Mechanical analysis method for unloading process of large-span steel structure

Abstract

The application discloses a mechanical analysis method for a large-span steel structure unloading process, solves the problem that a complex mechanical state is difficult to predict in the process of disassembling and supporting the large-span steel structure, can effectively realize mechanical numerical simulation of the process of disassembling and supporting the large-span steel structure, and achieves the purpose of predicting the deformation condition and internal force change condition of the main structure and the temporary support in the process of disassembling and supporting the steel structure.

Description

Technical Field

[0001] This invention belongs to the field of construction technology for large-span steel structures, and particularly relates to a mechanical analysis method for the unloading process of large-span steel structures. Background Technology

[0002] The unloading process of large-span steel structures is a complex and high-risk process. To ensure the smooth progress of unloading and the safety of the main structure, it is necessary to conduct a full-process mechanical simulation of the unloading process, predict the development and changes of the internal forces and deformations of temporary supports and the main structure, and then determine a reasonable unloading plan.

[0003] The mechanical analysis of the unloading process of large-span steel structures involves contact mechanics. Temporary supports can only withstand compressive forces, not tensile forces, and may come into contact with, detach from, or displace the main structure. Traditional simulation methods, such as the support displacement method, cannot simulate the detachment of the main structure and temporary supports. The Newton-Raphson method can simulate the detachment of the main structure and temporary supports through repeated iterations, but the computational load is large, and it may not converge when there are many support points.

[0004] Therefore, it is necessary to design a mechanical analysis method for the unloading process of large-span steel structures in order to more accurately and efficiently simulate the development of internal forces and deformations of the main structure and temporary supports during the unloading process. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of the prior art by disclosing a mechanical analysis method for the unloading process of a large-span steel structure, thus solving the problem of the difficulty in predicting the complex mechanical state during the dismantling of a large-span steel structure.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A mechanical analysis method for the unloading process of a large-span steel structure, comprising the following steps:

[0008] S1. Based on the configuration of the large-span steel structure and temporary supports, the stiffness matrix K of the main structure is calculated using the finite element method. s and self-weight load vector G s and initial displacement y s,0 Simultaneously calculate the stiffness matrix K of the temporary support. t Self-weight load vector G t and initial displacement y t,0 ;

[0009] S2, based on the stiffness matrix K s K t and self-weight load vector G s G tCalculate the displacement y of the large-span steel structure and temporary supports under their own weight loads. s,g and y t,g ;

[0010] S3, according to the stiffness matrix K s K t Calculate the displacement combination matrix A of the large-span steel structure and temporary supports under unit contact load, respectively. s,c and A t,c ;

[0011] S4. Based on the support positions of the temporary supports on the large-span steel structure, extract the initial displacement y of the support points of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c Simultaneously extract the initial displacement y of the temporary support point. t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c ;

[0012] S5. The initial displacement y of the support point of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c The initial displacement y of the temporary support point t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c Substituting into the linear complementary equation

[0013] (y s,0,c +y s,g,c -y t,0,c -y t,g,c )+(M s,c -M t,c )F c -ν=0

[0014] F c,i ≥0,ν i ≥0,F c,i ·ν i =0

[0015] In the formula, F c F is the interaction force vector between the temporary support and the main structure. c,i Let ν be the interaction force between the i-th temporary support and the main structure, and let ν be the slack variable vector. i Let i be the slack variable;

[0016] S6. Solve the linear complementary equations to calculate the interaction force F between the main structure and the temporary supports at each step of the dismantling process. c ;

[0017] S7. The interaction force F in step S6 is... c Applying force to the main structure and temporary supports, calculate the internal forces N of the main structure under the current state. s and deformation y s,1 and the internal force condition of the temporary support structure N t and deformation condition y t,1 ;

[0018] S8. Based on the temporary support descent steps during the dismantling process, redetermine the initial displacement y of the temporary support. t,0 By repeating steps S5, S6 and S7, the changes in internal forces and deformations of the main structure and temporary support structure during the dismantling and bracing process can be obtained, and the contact state and interaction forces of the main structure and temporary support structure can be accurately obtained.

