Simplified modeling method of underground diaphragm wall joint finite element model
By replacing joints with elastic elements in the finite element model and optimizing their structural parameters, the problems of low computational efficiency and poor convergence performance were solved, resulting in more efficient simulation and more accurate reflection of mechanical properties.
Patent Information
- Application Number
- CN202511068889.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-14
AI Technical Summary
Existing technologies have low computational efficiency and poor convergence performance when simulating diaphragm wall joints, and cannot effectively reflect the mechanical properties of the joints, especially for complex I-beam, cross-plate, and type II plate joints.
Elastic elements are used to replace joints. The simulation is carried out through a refined finite element model. The structural parameters of the elastic elements are optimized until the simulation results of the simplified finite element model are consistent with those of the refined finite element model. This reduces the number of meshes and eliminates contact elements.
It improves computational efficiency and model convergence performance, simplifies the modeling process, and can more accurately reflect the mechanical properties of the joint.
Smart Images
Figure CN120951671A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of finite element simulation technology, and in particular to a simplified modeling method for finite element models of underground continuous wall joints. Background Technology
[0002] With the development of urban underground engineering, diaphragm walls are increasingly being used in deep foundation pit support excavation construction. Currently, diaphragm walls are constructed in sections, with each standard section typically about 6.0m wide. The walls are connected by joints, commonly including interlocking pipe joints, I-beam joints, cross-plate joints, and Type II plate joints.
[0003] Finite element simulation is an important tool for foundation pit excavation design, risk assessment, and research. For foundation pits with small planar dimensions, joints have a significant impact on their deformation and stress. Generally, interlocking pipe joints are considered flexible joints, capable of transmitting only axial and shear forces in the horizontal direction, but not bending moments. For such joints, the stiffness of the diaphragm wall can be reduced for simulation. However, for I-beam, cross-plate, and Type II plate joints, current experimental results show that their mechanical behavior is relatively complex. The simple method of reducing the stiffness of the diaphragm wall cannot fully reflect their mechanical properties. Furthermore, because plate elements are used to simulate the diaphragm wall, the phenomenon of joint opening cannot be reflected in the calculation results.
[0004] Currently, in finite element method (FEM) calculations, detailed modeling is generally required for these joint nodes. This involves using solid elements for both the concrete and steel plate, and contact elements between them. Because the steel plate is much thinner than the diaphragm wall (typically 1 / 50 to 1 / 80 of the diaphragm wall thickness), the mesh size needs to be reduced to match the steel plate, resulting in a large number of meshes and severely impacting computational efficiency. Furthermore, the extensive use of contact elements between the steel plate and concrete can easily lead to non-convergence. This method is generally used in the calculation of local nodes, but in large-scale foundation pit simulations, it is almost impossible to implement on computers with conventional computing power. Summary of the Invention
[0005] One objective of this application is to provide a simplified modeling method for finite element models of diaphragm wall joints that can solve at least one of the defects in the aforementioned background art.
[0006] To achieve at least one of the above objectives, the technical solution adopted in this application is: a simplified modeling method for a finite element model of a diaphragm wall joint, comprising the following steps:
[0007] S100: Construct a localized, refined finite element model of the joint location of the continuous wall, apply the set simulation parameters, and perform simulation to obtain refined simulation data;
[0008] S200: Replace the joints in the refined finite element model with elastic elements to form a simplified finite element model, and apply the same simulation parameters as in step S100 to perform simulation and obtain simplified simulation data;
[0009] S300: Compare the obtained detailed simulation data and simplified simulation data, optimize the structural parameters of the elastic element based on the comparison results and update the simplified simulation data until the comparison results meet the threshold requirements. Then, when constructing the finite element model of the continuous wall, replace all joints with the corresponding elastic elements.
[0010] Preferably, if the process of simulating the refined finite element model and the simplified finite element model includes a bending simulation process, then in step S200, the elastic element includes a bending-resistant elastic element for resisting the bending of the continuous wall; the bending simulation process is simulated by a four-point bending test.
