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Steel Construction Published the List of Highly Influential Articles of 2020
2023 Vol. 38, No. 4
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2023, 38(4): 1-13.
doi: 10.13206/j.gjgSE23030402
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Abstract:
As the most common joint form of aluminum alloy single-layer latticed shells,aluminum alloy plate joints mainly bear the action of axial force and bending moment.The existing research results mainly focus on the stiffness model of the joint under the action of bending moment and axial force alone,and no model can simulate the stiffness characteristics of the joint under the action of bending moment and axial force.This paper will solve this problem through experimental exploration,numerical analysis and theoretical research,and propose an equivalent stiffness model that can consider both the bending moment and the axial force of the plate joint.Firstly,the bending and compression tests of aluminum alloy plate joints are carried out to preliminarily explore the deformation mechanism of joints under the action of bending moment and axial pressure alone.The test results show that the axial deformation and bending deformation of plate joints can be divided into four stages:bolt fixation stage,bolt slip stage,hole wall bearing stage and failure stage.Based on the test,a numerical analysis model is established to study the deformation mechanism of plate joints under the combined action of bending moment and axial force (eccentric force).The numerical analysis results show that the axial deformation mechanism under eccentric force is:1) with the increase of eccentric distance,the equivalent stiffness decreases gradually;2) When the eccentricity is small,the slip stage may occur twice.The deformation characteristics of bending under eccentric force are as follows:1) When the eccentricity is small,repeated sliding occurs;2) When the eccentricity is small,the axial force can improve the bending stiffness,but with the increase of the eccentricity,the axial force can reduce the bending stiffness.In aluminum alloy single-layer latticed shells,the eccentricity of plate joints at different positions is completely different,so it is impossible to accurately calculate the stiffness model of each joint.In order to facilitate calculation and use,the equivalent beam method simulation method can be used.According to the principle of equal axial deformation,bending deformation and yield load,the equivalent stiffness model of aluminum alloy plate joint can be theoretically deduced,and the calculation formula of the parameters of the equivalent two elements of the joint can be obtained.Establish the numerical analysis model and corresponding equivalent stiffness model of plate joints required for verification,and compare the axial and bending load-displacement curves of the two.The results show that the axial deformation and bending deformation of the equivalent beam element model are basically the same as that of the plate joint.Therefore,the Temcor node equivalent model proposed in this paper is accurate and can be used for the stability analysis of single-layer latticed shells.
As the most common joint form of aluminum alloy single-layer latticed shells,aluminum alloy plate joints mainly bear the action of axial force and bending moment.The existing research results mainly focus on the stiffness model of the joint under the action of bending moment and axial force alone,and no model can simulate the stiffness characteristics of the joint under the action of bending moment and axial force.This paper will solve this problem through experimental exploration,numerical analysis and theoretical research,and propose an equivalent stiffness model that can consider both the bending moment and the axial force of the plate joint.Firstly,the bending and compression tests of aluminum alloy plate joints are carried out to preliminarily explore the deformation mechanism of joints under the action of bending moment and axial pressure alone.The test results show that the axial deformation and bending deformation of plate joints can be divided into four stages:bolt fixation stage,bolt slip stage,hole wall bearing stage and failure stage.Based on the test,a numerical analysis model is established to study the deformation mechanism of plate joints under the combined action of bending moment and axial force (eccentric force).The numerical analysis results show that the axial deformation mechanism under eccentric force is:1) with the increase of eccentric distance,the equivalent stiffness decreases gradually;2) When the eccentricity is small,the slip stage may occur twice.The deformation characteristics of bending under eccentric force are as follows:1) When the eccentricity is small,repeated sliding occurs;2) When the eccentricity is small,the axial force can improve the bending stiffness,but with the increase of the eccentricity,the axial force can reduce the bending stiffness.In aluminum alloy single-layer latticed shells,the eccentricity of plate joints at different positions is completely different,so it is impossible to accurately calculate the stiffness model of each joint.In order to facilitate calculation and use,the equivalent beam method simulation method can be used.According to the principle of equal axial deformation,bending deformation and yield load,the equivalent stiffness model of aluminum alloy plate joint can be theoretically deduced,and the calculation formula of the parameters of the equivalent two elements of the joint can be obtained.Establish the numerical analysis model and corresponding equivalent stiffness model of plate joints required for verification,and compare the axial and bending load-displacement curves of the two.The results show that the axial deformation and bending deformation of the equivalent beam element model are basically the same as that of the plate joint.Therefore,the Temcor node equivalent model proposed in this paper is accurate and can be used for the stability analysis of single-layer latticed shells.
