Finite element modeling method and modeling system for super high-rise steel pipe concrete column construction process

Abstract

The invention provides a super high-rise steel tube concrete column construction process finite element modeling method and system, and the method comprises the steps: building a finite element model based on a steel tube, a construction node and a concrete unit structure, and setting material attributes, boundary conditions and contact attributes; applying axial force load caused by dead load to the wall and the top surface of each layer of steel pipe according to a construction step of every n layers, and so on until construction of all layers is completed, and simulating the construction process by setting a life-death unit; after construction of all layers is completed, axial force loads caused by live loads are applied at a time, and establishment of a refined finite element model is completed; and the rigidity, the bearing capacity and the anti-seismic property of the concrete-filled steel tubular column are calculated and analyzed through finite elements. According to the method, a'life-death unit 'is arranged to simulate the construction process, loading is carried out according to the n-layer one-step construction step, the contact attribute between the steel pipe and concrete is arranged in the simulation process, the bonding friction effect of an interface is considered, and refined finite element modeling of the concrete-filled steel tubular column of the super high-rise building is achieved.

Description

Technical Field

[0001] The present invention relates to the field of numerical calculation, and more specifically, to a finite element modeling method and system for the construction process of super high-rise concrete-filled steel tubular columns. Background Art

[0002] The concrete-filled steel tubular column is evolved from the spiral stirrup concrete column and is composed of a steel pipe and core concrete. The two jointly bear the load, can give full play to the material properties of steel and concrete, and has the advantages of high bearing capacity, good plasticity and toughness, good seismic performance, convenient construction, and good economy, so it has been widely used in long-span bridges and super high-rise buildings.

[0003] In actual super high-rise structures, the cross-sectional dimensions of concrete-filled steel tubular columns are large and the number of floors is many, and the finite element modeling is complex. The traditional finite element modeling method is difficult to accurately describe the change process of the mechanical behavior of concrete-filled steel tubular columns during construction and the force transmission mechanism between the steel pipe and the concrete. Summary of the Invention

[0004] In view of the need for super high-rise finite element modeling in the prior art, the present invention provides a finite element modeling method and system for the construction process of super high-rise concrete-filled steel tubular columns, which can realize the refined finite element modeling of super high-rise concrete-filled steel tubular columns.

[0005] According to the first aspect of the present invention, there is provided a finite element modeling method for the construction process of super high-rise concrete-filled steel tubular columns, including:

[0006] Determine the element structures of the steel pipe, construction joints, and concrete, and establish a finite element model, wherein the positions of the construction joints are set on each floor according to the design details;

[0007] Set the material properties and boundary conditions of the steel pipe and concrete according to the actual situation, and set the contact property between the steel pipe and the concrete;

[0008] Taking every n floors as a construction step, during the construction process of each construction step, apply the axial force load caused by the dead load on the steel pipe wall and top surface of each floor, and so on, and execute multiple construction steps until the construction of all floors is completed. Among them, in the n floors of each construction step, the construction process is simulated by setting birth and death elements, where n is a positive integer greater than or equal to 2;

[0009] After the construction of all floors is completed, apply the axial force load caused by the live load at one time to complete the establishment of the refined finite element model;

[0010] Analyze the stiffness, bearing capacity, and seismic performance of the super high-rise concrete-filled steel tubular column through finite element calculation.

[0011] On the basis of the above technical solutions, the present invention can also be improved as follows.

[0012] Optionally, the determination of the unit structures of the steel pipe, the structural joint, and the concrete includes:

[0013] The steel pipe and the structural joint adopt shell elements, and the concrete adopts three-dimensional solid elements.

[0014] Optionally, the setting of the material properties and boundary conditions of the steel pipe and the concrete according to the actual situation, and the setting of the contact property between the steel pipe and the concrete include:

[0015] Set the material properties of the steel pipe and the concrete. The bottom of the concrete-filled steel tube column is fixed, and spring constraints are set at the corresponding steel beam parts of each floor. The normal allowable gap is used to simulate the bond of the concrete-filled steel tube, and the Coulomb friction is used to simulate the tangential behavior of the concrete-filled steel tube. The "hard contact" is adopted in the normal direction.

[0016] Optionally, according to one construction step for every n floors, during the construction process of each construction step, axial force loads caused by dead loads are applied to the steel pipe wall and the top surface of each floor, including:

[0017] During the construction process of the concrete-filled steel tube column simulated by using the "birth and death element", the load is applied according to the construction steps of one step for every n floors. The self-weight construction of the component simulates the loading of the axial force load layer by layer. Among them, the additional gravity load of each floor acts uniformly on four points that are symmetrically located on the outer side of the steel pipe wall node area.

