Analysis method considering tangential and normal coupling effects of steel pipe-concrete interface

Abstract

The invention relates to the technical field of constructional engineering, and provides an analysis method considering tangential and normal coupling effects of a steel tube-concrete interface, which comprises the following steps: S1, constructing a finite element model of contact between a steel tube and concrete, with the inner wall surface of the steel tube as a principal surface and the outer surface of the concrete as a subordinate surface; s2, simulating a steel tube-concrete tangential behavior by adopting a coulomb friction model, and endowing the finite element model with a tangential contact attribute; s3, on the basis of normal contact attributes, a penalty function is adopted to define the mutual relation of steel pipe-concrete normal contact; and S4, analyzing the mechanical behavior of the finite element model based on the correlation. The method comprehensively considers the normal and tangential behaviors of the contact surface of the steel pipe and the concrete, improves the simulation accuracy, and improves the numerical analysis precision of the model.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and more specifically, to an analysis method considering tangential and normal coupling effects of a steel tube-concrete interface. Background Art

[0002] Steel tube concrete columns are widely used in engineering, and their sizes are gradually increasing. In practical applications, under the influence of external loads, creep shrinkage, temperature changes and other factors, the interface between the steel tube and the concrete in the steel tube concrete column may experience normal degassing and tangential bond friction at the same time. The two interact with each other and jointly affect the mechanical properties of steel tube concrete components or structures. A large number of experimental and numerical studies have shown that the degassing between the steel tube and the core concrete directly affects the bonding performance of the interface between the two, which will reduce the collaborative working performance between the steel tube and the core concrete, cause stress redistribution in the cross section of the debonding, the deformation of the steel tube and the concrete is not coordinated, and the stress distribution of the steel tube is uneven, which in turn leads to a reduction in the sleeve effect of the steel tube, thereby reducing the stiffness and bearing capacity of the steel tube concrete column.

[0003] Most existing numerical calculation methods consider normal and tangential behaviors separately, but do not pay enough attention to the coupling effect between the two, which leads to deviations between simulation results and reality. Therefore, studying a new method to improve simulation accuracy has important engineering application value. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides an analysis method which takes into account the tangential and normal coupling effects of the steel pipe-concrete interface, comprehensively considers the normal and tangential behaviors of the contact surface between the steel pipe and the concrete, improves the simulation accuracy, and improves the accuracy of the model numerical analysis.

[0005] According to a first aspect of the present invention, there is provided an analysis method considering the tangential and normal coupling effects of a steel tube-concrete interface, comprising: S1, construct a finite element model of the contact between the steel pipe and the concrete, where the inner wall of the steel pipe is used as the main surface and the outer surface of the concrete is used as the secondary surface; S2, using the Coulomb friction model to simulate the tangential behavior of the steel tube-concrete, and giving the tangential contact attribute to the finite element model; S3, based on the normal contact properties, a “penalty” function is used to define the mutual relationship of the normal contact between steel tube and concrete; S4, analyzing the mechanical behavior of the finite element model based on the mutual relationship.

[0006] Based on the above technical solution, the present invention can also make the following improvements.

[0007] Optionally, step S1 includes: S101. Based on finite element analysis software, take the inner wall surface of the steel pipe as the master surface and the outer surface of the concrete as the slave surface to construct a finite element model of the steel pipe-concrete contact; S102. Assign material properties to the finite element model; S103. Add boundary conditions and loads to the finite element model; S104. Perform a meshing operation on the finite element model.

[0008] Optionally, step S2 includes: S201. According to the Coulomb friction model, define the tangential contact property of the steel pipe-concrete contact and set the friction coefficient and the maximum shear stress ; S202. Define the normal allowable clearance y to simulate the bonding effect of the steel pipe-concrete contact.

[0009] Optionally, in step S3, the mutual relationship of the normal contact of the steel pipe-concrete is expressed by equations (1) and (2): (1) (2) Wherein, P is the normal compressive stress, K is the stiffness.

[0010] Optionally, step S4 includes: Input the expression of the mutual relationship into the finite element analysis software and output the analysis result of the mechanical behavior of the finite element model.

[0011] Optionally, the analysis result of the mechanical behavior includes at least the change of the bonding friction force and the debonding contour map.

[0012] Optionally, the analysis result of the mechanical behavior further includes any one or more of stress, strain, displacement, bearing capacity, ultimate bearing capacity, and stiffness.