2023, 38(4): 14-19.
doi: 10.13206/j.gjgS22030101
Abstract:
In recent years,single-layer aluminum alloy reticulated shells are widely used in long-span spatial structures,and the most commonly used joint form is plate joint.The joints of single-layer reticulated shells bear both axial force and bending moment.At present,most of the existing research results focus on the flexural performance of plate joints,and there is less research on their axial performance.In view of the above research status,this paper takes the axial performance of plate joints as the research object,carries out compressive tests,and establishes the corresponding numerical analysis model.The comparison results of test and numerical simulation show that the axial load-displacement curve of plate joints includes four stages:elastic stage,bolt slip stage,hole wall bearing stage and failure stage.The load-displacement curves of the test and numerical simulation are consistent,and the failure modes are all along the bolt hole at the beam end.Obviously,the numerical model is very accurate and can be used for subsequent parametric analysis.The numerical analysis models of different bolt clearance,bolt preload and bolt quantity are established to carry out parametric analysis on the axial performance of plate joints.The results of parametric analysis show that:1) with the increase of bolt clearance,the load-displacement curve of bolt embedding stage basically coincides,the bolt slip distance gradually increases,and the axial stiffness of hole wall in pressure stage is basically consistent with the ultimate load.2) With the increase of bolt preload,the initial load in bolt slip stage gradually increases,the slip distance is basically unchanged,and the load-displacement curve of hole wall bearing and failure stage completely coincide.3) With the decrease of the number of bolts,the axial bearing capacity of plate joints decreases most obviously,the shear bearing capacity takes the second place,and the reduction of flexural bearing capacity is the smallest.In the equal strength design of joints,the number of bolts should be determined according to the principle of equal axial bearing capacity.On the basis of experimental research and numerical analysis,the axial stiffness model of plate joints is studied.According to the load-displacement curve obtained from test and numerical simulation,the multi broken line simplified model can be used to describe the deformation mechanism of plate joints under axial force.Then,based on the deformation and force transmission mechanism of plate joints under axial force,the calculation formula of multi broken line simplified model is deduced.Comparing the simplified model with the experimental and numerical simulation results,it is found that the simplified model is in good agreement with the experimental and numerical simulation results in the elastic stage,sliding stage and hole wall pressure stage.In the failure stage,the ultimate bending moment of the simplified model is slightly smaller than the test and numerical simulation results.It is obvious that the derived multi broken line axial stiffness model satisfies the accuracy and safety requirements at the same time.
In recent years,single-layer aluminum alloy reticulated shells are widely used in long-span spatial structures,and the most commonly used joint form is plate joint.The joints of single-layer reticulated shells bear both axial force and bending moment.At present,most of the existing research results focus on the flexural performance of plate joints,and there is less research on their axial performance.In view of the above research status,this paper takes the axial performance of plate joints as the research object,carries out compressive tests,and establishes the corresponding numerical analysis model.The comparison results of test and numerical simulation show that the axial load-displacement curve of plate joints includes four stages:elastic stage,bolt slip stage,hole wall bearing stage and failure stage.The load-displacement curves of the test and numerical simulation are consistent,and the failure modes are all along the bolt hole at the beam end.Obviously,the numerical model is very accurate and can be used for subsequent parametric analysis.The numerical analysis models of different bolt clearance,bolt preload and bolt quantity are established to carry out parametric analysis on the axial performance of plate joints.The results of parametric analysis show that:1) with the increase of bolt clearance,the load-displacement curve of bolt embedding stage basically coincides,the bolt slip distance gradually increases,and the axial stiffness of hole wall in pressure stage is basically consistent with the ultimate load.2) With the increase of bolt preload,the initial load in bolt slip stage gradually increases,the slip distance is basically unchanged,and the load-displacement curve of hole wall bearing and failure stage completely coincide.3) With the decrease of the number of bolts,the axial bearing capacity of plate joints decreases most obviously,the shear bearing capacity takes the second place,and the reduction of flexural bearing capacity is the smallest.In the equal strength design of joints,the number of bolts should be determined according to the principle of equal axial bearing capacity.On the basis of experimental research and numerical analysis,the axial stiffness model of plate joints is studied.According to the load-displacement curve obtained from test and numerical simulation,the multi broken line simplified model can be used to describe the deformation mechanism of plate joints under axial force.Then,based on the deformation and force transmission mechanism of plate joints under axial force,the calculation formula of multi broken line simplified model is deduced.Comparing the simplified model with the experimental and numerical simulation results,it is found that the simplified model is in good agreement with the experimental and numerical simulation results in the elastic stage,sliding stage and hole wall pressure stage.In the failure stage,the ultimate bending moment of the simplified model is slightly smaller than the test and numerical simulation results.It is obvious that the derived multi broken line axial stiffness model satisfies the accuracy and safety requirements at the same time.