[0011] Preferably, during the bending simulation process, a gradually increasing load is applied to the joint positions corresponding to the refined finite element model and the simplified finite element model, and the bending deformation of the model is monitored; when the bending deformation of the refined finite element model and the simplified finite element model reaches the set deformation, the loading is stopped, and the first load displacement curve and the second load displacement curve corresponding to the refined finite element model and the simplified finite element model are obtained respectively; then in step S300, the elastic coefficient of the bending elastic element is optimized by comparing the first load displacement curve and the second load displacement curve.
[0012] Preferably, optimizing the elastic coefficient of the bending elastic element includes the following process: extracting multiple displacement-first load points from the first load displacement curve to construct a first point set; taking points from the second load curve according to the same displacement to obtain a second point set including multiple displacement-second load points; calculating the error between the first point set and the second point set; if the calculated error is greater than a set threshold, adjusting the elastic coefficient of the bending elastic element and updating the second point set until the calculated error is less than or equal to the set threshold.
[0013] Preferably, for scenarios where the two joints are close together, the process of simulating the refined finite element model and the simplified finite element model also includes a shear simulation process of the two adjacent joints; then in step S200, the elastic element also includes a shear-resistant elastic element for resisting the shearing of the continuous wall; the shear simulation process is simulated by shear test.
[0014] Preferably, during the shear simulation process, a gradually increasing load is applied to the region between two adjacent joints in the refined finite element model and the simplified finite element model, while the remaining positions of the model are fixed; the shear deformation of the model is monitored, and loading is stopped when the shear displacement of the refined finite element model and the simplified finite element model reaches the set deformation, thereby obtaining the third load displacement curve and the fourth load displacement curve corresponding to the refined finite element model and the simplified finite element model, respectively; then in step S300, the elastic coefficient of the shear elastic element is optimized by comparing the third load displacement curve and the fourth load displacement curve.
[0015] Preferably, optimizing the elastic coefficient of the shear elastic element includes the following process: extracting multiple displacement-third load points from the third load displacement curve to construct a third point set; taking points from the fourth load curve according to the same displacement to obtain a fourth point set including multiple displacement-fourth load points; calculating the error between the third point set and the fourth point set; if the calculated error is greater than a set threshold, adjusting the elastic coefficient of the bending elastic element and updating the fourth point set until the calculated error is less than or equal to the set threshold.
[0016] Preferably, the set deformation is 0.8% to 1.5% of the thickness of the continuous wall.
[0017] Preferably, the joint at the same location is suitable to be replaced by multiple elastic elements; the multiple elastic elements are suitable to be equally spaced along the loading direction; the elastic coefficient of the multiple elastic elements gradually decreases from the middle to both ends.
[0018] Preferably, the elastic coefficients of the multiple elastic elements decrease proportionally from the middle to both ends; wherein, the elastic coefficient of the elastic element at the end is 50% of the elastic coefficient of the elastic element in the middle.
[0019] Compared with the prior art, the beneficial effects of this application are as follows:
[0020] By simplifying the initial modeling process, elastic elements that provide an equivalent joint can be used to replace the joints in the finite element model, effectively reducing the number of meshes and thus improving the computational efficiency of the simulation. Secondly, eliminating the need to model joints in the model also saves a significant number of contact elements, greatly improving the model's convergence performance. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall workflow of this application.
[0022] Figure 2 This is a simulation diagram of bending simulation of the refined finite element model of the joint in this application.
[0023] Figure 3 This is a schematic diagram of the flexural elastic element in this application.
[0024] Figure 4 This is a simulation diagram illustrating the bending simulation of the simplified finite element model of the anti-bending elastic element in this application.
[0025] Figure 5 This is a schematic diagram of the arrangement of the flexural elastic elements in this application.
[0026] Figure 6 This is a simulation diagram of the shearing simulation of the refined finite element model of the joint in this application.
[0027] Figure 7 This is a schematic diagram of the shear elastic element in this application.
[0028] Figure 8 This is a simulation diagram of shear simulation performed on the simplified finite element model of the shear-resistant elastic element in this application.
[0029] Figure 9 This is a schematic diagram of the arrangement of the shear elastic elements in this application.