[0019] According to a preferred embodiment, in step S6, the Lemke algorithm is used to solve the linear complementary equations.

[0020] According to a preferred embodiment, in step S8

[0021] The displacement expressions for the main structure and the temporary support structure were calculated using the finite element method.

[0022] Substitute the displacement expressions of the main structure and the temporary support structure into the displacement compatibility equation of the main structure and the temporary support and solve it to obtain the interaction force between the main structure and the temporary support.

[0023] By substituting the interaction forces between the main structure and the temporary supports into the displacement expressions of the main structure and the temporary supports, the deformation of the main structure and the temporary supports during the unloading process of the large-span steel structure is obtained.

[0024] Substituting the deformation of the main structure and the temporary support structure into the deformation compatibility equation, we obtain the internal force conditions of the main structure and the temporary support structure.

[0025] According to a preferred embodiment, the displacement expression of the main structure is as follows:

[0026] y s =y s,0 +y s,g +A s,c F c

[0027] Among them, y sy represents the displacement vector of the main structure. s,0 y represents the initial displacement vector of the main structure. s,g A represents the displacement vector of the main structure under its own weight load. s,c F represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary supporting structure. c This represents the force vector of the interaction between the main structure and the temporary support structure.

[0028] According to a preferred embodiment, the displacement expression for the temporary support structure is as follows:

[0029] y t =y t,0 +y t,g -A t,c F c

[0030] Among them, y t y represents the displacement vector of the temporary support structure. t,0 Let y represent the initial displacement vector of the temporary support structure. t,g A represents the displacement vector of the temporary support structure under its own weight load. t,c It represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary support structure.

[0031] According to a preferred embodiment, the displacement compatibility equations for the main structure and temporary supports are as follows:

[0032] y s,i -y t,i -ν i =0

[0033] F c,i ≥0,ν i ≥0,F c,i ·ν i =0

[0034] Actually, y s,i y represents the displacement of the main structure at the i-th temporary support structure. t,i F represents the displacement of the i-th temporary support point. c,i ν represents the interaction force between the main structure and the i-th temporary support structure. i Let F be a non-negative slack variable. c,i ≥0 and ν i ≥0 is a non-negativity condition, F c,i ·ν i =0 indicates a complementary condition.

[0035] The aforementioned main solution of the present invention and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed by the present invention. Those skilled in the art, after understanding the solution of the present invention, will realize that there are many combinations based on existing technology and common knowledge, all of which are technical solutions to be protected by the present invention, and will not be exhaustively listed here.

[0036] The beneficial effects of this invention are as follows: The mechanical analysis method for the unloading process of large-span steel structures of this invention solves the problem of the difficulty in predicting the complex mechanical state during the dismantling of large-span steel structures. It can effectively realize the mechanical numerical simulation of the dismantling process of large-span steel structures and achieve the prediction of the deformation and internal force changes of the main structure and temporary supports during the dismantling process. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the mechanical analysis method for the unloading process of large-span steel structures according to the present invention. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0039] Example 1:

[0040] refer to Figure 1 As shown in the figure, a mechanical analysis method for the unloading process of a large-span steel structure is illustrated. The mechanical analysis method for the unloading process of a large-span steel structure includes the following steps:

[0041] Step S1: Based on the large-span steel structure and temporary support configuration, calculate the stiffness matrix K of the main structure using the finite element method. s and self-weight load vector G s and initial displacement y s,0 Simultaneously calculate the stiffness matrix K of the temporary support. t Self-weight load vector G t and initial displacement y t,0 .

[0042] Step S2: Based on the stiffness matrix K s K t and self-weight load vector G s G t Calculate the displacement y of the large-span steel structure and temporary supports under their own weight loads. s,g and yt,g .

[0043] Step S3: Based on the stiffness matrix K s K t Calculate the displacement combination matrix A of the large-span steel structure and temporary supports under unit contact load, respectively. s,c and A t,c .

[0044] Step S4: Based on the support positions of the temporary supports on the large-span steel structure, extract the initial displacement y of the support points of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c Simultaneously extract the initial displacement y of the temporary support point. t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c .