[0013] According to the second aspect of the present invention, there is provided an analysis system considering the tangential and normal coupling effects of the steel pipe-concrete interface, including: A modeling module for constructing a finite element model of the contact between the steel pipe and the concrete, wherein the inner wall surface of the steel pipe is used as the master surface and the outer surface of the concrete is used as the slave surface; A definition module for simulating the tangential behavior of the steel pipe-concrete by using the Coulomb friction model and assigning tangential contact properties to the finite element model; A relationship construction module for defining the mutual relationship of the normal contact of the steel pipe-concrete by using the "penalty" function based on the normal contact properties; An analysis module for analyzing the mechanical behavior of the finite element model based on the mutual relationship.

[0014] According to the third aspect of the present invention, an electronic device is provided, including a memory and a processor. When the processor executes a computer management program stored in the memory, the steps of the above analysis method considering the tangential and normal coupling effects of the steel pipe - concrete interface are realized.

[0015] According to the fourth aspect of the present invention, a computer - readable storage medium is provided, on which a computer management program is stored. When the computer management program is executed by a processor, the steps of the above analysis method considering the tangential and normal coupling effects of the steel pipe - concrete interface are realized.

[0016] An analysis method, system, electronic device and storage medium considering the tangential and normal coupling effects of the steel pipe - concrete interface provided by the present invention can consider the coupling effect of normal and tangential behaviors during numerical calculation and analysis for the steel pipe - concrete interface, improve the simulation accuracy of the steel pipe - concrete interface, enhance the numerical analysis accuracy of the model, and provide reliable data support for the subsequent optimization of the model structure. Description of the Drawings

[0017] Figure 1 It is a flowchart of an analysis method considering the tangential and normal coupling effects of the steel pipe - concrete interface provided by the present invention; Figure 2 It is a schematic diagram of the relationship between the normal allowable clearance and the compressive stress in a certain embodiment; Figure 3 It is a schematic diagram of the relationship between the tangential frictional stress and the normal compressive stress in a certain embodiment; Figure 4 It is a schematic diagram of the construction process simulation of a 72 - layer steel pipe - concrete column model in a certain embodiment; Figure 5 It is a result diagram of the bond friction force varying with the analysis step obtained in a certain embodiment; Figure 6 is a concrete horizontal delamination nephogram obtained in a certain embodiment. Among them, (a) is the concrete horizontal delamination nephogram at the moment when the axial force application is completed, (b) is the concrete horizontal delamination nephogram at the moment when the temperature drops by 15°, and (c) is the concrete horizontal delamination nephogram at the moment of the bearing capacity yield value; Figure 7 (a) - 7(c) are typical cross - section horizontal delamination nephograms. Among them, Figure 7 (a) is the typical cross - section horizontal delamination nephogram at the moment when the axial force application is completed, Figure 7 (b) is the typical cross - section horizontal delamination nephogram at the moment when the temperature drops by 15°, Figure 7 (c) is the typical cross - section horizontal delamination nephogram at the moment of the bearing capacity yield value; Figure 8 Block diagram of an analysis system provided by the present invention, which takes into account the tangential and normal coupling effects at the steel tube-concrete interface; Figure 9 Schematic diagram of the hardware structure of a possible electronic device provided by the present invention; Figure 10 Schematic diagram of the hardware structure of a possible computer-readable storage medium provided by the present invention. Specific embodiments

[0018] The following combines the accompanying drawings and embodiments to further describe in detail the specific embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0019] Figure 1 Flowchart of an analysis method provided by the present invention, which takes into account the tangential and normal coupling effects at the steel tube-concrete interface, as Figure 1 shown, the method includes steps S1 to S4: S1. Construct a finite element model of the contact between the steel tube and the concrete, where the inner wall surface of the steel tube is used as the master surface and the outer surface of the concrete is used as the slave surface; S2. Use the Coulomb friction model to simulate the tangential behavior of the steel tube-concrete, and assign tangential contact properties to the finite element model; S3. Based on the normal contact properties, use the "penalty" function to define the mutual relationship of the normal contact between the steel tube and the concrete; S4. Based on the mutual relationship, analyze the mechanical behavior of the finite element model.

[0020] It can be understood that based on the defects in the background technology, the embodiments of the present invention propose an analysis method that takes into account the tangential and normal coupling effects at the steel tube-concrete interface. This method is implemented based on finite element software such as ABAQUS, ANSYS, and MARC, and is applicable not only to steel tube concrete columns, but also to any component and structure with a steel tube-concrete interface. For the steel tube-concrete interface, this method can consider the coupling effect of normal and tangential behaviors during numerical calculation and analysis, improve the simulation accuracy of the steel tube-concrete interface, improve the numerical analysis accuracy of the model, and provide reliable data support for the subsequent optimization of the model structure.

