steel Structure Design Standard. On the basis of the above optimization, conventional elastic analysis was further carried out on the double-layer spoke cable network structure, such as modal analysis, cable network deformation analysis, cable internal force analysis, nonlinear buckling analysis, and stress ratio verification. The results showed that all indicators met the requirements of the specifications (such as the GB 50017-2017 Steel Structure Design Standards, etc.). Through the analysis of broken cables and broken ring beams, it was verified that the structure still has sufficient safety reserves in extreme situations, and that the structure has sufficient safety redundancy to ensure safety. Using finite element software, a 1∶1 actual simulation modeling analysis was conducted on the cable clamp node, and the designed envelope cable force was applied to the calculation model, verifying that the cable clamp force met the design requirements.The prestressed optimization results of the double-layer cable system structure obtained by the improved PSO algorithm meet the initial strength and stiffness requirements of the structure. Based on this, modal analysis, cable mesh deformation analysis, cable internal force analysis,nonlinear buckling analysis, stress ratio verification, cable and ring beam analysis are carried out to verify that the structure has sufficient safety redundancy. Therefore, the improved PSO provides an effective solution for the prestressed optimization problem of the cable network structure system, which can be used for solving similar problems in the future.
The Shunde Desheng Sports Center Training Center is the largest elliptical closed double layered spoke cable network structure built in the South China region. The structure of the training center consists of vertical V-braces, external compression rings, internal tension rings, support rods, radial stress cables, and circumferential stability cables. The plane is elliptical, with a plane size of 97 m × 83 m, with the length of the long and short axes of the cable mesh being 89 m×75 m respectively, the height of the middle pressure ring is 8.3 meters. In response to the drawbacks of the complex force finding program and difficult optimization of the spoke type double-layer cable network structure system, this paper applies the improved particle swarm optimization algorithm for the first time to the above problems. Particle Swarm Optimization (PSO) is a biomimetic optimization algorithm inspired by the natural biological phenomenon of birds foraging. Although it has emerged in various optimization fields, its application in the field of large-span prestressed structures is relatively limited. Given the above situation, based on the advantages and disadvantages of PSO optimization algorithm, an improved PSO algorithm is proposed. The improved algorithm avoids the disadvantage of the original method’s inertia coefficient w not being able to be updated according to the optimization process, which leads to low optimization efficiency in the later stage of the algorithm, significantly improving the optimization efficiency of the algorithm. An improved PSO algorithm program was developed using the programming software Matlab. Through the collaborative working mechanism between Matlab and ANSYS finite element software, the improved PSO was applied to the prestressed optimization of the double-layer spoke cable network structure system. The results showed that the optimized algorithm resulted in a maximum vertical displacement of only 33 mm in the prestressed state of the double-layer cable network structure, and the optimization effect was significant, meeting the regulatory requirements of GB 50017-2017 Steel Structure Design Standard. On the basis of the above optimization, conventional elastic analysis was further carried out on the double-layer spoke cable network structure, such as modal analysis, cable network deformation analysis, cable internal force analysis, nonlinear buckling analysis, and stress ratio verification. The results showed that all indicators met the requirements of the specifications (such as the GB 50017-2017 Steel Structure Design Standards, etc.). Through the analysis of broken cables and broken ring beams, it was verified that the structure still has sufficient safety reserves in extreme situations, and that the structure has sufficient safety redundancy to ensure safety. Using finite element software, a 1∶1 actual simulation modeling analysis was conducted on the cable clamp node, and the designed envelope cable force was applied to the calculation model, verifying that the cable clamp force met the design requirements.The prestressed optimization results of the double-layer cable system structure obtained by the improved PSO algorithm meet the initial strength and stiffness requirements of the structure. Based on this, modal analysis, cable mesh deformation analysis, cable internal force analysis,nonlinear buckling analysis, stress ratio verification, cable and ring beam analysis are carried out to verify that the structure has sufficient safety redundancy. Therefore, the improved PSO provides an effective solution for the prestressed optimization problem of the cable network structure system, which can be used for solving similar problems in the future.
