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Steel Construction Published the List of Highly Influential Articles of 2020
2023 Vol. 38, No. 9
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2023, 38(9): 1-8.
doi: 10.13206/j.gjgS23061401
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Abstract:
The application of timber to buildings can bring out the environmental characteristics of timber and make the building aesthetically. Fast-growing timber is abundant in China and can be used in the construction to reduce dependence on imported timber and reduce construction costs. However, due to the weak strength and uneven structure of fast-growing timber, there are some limitations in the application of construction. The introduction of light gauge steel can weaken the natural defects of timber, while timber can also solve the problem of instability of light gauge steel. Light gauge steel-fast growing timber structure is a new type of building structure that introduces steel into timber structure. It has the advantages of both steel and timber, and has certain prospects for application in building structures such as village houses. Since the mechanical behavior of self-tapping screw-connected light gauge steel-fast growing timber structures is influenced by the pullout resistance of self-tapping screws, and the existing studies on the pull-out resistance of self-tapping screws for such structures are not well studied. Therefore, a nail joint pullout test was conducted on steel-timber composite members made of domestic fast-growing fir timber and thin steel plates graded Q235. The thin steel plates and timber blocks were connected with self-tapping screws and placed in a homemade fixture. Using a testing machine to pull out the screws from the specimens to study their mechanical properties. Two important experimental parameters, including the thickness of the steel plate and the grain direction, were selected during the test to obtain the failure mode, ultimate load, and the ductility of the self-tapping screws. The results show that the failure mode of the specimens is all the damage of self-tapping screws pull-out. The threads are obviously damaged after the nails are pulled out. There is an accumulation of iron and timber chips in the threads, and the steel plate reamed and bulged. The dispersion of the specimens is low when the screws are pulled out perpendicularly in the direction of the grain, and the dispersion can be reduced by increasing the thickness of the steel plate. Simultaneity, the addition of light steel can significantly increase the ultimate load of specimens. The ultimate load at the end is lower than that in the other two directions, and the difference decreases gradually with the increase of steel plate thickness under the same conditions. When the self-tapping screws are pulled out from the radial direction and the chordal direction, the difference of load carrying capacity is not much, and the difference of ultimate load in the two directions was within 10%. When the steel plate thickness is 1.5 mm, the specimen shows better ductility than other specimens, while the overall ductility coefficient of the specimens is lower than 3. Finally, based on the European Code for the design of timber structures and Chinese Code for the design of steel structures, a formula to calculate the pull-out load capacity of steel-timber composite members composed of fir timber and thin steel plates connected by self-tapping screws was proposed, and the error of the formula was within 15%, which verified the applicability and accuracy of the formula.
The application of timber to buildings can bring out the environmental characteristics of timber and make the building aesthetically. Fast-growing timber is abundant in China and can be used in the construction to reduce dependence on imported timber and reduce construction costs. However, due to the weak strength and uneven structure of fast-growing timber, there are some limitations in the application of construction. The introduction of light gauge steel can weaken the natural defects of timber, while timber can also solve the problem of instability of light gauge steel. Light gauge steel-fast growing timber structure is a new type of building structure that introduces steel into timber structure. It has the advantages of both steel and timber, and has certain prospects for application in building structures such as village houses. Since the mechanical behavior of self-tapping screw-connected light gauge steel-fast growing timber structures is influenced by the pullout resistance of self-tapping screws, and the existing studies on the pull-out resistance of self-tapping screws for such structures are not well studied. Therefore, a nail joint pullout test was conducted on steel-timber composite members made of domestic fast-growing fir timber and thin steel plates graded Q235. The thin steel plates and timber blocks were connected with self-tapping screws and placed in a homemade fixture. Using a testing machine to pull out the screws from the specimens to study their mechanical properties. Two important experimental parameters, including the thickness of the steel plate and the grain