Method for judging rigid connection of rigid joint

Abstract

The application provides a rigid connection judging method of a rigid joint, comprising the following steps: establishing a standard rigid joint model, calculating according to the standard rigid joint model and material elastic-plastic parameters, and obtaining a first bending moment rotation angle curve of the standard rigid joint according to the calculation result; calculating according to the first bending moment rotation angle curve of the standard rigid joint and a limit bearing capacity, and obtaining a second bending moment rotation angle curve of the standard rigid joint according to the calculation result; establishing a to-be-detected rigid joint model according to the to-be-detected rigid joint, calculating according to the to-be-detected rigid joint model and material elastic-plastic parameters, and obtaining a bending moment rotation angle curve of the to-be-detected rigid joint according to the calculation result; and determining whether the to-be-detected rigid joint meets the requirement of rigid connection according to the bending moment rotation angle curve of the to-be-detected rigid joint and the second bending moment rotation angle curve of the standard rigid joint. The application can quickly and conveniently determine whether a beam-column joint meets the requirement of rigid connection.

Description

Technical Field

[0001] This application relates to the fields of civil engineering design, construction and appraisal technology, and in particular to a method for determining the rigid connection of a rigid joint. Background Technology

[0002] In portal frame structures used in industries such as metallurgy, coal mining, and power generation, the end portal frames bear significant stress and are considered weak points. According to current national standards, portal frame beam-column joints must be rigidly connected. However, in some cases, the design drawings provided by the design unit or the portal frame beam-column joints constructed by the construction unit differ from the joint forms specified in current national standards, specifications, and atlases. For example, in some cases, the joint forms constructed by the construction unit lack horizontal stiffeners on the column web. Therefore, when conducting structural reliability analysis, the assessment unit needs to determine whether the actual construction of the beam-column joints meets the requirements for rigid connections and then provide corresponding treatment recommendations. However, current technology typically relies on manual methods for assessment, which is slow and prone to errors. Summary of the Invention

[0003] In view of this, the present invention provides a method for determining the rigid connection of a rigid joint, thereby enabling a quick and convenient determination of whether a beam-column joint meets the requirements for a rigid connection.

[0004] The technical solution of this invention is implemented as follows:

[0005] A method for determining a rigid connection of a rigidly connected node, the method comprising:

[0006] Establish a standard rigid joint model, perform calculations based on the standard rigid joint model and material elastic-plastic parameters, and obtain the first moment-rotation curve of the standard rigid joint based on the calculation results.

[0007] The first moment-rotation curve and ultimate bearing capacity of the standard rigid joint are calculated, and the second moment-rotation curve of the standard rigid joint is obtained based on the calculation results.

[0008] A model of the rigid joint to be tested is established based on the model of the rigid joint to be tested and the elastic-plastic parameters of the material are calculated. The moment-rotation curve of the rigid joint to be tested is obtained based on the calculation results.

[0009] Based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection, determine whether the rigid connection to be tested meets the requirements of a rigid connection.

[0010] Preferably, the method further includes:

[0011] When it is determined that the rigid connection node to be tested does not meet the requirements of rigid connection, a finite element comparative analysis is performed based on the model of the rigid connection node to be tested and the standard rigid connection node model, and the reasons for not meeting the requirements of rigid connection are determined based on the analysis results.

[0012] Ideally, finite element software should be used to establish a standard rigid joint model and a rigid joint model to be tested.

[0013] Preferably, the calculation based on the first moment-rotation curve and ultimate bearing capacity of the standard rigid joint includes:

[0014] Based on the principle that the first shaded area and the second shaded area are equal, the calculation is performed according to the first bending moment-rotation curve and the ultimate bearing capacity of the standard rigid joint.

[0015] Wherein, the first shaded area is: the area enclosed by the first bending moment angle curve and the second bending moment angle curve before the first intersection point;

[0016] The second shaded area is the area enclosed by the first bending moment angle curve and the second bending moment angle curve after the first intersection point and before the second intersection point.

[0017] Preferably, determining whether the rigid connection to be tested meets the requirements of a rigid connection based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection includes:

[0018] When the top of the moment-rotation curve of the rigid connection to be tested exceeds the top of the second moment-rotation curve of the standard rigid connection, it is determined that the rigid connection to be tested meets the preset rigid connection requirements; otherwise, it is determined that the rigid connection to be tested does not meet the preset rigid connection requirements.

[0019] Preferably, determining whether the rigid connection to be tested meets the requirements of a rigid connection based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection includes:

[0020] When the moment-rotation curve of the rigid connection node to be tested is above the third intersection point, it is determined that the rigid connection node to be tested meets the minimum rigid connection requirements; otherwise, it is determined that the rigid connection node to be tested does not meet the minimum rigid connection requirements.