2023, 38(4): 20-28.
doi: 10.13206/j.gjgS22082601
Abstract:
Inspired by the fact that the front wing of Unicorn contains both a column and an air bag wall structure,the traditional aluminum alloy honeycomb panel is improved in this paper.A column structure is set at the end of the honeycomb wall of the aluminum alloy honeycomb panel core panel,that is,a wall end column beetle panel.Because about 10% of the columella in the front wing of Unicorn Fairy distributed in the middle of the honeycomb wall,the columella in the middle of the honeycomb wall was added for joint research.Three kinds of plates are taken as the research object to carry out test and finite element analysis.In order to fully simulate the performance of the integrated molded honeycomb panel and consider that the 3D printing technology cannot print aluminum alloy materials,the resin is used as the material in the experiment,and the 3D printing technology is used to make the integrated honeycomb panel specimen for testing to verify the accuracy of the computer simulation.In the experiment,three different configurations of honeycomb panels,namely,traditional honeycomb panel,wall center pillar beetle panel and wall end pillar beetle panel,were made with resin materials through 3D printing technology,and side pressure tests were carried out on them.It can be seen from the experimental data that the ultimate lateral compression bearing capacity of the wall end post beetle board is increased from 27.9 kN to 34.7 kN compared with the traditional honeycomb board;compared with the traditional honeycomb panel,the lateral compression ultimate bearing capacity of the wall pillar beetle panel is increased from 27.9 kN to 31.9 kN.It can be seen that the lateral pressure performance of wall end post beetle board is better than that of honeycomb board and wall center post beetle board.Secondly,the finite element model was established to compare with the experimental data for verification.Due to the influence of the holes left by the 3D printing process,the failure form of the test piece was slightly different from the stress distribution of the finite element model,but the low stress area in the center of the upper and lower edges of the plate was the same as the experiment.It can be seen from the comparison between the finite element simulation value and the experimental value that the average error between the simulation results and the experimental results is only 3.366%,which verifies the validity of the finite element model.Thirdly,three kinds of honeycomb panel finite element models based on aluminum alloy material properties were established,and the side pressure finite element analysis was carried out.The results show that compared with the traditional honeycomb panel,the yield bearing capacity and ultimate bearing capacity of the wall end post beetle panel are improved by 2.6% and 4.7% respectively.Finally,the four factors that affect the lateral compression performance of the beetle board,namely,the ratio of the column radius r to the side length L of the hexagonal honeycomb core α,the thickness of the beetle board core layer h1,the thickness of the upper and lower panels h2,and the thickness of the beetle board core layer honeycomb wall d,were compared and analyzed.Among them,the diameter length ratio increased from 0.312 5 to 0.5,the yield bearing capacity and the ultimate bearing capacity increased by 5.3% and 6% respectively;the wall thickness of the core layer of the beetle board increased from 1mm to 1.4mm,and the yield bearing capacity and ultimate bearing capacity increased by 3.3% and 6.5% respectively;the thickness of the core layer of the beetle board increased from 6 mm to 12 mm,and the yield bearing capacity and ultimate bearing capacity increased by 2.2% and 5.1% respectively;the thickness of the surface layer of the beetle board increased from 1 mm to 2.5 mm,and the yield bearing capacity and ultimate bearing capacity increased by 244% and 236% respectively.It is concluded that the thickness of the beetle board panel has a significant impact on the side pressure performance.