direction, were selected during the test to obtain the failure mode, ultimate load, and the ductility of the self-tapping screws. The results show that the failure mode of the specimens is all the damage of self-tapping screws pull-out. The threads are obviously damaged after the nails are pulled out. There is an accumulation of iron and timber chips in the threads, and the steel plate reamed and bulged. The dispersion of the specimens is low when the screws are pulled out perpendicularly in the direction of the grain, and the dispersion can be reduced by increasing the thickness of the steel plate. Simultaneity, the addition of light steel can significantly increase the ultimate load of specimens. The ultimate load at the end is lower than that in the other two directions, and the difference decreases gradually with the increase of steel plate thickness under the same conditions. When the self-tapping screws are pulled out from the radial direction and the chordal direction, the difference of load carrying capacity is not much, and the difference of ultimate load in the two directions was within 10%. When the steel plate thickness is 1.5 mm, the specimen shows better ductility than other specimens, while the overall ductility coefficient of the specimens is lower than 3. Finally, based on the European Code for the design of timber structures and Chinese Code for the design of steel structures, a formula to calculate the pull-out load capacity of steel-timber composite members composed of fir timber and thin steel plates connected by self-tapping screws was proposed, and the error of the formula was within 15%, which verified the applicability and accuracy of the formula.
2023, 38(9): 9-18.
doi: 10.13206/j.gjgS23040402
Abstract:
The cold-formed steel（CFS） structure system has the characteristics of lightweight components, fully assembled construction（without the need for large machinery at construction site）, fast and simple connection, safety and reliability, and is suitable for the construction of low and multi-story buildings in rural areas. Straw building is a highly energy-efficient building type, which can create a natural and comfortable indoor environment for residents, and has a good effect of energy saving and emission reduction. When the building is abandoned, the straw can also be biodegraded. Straw is rich in reserves and has the ability to sequester carbon, which has gradually become a green building material that has attracted attention. In the traditional CFS structure system, the platform inter-story connection is complicated, with weak connection strength and stiffness, and is prone to failure. The ledger-framed inter-story connection is prone to local buckling, as the studs bear the additional bending moment transmitted by the floor joists. The enclosure materials such as mineral wool, expanded polystyrene, extruded polystyrene are difficult to be widely used in rural buildings due to high energy consumption and high cost in the production. This paper proposed a platform-balloon type CFS-straw bale structure system, which combined CFS with straw bale and improved the platform CFS structure. This system meets the needs of green buildings and low energy consumption, and has unique advantages and large development space in rural areas. In order to investigate the seismic performance of the structure system subjected to earthquake, the finite element models of platform CFS structure, platform-balloon CFS structure, and platform-balloon CFS-straw bale structure were established respectively based on the actual project, and the natural frequencies of the three were obtained. The nonlinear time-history analysis of ground motion was carried out, and the seismic responses of the three subjected to different levels of earthquake were compared, including acceleration response, displacement response, and base shear-top displacement curve. It can be seen from the construction process of the actual project that compared with the platform CFS structure, the platform-balloon CFS structure has fewer components, simple joint configuration, convenient installation and good integrity, which is suitable for application in rural areas. The first three natural frequencies of platform-balloon CFS structure are higher than those of the platform CFS structure. Under the most unfavorable ground motion, the peak base shear force, peak roof displacement, and peak inter-story displacement of platform-balloon CFS structure are smaller than those of platform CFS structure, and the maximum inter-story drift of the structure meets the limit requirements of JGJ 227—2011 "Technical Specification for Low-rise Cold-fromed Thin-walled Steel Buildings" and GB 50011—2010 "Code for Seismic Design of Buildings". Those results indicate that the structural stiffness and seismic performance of the platform-balloon CFS structure are better than those of the platform CFS structure. Considering the influence of the straw wall, the peak base shear and peak roof displacement of the platform-balloon CFS structure are reduced by 12.5% and 30% respectively, indicating that the viscoelastic mechanical properties of straw wall can reduce the seismic response of CFS structure.
