CN116127637A - Characteristic reconstruction type design method for shield tunneling machine cutterhead panel structure - Google Patents

Abstract

A feature reconstruction design method for the shield machine cutterhead panel structure, firstly determine the cutter layout of the shield machine cutterhead panel, and establish a mechanical simulation model of the shield machine cutterhead panel: according to the actual shield machine cutterhead panel structure Design problems, extract the domain to be analyzed and the geometric and physical conditions; then establish the topology model of the shield machine cutter head panel feature reconstruction design domain; and then establish the feature reconstruction design mathematical model: to minimize the flexibility is the structure Optimum stiffness is the objective function, the variable density method is used to describe the structure optimization method, an optimization model driven by the physical field is established, and the optimization direction is determined each time; then the iterative optimization of the shield machine cutter head panel structure is carried out to obtain the constant volume ratio constraint The cutterhead panel structure of the shield machine with the highest rigidity under the conditions; finally, post-processing is performed on the optimized cutterhead panel structure of the shield machine; the invention improves the efficiency and quality of the design.

Description

A Feature Reconstruction Design Method for Shield Machine Cutterhead Panel Structure

technical field

The invention belongs to the technical field of shield machine cutter head panel structure design, and in particular relates to a characteristic reconstruction design method of a shield machine cutter head panel structure.

Background technique

With the increasing demand for underground space infrastructure in human society, the shield machine used for the construction of mountain tunnels and underground rail transit has been widely used. The shield machine cutter head panel is one of the most critical components of the shield machine. First, it plays a vital role in excavating tunnels. The quality of the cutter head panel structure directly affects the excavation work of the shield machine.

The working conditions of the shield machine are complex and harsh. At present, most shield machine faceplate designs are based on experience to design the faceplate reinforcement ribs. The analysis of the force situation is basically based on the friction between the faceplate and the soil layer to optimize the design of the faceplate (Feng Chang ,Zhu Shumin,Chen Guosan.Earth pressure balance shield cutter head optimization design and analysis[J].Machinery Manufacturing and Automation,2017,46(03):144-147+188.DOI:10.19344/j.cnki.issn1671-5276.2017. 03.041.), did not fully consider the force of each cutting tool on the panel, so the optimized rib structure of the cutter head panel cannot be applied to the real force of the tool when the panel of the shield machine is working.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned technologies, the purpose of the present invention is to provide a feature reconstruction design method for the shield machine cutter head panel structure, which improves the efficiency and quality of the design.

For achieving above object, the technical scheme that the present invention takes is:

A feature reconstruction design method for a shield machine cutter head panel structure, comprising the following steps:

1) Determine the mechanical simulation model of the shield machine panel:

1.1) Determine the relevant parameters of the shield machine panel:

Preliminarily set the parameters to be optimized for the shield machine panel, including: outer diameter d ₀ of the shield machine, maximum cutting diameter d ₁ of the tool, cutting radius d ₂ of the center knife, width b _{1 of} the positive cutting knife of the cutter head, and the overlapping amount of the tool e , the number of spokes of the cutter head N, the width of the edge cutter b ₂ ;

1.2) Determine the layout of the cutter head and cutter:

The minimum number of positive cutters required for the TBM panel is:

The number of positive cutting knives N ₁ of the cutter head is rounded to N ₀ , and the overlapping amount of positive cutting knives and central knives is:

c=(b ₁ -e)×(N ₀ -N ₁ ) (2)

Then the initial value of the tangent knife Archimedes spiral is:

The Archimedes spiral coefficient α is:

Then the curve equation of the positive cutter helical arrangement of the cutter head is:

ρ＝ρ ₀ +αθ (5)

Add other shield machine tools and determine the results of the tool layout of the entire cutterhead panel;

2) Establish the feature reconstruction model of the shield machine cutter head panel:

2.1) Establish the topological model of the shield machine cutter head panel feature reconstruction design domain:

The topology model of the design domain is established according to the determined cutter head structure. The characteristic reconstruction design method adopted takes the isotropic pseudo-density unit as the minimum unit of structure optimization, and the design domain is characterized as closely arranged pseudo-density units; The pseudo-density value x of the unit is used as a design variable, which reflects the corresponding relationship between material density and material properties; 1 and 0 of the pseudo-density value represent the presence or absence of structures at this position, and the design variable field x={x ₁ ,x ₂ ,..., _xi ,...} ^T characterizes the structure distribution in the design domain, and defines the design domain and non-design domain of the structure according to the pseudo-density value;

2.2) Establish the mathematical model of the feature reconstruction design method:

The goal of structural design is to determine the optimal structural path for the cutting force on the cutterhead panel of the shield machine to be transmitted to the fixed point between the corbel flange and the panel. The design objective is to maximize the stiffness of the panel structure, so the objective function of the optimized mathematical model is c (x), the constraint function is the opening ratio of the shield machine panel, that is, the final material volume fraction f in the design domain, and the panel material is determined. For the design objective and constraint function, the following mathematical model of the characteristic reconstruction design method is established:

In the formula: x _e is the element density, that is, the design variable; U is the displacement matrix; K is the stiffness matrix; V _(x) is the structure volume; V ₀ is the total volume; f is the volume fraction; u _e is the element displacement vector; k ₀ is the element stiffness matrix; p is the penalty factor;

2.3) Sensitivity analysis of feature reconstruction design method:

Before performing the iterative algorithm, it is necessary to conduct a sensitivity analysis of the objective function relative to the design variables. During the sensitivity analysis, the unit displacements of the i stress points need to be accumulated. The final sensitivity function is as follows:

3) Iterative optimization of shield machine panel structure:

The best structural model is obtained through continuous iterative optimization of material pseudo-density values, and the design variables, objective functions, constraint functions and their sensitivities about the design variables obtained in the previous steps are used as input, and the gradient-based OC algorithm is used to reconstruct the features. Optimize the mathematical model of the structure design method and update the design variables; until the objective function converges under the condition of satisfying the constraint conditions, so as to obtain the optimal panel structure that meets the material consumption;

4) Structural post-processing:

The optimally designed shield machine panel structure is smoothed and rounded, and then further modified according to the processing technology requirements and manufacturing assembly requirements to obtain the final design.

The present invention has following beneficial result:

Since the present invention does not rely on the long-term design experience of the designer, it can reduce the design labor cost of the enterprise; the present invention uses the feature reconstruction design, and it is the first to propose the actual stress situation of the cutter on the shield machine cutter head panel. To optimize the characteristics of the panel structure, so the design results have a more theoretical basis, the final structure is more reasonable, and the performance is more excellent;

Compared with the current mainstream shield machine panel design method, when using the present invention to design, it is no longer necessary to repeat the work of design, simulation, and improvement, which significantly improves work efficiency and design performance, thereby helping enterprises to better Respond to the rapidly changing market and achieve better production efficiency.

Description of drawings

Fig. 1 is a flowchart of the present invention.

Fig. 2 is a schematic diagram of the arrangement of cutterheads and cutters according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of the result of reconstructing the panel features of the shield machine according to the embodiment of the present invention.

Fig. 4 is a schematic diagram of the panel structure design of the shield machine according to the embodiment of the present invention.

Detailed ways

The present invention is described in detail below in conjunction with accompanying drawing and embodiment, and the method of the present invention can be used in the structural design of the panel of various spoke type shield machines, and the embodiment adopts the structural design of a certain type of 4-spoke shield machine as an example;

Referring to Fig. 1, a feature reconstruction design method of the shield machine cutterhead panel structure includes the following steps:

1) Determine the mechanical simulation model of the shield machine panel:

1.1) Determine the relevant parameters of the shield machine panel:

Initially set the parameters of the shield machine panel to be optimized, shield machine outer diameter d ₀ =6280mm, tool maximum cutting diameter d ₁ =6300mm, center knife cutting radius d ₂ =1900mm, cutter head positive cutting knife width b ₁ =100mm , the overlapping amount of the cutter is e=4mm, the number of spokes of the cutterhead is N=4, the width of the edge cutter is b ₂ =150mm, and the tangent cutter is arranged in a double helix;

1.2) Determine the layout of the cutter head and cutter:

The minimum number of positive cutters required for the TBM panel is:

The number of positive cutting knives N ₁ of the cutter head is rounded to N ₀ = 22, and the overlapping amount of positive cutting knives and central knives is:

c=(b ₁ -e)×(N ₀ -N ₁ )=(100-4)×(22-21.35)=62.4 (2)

Then the initial value of the tangent knife Archimedes spiral is:

The Archimedes spiral coefficient α is:

Then the curve equation of the double helix arrangement of the positive cutter arrangement on the cutterhead is:

The shell knives are evenly distributed along the circumference on the outermost side of the cutter head. In this embodiment, 4 shell knives are arranged, which are evenly distributed among the four spokes; the final arrangement of the cutters on the cutter head is shown in Figure 2, and it can be seen from the figure that the hollow circles represent The position of the cutter, the solid circle is the position of the four shell knives;

2) Establish the feature reconstruction model of the shield machine cutter head panel:

2.1) Establish the topological model of the shield machine cutter head panel feature reconstruction design domain:

The topology model of the design domain is established according to the determined cutter head structure. The characteristic reconstruction design method adopted takes the isotropic pseudo-density unit as the minimum unit of structure optimization, and the design domain is characterized as closely arranged pseudo-density units; The pseudo-density value x of the unit is used as a design variable, which reflects the corresponding relationship between material density and material properties; 1 and 0 of the pseudo-density value represent the presence or absence of structures at this position, and the design variable field x={x ₁ ,x ₂ ,..., _xi ,...} ^T characterizes the structure distribution in the design domain. The central soil flow rate of the shield machine is small, and it is easy to form accumulation cutting. The force of the shield machine increases with the increase of the radius , the force at the center is not included in this embodiment, and the pseudo-density value of the center is defined as 0 in advance, the force in the design domain is the position of the cutter layout on the shield machine panel determined in the previous step, and the fixed constraint points are the shield machine corbel flange and shield The lapping surface of the mechanism cutter head panel;

2.2) Establish the mathematical model of the feature reconstruction design method:

The structural design goal of this embodiment is to transfer the force of the tool on the panel of the shield machine to the optimal structural path of the fixed point of the panel, the corbel flange and the panel. The design objective is to maximize the rigidity of the panel structure, so the mathematical model is optimized The objective function is c(x), the constraint function is the opening ratio of the shield machine panel, that is, the final material volume fraction f in the design domain, and the panel material is Q235, so the Young’s modulus used in the element stiffness matrix K is 210GPa, and Poisson’s ratio is 0.3, for the design objective and constraint function, the following topology optimization mathematical model is established:

In the formula: x _e is the element density, that is, the design variable; U is the displacement matrix; K is the stiffness matrix; V _(x) is the structure volume; V ₀ is the total volume; f is the volume fraction; u _e is the element displacement vector; k ₀ is the element stiffness matrix; p is the penalty factor;

2.3) Sensitivity analysis of feature reconstruction design method:

Before performing the iterative algorithm, it is necessary to conduct a sensitivity analysis of the objective function relative to the design variables. The shield machine cutterhead panel used in this embodiment has many stress points, so the i stress points need to be included in the sensitivity analysis The unit displacements of the points are added up, and the final sensitivity function is as follows:

3) Iterative optimization of shield machine panel structure:

The best structural model is obtained through continuous iterative optimization of material pseudo-density values, and the design variables, objective functions, constraint functions and their sensitivities about the design variables obtained in the previous steps are used as input, and the gradient-based OC algorithm is used to reconstruct the features. Optimize the mathematical model of structural design method, and update the design variables; until the objective function converges under the condition of satisfying the constraint conditions, so as to obtain the optimal panel structure that meets the material consumption; the convergence condition of this embodiment is the objective function of two adjacent iterations The difference is less than 0.01; at the end of the optimization, the volume fraction of the design result is 40% of the entire design domain, and the final feature reconstruction design structure is shown in Figure 3. It can be seen that the cross structure in the center is the spoke of the cutterhead, and the rest are The panel structure obtained by feature reconstruction design;

4) Structural post-processing:

The optimally designed shield machine panel structure is smoothed and rounded, and then further modified according to the processing technology requirements and manufacturing assembly requirements to obtain the final design. The smooth and rounded shield machine panel structure results are shown in Figure 4.