Inspired by the fact that the front wing of Unicorn contains both a column and an air bag wall structure,the traditional aluminum alloy honeycomb panel is improved in this paper.A column structure is set at the end of the honeycomb wall of the aluminum alloy honeycomb panel core panel,that is,a wall end column beetle panel.Because about 10% of the columella in the front wing of Unicorn Fairy distributed in the middle of the honeycomb wall,the columella in the middle of the honeycomb wall was added for joint research.Three kinds of plates are taken as the research object to carry out test and finite element analysis.In order to fully simulate the performance of the integrated molded honeycomb panel and consider that the 3D printing technology cannot print aluminum alloy materials,the resin is used as the material in the experiment,and the 3D printing technology is used to make the integrated honeycomb panel specimen for testing to verify the accuracy of the computer simulation.In the experiment,three different configurations of honeycomb panels,namely,traditional honeycomb panel,wall center pillar beetle panel and wall end pillar beetle panel,were made with resin materials through 3D printing technology,and side pressure tests were carried out on them.It can be seen from the experimental data that the ultimate lateral compression bearing capacity of the wall end post beetle board is increased from 27.9 kN to 34.7 kN compared with the traditional honeycomb board;compared with the traditional honeycomb panel,the lateral compression ultimate bearing capacity of the wall pillar beetle panel is increased from 27.9 kN to 31.9 kN.It can be seen that the lateral pressure performance of wall end post beetle board is better than that of honeycomb board and wall center post beetle board.Secondly,the finite element model was established to compare with the experimental data for verification.Due to the influence of the holes left by the 3D printing process,the failure form of the test piece was slightly different from the stress distribution of the finite element model,but the low stress area in the center of the upper and lower edges of the plate was the same as the experiment.It can be seen from the comparison between the finite element simulation value and the experimental value that the average error between the simulation results and the experimental results is only 3.366%,which verifies the validity of the finite element model.Thirdly,three kinds of honeycomb panel finite element models based on aluminum alloy material properties were established,and the side pressure finite element analysis was carried out.The results show that compared with the traditional honeycomb panel,the yield bearing capacity and ultimate bearing capacity of the wall end post beetle panel are improved by 2.6% and 4.7% respectively.Finally,the four factors that affect the lateral compression performance of the beetle board,namely,the ratio of the column radius r to the side length L of the hexagonal honeycomb core α,the thickness of the beetle board core layer h1,the thickness of the upper and lower panels h2,and the thickness of the beetle board core layer honeycomb wall d,were compared and analyzed.Among them,the diameter length ratio increased from 0.312 5 to 0.5,the yield bearing capacity and the ultimate bearing capacity increased by 5.3% and 6% respectively;the wall thickness of the core layer of the beetle board increased from 1mm to 1.4mm,and the yield bearing capacity and ultimate bearing capacity increased by 3.3% and 6.5% respectively;the thickness of the core layer of the beetle board increased from 6 mm to 12 mm,and the yield bearing capacity and ultimate bearing capacity increased by 2.2% and 5.1% respectively;the thickness of the surface layer of the beetle board increased from 1 mm to 2.5 mm,and the yield bearing capacity and ultimate bearing capacity increased by 244% and 236% respectively.It is concluded that the thickness of the beetle board panel has a significant impact on the side pressure performance.
2023, 38(4): 29-34.