The cold-formed steel（CFS） structure system has the characteristics of lightweight components, fully assembled construction（without the need for large machinery at construction site）, fast and simple connection, safety and reliability, and is suitable for the construction of low and multi-story buildings in rural areas. Straw building is a highly energy-efficient building type, which can create a natural and comfortable indoor environment for residents, and has a good effect of energy saving and emission reduction. When the building is abandoned, the straw can also be biodegraded. Straw is rich in reserves and has the ability to sequester carbon, which has gradually become a green building material that has attracted attention. In the traditional CFS structure system, the platform inter-story connection is complicated, with weak connection strength and stiffness, and is prone to failure. The ledger-framed inter-story connection is prone to local buckling, as the studs bear the additional bending moment transmitted by the floor joists. The enclosure materials such as mineral wool, expanded polystyrene, extruded polystyrene are difficult to be widely used in rural buildings due to high energy consumption and high cost in the production. This paper proposed a platform-balloon type CFS-straw bale structure system, which combined CFS with straw bale and improved the platform CFS structure. This system meets the needs of green buildings and low energy consumption, and has unique advantages and large development space in rural areas. In order to investigate the seismic performance of the structure system subjected to earthquake, the finite element models of platform CFS structure, platform-balloon CFS structure, and platform-balloon CFS-straw bale structure were established respectively based on the actual project, and the natural frequencies of the three were obtained. The nonlinear time-history analysis of ground motion was carried out, and the seismic responses of the three subjected to different levels of earthquake were compared, including acceleration response, displacement response, and base shear-top displacement curve. It can be seen from the construction process of the actual project that compared with the platform CFS structure, the platform-balloon CFS structure has fewer components, simple joint configuration, convenient installation and good integrity, which is suitable for application in rural areas. The first three natural frequencies of platform-balloon CFS structure are higher than those of the platform CFS structure. Under the most unfavorable ground motion, the peak base shear force, peak roof displacement, and peak inter-story displacement of platform-balloon CFS structure are smaller than those of platform CFS structure, and the maximum inter-story drift of the structure meets the limit requirements of JGJ 227—2011 "Technical Specification for Low-rise Cold-fromed Thin-walled Steel Buildings" and GB 50011—2010 "Code for Seismic Design of Buildings". Those results indicate that the structural stiffness and seismic performance of the platform-balloon CFS structure are better than those of the platform CFS structure. Considering the influence of the straw wall, the peak base shear and peak roof displacement of the platform-balloon CFS structure are reduced by 12.5% and 30% respectively, indicating that the viscoelastic mechanical properties of straw wall can reduce the seismic response of CFS structure.
2023, 38(9): 19-27.
doi: 10.13206/j.gjgS22052202
Abstract:
The grid wall structure is a new type of lateral force resistance system obtained by meshing steel plate walls, which has the advantages of good seismic performance, light welding workload, convenient processing and transportation of components, convenient construction and installation, etc. It meets the current policy requirement of vigorously developing assembled steel structures. The current research on grid wall structures is mainly focused on mechanical properties, but it has not yet been applied in practical engineering design. In order to explore the feasibility of its application in practical engineering, based on the steel frame-steel plate shear wall structure of Building 9# of the Lanzhou New District Sheltered Housing Construction Project（Phase II）, the structural arrangement and design were carried out using steel frame-grid wall structure, the structural calculation model was established in YJK and MIDAS/Gen software, and the overall structural analysis, members load bearing capacity verification and key joints design and analysis were carried out under the same technical parameters and loading conditions. Elastic analysis of steel frame-grid wall structures in YJK and MIDAS/Gen was carried out to obtain the overall indices of the structures and compared with the overall indices of the original steel frame-steel plate shear wall structures. The results show that the lateral force-resisting members of the steel frame-grid wall structure are arranged regularly in plan and elevation, and the indicators obtained by both software are close to each other and meet the code requirements. Although its lateral stiffness is slightly lower than the steel frame-steel plate shear wall structure, the steel grid wall uses less steel and less