[0021] In a possible embodiment, step S1 includes: S101. Based on the finite element analysis software, first construct a steel tube model and a concrete model, and then use the inner wall surface of the steel tube as the master surface and the outer surface of the concrete as the slave surface to construct a finite element model of the contact between the steel tube and the concrete; S102. Assign material properties to the finite element model of the contact between the steel tube and the concrete, such as physical properties, chemical properties, and / or mechanical properties; S103. Add boundary conditions and loads to the finite element model; S104. Perform a meshing operation on the finite element model.

[0022] In a possible embodiment, step S2 includes: S201. Define the tangential contact property of the steel tube - concrete contact according to the Coulomb friction model, and set the friction coefficient and the maximum shear stress ; S202. Define the normal allowable gap y to simulate the bonding effect of the steel tube - concrete contact.

[0023] It can be understood that, as Figure 2 shows the relationship between the normal allowable gap and the compressive stress, Figure 3 shows the relationship between the tangential frictional stress and the normal compressive stress. Based on Figure 2 and Figure 3 the relationships shown, set the friction coefficient , the maximum shear stress and the normal allowable gap y to simulate the tangential behavior and normal behavior of the steel tube - concrete contact.

[0024] In a possible embodiment, in step S3, the mutual relationship of the normal contact between the steel tube and the concrete is expressed by equations (1) and (2): (1) (2) Wherein, P is the normal compressive stress, K is the stiffness.

[0025] It can be understood that expressions (1) and (2) can reflect the tangential bonding friction and normal de - coupling effect of the steel tube - concrete contact interface. Inputting them into the finite element analysis software can obtain the analysis results considering the tangential bonding friction and normal de - coupling effect of the steel tube - concrete contact interface.

[0026] Therefore, in a possible embodiment, step S4 includes: Input the expression of the mutual relationship into the finite element analysis software and output the analysis result of the mechanical behavior of the finite element model.

[0027] The analysis result of the mechanical behavior at least includes the change result diagram of the bonding friction force as shown in Figure 5 and the de - coupling cloud diagram as shown in Figure 6(a) - 6(c) , and may also include any one or more of stress, strain, displacement, bearing capacity, ultimate bearing capacity, and stiffness.

[0028] An example will be given in combination with a specific implementation scenario.

[0029] As Figure 4 shown, the total height of the finite element model of the steel pipe in contact with the concrete is 288 m (storey height 4 m, a total of 72 storeys). The cross-section of the steel pipe wall is D1600×30, the steel strength grade is Q355, and the concrete strength grade is C60; the standard value of the yield strength of the steel is 345 Mpa, and the standard value of the concrete strength is 38.5 Mpa / 2.85 Mpa. The bottom is fixed (U1 = U2 = U3 = UR1 = UR2 = UR3 = 0, where U1, U2, and U3 refer to the linear displacement amounts in the X, Y, and Z directions of the three-dimensional space, and UR1, UR2, and UR3 represent the rotational displacement amounts in the X, Y, and Z directions of the three-dimensional space). Spring constraints are set at the corresponding steel beam positions on each storey, and the spring stiffness is taken as 30 kN / mm. The specific steps are as follows: (1) Establish a finite element model of the steel pipe in contact with the concrete. Take the inner wall surface of the steel pipe as the master surface and the outer surface of the concrete as the slave surface to establish the contact between the steel pipe and the concrete interface.

[0030] (2) For the tangential contact property, Coulomb friction is used to simulate the tangential behavior of the steel pipe - concrete, and the friction coefficient is set to 0.4 and the maximum shear stress is 2.04 MPa; the allowable normal clearance y = 0.008 mm is defined to simulate the bonding effect.

[0031] (3) For the normal contact property, the "penalty" method is used to define the relationship between the normal clearance and the normal compressive stress P when the steel pipe - concrete is in normal contact. The normal compressive stress P and stiffness K are calculated through equations (1) and (2), and P = 0.5625 MPa and K = 70.31 MPa / mm are obtained respectively.

[0032] (4) As Figure 4 shown, the loading is carried out in 12 analysis steps. First, the axial force is applied, then the concrete is cooled (for example, cooled by 15 °C), and finally the axial load is applied until the specimen fails. After the finite element calculation is completed, the variation of the bonding friction force with the analysis step and the void cloud diagram are output.