[0021] The coordinates of the third intersection point are (Φy, M0); Φy is the abscissa of the turning point of the second bending moment-rotation curve of the standard rigid joint, and M0 is the actual load.

[0022] As can be seen above, in the method for determining the rigid connection of a rigid joint in this invention, a standard rigid joint model is first established. Calculations are then performed based on the standard rigid joint model and the material's elastic-plastic parameters to obtain the first moment-rotation curve of the standard rigid joint. Next, calculations are performed based on the first moment-rotation curve and the ultimate bearing capacity of the standard rigid joint to obtain the second moment-rotation curve. Subsequently, a model of the rigid joint to be tested is established, and calculations are performed based on the model and the material's elastic-plastic parameters to obtain the moment-rotation curve of the rigid joint to be tested. Finally, based on the moment-rotation curve of the rigid joint to be tested and the second moment-rotation curve of the standard rigid joint, it is determined whether the rigid joint to be tested meets the requirements for a rigid connection. This allows for a quick and convenient determination of whether the rigid joint to be tested (i.e., the beam-column joint to be tested) meets the requirements for a rigid connection. For example, it can quickly and conveniently determine whether the beam-column joint of a portal frame in actual industrial production meets the requirements for a rigid connection. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the method for determining the rigid connection of a rigid node in a specific embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of various moment-rotation curves in a specific embodiment of the present invention. Detailed Implementation

[0025] To make the technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a flowchart illustrating the method for determining the rigid connection of a rigidly connected node in an embodiment of the present invention. Figure 1 As shown, the method for determining the rigid connection of a rigid node in this embodiment of the invention includes the following steps:

[0027] Step 101: Establish a standard rigid joint model, perform calculations based on the standard rigid joint model and material elastic-plastic parameters, and obtain the first moment-rotation curve of the standard rigid joint based on the calculation results.

[0028] In the technical solution of this application, a standard rigid joint model can first be established based on the standard rigid joint. This standard rigid joint conforms to the provisions and requirements of current national standards, specifications, and atlases. After establishing the standard rigid joint model, calculations can be performed based on this model, considering the material's elastic-plastic parameters. After obtaining the calculation results, the first moment-rotation angle (M-Φ) curve of the standard rigid joint can be plotted based on these results; that is, the moment-rotation angle curve of the actual standard rigid joint considering the material's elastic-plastic parameters.

[0029] For example, as an illustration, in a specific embodiment of the present invention, the first moment-rotation angle (M-Φ) curve of the standard rigid joint can be as follows: Figure 2 As shown.

[0030] Furthermore, in the technical solution of this application, various specific implementation methods can be used to establish a standard rigid connection node model.

[0031] For example, as an example, in a specific embodiment of the present invention, finite element software (e.g., Abapus and other finite element software) can be used to build a standard rigid joint model.

[0032] Step 102: Calculate the first moment-rotation curve and ultimate bearing capacity of the standard rigid joint, and obtain the second moment-rotation curve of the standard rigid joint based on the calculation results.

[0033] In the technical solution of this application, after obtaining the first moment-rotation curve of the standard rigid joint, corresponding calculations can be performed based on the first moment-rotation curve and the ultimate bearing capacity Mu, and the second moment-rotation curve of the standard rigid joint can be drawn based on the calculation results, that is, the moment-rotation curve of the standard rigid joint in the engineering design.

[0034] Based on the law of conservation of energy, an equivalent simplified model for practical engineering applications can be obtained. This model is a bilinear model, as follows: Figure 2 As shown.

[0035] In addition, in the technical solution of this application, various specific implementation methods can be used to calculate based on the first bending moment-rotation curve and ultimate bearing capacity of the standard rigid connection node.

[0036] For example, as an illustration, in a specific embodiment of the present invention, the calculation can be performed based on the first moment-rotation curve and the ultimate bearing capacity of the standard rigid joint, according to the principle that the first shaded area S1 and the second shaded area S2 are equal; wherein, the first shaded area S1 is the area enclosed by the first moment-rotation curve and the second moment-rotation curve before the first intersection point; the second shaded area S2 is the area enclosed by the first moment-rotation curve and the second moment-rotation curve after the first intersection point and before the second intersection point; as such Figure 2 As shown.

[0037] Step 103: Establish a model of the rigid joint to be tested based on the model of the rigid joint to be tested and the elastic-plastic parameters of the material. Calculate the moment-rotation curve of the rigid joint to be tested based on the calculation results.