welding work than the corresponding steel plate shear wall. When checking the load capacity of a member, as the calculating length method for T-section steel members of steel grid walls is not yet clear, it is unable to use the first-order elastic analysis method for member stability calculations, so the members were checked using the direct analysis method. Considering the overall initial defects and the component initial defects, the non-linear analysis under each load combination was carried out and the results showed that the strength stress ratios of all steel members are less than 1.0 and the load capacity of the members meets the code requirements. The fishtail plate, as the connecting component between the T-section steel components and the edge components, is essential for the energy consumption performance of the steel grid wall. To ensure the reliability of the connection, further analysis of the mechanical properties of the fishtail plate was carried out. A refined finite element model of the 3-story local substructure of this steel grid wall was established in the finite element software ABAQUS, and the analysis was carried out after applying the internal forces at the top of the columns, the loads on the beams and the lateral displacements at the top of the columns at each story under the load envelope combination. The results show that the fishtail plate, T-section steel components and edge components don′t yield under the design load, and when the lateral loading continues until the fishtail plate yields, most of the T-section steel components, the beam ends and the compressed side of the column footings at the ground floor have already yielded at this time, meeting the design requirement of "strong joints, weak components".
The grid wall structure is a new type of lateral force resistance system obtained by meshing steel plate walls, which has the advantages of good seismic performance, light welding workload, convenient processing and transportation of components, convenient construction and installation, etc. It meets the current policy requirement of vigorously developing assembled steel structures. The current research on grid wall structures is mainly focused on mechanical properties, but it has not yet been applied in practical engineering design. In order to explore the feasibility of its application in practical engineering, based on the steel frame-steel plate shear wall structure of Building 9# of the Lanzhou New District Sheltered Housing Construction Project（Phase II）, the structural arrangement and design were carried out using steel frame-grid wall structure, the structural calculation model was established in YJK and MIDAS/Gen software, and the overall structural analysis, members load bearing capacity verification and key joints design and analysis were carried out under the same technical parameters and loading conditions. Elastic analysis of steel frame-grid wall structures in YJK and MIDAS/Gen was carried out to obtain the overall indices of the structures and compared with the overall indices of the original steel frame-steel plate shear wall structures. The results show that the lateral force-resisting members of the steel frame-grid wall structure are arranged regularly in plan and elevation, and the indicators obtained by both software are close to each other and meet the code requirements. Although its lateral stiffness is slightly lower than the steel frame-steel plate shear wall structure, the steel grid wall uses less steel and less welding work than the corresponding steel plate shear wall. When checking the load capacity of a member, as the calculating length method for T-section steel members of steel grid walls is not yet clear, it is unable to use the first-order elastic analysis method for member stability calculations, so the members were checked using the direct analysis method. Considering the overall initial defects and the component initial defects, the non-linear analysis under each load combination was carried out and the results showed that the strength stress ratios of all steel members are less than 1.0 and the load capacity of the members meets the code requirements. The fishtail plate, as the connecting component between the T-section steel components and the edge components, is essential for the energy consumption performance of the steel grid wall. To ensure the reliability of the connection, further analysis of the mechanical properties of the fishtail plate was carried out. A refined finite element model of the 3-story local substructure of this steel grid wall was established in the finite element software ABAQUS, and the analysis was carried out after applying the internal forces at the top of the columns, the loads on the beams and the lateral displacements at the top of the columns at each story under the load envelope combination. The results show that the fishtail plate, T-section steel components and edge components don′t yield under the design load, and when the lateral loading continues until the fishtail plate yields, most of the T-section steel components, the beam ends and the compressed side of the column footings at the ground floor have already yielded at this time, meeting the design requirement of "strong joints, weak components".