[0018] Optionally, the analysis of the stiffness, bearing capacity, and seismic performance of the super-high-rise concrete-filled steel tube column through finite element calculation includes:

[0019] After the refined finite element model is established, the concrete of all floors is cooled down. After cooling, axial force loads are applied for finite element calculation until the concrete-filled steel tube column shows a failure phenomenon, and the axial force-displacement curve of the concrete-filled steel tube column, the debonding distribution between the steel pipe and the concrete, and the debonding distribution of the joint structure are obtained;

[0020] Based on the axial force-displacement curve of the concrete-filled steel tube column, the debonding distribution between the steel pipe and the concrete, and the debonding distribution of the joint structure, calculate and analyze the stiffness, bearing capacity, and seismic performance of the super-high-rise concrete-filled steel tube column.

[0021] Optionally, it further includes:

[0022] Establish three structural models with joints, and analyze the stiffness, bearing capacity, and seismic performance of the super-high-rise concrete-filled steel tube column through finite element calculation;

[0023] Among them, the first structural model is provided with inner ring ribs at the upper and lower flanges at a preset distance from the beam height of the floor node;

[0024] The second structural model is provided with a two-way through beam at the floor node;

[0025] The third structural model has the above-mentioned bidirectional through beams and inner ring plates at the floor nodes.

[0026] According to a second aspect of the present invention, a finite element modeling system for a super high-rise concrete-filled steel tube column construction process is provided, comprising:

[0027] Establishing a module for determining the unit structure of steel pipes, structural nodes and concrete, and establishing a finite element model, wherein the positions of the structural nodes are set at each layer according to the design details;

[0028] A setting module, used to set the material properties and boundary conditions of the steel pipe and concrete according to actual conditions, and to set the contact properties between the steel pipe and concrete;

[0029] The construction simulation module is used to follow one construction step for every n layers. During the construction process of each construction step, the axial force caused by the dead load is applied to the wall and top surface of each layer of steel pipe, and so on, and multiple construction steps are executed until the construction of all layers is completed. Among them, in the n layers of each construction step, the construction process is simulated by setting the life and death unit, and n is a positive integer greater than or equal to 2; after the construction of all layers is completed, the axial force caused by the live load is applied at one time to complete the establishment of the refined finite element model;

[0030] The analysis module is used to analyze the stiffness, bearing capacity and seismic performance of super-high-rise concrete-filled steel tube columns through finite element calculation.

[0031] The present invention provides a finite element modeling method and modeling system for the construction process of a super-high-rise steel tube concrete column. The method simulates the construction process by setting a "life and death unit" and loads the structure according to the n-layer construction step. During the simulation process, the contact properties between the steel tube and the concrete are set to consider the bonding and friction effects of the interface, thereby realizing refined finite element modeling of the steel tube concrete column of a super-high-rise building. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of a finite element modeling method for a super high-rise concrete-filled steel tube column construction process provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a model node structure according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a finite element model node structure according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of constraint conditions in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of horizontal de-stressing gap distribution of concrete-filled steel tubes when a 72-story model is cooled by 15°C in an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of the horizontal separation gap between the concrete of a typical floor and the steel pipe wall when the temperature of the 72-story model in the embodiment of the present invention drops by 15°C at the end

[0038] Figure 7 Schematic diagram of the vertical shrinkage deformation of a typical floor of the 72-story model at the end of temperature drop in the embodiment of the present invention

[0039] Figure 8 Schematic diagram of the vertical separation of the inner ring plate in the embodiment of the present invention (at the end of temperature drop)

[0040] Figure 9 Schematic diagram of the vertical separation of the flange of the through beam in the embodiment of the present invention (at the end of temperature drop)

[0041] Figure 10 Schematic diagram of the vertical separation of the inner ring plate in the embodiment of the present invention (at the end of temperature drop)

[0042] Figure 11 Axial pressure between the concrete at the bottom of the concrete-filled steel tube column with a 72-story node structure and the steel pipe wall in the embodiment of the present invention

[0043] Figure 12 Schematic diagram of the force-displacement curve of the concrete-filled steel tube column on the first floor in the embodiment of the present invention

[0044] Figure 13 Schematic diagram of the structure of a finite element modeling system for the construction process of super high-rise concrete-filled steel tube columns provided in the embodiment of the present invention Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. In addition, the technical features in each embodiment or individual embodiment provided by the present invention can be combined with each other arbitrarily to form a feasible technical solution. Such combination is not restricted by the order of steps and / or the pattern of structural composition, but must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0046] Figure 1 Flowchart of a finite element modeling method for the construction process of super high-rise concrete-filled steel tube columns provided in an embodiment of the present invention, asFigure 1 As shown in the figure, the method includes:

[0047] Step 1: Determine the unit structures of the steel pipe, the structural joint, and the concrete, and establish a finite element model. Among them, the positions of the structural joints are set on each floor according to the design details.