[0030] Figure 10 This is a schematic diagram of the simplified finite element model of the continuous wall in this application. Detailed Implementation
[0031] The present application will now be further described in conjunction with specific embodiments. It should be noted that, in the description of this specification, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0032] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.
[0033] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0036] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.
[0037] One preferred embodiment of this application, such as Figure 1 As shown, a simplified modeling method for a finite element model of a diaphragm wall joint includes the following steps:
[0038] S100: Construct a localized, refined finite element model of the joint location of the continuous wall, apply the set simulation parameters, and perform simulation to obtain refined simulation data.
[0039] S200: Replace the joints in the refined finite element model with elastic elements to form a simplified finite element model, and apply the same simulation parameters as in step S100 to perform the simulation and obtain simplified simulation data.
[0040] S300: Compare the obtained detailed simulation data and simplified simulation data, optimize the structural parameters of the elastic element based on the comparison results and update the simplified simulation data until the comparison results meet the threshold requirements. Then, when constructing the finite element model of the continuous wall, replace all joints with the corresponding elastic elements.
[0041] As can be understood from the foregoing, when constructing the finite element model of a continuous wall, the joint location is a place where stress is concentrated, so it is necessary to model the joint location in detail. This results in the mesh density at the joint location being significantly higher than that at other locations on the continuous wall, which in turn significantly increases the overall mesh data of the continuous wall and causes a sharp increase in the computational load during simulation.
[0042] In the technical solution of this application, based on the working nature of the joint, elastic elements can be used to replace the joint during the modeling process. Since elastic elements are units used for connection and constraint in simulation software, they directly simulate material deformation behavior through preset physical parameters. Therefore, it is not necessary to discretize the structure into multiple mesh elements during the simulation process. That is, by replacing the joint with elastic elements, the local fine mesh positions of the joint location in the traditional continuous wall finite element model can be eliminated, thereby significantly reducing the number of meshes in the continuous wall simulation. Specifically, the number of meshes can be reduced by more than 90%, which can greatly improve the computational efficiency of the simulation.
[0043] To ensure that the elastic element accurately reflects the mechanical properties of the joint in the diaphragm wall, a detailed model of the local area where the joint is installed in the diaphragm wall can be created. Then, the mechanical changes of the joint during use are obtained by simulating this detailed finite element model of the local area. Next, a simplified finite element model is constructed by replacing the joint with the elastic element. This simplified finite element model is simulated under the same conditions, and the structural parameters of the elastic element are optimized based on the simulation results. This process continues until the simulation results of the simplified finite element model are essentially consistent with those of the detailed finite element model. At this point, the mechanical properties of the elastic element can be considered to be essentially consistent with those of the joint. Finally, the optimized elastic element is used to replace the joint in the diaphragm wall finite element module to simplify the model, resulting in the following... Figure 10 The simplified finite element model of the continuous wall is shown.
[0044] It is also understandable that, since joints are generally made of steel plates, the material of the joint needs to be limited to steel when constructing the finite element model. And as... Figure 3 and Figure 7 As shown, the joint is set between two consecutive sections of the continuous wall, that is, between the first section and the subsequent section. Since the materials of the first section and the subsequent section are different from the material of the joint, in order to ensure that the deformation trend of the joint and the continuous wall are consistent during the simulation, it is often necessary to set a large number of contact elements for the joint.
[0045] In this embodiment, elastic elements are used instead of joints. Since the structure of the elastic element itself is not reflected in the finite element model, it only provides an elastic constraint between the preceding and subsequent slots of the diaphragm wall. Therefore, when simulating the diaphragm wall finite element model, all contact elements previously set for the joints can be omitted, thereby effectively improving the convergence performance of the diaphragm wall finite element model.
[0046] It should be understood that in this embodiment, the construction and simulation optimization processes of the refined finite element model in step S100 and the simplified finite element model in step S200 are performed before the construction of the diaphragm wall finite element model. Although this process increases the construction steps of the diaphragm wall finite element model, it simplifies the structure of the diaphragm wall finite element model; at the same time, the optimized elastic elements can also be used to replace the same joints in other projects.