2023, 38(9): 28-36.
doi: 10.13206/j.gjgS22062102
Abstract:
In the backdrop of rural revitalization, dual carbon targets, the upgrading of the construction industry, and the trend towards prefabricated construction, China′s rural economy has experienced a remarkable surge in development. Fueled by the boom in residential construction, the development of rural housing has shifted its focus from mere quantity increase to a substantial improvement in quality. The enhancement of living conditions and construction standards has become an inevitable imperative for the next phase of rural housing development. The lightweight steel frame structural system stands out for its characteristics of lightweight components, easy transportability, and excellent seismic performance, making it a suitable choice for low-rise residential buildings in rural areas. However, existing welding and bolted connection methods fall short of meeting the demands for cost-effectiveness and simplified construction procedures. To address these issues, this paper presents a novel rural light steel frame structural system, taking into account the challenges posed by the backward transportation and construction conditions in rural areas. This innovative system incorporates self-tapping screw connection nodes and rectangular steel tube special-shaped composite columns. Through a comprehensive study on the structural and node design methods, this new system was applied to the prefabricated steel structures in Desheng Village. The article elaborates on the key technologies adopted during the design and construction processes, which include BIM forward design for prefabricated rural housing, the straightforward assembly of composite-shaped columns, the assembly of spiral steel pile cap nodes, and simplified node connection and installation techniques. The results demonstrate that this novel structural system meets all the relevant regulatory requirements and ensures safety and reliability. The calculated shear resistance of screws using modified British standards and pull-out resistance of screws using European standards are slightly conservative, ensuring a secure engineering application. The proposed key technologies not only fulfill the intrinsic requirements of green and eco-friendly construction, simplicity in execution, and cost-effectiveness for rural housing but also make them well-suited for broad implementation in rural areas.
In the backdrop of rural revitalization, dual carbon targets, the upgrading of the construction industry, and the trend towards prefabricated construction, China′s rural economy has experienced a remarkable surge in development. Fueled by the boom in residential construction, the development of rural housing has shifted its focus from mere quantity increase to a substantial improvement in quality. The enhancement of living conditions and construction standards has become an inevitable imperative for the next phase of rural housing development. The lightweight steel frame structural system stands out for its characteristics of lightweight components, easy transportability, and excellent seismic performance, making it a suitable choice for low-rise residential buildings in rural areas. However, existing welding and bolted connection methods fall short of meeting the demands for cost-effectiveness and simplified construction procedures. To address these issues, this paper presents a novel rural light steel frame structural system, taking into account the challenges posed by the backward transportation and construction conditions in rural areas. This innovative system incorporates self-tapping screw connection nodes and rectangular steel tube special-shaped composite columns. Through a comprehensive study on the structural and node design methods, this new system was applied to the prefabricated steel structures in Desheng Village. The article elaborates on the key technologies adopted during the design and construction processes, which include BIM forward design for prefabricated rural housing, the straightforward assembly of composite-shaped columns, the assembly of spiral steel pile cap nodes, and simplified node connection and installation techniques. The results demonstrate that this novel structural system meets all the relevant regulatory requirements and ensures safety and reliability. The calculated shear resistance of screws using modified British standards and pull-out resistance of screws using European standards are slightly conservative, ensuring a secure engineering application. The proposed key technologies not only fulfill the intrinsic requirements of green and eco-friendly construction, simplicity in execution, and cost-effectiveness for rural housing but also make them well-suited for broad implementation in rural areas.