[0048] Step 2: Set the material properties and boundary conditions of the steel pipe and the concrete according to the actual situation, and set the contact property between the steel pipe and the concrete.

[0049] Step 3: Take every n floors as a construction step. During the construction process of each construction step, apply the axial force load caused by the dead load on the steel pipe wall and the top surface of each floor, and so on. Execute multiple construction steps until the construction of all floors is completed. Among them, in the n floors of each construction step, simulate the construction process by setting birth and death elements, where n is a positive integer greater than or equal to 2.

[0050] Step 4: After the construction of all floors is completed, apply the axial force load caused by the live load at one time to complete the establishment of the refined finite element model.

[0051] Step 5: Analyze the stiffness, bearing capacity, and seismic performance of the super high-rise concrete-filled steel tubular column through finite element calculation.

[0052] In some specific embodiments of the present invention, the diameter of the concrete in the model is 1540 mm, and the wall thickness of the steel pipe is 30 mm. The single-story height of the 72-story concrete-filled steel tubular single-column model is 4 m, and the total height of the model is 288 m. Three node structure models are established, as Figure 2 shown. Among them, Figure 2 (a) in it is the elevation view of the single-story concrete-filled steel tubular column, and (b), (c), and (d) are the plan views of Model 1, Model 2, and Model 3 respectively. Among them, in the structure of Model 1, 120×20 mm inner ring ribs are set at the upper and lower flanges of the floor node beam with a height of 800 mm, and the node construction method is adopted by SEG Plaza Building; in the structure of Model 2, two-way through beams are set at the floor nodes, and the beam section adopts H800×300×14×20 mm; in the structure of Model 3, the above-mentioned two-way through beams and inner ring plates are set at the floor nodes. The material model of the steel adopts the isotropic hardening plasticity model, which satisfies the Von Mises yield criterion; the stress-strain relationship adopts the double-line linear hardening model, and the elastic modulus of the hardening section is taken as 0.01E S , the material strength grade is Q345, and the yield strength of the steel adopts the standard value of 345 MPa. The material model of the concrete adopts the plastic damage model, and the uniaxial stress-strain relationship adopts the calculation formula given in Appendix C of the "Code for Design of Concrete Structures" (GB50010-2010). The concrete strength grade is C60, the strength adopts the standard value of 38.5 MPa, and the Poisson's ratio is 0.2.

[0053] The specific steps of the refined modeling process of super high-rise concrete-filled steel tubular columns are as follows:

[0054] (1) Shell elements are used for steel pipes and structural joints, and three-dimensional solid elements are used for concrete. The detailed joint structure drawings are as Figure 3 shown. A finite element model is established. Among them, Figure 3 the (a), (b), and (c) in are the schematic diagrams of the finite element model joint structures of Model 1, Model 2, and Model 3 respectively. Set the material properties, fix the column bottom, U1 = U2 = U3 = UR1 = UR2 = UR3 = 0, where U1, U2, U3, UR1, UR2, and UR3 represent the six degrees of freedom of the concrete column. Spring constraints are set at the positions corresponding to the steel beams on each floor, and the spring stiffness is taken as 30 kN / mm. Figure 4 The schematic diagram of the constraint conditions is shown. The bond between concrete-filled steel tubes is simulated by a normal allowable gap of 0.008 mm, and the tangential behavior of concrete-filled steel tubes is simulated by Coulomb friction, with a friction coefficient of 0.4 and a maximum shear stress of 2.04 Mpa; the "hard contact" is adopted in the normal direction.

[0055] (2) The "birth and death element" is used to simulate the construction process of the concrete-filled steel tubular column. Loading is carried out according to the construction steps of six floors at a time. The self-weight construction of the component is simulated by layer-by-layer loading, and the additional gravity load of each layer acts evenly on the four symmetric points on the outer node area of the steel pipe wall (equivalent to an axial compression ratio of 0.2, that is, the dead load is applied).