doi: 10.13206/j.gjgS22063003
Abstract:
Single-layer aluminum alloy latticed shell has many advantages such as light weight,corrosion resistance and beautiful shape,which has been widely used in large-span spatial structures in recent years.Because of the simple structure and convenient installation,plate joint has become one of the most commonly used joint forms of single-layer aluminum alloy reticulated shells.However,because the joint is only connected with the flange of aluminum alloy beam through the cover plate,but not connected with the web,the shear bearing capacity and in-plane axial stiffness of the joint are seriously insufficient and prone to instability and failure,which can not meet the performance requirements of large-span aluminum alloy reticulated shells.In this paper,on the basis of the existing joints,a new type of flower-gusset joint is proposed.In order to explore the shear performance and failure mode of the new aluminum alloy flower-gusset joint,the shear tests of the new type of joint and the traditional plate joint are carried out in this paper.The failure modes and load-displacement curves of the two joints under the out-of-plane load are obtained,and the shear performance of the new type of flower-gusset joint is analyzed.ABAQUS software was used to conduct numerical simulation analysis on the whole loading process of the new type of joint,and the reliability of the finite element model was verified.The results show that the failure mode of plate joints is mainly the tensile-shear failure of the cover plate,and there is no obvious bending failure of the aluminum alloy beam.The failure mode of the new type of joint is mainly manifested as the bending failure of the aluminum alloy beam,the warping of the cover plate and the tearing of the flower-gusset,which is mainly due to the effective sharing of the flower-gusset in the new type of joint and the transfer of a large part of the shear force.The flower-gusset changes the force transmission mode and failure mode of the traditional plate joint,and the aluminum alloy beam webs are connected through it to form an integrated body,which more effectively shares and transmits the shear force,reduces the shear load of the cover plate,improves the shear performance of the joint,thus changing the shortcomings of the brittle failure of the plate joint,so that it has good ductility and energy dissipation capacity.Therefore,compared with the traditional plate joint,the shear bearing capacity of the new joint is increased by 47.4% and the shear stiffness is increased by 103.9% due to the addition of the annular groove in the central area of the new joint,which has a good prospect for engineering application.The finite element analysis results of the new joint show that the linear segment of the load-displacement curve obtained by the finite element analysis is in good agreement with the measured displacement,the error is less than 5%,and the error of the shear bearing capacity is only 0.14%,which verifies the reliability of the finite element simulation results.When the new type of joint is subjected to the ultimate load,the partial stress of the upper and lower cover plates connected with the bar is large.However,most areas of the upper cover plate are plastic,and only a small part of the lower cover plate is plastic.Stress concentration occurs at the bolt hole and the junction of the ring tooth and the groove body.
Single-layer aluminum alloy latticed shell has many advantages such as light weight,corrosion resistance and beautiful shape,which has been widely used in large-span spatial structures in recent years.Because of the simple structure and convenient installation,plate joint has become one of the most commonly used joint forms of single-layer aluminum alloy reticulated shells.However,because the joint is only connected with the flange of aluminum alloy beam through the cover plate,but not connected with the web,the shear bearing capacity and in-plane axial stiffness of the joint are seriously insufficient and prone to instability and failure,which can not meet the performance requirements of large-span aluminum alloy reticulated shells.In this paper,on the basis of the existing joints,a new type of flower-gusset joint is proposed.In order to explore the shear performance and failure mode of the new aluminum alloy flower-gusset joint,the shear tests of the new type of joint and the traditional plate joint are carried out in this paper.The failure modes and load-displacement curves of the two joints under the out-of-plane load are obtained,and the shear performance of the new type of flower-gusset joint is analyzed.ABAQUS software was used to conduct numerical simulation analysis on the whole loading process of the new type of joint,and the reliability of the finite element model was verified.The results show that the failure mode of plate joints is mainly the tensile-shear failure of the cover plate,and there is no obvious bending failure of the aluminum alloy beam.The failure mode of the new type of joint is mainly manifested as the bending failure of the aluminum alloy beam,the warping of the cover plate and the tearing of the flower-gusset,which is mainly due to the effective sharing of the flower-gusset in the new type of joint and the transfer of a large part of the shear force.The flower-gusset changes the force transmission mode and failure mode of the traditional plate joint,and the aluminum alloy beam webs are connected through it to form an integrated body,which more effectively shares and transmits the shear force,reduces the shear load of the cover plate,improves the shear performance of the joint,thus changing the shortcomings of the brittle failure of the plate joint,so that it has good ductility and energy dissipation capacity.Therefore,compared with the traditional plate joint,the shear bearing capacity of the new joint is increased by 47.4% and the shear stiffness is increased by 103.9% due to the addition of the annular groove in the central area of the new joint,which has a good prospect for engineering application.The finite element analysis results of the new joint show that the linear segment of the load-displacement curve obtained by the finite element analysis is in good agreement with the measured displacement,the error is less than 5%,and the error of the shear bearing capacity is only 0.14%,which verifies the reliability of the finite element simulation results.When the new type of joint is subjected to the ultimate load,the partial stress of the upper and lower cover plates connected with the bar is large.However,most areas of the upper cover plate are plastic,and only a small part of the lower cover plate is plastic.Stress concentration occurs at the bolt hole and the junction of the ring tooth and the groove body.