2023, 38(9): 37-44.
doi: 10.13206/j.gjgS22092801
Abstract:
With the development of villages and towns, the residents of villages and towns have a higher level of demand for housing, and the importance of prefabricated building and green construction in new rural construction is gradually increased. The author′s team put forward a new simple prefabricated special-shaped column and its steel frame structure system for low-rise residential buildings in villages and towns. Firstly, this paper describes the structure, joint form and characteristics of the new recommended prefabricated special-shaped column. The special-shaped column consists of three single columns with rectangular cross-section and L-shaped arrangement. The single column is fastened with U-shaped connectors and L-shaped connectors by tapping screws. The connection joints of the special-shaped column are all connected by tapping screws without welding at all. The system has the advantages: small environmental pollution, low operation difficulty, low cost, easy purchase of steel, easy transportation of components and easy prefabricating process, which meets the development needs of the National Rural Revitalization Strategy for green residential construction. Then, based on the new structure system, this paper establishes the calculation model of the housing project with the help of PKPM, completes the structure analysis and design of the housing project, obtains various structural indexes and deformation diagrams under different conditions, and designs and checks the joints with reference to relevant specifications. Finally, this paper summarizes the difficulties encountered in the construction process. In order to solve the difficulties encountered in construction: the construction work surface of beam-column joints and beam-beam joints is high and the operation at high altitude is difficult and there are potential safety hazards; the installation of the new system avoids large-scale machinery as far as possible, and the manual direct lifting component is too difficult to operate, which is easy to damage the joint during lifting and has potential safety hazards. Three key construction techniques are proposed: simplified connection method of tapping screw joint, double-ladder lifting method and temporary fixing measures for frame lifting. The simplified connection method of self-tapping screw joint improves the efficiency and accuracy of connection of self-tapping screw joint and the safety of construction. The double-ladder lifting method reduces the difficulty of lifting the components manually, avoids the damage of the joint during lifting and improves the efficiency and safety of lifting the components. Temporary fixing measures for frame lifting avoid frame rollover during manual lifting and improve the safety of frame lifting. The above three key technologies improve the efficiency and safety of the new simple prefabricated special-shaped column structure in the construction process.
With the development of villages and towns, the residents of villages and towns have a higher level of demand for housing, and the importance of prefabricated building and green construction in new rural construction is gradually increased. The author′s team put forward a new simple prefabricated special-shaped column and its steel frame structure system for low-rise residential buildings in villages and towns. Firstly, this paper describes the structure, joint form and characteristics of the new recommended prefabricated special-shaped column. The special-shaped column consists of three single columns with rectangular cross-section and L-shaped arrangement. The single column is fastened with U-shaped connectors and L-shaped connectors by tapping screws. The connection joints of the special-shaped column are all connected by tapping screws without welding at all. The system has the advantages: small environmental pollution, low operation difficulty, low cost, easy purchase of steel, easy transportation of components and easy prefabricating process, which meets the development needs of the National Rural Revitalization Strategy for green residential construction. Then, based on the new structure system, this paper establishes the calculation model of the housing project with the help of PKPM, completes the structure analysis and design of the housing project, obtains various structural indexes and deformation diagrams under different conditions, and designs and checks the joints with reference to relevant specifications. Finally, this paper summarizes the difficulties encountered in the construction process. In order to solve the difficulties encountered in construction: the construction work surface of beam-column joints and beam-beam joints is high and the operation at high altitude is difficult and there are potential safety hazards; the installation of the new system avoids large-scale machinery as far as possible, and the manual direct lifting component is too difficult to operate, which is easy to damage the joint during lifting and has potential safety hazards. Three key construction techniques are proposed: simplified connection method of tapping screw joint, double-ladder lifting method and temporary fixing measures for frame lifting. The simplified connection method of self-tapping screw joint improves the efficiency and accuracy of connection of self-tapping screw joint and the safety of construction. The double-ladder lifting method reduces the difficulty of lifting the components manually, avoids the damage of the joint during lifting and improves the efficiency and safety of lifting the components. Temporary fixing measures for frame lifting avoid frame rollover during manual lifting and improve the safety of frame lifting. The above three key technologies improve the efficiency and safety of the new simple prefabricated special-shaped column structure in the construction process.