[0047] It should also be noted that the specific configuration method for the elastic unit varies depending on the working scenario of the joint. For example... Figure 2 and Figure 3 As shown, for scenarios where the lengths of the initial and subsequent grooves on both sides of the joint are relatively long, or in other words, where the distance between two adjacent joints is large; the joint is mainly used to resist the bending deformation of the continuous wall during use, in which case the elastic element can be a bending-resistant elastic element. For example... Figure 6 and Figure 7 As shown, for scenarios where the lengths of the preceding and subsequent slots on both sides of the joint are relatively short, or in other words, the distance between two adjacent joints is relatively short, the joint is mainly used to resist shear between the preceding and subsequent slots on both sides of the joint during use. In this case, shear-resistant elastic elements can be used. For ease of understanding, the model simplification process for the two scenarios will be described in detail below.
[0048] 1. For scenarios where the lengths of the initial and subsequent grooves on both sides of the joint are relatively long.
[0049] In this embodiment, as Figures 2 to 4As shown, the process of simulating the refined finite element model and the simplified finite element model includes the bending simulation process, in which the bending elastic element is connected to the preceding groove segment and the subsequent groove segment at both ends respectively; the bending simulation process is simulated by a four-point bending test.
[0050] Specifically, the process of the four-point bending test using the refined finite element model is as follows: Figure 2 As shown, taking a cross-plate joint as an example, a pair of fixed supports and a pair of sliding supports are set in the simulation software. The two fixed supports are set on the upper and lower sides of the first groove segment, respectively, and the two sliding supports are set on the upper and lower sides of the subsequent groove segment, respectively. Then, a gradually increasing load is applied to the position of the cross-plate joint in the refined finite element model, and the bending deformation of the model is monitored. Specifically, if the load is applied from top to bottom, the distance between the upper fixed support and the sliding support is smaller than the distance between the lower fixed support and the sliding support; conversely, if the load is applied from bottom to top, the distance between the upper fixed support and the sliding support is larger than the distance between the lower fixed support and the sliding support. When the bending deformation of the refined finite element model reaches the set deformation, the loading is stopped, and the first load-displacement curve corresponding to the refined finite element model is obtained.
[0051] The specific process of the four-point bending test for the simplified finite element model is basically the same as that for the refined finite element model, except that the cross-shaped steel plate joint is replaced with a bending elastic element. Through the corresponding four-point bending test, the second load-displacement curve corresponding to the simplified finite element model can be obtained. Finally, in step S300, the elastic coefficient of the bending elastic element is optimized by comparing the first and second load-displacement curves.
[0052] In this embodiment, optimizing the elastic coefficient of the bending elastic element includes the following process: Multiple displacement-first load points are extracted from the first load-displacement curve to construct a first point set. Points are taken from the second load curve according to the same displacement to obtain a second point set including multiple displacement-second load points. The error between the first and second point sets is calculated. If the calculated error is greater than a set threshold, the elastic coefficient of the bending elastic element is adjusted and the second point set is updated until the calculated error is less than or equal to the set threshold.
[0053] Understandably, to ensure accurate error calculation of the first and second load displacement curves, the points obtained from the first and second point sets need to be evenly distributed; specifically, points can be selected based on consistent displacement differences between adjacent points. For example, if the deformation is set to X, then starting from deformation point 0, points are selected with a displacement difference of 0.05X, resulting in 21 displacement-load points, meaning that both the first and second point sets have 21 corresponding points.
[0054] There are several ways to calculate the error between the first and second point sets, including mean square error, root mean square error, weighted average error, Euclidean distance, and cosine similarity. Those skilled in the art can choose the specific calculation method according to their actual needs; the error threshold will vary depending on the calculation method. Taking weighted average error calculation as an example, the set error value can be 0.01; that is, if the weighted average error calculated for the first and second point sets is less than or equal to 0.01, it indicates that the elastic coefficient of the current elastic element meets the mechanical performance requirements of the actual joint in the continuous wall; otherwise, the elastic coefficient of the elastic element is adjusted and updated, and the simulation is repeated to update the second point set until the weighted average error between the first and second point sets is less than or equal to 0.01.
