A cable force calculation method for cable tensioning construction of a hybrid structure with cable groups

Abstract

The present invention discloses a cable tensioning construction cable force calculation method for a hybrid structure with cable groups, belonging to the technical field of cable tensioning construction cable force calculation. The present invention is based on the target cable force of the structural design, and the conversion data is derived from the structural design model and imported into MIDAS Gen to establish a structural analysis model considering the cable construction process. According to the predetermined cable installation and tensioning sequence, the initial internal force is applied for calculation and analysis. In the iterative calculation, the initial internal force applied in the model is corrected by means of the initial internal force loss adjustment coefficient vector. After iteration, the error between the cable force value of the corresponding working condition and the target cable force value meets the requirement, so as to realize the rapid determination of the cable force of the hybrid structure with cable groups. In the method, the characteristics of the data table format standard of MIDAS Gen are used to realize rapid data processing; and the compressible rod unit is used in the analysis model instead of the cable unit.

Description

Technical Field

[0001] The invention belongs to the technical field of cable construction, and in particular relates to a cable force calculation method for cable tensioning construction of a building with a cable group hybrid structure. Background Art

[0002] Commonly used methods for determining cable forces in cable tensioning construction include the forward iteration method, the reverse disassembly method, the reverse disassembly forward iteration method, the stress-free state method, etc. Existing calculation methods all have certain limitations, such as the forward iteration method has a slow convergence speed and a long solution time; the reverse disassembly method and the stress-free state make it difficult to consider the influence of concrete time-varying effects; the reverse disassembly-forward interactive iteration method has a cumbersome iterative process and a large amount of analysis and calculation.

[0003] Therefore, it is necessary to provide a method for calculating the cable force of cable-tensioned construction of a hybrid structure building with a group of cables. The modeling idea is simple, the operation is quick, the solution accuracy is high, and the number of iterations is small. The influence of factors such as the construction of post-casting strips and secondary structure engineering construction can be considered according to the progress of on-site construction to achieve rapid adjustment of the model. It is a fast and effective method for determining the cable force of cable-tensioned construction. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a fast and effective method for calculating the cable force in the cable tensioning construction of a hybrid structure building with a group of cables.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for calculating the cable force of cable tensioning construction of a cable group hybrid structure building, comprising the following steps:

[0007] S1: Use MIDAS Gen to establish a structural analysis model for the cable construction process, and preset The installation and tensioning sequence of each cable unit is used to set the target cable force under the corresponding working conditions. , calculate the corresponding value without initial internal force Cable force value of working condition , where {} represents an array;

[0008] S2: Calculate the first n +1 iteration The initial internal force of the cable unit :

[0009]

[0010] In the formula, For the n The deviation value of the design cable force value of the iteration satisfies ,in, The initial internal force applied to the cables in the established cable construction process structural analysis model is: To apply the initial internal force When the finite element analysis is performed, the corresponding Cable force value under working conditions; is the initial internal force loss adjustment coefficient, ,in, For the The cable unit is n After the first iteration, the initial internal force adjustment mitigation coefficient is used for the n +1 iteration;

[0011] S3: Calculate the n The target value error rate of the iteration , if the maximum error rate , is the allowable error rate, the accuracy requirement is met and the iteration is exited; if , then continue to iterate according to step S2 until , and the initial internal force applied in the last iteration As cable tensioning construction cable force.

[0012] Further, in n =1, sets the initial internal force adjustment mitigation coefficient for the first iteration =0.5, target value allowable error rate =1%, mitigation factor adjustment factor .

[0013] Further, in n The initial internal force adjustment mitigation coefficient of the iteration Greater than n -1 iteration of initial internal force adjustment mitigation coefficient When n The mitigation factor adjustment factor in the iteration .

[0014] further, The normalized data after each iteration of calculation can be copied from MIDAS Gen to Excel for automatic extraction.