[0056] (3) After step (2) is completed, an axial force load of 24480 kN is applied at one time (equivalent to an axial compression ratio of 0.2, that is, the live load is applied).

[0057] (4) After the axial force is applied, the concrete of floors 1 to 72 is gradually cooled from 15° to 0°.

[0058] (5) A refined finite element model is established, an axial force load is applied, and finite element calculations are carried out until the concrete-filled steel tube shows a failure phenomenon, obtaining the axial force-displacement curve of the concrete-filled steel tube, the separation distribution between the steel pipe and the concrete, the separation distribution of the joint structure, etc.

[0059] The horizontal separation laws between the concrete and the steel pipe wall of the three joint structure models are basically similar. Figure 5 Shown is the horizontal separation gap diagram between the concrete and the steel pipe wall of the 72-story joint structure model at the moment when the cooling is completed. Before cooling, there is almost no obvious separation between the concrete and the steel pipe wall; when the cooling is completed, different degrees of horizontal separation occur between the steel pipe wall and the concrete, with a maximum separation gap of 0.25 mm, which is basically consistent with the measured separation gap of 0.1 - 0.2 mm.

[0060] The horizontal separation gap diagrams between the concrete and the steel pipe wall of typical floors of the three joint structure models. Figure 6It shows the horizontal separation gap between the concrete and the steel pipe wall at the end of the temperature drop of the 72-story model by 15°C. The horizontal separation between the concrete and the steel pipe wall mainly occurs in the areas on both sides below the loading points in the middle of each floor; the separation range shows a trend of being small at the bottom floors and large at the middle and upper floors; the separation range of the concrete-filled steel tubes from the 1st to the 6th floor is 65% - 75%; from the 7th to the 42nd floor is 85% - 90%; from the 43rd to the 72nd floor is 95% - 98%.

[0061] Figure 7 Shown is the vertical shrinkage deformation diagram of the concrete of the 72-story model with joint structures at the moment when the temperature drop is completed. Among them, Figure 7 (a), (b), and (c) respectively show the schematic diagrams of the vertical shrinkage deformation of the bottom floors (1 - 6 floors), the middle floors (37 - 42 floors), and the upper floors (67 - 72 floors). The vertical deformation of the concrete caused by the cooling shrinkage accumulates layer by layer, and the maximum vertical shrinkage deformation at the top of the column is 29.232 - 29.712 mm.

[0062] Figure 8 It is a schematic diagram of the separation distance between the inner ring plate and the concrete, Figure 8 which respectively shows the schematic diagrams of the vertical separation distance of the inner ring plate of the typical cross-sections of the bottom floors (1 - 6 floors), the middle floors (7 - 42 floors), and the upper floors (43 - 72 floors). There is almost no separation between the top surface of the inner ring plate and the concrete on each floor. There is almost no separation at the bottom surface of the inner ring plate from the 1st to the 6th floor; the separation distance at the bottom surface of the inner ring plate from the 7th to the 42nd floor is about 0.13 mm; the separation distance at the bottom surface of the inner ring plate from the 43rd to the 72nd floor is about 0.253 mm.

[0063] Figure 9 It is a schematic diagram of the separation distance between the flange of the through beam and the concrete, Figure 9 which respectively shows the schematic diagrams of the vertical separation of the flange of the through beam of the typical cross-sections of the bottom floors (1 - 6 floors), the middle floors (7 - 42 floors), and the upper floors (43 - 72 floors). There is almost no separation between the top surface of the through beam and the concrete on each floor. There is almost no separation at the bottom surface of the through beam from the 1st to the 6th floor; the local separation distance at the bottom surface of the through beam from the 7th to the 42nd floor due to the warping of the steel beam is about 0.305 mm; the separation distance at the bottom surface of the through beam from the 43rd to the 72nd floor is about 0.215 mm.

[0064] Figure 10 It is a schematic diagram of the separation distance between the inner ring plate and the concrete, Figure 10 which respectively shows the schematic diagrams of the separation distance between the inner ring plate and the concrete of the typical cross-sections of the bottom floors (1 - 6 floors), the middle floors (7 - 42 floors), and the upper floors (43 - 72 floors). There is almost no separation between the top surface of the inner ring plate and the concrete on each floor. There is almost no separation at the bottom surface of the inner ring plate from the 1st to the 6th floor; there is almost no separation at the bottom surface of the inner ring plate from the 7th to the 42nd floor; the separation distance at the bottom surface of the inner ring plate from the 43rd to the 72nd floor is about 0.204 mm.