2023, 38(4): 35-40.
doi: 10.13206/j.gjgS22052301
Abstract:
Single layer aluminum alloy reticulated shells based on gusset joints are widely used in long-span spatial structures.At present,the spring element method is used to simulate the mechanical properties of the gusset joint single-layer aluminum alloy reticulated shell.Although the spring element method is accurate,the modeling method is complex and not easy for engineers to use.Therefore,this paper takes the equivalent method of gusset joints as the research object,uses the equivalent beam element to simulate the mechanical properties of gusset joints,gives the calculation formula of the equivalent method,and verifies the effectiveness of the method through numerical simulation and quasi-static test.Then using this method,the effects of the length of the joint domain and the camber height on the slab joints are analyzed.Through the early compression and bending tests,it is found that the load-displacement curve of gusset joints under the axial force and bending moment includes four stages:elastic stage,bolt slip stage,hole wall pressure stage and failure stage.Therefore,under the bending moment or axial force,the load-displacement curve of gusset joints is approximately a four fold line model.Although the four fold line model can be realized by using the spring element method,it also has cumbersome calculation and difficult modeling.In order to simplify the calculation,the equivalent beam elements are used to simulate the gusset joint,and the four fold line model is transformed into the double fold line model according to the principle of equivalent yield load and equivalent yield displacement.Based on the deformation mechanism of gusset joints,the deformation mechanism under the separate action of axial force and bending moment is deduced,and the calculation method of equivalent beam element is proposed based on the equivalence principle.In single-layer aluminum alloy reticulated shells,the joints often bear the effects of axial force and bending moment (eccentric force) at the same time.In order to verify the effectiveness of the equivalent method under eccentric force,the gusset joint and the corresponding equivalent beam element model are established,and then the same eccentric force is applied.The axial force-axial deformation curve and moment-rotation curve of the gusset joint model and the corresponding equivalent model are extracted respectively.By comparing the curves of the two models,it is found that the axial deformation and bending deformation of the equivalent beam under different eccentric forces are very consistent with the gusset joints.At the same time,in order to verify the accuracy of the equivalent method under quasi-static load conditions,a group of quasi-static test results are quoted,and the corresponding equivalent analysis model is established.it is found that the equivalent method can be used to simulate the mechanical properties of gusset joints under reciprocating load.In conclusion,this method can be used to simulate gusset joints under different working conditions.Using this equivalent method,a numerical analysis model is established to analyze the effects of joint domain length and camber height on slab joints.The results show that:1) the increase of joint domain length has a certain weakening effect on the overall stiffness of the structure,and the weakening effect is gradually decreasing,but has little effect on the bearing capacity.2) With the increase of camber height,the stress state of the joint changes,and the bearing capacity and stiffness are significantly improved.In the structural design of single-layer aluminum alloy reticulated shell with gusset joints,the length of joint area and camber height should be reasonably selected.
Single layer aluminum alloy reticulated shells based on gusset joints are widely used in long-span spatial structures.At present,the spring element method is used to simulate the mechanical properties of the gusset joint single-layer aluminum alloy reticulated shell.Although the spring element method is accurate,the modeling method is complex and not easy for engineers to use.Therefore,this paper takes the equivalent method of gusset joints as the research object,uses the equivalent beam element to simulate the mechanical properties of gusset joints,gives the calculation formula of the equivalent method,and verifies the effectiveness of the method through numerical simulation and quasi-static test.Then using this method,the effects of the length of the joint domain and the camber height on the slab joints are analyzed.Through the early compression and bending tests,it is found that the load-displacement curve of gusset joints under the axial force and bending moment includes four stages:elastic stage,bolt slip stage,hole wall pressure stage and failure stage.Therefore,under the bending moment or axial force,the load-displacement curve of gusset joints is approximately a four fold line model.Although the four fold line model can be realized by using the spring element method,it also has cumbersome calculation and difficult modeling.In order to simplify the calculation,the equivalent beam elements are used to simulate the gusset joint,and the four fold line model is transformed into the double fold line model according to the principle of equivalent yield load and equivalent yield displacement.Based on the deformation mechanism of gusset joints,the deformation mechanism under the separate action of axial force and bending moment is deduced,and the calculation method of equivalent beam element is proposed based on the equivalence principle.In single-layer aluminum alloy reticulated shells,the joints often bear the effects of axial force and bending moment (eccentric force) at the same time.In order to verify the effectiveness of the equivalent method under eccentric force,the gusset joint and the corresponding equivalent beam element model are established,and then the same eccentric force is applied.The axial force-axial deformation curve and moment-rotation curve of the gusset joint model and the corresponding equivalent model are extracted respectively.By comparing the curves of the two models,it is found that the axial deformation and bending deformation of the equivalent beam under different eccentric forces are very consistent with the gusset joints.At the same time,in order to verify the accuracy of the equivalent method under quasi-static load conditions,a group of quasi-static test results are quoted,and the corresponding equivalent analysis model is established.it is found that the equivalent method can be used to simulate the mechanical properties of gusset joints under reciprocating load.In conclusion,this method can be used to simulate gusset joints under different working conditions.Using this equivalent method,a numerical analysis model is established to analyze the effects of joint domain length and camber height on slab joints.The results show that:1) the increase of joint domain length has a certain weakening effect on the overall stiffness of the structure,and the weakening effect is gradually decreasing,but has little effect on the bearing capacity.2) With the increase of camber height,the stress state of the joint changes,and the bearing capacity and stiffness are significantly improved.In the structural design of single-layer aluminum alloy reticulated shell with gusset joints,the length of joint area and camber height should be reasonably selected.