2024, 39(8): 37-44.
doi: 10.13206/j.gjgS23092701
Abstract:
Based on the Desheng Sports Center Stadium project in Shunde, this paper starts from the key difficulties of the project and focuses on the feature of site conditions, complex roof shape, and limited support conditions. It discusses and analyzes the overall roof structure scheme, proposing an arch structure system that is compatible with complex architectural shapes and can achieve spatial synergy. The stadium roof combines the giant arch structure, tensioned cable grid structure, and a visiting corridor structure with a sightseeing function, effectively addressing the requirements of large span, large cantilever, and the need for visitor activities. The main feature of this system is the use of the four landing cylindrical shape of the roof to set up four giant lattice columns, which, together with the inner ring triangular trusses, form a giant arch structure system with spatial synergy. Once the scheme is determined, the analysis of the giant arch structure system focuses on load analysis, deformation control, and load-bearing capacity check to ensure the reasonable transmission and safe stability of the giant arch structure system. The tensioned cable grid structure is analyzed and designed for cable forces to ensure that the cables do not slack under the most unfavorable working conditions. The complex and critical nodes of the project are analyzed using solid finite element analysis, and through force calculations and structural reinforcement, it is ensured that the nodes work elastically under complex stress conditions. Finally, the analysis and comparison of the monitoring data of the roof steel structure are conducted, including the deformation and stress changes of the steel members before closure, after closure, during the dismantling of the formwork, and during the secondary installation of the roof. The results show that all monitoring data did not exceed the design warning values and met the design requirements. The comprehensive analysis shows that the large-span and complex steel structure of the stadium project using the giant arch + tensioned cable grid + visiting corridor structure system has sufficient stability and safety redundancy. The structural system and design method can serve as a reference for similar projects.
Based on the Desheng Sports Center Stadium project in Shunde, this paper starts from the key difficulties of the project and focuses on the feature of site conditions, complex roof shape, and limited support conditions. It discusses and analyzes the overall roof structure scheme, proposing an arch structure system that is compatible with complex architectural shapes and can achieve spatial synergy. The stadium roof combines the giant arch structure, tensioned cable grid structure, and a visiting corridor structure with a sightseeing function, effectively addressing the requirements of large span, large cantilever, and the need for visitor activities. The main feature of this system is the use of the four landing cylindrical shape of the roof to set up four giant lattice columns, which, together with the inner ring triangular trusses, form a giant arch structure system with spatial synergy. Once the scheme is determined, the analysis of the giant arch structure system focuses on load analysis, deformation control, and load-bearing capacity check to ensure the reasonable transmission and safe stability of the giant arch structure system. The tensioned cable grid structure is analyzed and designed for cable forces to ensure that the cables do not slack under the most unfavorable working conditions. The complex and critical nodes of the project are analyzed using solid finite element analysis, and through force calculations and structural reinforcement, it is ensured that the nodes work elastically under complex stress conditions. Finally, the analysis and comparison of the monitoring data of the roof steel structure are conducted, including the deformation and stress changes of the steel members before closure, after closure, during the dismantling of the formwork, and during the secondary installation of the roof. The results show that all monitoring data did not exceed the design warning values and met the design requirements. The comprehensive analysis shows that the large-span and complex steel structure of the stadium project using the giant arch + tensioned cable grid + visiting corridor structure system has sufficient stability and safety redundancy. The structural system and design method can serve as a reference for similar projects.