[0065] Figure 11 Shows the schematic diagram of the axial pressure of the concrete at the bottom of the concrete-filled steel tubular column with a 72-story joint structure and the steel pipe wall. Among them, Figure 11 Figure (a) in it shows the axial force at the bottom of the concrete-filled steel tubular column at each construction step before cooling. The self-weight of the structure is one step every 6 floors, and the full-floor dead load and live load are added at the 13th step; Figure (b) shows the change diagram of the axial force of the concrete at the bottom of the column and the steel pipe wall during the process of cooling down in ten levels; Figure (c) shows the change diagram of the axial force of the concrete at the bottom of the column and the steel pipe wall when loading continues after cooling. The internal force distribution and transfer laws of the concrete and the steel pipe wall in the three models are basically similar; as the concrete cools and shrinks, the axial force of the concrete gradually decreases by 9-10%, and the axial force of the steel pipe wall gradually increases by 15-16%. After cooling, when the vertical load is continuously applied, the increasing rate of the axial force of the steel pipe wall is 1.2-1.4 times that of the axial force of the concrete before cooling, resulting in the steel pipe wall entering yield first. The axial force borne by the steel pipe wall begins to decrease, and the axial force of the concrete increases sharply until it is crushed.

[0066] Figure 12 Is the axial force-displacement curve of the first-floor column in the concrete-filled steel tubular column with a 72-story joint structure. It can be seen from the figure that the yield bearing capacity and ultimate bearing capacity of Model 3 (penetrating beam + inner ring plate) are the largest, the yield bearing capacity and ultimate bearing capacity of Model 1 (inner ring plate) are the smallest, and Model 2 is in the middle.

[0067] It should be noted that the refined finite element modeling method proposed in the embodiments of the present invention is not only applicable to concrete-filled steel tubular columns, but also applicable to any component and structure with a steel-concrete interface. At the same time, the embodiments of the present invention can be implemented not only with ABAQUS software, but also with finite element software such as ANSYS and MARC. These contents all belong to the protection scope of the present invention.

[0068] See Figure 13 , which is a finite element modeling system for the construction process of a super-high-rise concrete-filled steel tubular column provided by an embodiment of the present invention. The modeling system includes:

[0069] A building module 1301, which is used to determine the unit structures of the steel pipe, the construction joint, and the concrete, and establish a finite element model, wherein the position of the construction joint is set on each floor according to the design details;

[0070] A setting module 1302, which is used to set the material properties and boundary conditions of the steel pipe and the concrete according to the actual situation, and set the contact property between the steel pipe and the concrete;

[0071] The construction simulation module 1303 is used to apply the axial force load caused by the dead load on the steel pipe wall and the top surface of each layer during the construction process of each construction step according to one construction step for every n layers, and so on, and execute multiple construction steps until the construction of all layers is completed. Among them, in the n layers of each construction step, the construction process is simulated by setting birth and death elements; after the construction of all layers is completed, the axial force load caused by the live load is applied at one time to complete the establishment of the refined finite element model;

[0072] The analysis module 1304 is used to analyze the stiffness, bearing capacity and seismic performance of the super high-rise concrete-filled steel tube column through finite element calculation.

[0073] It can be understood that a finite element modeling system for the construction process of a super high-rise concrete-filled steel tube column provided by the present invention corresponds to the finite element modeling method for the construction process of a super high-rise concrete-filled steel tube column provided in the foregoing embodiments. The relevant technical features of the finite element modeling system for the construction process of a super high-rise concrete-filled steel tube column can refer to the relevant technical features of the slicing fusion method of the multi-source heterogeneous model, which will not be elaborated here.

[0074] A finite element modeling method and modeling system for the construction process of a super high-rise concrete-filled steel tube column provided by an embodiment of the present invention simulate the construction process by setting "birth and death elements", load according to the construction step of n layers in one step, and set the contact property between the steel pipe and the concrete during the simulation process to consider the bonding friction effect of the interface, so as to realize the refined finite element modeling of the concrete-filled steel tube column of the super high-rise building.