2023, 38(9): 45-52.
doi: 10.13206/j.gjgS22110901
Abstract:
With the promotion of new urbanization, the proportion of prefabricated steel structure buildings has increased year by year. However, the existing steel structure systems applied in rural buildings face problems such as poor living quality, low level of components standardization, inconvenient transportation and installation, low construction quality, and serious pollution and waste. It is urgent to develop low-cost, simple-constructed, ecological prefabricated light steel structure systems residence and corresponding construction technologies. The light steel frame-grid wall structure not only has the advantages of excellent seismic performance, light components and easy transportation, but also can be wholly connected by bolts or self-tapping screws, which is convenient for installation. In order to study the simple construction technology and lateral performance of this structure, a single-story house with a steel frame-steel, wood and bamboo grid wall hybrid structure system wholly connected by screws was built, and its in-situ experiment was carried out. Taking a light steel frame-steel grid wall in this project as an example, this paper expounds the simple construction technology of the light steel frame-steel grid wall from the column base, foundation, installation of frame and steel gird, and fixing of wallboard, and its lateral performance was obtained through the in-situ static experiment. The research shows that the light steel frame-steel grid wall is easy to install, which can save manpower and material resources, and is suitable for application in rural areas, and the lateral performance of the light steel frame-steel grid wall with this construction technology can meet the design requirements.
With the promotion of new urbanization, the proportion of prefabricated steel structure buildings has increased year by year. However, the existing steel structure systems applied in rural buildings face problems such as poor living quality, low level of components standardization, inconvenient transportation and installation, low construction quality, and serious pollution and waste. It is urgent to develop low-cost, simple-constructed, ecological prefabricated light steel structure systems residence and corresponding construction technologies. The light steel frame-grid wall structure not only has the advantages of excellent seismic performance, light components and easy transportation, but also can be wholly connected by bolts or self-tapping screws, which is convenient for installation. In order to study the simple construction technology and lateral performance of this structure, a single-story house with a steel frame-steel, wood and bamboo grid wall hybrid structure system wholly connected by screws was built, and its in-situ experiment was carried out. Taking a light steel frame-steel grid wall in this project as an example, this paper expounds the simple construction technology of the light steel frame-steel grid wall from the column base, foundation, installation of frame and steel gird, and fixing of wallboard, and its lateral performance was obtained through the in-situ static experiment. The research shows that the light steel frame-steel grid wall is easy to install, which can save manpower and material resources, and is suitable for application in rural areas, and the lateral performance of the light steel frame-steel grid wall with this construction technology can meet the design requirements.
2023, 38(9): 53-55.
doi: 10.13206/j.gjgS23022120
Abstract:
A brief introduction on the limiting width-to-thickness ratio of web of GB 50017—2017 is presented for axially loaded H-column, and possible problems are pointed out. The edge yielding criteria is used to approximate the overall instability of the column and to determine the web stresses at this state to compute the local buckling stress of the web and the corresponding normalized width-to-thickness ratio of the web. Based on the effective width formulas of plates in AISI and European codes EC3-1-5, the limiting width-to-thickness ratio of the web at which the full width is effective is obtained. The results revealed that the limiting ratio shall be related to the normalized slenderness of column. Comparison with the current code formula is given. Approximate formulas are proposed. The presented method is more rational because it considers the effect of overall bending on the web stress distribution and local buckling.
A brief introduction on the limiting width-to-thickness ratio of web of GB 50017—2017 is presented for axially loaded H-column, and possible problems are pointed out. The edge yielding criteria is used to approximate the overall instability of the column and to determine the web stresses at this state to compute the local buckling stress of the web and the corresponding normalized width-to-thickness ratio of the web. Based on the effective width formulas of plates in AISI and European codes EC3-1-5, the limiting width-to-thickness ratio of the web at which the full width is effective is obtained. The results revealed that the limiting ratio shall be related to the normalized slenderness of column. Comparison with the current code formula is given. Approximate formulas are proposed. The presented method is more rational because it considers the effect of overall bending on the web stress distribution and local buckling.