[0038] In the technical solution of this application, a model of the rigid joint to be tested can be established based on the model, and then calculations can be performed based on this model, taking into account the material's elastic-plastic parameters. After obtaining the calculation results, the moment-rotation curve of the rigid joint to be tested can be plotted based on the calculation results, that is, the moment-rotation curve of the actual rigid joint to be tested when considering the material's elastic-plastic parameters.

[0039] For example, as an illustration, in a specific embodiment of the present invention, the moment-rotation curve of the rigidly connected node to be detected can be as follows: Figure 2 As shown.

[0040] In addition, various specific implementation methods can be used to establish the model of the rigidly connected node to be detected in the technical solution of this application.

[0041] For example, as an example, in a specific embodiment of the present invention, finite element software (e.g., Abapus or other finite element software) can also be used to build the model of the rigidly connected node to be detected.

[0042] Step 104: Based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection, determine whether the rigid connection to be tested meets the requirements of a rigid connection.

[0043] In the technical solution of this application, after obtaining the moment-rotation curve of the rigid connection to be tested, it is possible to determine whether the rigid connection to be tested meets the requirements of rigid connection based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection.

[0044] In the technical solution of this application, various specific implementation methods can be used to implement step 104 above. The following will use several specific implementation methods as examples to describe the technical solution of this application in detail.

[0045] For example, as an example, in one specific embodiment of the present invention, step 104 may include:

[0046] When the top of the moment-rotation curve of the rigid connection to be tested exceeds the top of the second moment-rotation curve of the standard rigid connection, it is determined that the rigid connection to be tested meets the preset rigid connection requirements; otherwise, it is determined that the rigid connection to be tested does not meet the preset rigid connection requirements.

[0047] For example, such as Figure 2 As shown, the top of the moment-rotation curve of the rigid connection to be tested is lower than the top of the second moment-rotation curve of the standard rigid connection. Therefore, it can be determined that the rigid connection to be tested does not meet the requirements of a rigid connection.

[0048] In addition, Mu mentioned above is the ultimate bearing capacity. However, in actual application scenarios, it is not necessarily necessary to meet the requirements of this ultimate bearing capacity. It is only necessary to meet the requirements of the actual load M0.

[0049] Therefore, as an example, in a specific embodiment of the present invention, step 104 may include:

[0050] When the moment-rotation curve of the rigid connection node to be tested is above the third intersection point, it is determined that the rigid connection node to be tested meets the minimum rigid connection requirements; otherwise, it is determined that the rigid connection node to be tested does not meet the minimum rigid connection requirements.

[0051] The coordinates of the third intersection point are (Φy, M0); Φy is the abscissa of the turning point of the second bending moment-rotation curve of the standard rigid joint, and M0 is the actual load.

[0052] When the moment-rotation curve of the rigid connection to be tested is above the third intersection point, the ordinate of the top of the moment-rotation curve will necessarily be greater than the actual load M0, and the slope of the moment-rotation curve will also necessarily be greater than the slope threshold under normal structural use. Therefore, the rigid connection to be tested at this time must have met the minimum rigid connection requirements. Figure 2 As shown.

[0053] When the moment-rotation curve of the rigid connection to be tested is located at or below the third intersection point, the slope of the moment-rotation curve of the rigid connection to be tested will be less than or equal to the preset slope threshold. Therefore, the rigid connection to be tested will not meet the minimum rigid connection requirements at this time.

[0054] Therefore, by using the steps 101 to 104 above, it is possible to quickly and easily determine whether the rigid connection node to be tested (i.e., the beam-column node to be tested) meets the requirements for rigid connection.

[0055] Additionally, as an example, in a specific embodiment of the present invention, when it is determined that the rigid connection node to be detected does not meet the requirements of a rigid connection, the above method may further include:

[0056] Finite element analysis was performed on the model of the rigid connection to be tested and the standard rigid connection model to determine the reasons why the rigid connection requirements were not met.

[0057] For example, when the rigid connection node to be tested does not meet the requirements of a rigid connection, the model of the rigid connection node to be tested can be compared with the standard rigid connection node model. Based on the comparison results, a finite element analysis can be performed to find the differences between the two models. Thus, based on the differences between the two models, the reason why the rigid connection node to be tested does not meet the requirements of a rigid connection can be determined.

[0058] For example, assuming that the above finite element comparative analysis can determine that the element lacking horizontal stiffening ribs in the model of the rigid joint to be tested is missing, it can be preliminarily determined that the reason why the rigid joint to be tested does not meet the requirements of rigid connection is because it lacks horizontal stiffening ribs.

[0059] Therefore, through the above finite element comparative analysis, the specific reasons why the rigid connection node under test did not meet the requirements of rigid connection can be preliminarily determined.