2023, 38(4): 41-48.
doi: 10.13206/j.gjgS23021002
Abstract:
In order to improve the computational efficiency of the aluminum alloy honeycomb plate composite reticulated shell,the finite element analysis model was established by using the coupling method (contact model) and the complete coordination method.The finite element analysis results were compared with the bearing capacity test results of the aluminum alloy honeycomb plate composite reticulated shell.Based on the two types of finite element analysis methods,the large-span aluminum alloy honeycomb plate composite reticulated shell model was established,and the complete coordination method with the reduction coefficient was proposed as the simplified calculation method of the aluminum alloy honeycomb plate composite reticulated shell.Based on the above simplified calculation method,the finite element analysis model is established,and the variation of natural frequency of aluminum alloy honeycomb plate composite reticulated shell under different rise-span ratios (1/4,1/5,1/6),different spans (40,50,60 m) and different plate thicknesses (5,10,15 mm) was studied by ANSYS software.The time-history analysis of aluminum alloy honeycomb plate composite reticulated shell were carried out.The dynamic displacement response of the structure and the proportion of the members entering the plasticity were comprehensively studied and the acceleration amplitude of the reticulated shell was obtained when it was destroyed.The influence of different rise-span ratios,different spans and different plate thicknesses on the progressive collapse resistance of aluminum alloy honeycomb plate composite reticulated shell under strong earthquake was discussed.The results show that when the plate thickness is reduced by 20%,the error between the finite element analysis results and the experimental results is 5.87%,and the error is within a reasonable range.The complete coordination method with a reduction factor of 0.8 was proposed as a simplified calculation method for aluminum alloy honeycomb composite reticulated shells,and it is applied to the natural frequency analysis of composite reticulated shells and the progressive of composite reticulated shells under strong earthquakes.Through the modal analysis of the composite reticulated shell,it is found that the natural frequency of the composite reticulated shell increases slightly with the increase of the order.The decrease of the rise-span ratio will cause the decrease of the natural frequency of the composite reticulated shell.The decrease of span and the increase of plate thickness will increase the natural frequency of the composite reticulated shell.Through the time-history analysis of the composite reticulated shell,it is found that with the continuous increase of the acceleration amplitude,the maximum displacement of joint and the proportion of members entering the plasticity of the aluminum alloy honeycomb plate composite reticulated shell with different rise-span ratio,different span and different plate thickness are gradually increasing.When the acceleration amplitude is 325 m/s2,375 m/s2 and 400 m/s2,the composite reticulated shell with rise-span ratio of 1/4,1/5,and 1/6 successively collapses under the action of El Centro wave.When the acceleration amplitude is 300 m/s2 and 350 m/s2,the composite reticulated shells with spans of 40 m and 50 m successively collapse under the action of El Centro wave.When the acceleration amplitude is 225 m/s2 and 575 m/s2,the composite reticulated shell with plate thickness of 5 mm and 15 mm successively collapses under the action of El Centro wave.The decrease of rise-span ratio,the increase of span and the increase of plate thickness will increase the acceleration amplitude of the composite reticulated shell under the action of El Centro wave,which further confirms the improvement of the progressive collapse resistance of the aluminum alloy honeycomb plate composite reticulated shell.