[0045] Step S5: Calculate the initial displacement y of the support points of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c The initial displacement y of the temporary support point t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c Substituting into the linear complementary equation

[0046] (y s,0,c +y s,g,c -y t,0,c -y t,g,c )+(M s,c -M t,c )F c -ν=0

[0047] F c,i ≥0,ν i ≥0,F c,i ·ν i =0

[0048] In the formula, F c F is the interaction force vector between the temporary support and the main structure. c,i Let ν be the interaction force between the i-th temporary support and the main structure, and let ν be the slack variable vector. i Let be the i-th slack variable.

[0049] Step S6: Solve the linear complementary equations to calculate the interaction force F between the main structure and the temporary supports at each step of the dismantling process. c .

[0050] Preferably, in step S6, the Lemke algorithm is used to solve the linear complementary equations.

[0051] Step S7: The interaction force F from step S6 c Applying force to the main structure and temporary supports, calculate the internal forces N of the main structure under the current state. s and deformation condition y s,1 and the internal force condition of the temporary support structure N t and deformation condition y t,1 .

[0052] Step S8: Based on the temporary support descent steps during the dismantling process, redetermine the initial displacement y of the temporary support. t,0 By repeating steps S5, S6 and S7, the changes in internal forces and deformations of the main structure and temporary support structure during the dismantling and bracing process can be obtained, and the contact state and interaction forces of the main structure and temporary support structure can be accurately obtained.

[0053] Preferably, in step S8, the displacement expressions of the main structure and the temporary support structure are calculated using the finite element method.

[0054] Substituting the displacement expressions of the main structure and the temporary support structure into the displacement compatibility equation of the main structure and the temporary support structure and solving it, the interaction force between the main structure and the temporary support structure is obtained.

[0055] By substituting the interaction forces between the main structure and the temporary supports into the displacement expressions of the main structure and the temporary supports, the deformation of the main structure and the temporary supports during the unloading process of the large-span steel structure can be obtained.

[0056] Substituting the deformation of the main structure and the temporary support structure into the deformation compatibility equation, we obtain the internal force conditions of the main structure and the temporary support structure.

[0057] Furthermore, the displacement expression for the main structure is as follows:

[0058] y s =y s,0 +y s,g +A s,c F c

[0059] Among them, y s y represents the displacement vector of the main structure. s,0 y represents the initial displacement vector of the main structure. s,gA represents the displacement vector of the main structure under its own weight load. s,c F represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary supporting structure. c This represents the force vector of the interaction between the main structure and the temporary support structure.

[0060] Furthermore, the displacement expression for the temporary support structure is as follows:

[0061] y t =y t,0 +y t,g -A t,c F c

[0062] Among them, y t y represents the displacement vector of the temporary support structure. t,0 Let y represent the initial displacement vector of the temporary support structure. t,g A represents the displacement vector of the temporary support structure under its own weight load. t,c It represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary support structure.

[0063] Furthermore, the displacement compatibility equations for the main structure and temporary supports are as follows:

[0064] y s,i -y t,i -ν i =0

[0065] F c,i ≥0,ν i ≥0,F c,i ·ν i =0

[0066] Actually, y s,i y represents the displacement of the main structure at the i-th temporary support structure. t,i F represents the displacement of the i-th temporary support point. c,i ν represents the interaction force between the main structure and the i-th temporary support structure. i Let F be a non-negative slack variable. c,i ≥0 and ν i ≥0 is a non-negativity condition, F c,i ·ν i =0 indicates a complementary condition.

[0067] The mechanical analysis method for the unloading process of large-span steel structures in this invention solves the problem of predicting the complex mechanical state during the dismantling of large-span steel structures. It can effectively realize the mechanical numerical simulation of the dismantling process of large-span steel structures and predict the deformation and internal force changes of the main structure and temporary supports during the dismantling process.