[0015] Furthermore, compressible bar elements are used instead of cable elements in the structural analysis model.

[0016] Furthermore, before the iteration, according to the principle of action superposition, the model without initial internal force is calculated to determine the additional cable force generated by the load action other than the cable tensioning construction action. The initial internal force applied in the first iteration is calculated. When the additional cable force is removed.

[0017] The beneficial effects of the present invention are:

[0018] (1) A simple, fast and easy-to-implement method is provided to calculate the cable tension of cable-tensioned hybrid building structures with cable groups. The overall analysis model is established using the MIDAS Gen module that takes into account the construction process. The characteristics of the hybrid structure, such as the large variety of components and the complex internal force distribution, can be taken into account. The relevant model information can be directly derived from the structural design model to ensure the accuracy of the analysis model. The model can also be adjusted quickly and some complex structural behaviors during the construction process can be considered. For example, the influence of factors such as the construction of post-cast joints and secondary structural engineering can be considered according to the progress of on-site construction during actual construction conditions. The time-varying effect of concrete can also be realized.

[0019] (2) By directly exporting relevant model information from the structural design model to MIDAS Gen, the built-in working condition combination function of MIDASGen can be used to check whether the structure meets the requirements of the specification under the action during the construction process. If it meets the requirements, the determined tensioning construction sequence is a reasonable sequence, and the tensioning cable force value of each cable corresponding to the construction step is the tensioning construction cable force. If it does not meet the requirements, the installation and tensioning sequence of the cables need to be adjusted.

[0020] (3) In the analysis model, compressible rod elements are used instead of cable elements. Considering the principle of action superposition, the model without initial internal force is first calculated to determine the additional cable force generated by the load action other than the cable tensioning construction action. The initial internal force applied in the first iteration is calculated. When this part of the effect is separated, the stability of the iteration and the effectiveness of the initial internal force applied can be greatly improved. This method provides a method for determining the initial internal force applied.

[0021] (4) It is proposed to introduce the initial internal force adjustment mitigation coefficient and the mitigation coefficient adjustment coefficient to improve the iteration stability and iteration efficiency.

[0022] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0024] Figure 1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0025] like Figure 1As shown, the present invention provides a method for calculating the cable force of cable tensioning construction of a cable group hybrid structure building, comprising the following steps:

[0026] Step 1: Export the conversion data from the structural design model and import it into the MIDAS Gen structural analysis software. According to the predetermined cable installation and tensioning sequence, establish a structural analysis model that takes into account the cable construction process. Considering the iterative effect, the cable unit uses a compressible rod unit instead of a cable unit. In this application, the compressible rod unit is a truss unit.

[0027] Step 2: Set the target value of the design cable force under the corresponding working conditions , the corresponding value without initial internal force is calculated by MIDAS Gen built-in algorithm Cable force value of working condition ;

[0028] Step 3: Calculate the initial internal forces of each cable at the first iteration ;

[0029] Step 4: Set the initial internal force adjustment mitigation coefficient for the first iteration =0.5, target value allowable error rate =1%, mitigation factor adjustment factor ;

[0030] Step 5: Apply initial internal force When the finite element analysis is performed, the corresponding Cable force value under working conditions ;in, The normalized data after each iteration calculation can be copied from MIDAS Gen to Excel for automatic extraction;

[0031] Step 6: Calculate the deviation of the design cable force to meet ;

[0032] Step 7: Calculate n The target value error rate of the iteration , if the maximum error rate , the accuracy requirement is met and the iteration is exited; and the n -1 initial internal force applied in iterations As the cable tensioning construction cable force; if it does not meet the accuracy requirements, continue with the following steps;

[0033] Step 8: Determine the deviation value of the designed cable force , No. n -1 initial internal force applied in iterations Determine the initial internal force loss adjustment coefficient ,in, For the The cable unit is n After the first iteration, the initial internal force adjustment mitigation coefficient is used for the n +1 iteration;

[0034] Step 9: n +1 iteration of applying initial internal forces By n Apply initial internal forces for iterations , the deviation value of the design cable force value of the nth iteration , initial internal force loss adjustment coefficient Calculate and determine,

[0035]

[0036] Step 10: Apply initial internal force , continue iterating until .