[0060] In summary, in the technical solution of this invention, a standard rigid connection node model is first established. Calculations are then performed based on the standard rigid connection node model and the material's elastic-plastic parameters to obtain the first moment-rotation curve of the standard rigid connection node. Next, calculations are performed based on the first moment-rotation curve and the ultimate bearing capacity of the standard rigid connection node to obtain the second moment-rotation curve. Subsequently, a model of the rigid connection node to be tested is established based on the rigid connection node to be tested. Calculations are then performed based on the model of the rigid connection node to be tested and the material's elastic-plastic parameters to obtain the moment-rotation curve of the rigid connection node to be tested. Finally, based on the moment-rotation curve of the rigid connection node to be tested and the second moment-rotation curve of the standard rigid connection node, it is determined whether the rigid connection node to be tested meets the requirements for a rigid connection. This allows for a quick and convenient determination of whether the rigid connection node to be tested (i.e., the beam-column joint to be tested) meets the requirements for a rigid connection. For example, it can quickly and conveniently determine whether the beam-column joint of a portal frame in actual industrial production meets the requirements for a rigid connection.

[0061] By using the methods described above, assessment units can analyze the performance of various non-standard beam-column joint connections in actual engineering projects and determine whether they meet the requirements for rigid connections. Furthermore, further analysis can be conducted to preliminarily determine the specific reasons why the tested rigid connection does not meet the requirements, allowing for targeted remedial suggestions. For example, for joints that meet the rigid connection requirements, further reinforcement according to standard joint forms is unnecessary; while for joints that do not meet the requirements, the reasons for reduced stiffness can be identified, allowing for targeted reinforcement and modification, improving production efficiency and saving project costs.

[0062] Therefore, the method for determining the rigid connection of the rigid node described above in this invention has a wide range of applications and the determination results are relatively accurate; it can not only effectively save manpower and material resources, but also improve the intelligence of detection.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining a rigid connection of a rigidly connected node, characterized in that, The method includes: Establish a standard rigid joint model, perform calculations based on the standard rigid joint model and material elastic-plastic parameters, and obtain the first moment-rotation curve of the standard rigid joint based on the calculation results. The first moment-rotation curve and ultimate bearing capacity of the standard rigid joint are calculated, and the second moment-rotation curve of the standard rigid joint is obtained based on the calculation results. A model of the rigid joint to be tested is established based on the model of the rigid joint to be tested and the elastic-plastic parameters of the material are calculated. The moment-rotation curve of the rigid joint to be tested is obtained based on the calculation results. Based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of the standard rigid connection, determine whether the rigid connection to be tested meets the requirements of rigid connection. The calculation based on the first moment-rotation curve and ultimate bearing capacity of the standard rigid joint includes: Based on the principle that the first shaded area and the second shaded area are equal, the calculation is performed according to the first bending moment-rotation curve and the ultimate bearing capacity of the standard rigid joint. Wherein, the first shaded area is: the area enclosed by the first bending moment angle curve and the second bending moment angle curve before the first intersection point; The second shaded area is the area enclosed by the first bending moment angle curve and the second bending moment angle curve after the first intersection point and before the second intersection point.

2. The method according to claim 1, characterized in that, The method further includes: When it is determined that the rigid connection node to be tested does not meet the requirements of rigid connection, a finite element comparative analysis is performed based on the model of the rigid connection node to be tested and the standard rigid connection node model, and the reasons for not meeting the requirements of rigid connection are determined based on the analysis results.

3. The method according to claim 1, characterized in that: A standard rigid joint model and a rigid joint model to be tested were established using finite element software.

4. The method according to claim 1, characterized in that, The process of determining whether the rigid connection to be tested meets the requirements of a rigid connection based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of a standard rigid connection includes: When the top of the moment-rotation curve of the rigid connection to be tested exceeds the top of the second moment-rotation curve of the standard rigid connection, it is determined that the rigid connection to be tested meets the preset rigid connection requirements; otherwise, it is determined that the rigid connection to be tested does not meet the preset rigid connection requirements.

5. The method according to claim 1, characterized in that, The process of determining whether the rigid connection to be tested meets the requirements of a rigid connection based on the moment-rotation curve of the rigid connection to be tested and the second moment-rotation curve of a standard rigid connection includes: When the moment-rotation curve of the rigid connection node to be tested is above the third intersection point, it is determined that the rigid connection node to be tested meets the minimum rigid connection requirements; otherwise, it is determined that the rigid connection node to be tested does not meet the minimum rigid connection requirements. The coordinates of the third intersection point are ( M0); M0 represents the x-coordinate of the inflection point of the second moment-rotation curve of the standard rigid connection node, and M0 represents the actual load applied.

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