[0068] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mechanical analysis method for the unloading process of a large-span steel structure, characterized in that, The mechanical analysis method for the unloading process of the large-span steel structure includes the following steps: S1. Based on the configuration of the large-span steel structure and temporary supports, the stiffness matrix K of the main structure is calculated using the finite element method. s and self-weight load vector G s and initial displacement y s,0 Simultaneously calculate the stiffness matrix K of the temporary support. t Self-weight load vector G t and initial displacement y t,0 ; S2, based on the stiffness matrix K s K t and self-weight load vector G s G t Calculate the displacement y of the large-span steel structure and temporary supports under their own weight loads. s,g and y t,g ; S3, according to the stiffness matrix K s K t Calculate the displacement combination matrix A of the large-span steel structure and temporary supports under unit contact load, respectively. s,c and A t,c ; S4. Based on the support positions of the temporary supports on the large-span steel structure, extract the initial displacement y of the support points of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c Simultaneously extract the initial displacement y of the temporary support point. t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c ; S5. The initial displacement y of the support point of the large-span steel structure. s,0,c Displacement y under self-weight load s,g,c The displacement combination matrix M generated by the temporary support load. s,c The initial displacement y of the temporary support point t,0,c Displacement y under self-weight load t,g,c The displacement combination matrix M generated by the action of the main structure t,c Substituting into the linear complementary equation In the formula, This represents the interaction force vector between the temporary support and the main structure. For the first i The interaction force between the temporary support and the main structure Let be the slack variable vector. For the first i One slack variable; S6. Solve the linear complementary equations to calculate the interaction forces between the main structure and the temporary supports at each step of the dismantling process. ; S7. The interaction forces in step S6 Applying force to the main structure and temporary supports, calculate the internal forces N of the main structure under the current state. s and deformation and the internal force condition of the temporary support structure N t and deformation ; S8. Based on the temporary support descent steps during the dismantling process, redetermine the initial displacement y of the temporary support. t,0 By repeating steps S5, S6 and S7, the changes in internal forces and deformations of the main structure and temporary support structure during the dismantling and bracing process can be obtained, and the contact state and interaction forces of the main structure and temporary support structure can be accurately obtained.

2. The mechanical analysis method for the unloading process of a large-span steel structure as described in claim 1, characterized in that, In step S6, the Lemke algorithm is used to solve the linear complementary equations.

3. The mechanical analysis method for the unloading process of a large-span steel structure as described in claim 1, characterized in that, In step S8, The displacement expressions for the main structure and the temporary support structure were calculated using the finite element method. Substitute the displacement expressions of the main structure and the temporary support structure into the displacement compatibility equation of the main structure and the temporary support and solve it to obtain the interaction force between the main structure and the temporary support. By substituting the interaction forces between the main structure and the temporary supports into the displacement expressions of the main structure and the temporary supports, the deformation of the main structure and the temporary supports during the unloading process of the large-span steel structure is obtained. Substituting the deformation of the main structure and the temporary support structure into the deformation compatibility equation, we obtain the internal force conditions of the main structure and the temporary support structure.

4. The mechanical analysis method for the unloading process of a large-span steel structure as described in claim 3, characterized in that, The displacement expression for the main structure is as follows: in, Represents the displacement vector of the main structure. This represents the initial displacement vector of the main structure. This represents the displacement vector of the main structure under its own weight load. This represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary supporting structure. This represents the force vector of the interaction between the main structure and the temporary support structure.

5. The mechanical analysis method for the unloading process of a large-span steel structure as described in claim 3, characterized in that, The displacement expression for the temporary support structure is as follows: in, This represents the displacement vector of the temporary support structure. This represents the initial displacement vector of the temporary support structure. This represents the displacement vector of the temporary support structure under its own weight load. It represents the matrix consisting of displacement vectors caused by the unit force exerted on the main structure by the temporary support structure.

6. The mechanical analysis method for the unloading process of a large-span steel structure as described in claim 3, characterized in that, The displacement compatibility equations for the main structure and temporary supports are as follows: in, Indicates the main structure in the first i Displacement at the temporary support structure Indicates the first i Displacement of the temporary support structure's support points Indicates the main structure and the first i The interaction forces of the temporary support structure Let be a non-negative slack variable. and The condition is non-negative. These are complementary conditions.

Images