Claims (1)

1. The characteristic reconstruction type design method of the shield tunneling machine cutterhead panel structure is characterized by comprising the following steps of:

1) Determining a mechanical simulation model of a shield tunneling machine panel:

1.1 Determining shield machine panel related parameters:

parameters of the shield tunneling machine panel required to be optimized are initially set, and the parameters comprise: outer diameter d of shield machine ₀ Maximum cutting diameter d of tool ₁ Center knife cutting radius d ₂ Width b of cutter head tangent ₁ The superposition amount e of the cutters, the number N of cutter disc spokes and the width b of the edge cutter ₂ ；

1.2 Determining cutter head cutter arrangement:

the minimum number of the tangent cutters required by the shield tunneling machine panel is as follows:

number of tangent cutters N of cutter head ₁ N is obtained after rounding ₀ The overlapping amount of the positive cutting knife and the center knife is as follows:

c＝(b ₁ -e)×(N ₀ -N ₁ ) (2)

the initial value of the tangent knife archimedes spiral is:

the archimedes spiral coefficient α is:

the cutter head tangent cutter spiral arrangement curve equation is:

ρ＝ρ ₀ +αθ (5)

adding other shield tunneling machine cutters and determining the arrangement result of the cutter of the whole cutter head panel;

2) Establishing a shield tunneling machine cutterhead panel characteristic reconstruction model:

2.1 Building a shield tunneling machine cutterhead panel characteristic reconstruction design domain topology model:

establishing a design domain topology model according to the determined cutter head structure, wherein the adopted characteristic reconstruction design method takes isotropic pseudo-density units as the minimum unit of structural optimization, and the design domain is characterized as closely arranged pseudo-density units; taking a pseudo density value x of the pseudo density unit as a design variable, wherein the pseudo density value x reflects the corresponding relation between the material density and the material property; the pseudo-density values 1 and 0 represent the presence or absence of the position structure, respectively, and the design variable field x= { x ₁ ,x ₂ ,...,x _i ,...} ^T Characterizing the structure distribution in the design domain, and defining the design domain and the non-design domain of the structure according to the pseudo density value;

2.2 Establishing a mathematical model of a characteristic reconstruction design method:

the structural design target is to determine the optimal structural path of the cutting force born by the cutter of the cutter head panel of the shield machine to Niu Tuifa blue and panel fixing points, the design target is the rigidity of the panel structure to be maximum, therefore, the objective function of the optimized mathematical model is c (x), the constraint function is the opening rate of the panel of the shield machine, namely the final material volume fraction f of the design domain, the panel material is determined, and for the design target and the constraint function, the following characteristic reconstruction design method mathematical model is established:

wherein: x is x _e Is the unit density, i.e., the design variable; u is a displacement matrix; k is justA degree matrix; v (V) _(x) Is the structural volume; v (V) ₀ Is the total volume; f is the volume fraction; u (u) _e Is a unit displacement vector; k (k) ₀ Is a matrix of cell stiffness; p is a penalty factor;

2.3 Sensitivity analysis of the feature reconstruction design method:

before the iterative algorithm is carried out, sensitivity analysis is needed to be carried out on the objective function relative to the design variables, the unit displacement amounts of i stress points are accumulated when the sensitivity analysis is carried out, and the final sensitivity function is as follows:

3) Iterative optimization of shield machine panel structure:

obtaining an optimal structural model through continuous iterative optimization of material pseudo-density values, taking the design variables, the objective functions, the constraint functions and the sensitivity thereof about the design variables obtained in the previous steps as input, optimizing a mathematical model of a characteristic reconstruction design method by using a gradient-based OC algorithm, and updating the design variables; until the objective function converges under the condition of meeting the constraint condition, thereby obtaining the optimal panel structure meeting the material consumption;

4) Structural post-treatment:

and carrying out smooth rounding treatment on the optimally designed shield machine panel structure, and further modifying according to the processing technology requirements and the manufacturing and assembling requirements to obtain the final design.

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