In order to improve the computational efficiency of the aluminum alloy honeycomb plate composite reticulated shell,the finite element analysis model was established by using the coupling method (contact model) and the complete coordination method.The finite element analysis results were compared with the bearing capacity test results of the aluminum alloy honeycomb plate composite reticulated shell.Based on the two types of finite element analysis methods,the large-span aluminum alloy honeycomb plate composite reticulated shell model was established,and the complete coordination method with the reduction coefficient was proposed as the simplified calculation method of the aluminum alloy honeycomb plate composite reticulated shell.Based on the above simplified calculation method,the finite element analysis model is established,and the variation of natural frequency of aluminum alloy honeycomb plate composite reticulated shell under different rise-span ratios (1/4,1/5,1/6),different spans (40,50,60 m) and different plate thicknesses (5,10,15 mm) was studied by ANSYS software.The time-history analysis of aluminum alloy honeycomb plate composite reticulated shell were carried out.The dynamic displacement response of the structure and the proportion of the members entering the plasticity were comprehensively studied and the acceleration amplitude of the reticulated shell was obtained when it was destroyed.The influence of different rise-span ratios,different spans and different plate thicknesses on the progressive collapse resistance of aluminum alloy honeycomb plate composite reticulated shell under strong earthquake was discussed.The results show that when the plate thickness is reduced by 20%,the error between the finite element analysis results and the experimental results is 5.87%,and the error is within a reasonable range.The complete coordination method with a reduction factor of 0.8 was proposed as a simplified calculation method for aluminum alloy honeycomb composite reticulated shells,and it is applied to the natural frequency analysis of composite reticulated shells and the progressive of composite reticulated shells under strong earthquakes.Through the modal analysis of the composite reticulated shell,it is found that the natural frequency of the composite reticulated shell increases slightly with the increase of the order.The decrease of the rise-span ratio will cause the decrease of the natural frequency of the composite reticulated shell.The decrease of span and the increase of plate thickness will increase the natural frequency of the composite reticulated shell.Through the time-history analysis of the composite reticulated shell,it is found that with the continuous increase of the acceleration amplitude,the maximum displacement of joint and the proportion of members entering the plasticity of the aluminum alloy honeycomb plate composite reticulated shell with different rise-span ratio,different span and different plate thickness are gradually increasing.When the acceleration amplitude is 325 m/s2,375 m/s2 and 400 m/s2,the composite reticulated shell with rise-span ratio of 1/4,1/5,and 1/6 successively collapses under the action of El Centro wave.When the acceleration amplitude is 300 m/s2 and 350 m/s2,the composite reticulated shells with spans of 40 m and 50 m successively collapse under the action of El Centro wave.When the acceleration amplitude is 225 m/s2 and 575 m/s2,the composite reticulated shell with plate thickness of 5 mm and 15 mm successively collapses under the action of El Centro wave.The decrease of rise-span ratio,the increase of span and the increase of plate thickness will increase the acceleration amplitude of the composite reticulated shell under the action of El Centro wave,which further confirms the improvement of the progressive collapse resistance of the aluminum alloy honeycomb plate composite reticulated shell.
2023, 38(4): 49-51.
doi: 10.13206/j.gjgS23010320
Abstract:
According to thin-wall component theory,equilibrium differential equations for C-and Z-purlins under wind-suction are derived,and finite element analysis is carried out.The result reveals that for Z-purlins,the twisting moment in the differential equation is very small,implying that the twisting deformation of Z-purlin under wind suction is very small,the thin-wall component theoretical results are in good agreement with those of the FEM analysis.The load-carrying capacity of Z purlin is greater than C-purlin of the same section size,and it is recommended that Z-purlins be used in precedence in practice
According to thin-wall component theory,equilibrium differential equations for C-and Z-purlins under wind-suction are derived,and finite element analysis is carried out.The result reveals that for Z-purlins,the twisting moment in the differential equation is very small,implying that the twisting deformation of Z-purlin under wind suction is very small,the thin-wall component theoretical results are in good agreement with those of the FEM analysis.The load-carrying capacity of Z purlin is greater than C-purlin of the same section size,and it is recommended that Z-purlins be used in precedence in practice