[0037] in, Adjust the mitigation coefficient for the initial internal force. The initial internal force adjustment mitigation coefficient after the first iteration is used for the second iteration. Mitigation factor adjustment factor can be introduced Automatically increase or decrease according to the effect of the current iteration, for example, if , indicating the n The initial internal force adjustment of the iteration can be larger to improve the iteration efficiency. After the judgment, let , can be set , so that the mitigation effect of the n+1th iteration is reduced.

[0038] Taking into account the principle of superposition of actions, the model without initial internal force is first calculated to determine the additional cable force generated by load actions other than the cable tensioning construction action. This part of the action is stripped off during iteration, which greatly improves the stability of the iteration and the effectiveness of the applied initial internal force.

[0039] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for calculating the cable force of cable tensioning construction of a cable-group hybrid structure building, characterized in that: The following steps are involved: S1: Use MIDAS Gen to establish a structural analysis model for the cable construction process, and preset The installation and tensioning sequence of each cable unit is used to set the target cable force under the corresponding working conditions. , calculate the corresponding value without initial internal force Cable force value of working condition , where {} represents an array; S2: Calculate the first n +1 iteration The initial internal force of the cable unit : In the formula, For the n The deviation value of the design cable force value of the iteration satisfies ,in, The initial internal force applied to the cable in the established cable construction process structural analysis model is: To apply the initial internal force When the finite element analysis is performed, the corresponding Cable force value under working conditions; is the initial internal force loss adjustment coefficient, ,in, For the The cable unit is n After the first iteration, the initial internal force adjustment mitigation coefficient is used for the n +1 iteration; in, Adjust the mitigation coefficient for the initial internal force. The initial internal force adjustment mitigation coefficient after the first iteration is used for the second iteration. Mitigation factor adjustment factor can be introduced Automatically increase or decrease according to the effect of the current iteration. , then it means n The initial internal force adjustment of the iteration can be larger to improve the iteration efficiency. After the judgment, let , can be set , so that the mitigation effect of the n+1th iteration is reduced; S3: Calculate the n The target value error rate of the iteration , if the maximum error rate , is the allowable error rate, the accuracy requirement is met and the iteration is exited; if , then continue to iterate according to step S2 until , and the initial internal force applied in the last iteration As cable tensioning construction cable force.

2. The cable force calculation method for cable tensioning construction of a cable-group hybrid structure building according to claim 1 is characterized by: exist n =1, sets the initial internal force adjustment mitigation coefficient for the first iteration =0.5, target value allowable error rate =1%, mitigation factor adjustment factor .

3. The cable force calculation method for cable tensioning construction of a cable-group hybrid structure building according to claim 1 is characterized in that: In the n The initial internal force adjustment mitigation coefficient of the iteration Greater than n -1 iteration of initial internal force adjustment mitigation coefficient When n The mitigation factor adjustment factor in the iteration .

4. The cable force calculation method for cable tensioning construction of a cable-group hybrid structure building according to claim 1 is characterized by: The normalized data after each iteration of calculation can be copied from MIDAS Gen to Excel for automatic extraction.

5. The cable force calculation method for cable tensioning construction of a cable-group hybrid structure building according to claim 1 is characterized by: In the structural analysis model, compressible bar elements are used instead of cable elements.

6. The cable force calculation method for cable tensioning construction of a cable-group hybrid structure building according to claim 1 is characterized by: Before iteration, according to the principle of action superposition, the model without initial internal force is calculated to determine the additional cable force generated by the load action other than the cable tensioning construction action. The initial internal force applied in the first iteration is calculated. When the additional cable force is removed.

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