2024, 39(8): 45-51.
doi: 10.13206/j.gjgS23092701
Abstract:
With the development of social economy and the improvement of people’s living standard, the building with large-span floor has gradually developed. The vertical natural vibration frequency of floor structures is getting closer to the load frequency of human activities, which may generate dynamic response affecting comfort. Therefore, the vibration comfort problem in the building floor has begun to attract people’s attention. The comfort problem needs to be considered in the structural design stage. If the vibration comfort problem of the floor structure is found after the completion of the project, it is difficult and costly to strengthen. In this paper, the structure of large-span floor system in rehearsal room was taken as the engineering background, The frequency of the first order overall vertical mode of the large-span floor structure is low, which is close to the vibration load frequency generated by the users of the rehearsal hall, and the floor is prone to produce dynamic responses that affect comfort. Therefore, the vibration comfort control was conducted in the structural design stage for the large-span floor structure of the rehearsal hall, according to the current national standard JGJ/T 441-2019 Technical Standard for Human Comfort of the Floor Vibration. Firstly, through modal analysis, the dynamic characteristics of the floor system, the location of the maximum vibration point and the time history curves of the excitation loads were determined. Secondly, through dynamic response analysis, the comfort of various vibration load conditions was evaluated, and the controlling vibration load condition for the comfort of the floor system in rehearsal room was determined. When no vibration reduction measures are taken, under the control condition of crowd dancing excitation, the steady-state peak acceleration of the most unfavorable vibration point of the floor is as high as 1.047m/s2, and the dancers will obviously feel uncomfortable. Lastly, the vibration reduction design for the floor system was conducted by means of tuned mass damper (TMD). The influence of TMD’s mass, damping ratio and frequency ratio on the vibration reduction ratio was studied. The peak acceleration of the maximum vibration point of the floor system during the steady-state vibration stage was successfully controlled to 0.4837m/s2（within the limit of standard）, and the vibration reduction rate is 53.8%, which meets the requirements of the dancing crowd for comfort.
With the development of social economy and the improvement of people’s living standard, the building with large-span floor has gradually developed. The vertical natural vibration frequency of floor structures is getting closer to the load frequency of human activities, which may generate dynamic response affecting comfort. Therefore, the vibration comfort problem in the building floor has begun to attract people’s attention. The comfort problem needs to be considered in the structural design stage. If the vibration comfort problem of the floor structure is found after the completion of the project, it is difficult and costly to strengthen. In this paper, the structure of large-span floor system in rehearsal room was taken as the engineering background, The frequency of the first order overall vertical mode of the large-span floor structure is low, which is close to the vibration load frequency generated by the users of the rehearsal hall, and the floor is prone to produce dynamic responses that affect comfort. Therefore, the vibration comfort control was conducted in the structural design stage for the large-span floor structure of the rehearsal hall, according to the current national standard JGJ/T 441-2019 Technical Standard for Human Comfort of the Floor Vibration. Firstly, through modal analysis, the dynamic characteristics of the floor system, the location of the maximum vibration point and the time history curves of the excitation loads were determined. Secondly, through dynamic response analysis, the comfort of various vibration load conditions was evaluated, and the controlling vibration load condition for the comfort of the floor system in rehearsal room was determined. When no vibration reduction measures are taken, under the control condition of crowd dancing excitation, the steady-state peak acceleration of the most unfavorable vibration point of the floor is as high as 1.047m/s2, and the dancers will obviously feel uncomfortable. Lastly, the vibration reduction design for the floor system was conducted by means of tuned mass damper (TMD). The influence of TMD’s mass, damping ratio and frequency ratio on the vibration reduction ratio was studied. The peak acceleration of the maximum vibration point of the floor system during the steady-state vibration stage was successfully controlled to 0.4837m/s2（within the limit of standard）, and the vibration reduction rate is 53.8%, which meets the requirements of the dancing crowd for comfort.
2024, 39(8): 52-54.
doi: 10.13206/j.gjgS24031921
Abstract:
The tensile capacity of a high-strength bolt,determined by the bolt itself and the steel plate respectively is introduced, the effect of bolt hole is considered. The required thickness of extended unstiffened end-plate is presented, and the weak-end-plate and strong tensile high-strength bolt requirement for seismic design is discussed. A correct plastic mechanism, in which 1/4 elliptical conical plastic surface is included, is used to determine the thickness of stiffened end-plate. The thickness by the new equation is found to be 4~10% thicker than by the equation in GB 51022-2015. The thickness of the stiffened end plate is found to be about 0.75 times the thickness of the unstiffened end plate.