[0033] Figure 5 Shown are the variations of the bonding friction force with the analysis step calculated for Model 1 (bonding + friction), Model 2 (friction + allowable normal clearance y = 0.008 mm), and Model 3 (friction + allowable normal clearance y = 0 mm). From Figure 5It can be seen that during the step-by-step loading stage, the calculation results of Model 2 are relatively close to those of Model 1; during the temperature drop stage, there is a large area of normal separation between the steel pipe and the concrete. The drop amplitude of Model 2 exceeds 90%, and the drop amplitude of Model 1 is about 13.7%. Using the Coulomb friction model and the normal contact model in Model 2 can more realistically reflect the influence of normal separation on the bonding effect.

[0034] The separation nephogram of the concrete-filled steel tubular column calculated by Model 2 is shown in (a)~(c) in Figure 6 and Figure 7 (a)~7(c). It can be seen from (a) in Figure 6 and Figure 7 (a) that after the axial force is applied, there is almost no obvious separation phenomenon in the column, and the maximum separation occurs in the middle floor, with a maximum value of about 0.056mm; it can be seen from (b) in Figure 6 and Figure 7 (b) that after the temperature drops by 15°C, the separation value at the bottom is about 0.368mm, the separation value in the middle is about 0.309mm, and the separation value at the top is about 0.131mm; it can be seen from (c) in Figure 6 and Figure 7 (c) that at the moment of the bearing capacity yield value (i.e., when the column yields), the separation value of the concrete-filled steel tube at the bottom further increases, with the separation value being about 0.438mm, and the separation values in the middle and at the top increase slightly. The separation value in the middle is about 0.323mm, and the separation value at the top is about 0.139mm.

[0035] The above analysis results show that the method of the present invention can truly simulate the coupling effect of tangential bond friction and normal separation at the steel-concrete interface.

[0036] Figure 8 The structural diagram of an analysis system considering the tangential and normal coupling effects at the steel-concrete interface provided by an embodiment of the present invention is shown in Figure 8 As shown, an analysis system considering the tangential and normal coupling effects at the steel-concrete interface includes a modeling module, a definition module, a relationship construction module, and an analysis module, where: The modeling module is used to construct a finite element model of the contact between the steel pipe and the concrete, where the inner wall surface of the steel pipe is used as the master surface and the outer surface of the concrete is used as the slave surface; The definition module is used to simulate the tangential behavior of the steel-concrete using the Coulomb friction model and endow the finite element model with tangential contact attributes; The relationship construction module is used to define the mutual relationship of the normal contact between the steel pipe and the concrete using the "penalty" function based on the normal contact attributes; The analysis module is used to analyze the mechanical behavior of the finite element model based on the mutual relationship.

[0037] It can be understood that an analysis system provided by the present invention that takes into account the tangential and normal coupling effects at the steel tube-concrete interface corresponds to the analysis method provided by each of the foregoing embodiments that takes into account the tangential and normal coupling effects at the steel tube-concrete interface. The relevant technical features of the analysis system that takes into account the tangential and normal coupling effects at the steel tube-concrete interface can refer to the relevant technical features of the analysis method that takes into account the tangential and normal coupling effects at the steel tube-concrete interface, and will not be elaborated herein.

[0038] Please refer to Figure 9 , Figure 9 which is a schematic diagram of an embodiment of an electronic device provided by an embodiment of the present invention. As Figure 9 shown, an embodiment of the present invention provides an electronic device, including a memory 910, a processor 920, and a computer program 911 stored on the memory 910 and executable on the processor 920. When the processor 920 executes the computer program 911, the following steps are implemented: S1, construct a finite element model of the contact between the steel tube and the concrete, wherein the inner wall surface of the steel tube is used as the master surface and the outer surface of the concrete is used as the slave surface; S2, use the Coulomb friction model to simulate the tangential behavior of the steel tube-concrete, and assign tangential contact properties to the finite element model; S3, based on the normal contact properties, use the "penalty" function to define the mutual relationship of the normal contact between the steel tube and the concrete; S4, based on the mutual relationship, analyze the mechanical behavior of the finite element model.

[0039] Please refer to Figure 10 , Figure 10 which is a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. As Figure 10 shown, this embodiment provides a computer-readable storage medium 1000, on which a computer program 1011 is stored. When the computer program 1011 is executed by a processor, the following steps are implemented: S1, construct a finite element model of the contact between the steel tube and the concrete, wherein the inner wall surface of the steel tube is used as the master surface and the outer surface of the concrete is used as the slave surface; S2, use the Coulomb friction model to simulate the tangential behavior of the steel tube-concrete, and assign tangential contact properties to the finite element model; S3, based on the normal contact properties, use the "penalty" function to define the mutual relationship of the normal contact between the steel tube and the concrete; S4, based on the mutual relationship, analyze the mechanical behavior of the finite element model.