[0055] Specifically, in the process of obtaining the first load displacement curve and the second load displacement curve, the specific value of the set deformation is generally related to the thickness of the continuous wall. The thicker the continuous wall, the stronger its bending resistance, and thus the smaller the value of the deformation, and vice versa. Preferably, in this embodiment, the set deformation value is 0.8% to 1.5% of the thickness of the continuous wall; for example, for a 1m thick continuous wall, the set deformation is 8cm to 15cm.
[0056] In this embodiment, when setting up the elastic element, if the continuous wall is thin, a single elastic element can replace the joint. However, for thicker continuous walls, a single elastic element is insufficient to represent the mechanical performance of the joint within the continuous wall, often requiring multiple elastic elements; that is, as shown below. Figure 5 As shown, a joint at the same location can be replaced by multiple elastic elements; these elastic elements can be spaced equally along the loading direction. The structure of the joint indicates that the stiffness is higher in the middle and slightly weaker at both ends; therefore, when setting up multiple elastic elements, their elastic coefficient can gradually decrease from the middle to both ends.
[0057] It is understandable that there are multiple ways to decrease the elastic coefficient of multiple elastic elements from the middle to both ends, such as proportional reduction or arithmetic reduction. For ease of understanding, let's take... Figure 5 Taking the five bending elastic elements shown as an example, the bending elastic elements at both ends of the figure are represented by red boxes, and the remaining bending elastic elements are represented by red squares; the middle bending elastic element is labeled k, the two downward bending elastic elements are labeled k-1 and k-2 respectively, and the two upward bending elastic elements are labeled k+1 and k+2 respectively.
[0058] If a proportional reduction method is adopted, the elastic coefficient of the middle bending elastic element can be set as A. From the middle to the end, the elastic coefficient of the next elastic element in an adjacent elastic element is 0.8 times that of the previous elastic element. Then, the elastic coefficient of the bending elastic elements labeled k-1 and k+1 is 0.8A; and the elastic coefficient of the bending elastic elements labeled k-2 and k+2 is 0.64A.
[0059] If an arithmetic reduction method is used, the elastic coefficient of the middle bending elastic element can be set as A, and the elastic coefficient decreases by 20% from the middle to the ends. Then, the elastic coefficient of the bending elastic element labeled k-1 and k+1 is 0.8A; and the elastic coefficient of the bending elastic element labeled k-2 and k+2 is 0.6A.
[0060] Both of the above-mentioned methods of reducing the elastic coefficient can meet the requirements of this application, and those skilled in the art can choose according to actual needs; preferably, it is sufficient to ensure that the elastic coefficient of the end elastic unit is 50% of the elastic coefficient of the middle elastic unit.
[0061] Second, for scenarios where the distance between two adjacent connectors is short.
[0062] In this embodiment, as Figures 6 to 8 As shown, the simulation process of the refined finite element model and the simplified finite element model also includes the shear simulation process of two joints. At this time, the shear elastic element can be set along the thickness direction of the continuous wall, and its two ends are connected to the first groove segment and the subsequent groove segment respectively. The shear simulation process is simulated by shear test.
[0063] Specifically, the detailed process of the shear test using the refined finite element model is as follows: Figure 6 As shown, taking a cross-plate joint as an example, the refined finite element model can be divided into three segments: a middle segment between two adjacent cross-plate joints and side segments on both sides of the middle segment. Two pairs of fixed supports are set in the simulation software, with the two pairs of fixed supports positioned on the upper and lower sides of the two side segments respectively. Then, a gradually increasing load is applied to the middle segment in the refined finite element model, and the shear deformation of the model is monitored. Specifically, if the load is applied from top to bottom, the distance between the two fixed supports on the upper side of the model is greater than the distance between the two fixed supports on the lower side; conversely, if the load is applied from bottom to top, the distance between the two fixed supports on the upper side of the model is less than the distance between the two fixed supports on the lower side. Loading is stopped when the shear displacement of the refined finite element model reaches the set deformation, resulting in the third load-displacement curve corresponding to the refined finite element model.