[0075] It should be noted that in the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0076] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0077] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded computers, or other programmable data processing devices to generate a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in one flow Figure 1 or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0078] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in one flow Figure 1 or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0081] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A finite element modeling method for the construction process of super high-rise concrete-filled steel tubular columns, characterized in that Including: Determine the unit structures of steel pipes, structural joints and concrete, and establish a finite element model, where the positions of the structural joints are set on each floor according to the design details; Set the material properties and boundary conditions of the steel pipes and concrete according to the actual situation, and set the contact properties between the steel pipes and concrete; Taking every n floors as a construction step, during the construction process of each construction step, apply the axial force load caused by the dead load on the steel pipe wall and the top surface of each floor, and so on, execute multiple construction steps until the construction of all floors is completed, where, for the n floors of each construction step, simulate the construction process by setting birth and death elements, where n is a positive integer greater than or equal to 2; After the construction of all floors is completed, apply the axial force load caused by the live load at one time to complete the establishment of the refined finite element model; Analyze the stiffness, bearing capacity and seismic performance of the super high-rise concrete-filled steel tube columns through finite element calculation.

2. The finite element modeling method according to claim 1, wherein, The determination of the unit structures of the steel pipes, structural joints and concrete includes: The steel pipes and the structural joints adopt shell elements, and the concrete adopts three-dimensional solid elements.

3. The finite element modeling method according to claim 1, characterized in that The setting of the material properties and boundary conditions of the steel pipes and concrete according to the actual situation, and the setting of the contact properties between the steel pipes and concrete includes: Set the material properties of the steel pipes and concrete, fix the bottom of the concrete-filled steel tube column, set spring constraints at the corresponding steel beam parts of each floor, simulate the bond of the concrete-filled steel tube by using the normal allowable gap, simulate the tangential behavior of the concrete-filled steel tube by using Coulomb friction, and adopt "hard contact" in the normal direction.

4. The finite element modeling method according to claim 1, wherein The application of the axial force load caused by the dead load on the steel pipe wall and the top surface of each floor during the construction process of each construction step includes: During the construction process of the concrete-filled steel tube column simulated by using "birth and death elements", carry out load loading according to the construction steps of n floors in one step, and simulate the loading of the axial force load layer by layer for the self-weight of the member, where the additional gravity load of each floor acts uniformly on four points symmetrically on the outside node area of the steel pipe wall.

5. The finite element modeling method according to claim 1 or 4, characterized in that The analysis of the stiffness, bearing capacity and seismic performance of the super high-rise concrete-filled steel tube columns through finite element calculation includes: After the refined finite element model is established, cool down the concrete of all floors. After cooling down, apply the axial force load and carry out finite element calculation until the concrete-filled steel tube column shows a failure phenomenon, and obtain the axial force-displacement curve of the concrete-filled steel tube column, the debonding distribution between the steel pipe and the concrete, and the debonding distribution of the joint structure; Based on the axial force-displacement curve of the concrete-filled steel tube column, the debonding distribution between the steel pipe and the concrete, and the debonding distribution of the joint structure, calculate and analyze the stiffness, bearing capacity and seismic performance of the super high-rise concrete-filled steel tube columns.

6. The finite element modeling method according to claim 1, characterized in that Also including: Establish three structural models with joints, and analyze the stiffness, bearing capacity and seismic performance of the super high-rise concrete-filled steel tube columns through finite element calculation; Among them, the first structural model sets inner ring ribs at the upper and lower flanges at a preset distance from the beam height of the floor node; The second structural model sets bidirectional through beams at the floor nodes; The third structural model sets the above-mentioned bidirectional through beams and inner ring plates at the floor nodes.

7. A finite element modeling system for the construction process of super high-rise concrete-filled steel tubular columns, characterized in that, Including: A building module, which is used to determine the element structures of steel pipes, structural joints and concrete, and establish a finite element model, wherein the positions of the structural joints are set on each floor according to the design details; A setting module, which is used to set the material properties and boundary conditions of the steel pipes and concrete according to the actual situation, and set the contact property between the steel pipes and concrete; A construction simulation module, which is used to perform a construction step for every n floors. During the construction process of each construction step, axial force loads caused by dead loads are applied to the steel pipe walls and top surfaces of each floor, and so on, and multiple construction steps are executed until the construction of all floors is completed, wherein, for the n floors of each construction step, the construction process is simulated by setting birth and death elements, and n is a positive integer greater than or equal to 2; after the construction of all floors is completed, the axial force loads caused by live loads are applied at one time to complete the establishment of the refined finite element model; An analysis module, which is used to analyze the stiffness, bearing capacity and seismic performance of super high-rise concrete-filled steel tube columns through finite element calculation.

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