[0040] An analysis method, system, and storage medium provided by an embodiment of the present invention for considering the coupling effect of the tangential and normal directions at the steel tube-concrete interface. For the steel tube-concrete interface, the coupling effect of the normal and tangential behaviors can be considered during numerical calculation and analysis, improving the simulation accuracy of the steel tube-concrete interface and the numerical analysis accuracy of the model, and providing reliable data support for subsequent model structure optimization.

[0041] It should be noted that in the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0042] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, system, or 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 storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0043] 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 process and / or block in the flowcharts and / or block diagrams, and the combination of processes 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 processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0044] 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 generate a manufactured article including instruction means that implement the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0045] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide means for implementing the functions specified in Figure 1The steps of the functions specified in one process or multiple processes and / or boxes Figure 1 One box or multiple boxes

[0046] 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 creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0047] 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 modifications and variations.

Claims

1. An analysis method considering the tangential and normal coupling effects at the steel tube-concrete interface, characterized in that Including: S1. Construct a finite element model of the contact between the steel pipe and the concrete, where the inner wall surface of the steel pipe is used as the master surface and the outer surface of the concrete is used as the slave surface; S2. Use the Coulomb friction model to simulate the tangential behavior of the steel pipe - concrete, and endow the finite element model with tangential contact properties; S3. Based on the normal contact properties, use the "penalty" function to define the mutual relationship of the normal contact between the steel pipe and the concrete; S4. Based on the mutual relationship, analyze the mechanical behavior of the finite element model.

2. The analysis method considering the tangential and normal coupling effects of the steel tube-concrete interface according to claim 1, wherein Step S1 includes: S101. Based on the finite element analysis software, use the inner wall surface of the steel pipe as the master surface and the outer surface of the concrete as the slave surface to construct a finite element model of the contact between the steel pipe and the concrete; S102. Endow the finite element model with material properties; S103. Add boundary conditions and loads to the finite element model; S104. Perform a meshing operation on the finite element model.

3. The analysis method considering the tangential and normal coupling effects of the steel tube-concrete interface according to claim 1, wherein, Step S2 includes: S201, Define the tangential contact property of the steel tube-concrete contact according to the Coulomb friction model, and set the friction coefficient and the maximum shear stress ; S202. Define the normal allowable clearance y to simulate the bonding effect of the steel pipe - concrete contact.

4. The analysis method considering the tangential and normal coupling effects at the steel tube-concrete interface according to claim 3, characterized in that In step S3, the mutual relationship of the normal contact between the steel pipe and the concrete is expressed as formula (1) and formula (2): （1） （2） Among them, P is the normal compressive stress, K is the stiffness.

5. A method for analyzing the tangential and normal coupling effects at the steel tube-concrete interface according to any one of claims 1 to 4, characterized in that Step S4 includes: Input the expression of the mutual relationship into the finite element analysis software, and output the analysis result of the mechanical behavior of the finite element model.

6. The analysis method considering the tangential and normal coupling effects of the steel tube-concrete interface according to claim 5, wherein The analysis result of the mechanical behavior at least includes the change of bonding friction force and the void cloud diagram.

7. An analysis method considering the tangential and normal coupling effects of the steel tube-concrete interface according to claim 6, characterized in that The analysis result of the mechanical behavior also includes any one or more of stress, strain, displacement, bearing capacity, ultimate bearing capacity, and stiffness.

8. An analysis system considering the tangential and normal coupling effects at the steel tube-concrete interface, characterized in that, Including: A modeling module for constructing a finite element model of the contact between the steel pipe and the concrete, where the inner wall surface of the steel pipe is used as the master surface and the outer surface of the concrete is used as the slave surface; A definition module for using the Coulomb friction model to simulate the tangential behavior of the steel pipe - concrete and endowing the finite element model with tangential contact properties; A relationship construction module for defining the mutual relationship of the normal contact between the steel pipe and the concrete using the "penalty" function based on the normal contact properties; An analysis module for analyzing the mechanical behavior of the finite element model based on the mutual relationship.

9. An electronic device, characterized in that, Including a memory and a processor, when the processor executes the computer management - type program stored in the memory, it realizes the steps of the analysis method considering the tangential and normal coupling effects of the steel pipe - concrete interface as described in any one of claims 1 - 7.

10. A computer-readable storage medium, characterized in that, Stored thereon is a computer management - type program, when the computer management - type program is executed by the processor, it realizes the steps of the analysis method considering the tangential and normal coupling effects of the steel pipe - concrete interface as described in any one of claims 1 - 7.

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