[0064] The specific process of the shear test for the simplified finite element model is basically the same as that for the refined finite element model, except that the cross-plate joint is replaced with a shear elastic element. Through the corresponding shear test, the fourth load-displacement curve corresponding to the simplified finite element model can be obtained. Finally, in step S300, the elastic coefficient of the shear elastic element is optimized by comparing the third and fourth load-displacement curves.
[0065] In this embodiment, optimizing the elastic coefficient of the shear elastic element includes the following process: Multiple displacement-third load points are extracted from the third load-displacement curve to construct a third point set. Points are taken from the fourth load curve according to the same displacement to obtain a fourth point set including multiple displacement-fourth load points. The error between the third and fourth point sets is calculated. If the calculated error is greater than a set threshold, the elastic coefficient of the shear elastic element is adjusted and the fourth point set is updated until the calculated error is less than or equal to the set threshold.
[0066] Understandably, to ensure accurate error calculations for the third and fourth load displacement curves, the points obtained from the third and fourth point sets need to be evenly distributed. Specifically, points can be selected based on consistent displacement differences between adjacent points. For example, if the deformation is set to X, then starting from deformation point 0, points are selected with a displacement difference of 0.05X, resulting in 21 displacement-load points. That is, both the third and fourth point sets have 21 corresponding points.
[0067] There are several methods for calculating the error of the third and fourth point sets, including mean square error, root mean square error, weighted average error, Euclidean distance, and cosine similarity. Those skilled in the art can choose the specific calculation method according to their actual needs; the error threshold will also differ depending on the calculation method. Taking weighted average error calculation as an example, the set error value can be 0.01.
[0068] Specifically, in obtaining the third and fourth load-displacement curves, the specific value of the set deformation is generally related to the thickness of the continuous wall. The thicker the continuous wall, the stronger its shear resistance, and thus the smaller the value of the deformation, and vice versa. Preferably, in this embodiment, the set deformation value is 0.8% to 1.5% of the thickness of the continuous wall; for example, for a 1m thick continuous wall, the set deformation is 8cm to 15cm.
[0069] In this embodiment, when setting up the elastic element, if the continuous wall is thin, a single elastic element can replace the joint. However, for thicker continuous walls, a single elastic element is insufficient to represent the mechanical performance of the joint within the continuous wall, often requiring multiple elastic elements; that is, as shown below. Figure 9 As shown, a joint at the same location can be replaced by multiple elastic elements; these elastic elements can be spaced equally along the loading direction. The structure of the joint indicates that the stiffness is higher in the middle and slightly weaker at both ends; therefore, when setting up multiple elastic elements, their elastic coefficient can gradually decrease from the middle to both ends.
[0070] It is understandable that there are multiple ways to decrease the elastic coefficient of multiple elastic elements from the middle to both ends, such as proportional reduction or arithmetic reduction. For ease of understanding, let's take... Figure 9 Taking the five shear elastic elements corresponding to each joint position as an example, the shear elastic elements at both ends are represented by red circles, and the remaining shear elastic elements are represented by red dots. Both of the above-mentioned methods of reducing the elastic coefficient can meet the requirements of this application, and those skilled in the art can choose according to actual needs; preferably, it is sufficient to ensure that the elastic coefficient of the end elastic elements is 50% of the elastic coefficient of the middle elastic elements.
[0071] Those skilled in the art should understand that, for the technical solution of this application, if all joints in the finite element model of the diaphragm wall conform to scenario one above, i.e., the lengths of the preceding and subsequent grooves on both sides of the joint are relatively long, then only a four-point bending test needs to be performed on the joints; that is, when constructing the finite element model of the diaphragm wall, only bending elastic elements need to be used to replace the joints. If all joints conform to scenario two above, i.e., the distance between two adjacent joints is relatively short, then only a shear test needs to be performed on the joints; that is, when constructing the finite element model of the diaphragm wall, only shear elastic elements need to be used to replace the joints. If some joints conform to scenario one above and some joints conform to scenario two above, then only a four-point bending test needs to be performed on the joints conforming to scenario one, and a shear test needs to be performed on the joints conforming to scenario two; that is, when constructing the finite element model of the diaphragm wall, the corresponding joints need to be replaced by bending elastic elements and shear elastic elements respectively.
[0072] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.
Claims
1. A simplified modeling method for a finite element model of a diaphragm wall joint, characterized in that, Includes the following steps: S100: Construct a localized, refined finite element model of the joint location of the continuous wall, apply the set simulation parameters, and perform simulation to obtain refined simulation data; S200: Replace the joints in the refined finite element model with elastic elements to form a simplified finite element model, and apply the same simulation parameters as in step S100 to perform simulation and obtain simplified simulation data; S300: Compare the obtained detailed simulation data and simplified simulation data, optimize the structural parameters of the elastic element based on the comparison results and update the simplified simulation data until the comparison results meet the threshold requirements. Then, when constructing the finite element model of the continuous wall, replace all joints with the corresponding elastic elements.
2. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 1, characterized in that, The process of simulating the refined finite element model and the simplified finite element model includes a bending simulation process. In step S200, the elastic element includes a bending elastic element for resisting the bending of the continuous wall. The bending simulation process is simulated by a four-point bending test.
3. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 2, characterized in that, During the bending simulation process, gradually increasing loads are applied to the joint locations corresponding to the refined finite element model and the simplified finite element model, and the bending deformation of the model is monitored. Loading is stopped when the bending deformation of the refined finite element model and the simplified finite element model reaches the set deformation amount, and the first load displacement curve and the second load displacement curve corresponding to the refined finite element model and the simplified finite element model are obtained respectively. In step S300, the elastic coefficient of the bending elastic element is optimized by comparing the first load displacement curve and the second load displacement curve.
4. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 3, characterized in that, Optimizing the elastic coefficient of the bending elastic element involves the following process: Extract multiple displacement-first load points from the first load displacement curve to construct a first point set; By taking points from the second load curve with the same displacement, a second set of points including multiple displacement-second load points is obtained; Calculate the error between the first point set and the second point set. If the calculated error is greater than the set threshold, adjust the elastic coefficient of the anti-bending elastic element and update the second point set until the calculated error is less than or equal to the set threshold.
5. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 2, characterized in that, For scenarios where two joints are close together, the process of simulating the refined finite element model and the simplified finite element model also includes the shear simulation process of the two adjacent joints. In step S200, the elastic element also includes a shear-resistant elastic element for resisting shearing of the continuous wall; the shear simulation process is simulated by shear test.
6. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 5, characterized in that, During the shear simulation process, a gradually increasing load is applied to the region between two adjacent joints in both the refined and simplified finite element models, while the rest of the model is fixed. The shear deformation of the model is monitored. Loading is stopped when the shear displacement of the refined finite element model and the simplified finite element model reaches the set deformation. The third load displacement curve and the fourth load displacement curve corresponding to the refined finite element model and the simplified finite element model are obtained respectively. In step S300, the elastic coefficient of the shear elastic element is optimized by comparing the third load displacement curve and the fourth load displacement curve.
7. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 6, characterized in that, The optimization of the elastic coefficient of the shear elastic element includes the following process: extract multiple displacement-third load points from the third load displacement curve to construct a third point set; take points from the fourth load curve according to the same displacement to obtain a fourth point set including multiple displacement-fourth load points; calculate the error between the third point set and the fourth point set; if the calculated error is greater than a set threshold, adjust the elastic coefficient of the bending elastic element and update the fourth point set until the calculated error is less than or equal to the set threshold.
8. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 3 or 6, characterized in that, The set deformation is 0.8% to 1.5% of the thickness of the continuous wall.
9. The simplified modeling method for the finite element model of a diaphragm wall joint as described in any one of claims 2-7, characterized in that, For joints in the same location, it is appropriate to replace them with multiple flexible units; Multiple elastic elements are suitable for being equally spaced along the loading direction; The elastic coefficients of multiple elastic elements gradually decrease from the middle to both ends.
10. The simplified modeling method for the finite element model of the diaphragm wall joint as described in claim 9, characterized in that, The elastic coefficients of multiple elastic elements decrease proportionally from the middle to both ends; The elastic coefficient of the end elastic element is 50% of that of the middle elastic element.