CN110414068A - A Method of Analyzing the Strength and Stability of C-Shaped Tunnel Pipe Using Finite Element Software - Google Patents

Abstract

The invention discloses a kind of using finite element analysis software C-shaped tunneltron intensity and the method for stability, the present invention is based on C-shaped tunneltron limit load analysis, Eigenvalue Buckling Analysis and nonlinear buckling analysis in method, it is desirable to provide a kind of software for being automatically performed C-shaped tunneltron intensity and stability analysis and exporting analysis result.The software writes corresponding algorithm routine with APDL language in ANSYS, carries out secondary development to ANSYS software in conjunction with VB language.Software program interface is simple, easily operated, facilitates the structure design of C-shaped tunneltron.User can carry out finite element analysis to C-shaped tunneltron by the software, evaluate influence of the Different structural parameters to C-shaped tunneltron intensity and stability, simplify the analytic process to C-shaped tunneltron, also the optimization for tunneltron dimensional structure provides reference frame.

Description

A Method of Analyzing the Strength and Stability of C-Shaped Tunnel Pipe Using Finite Element Software

technical field

The invention relates to a method for analyzing the strength and stability of a tunnel pipe, in particular to a method for analyzing the strength and stability of a C-shaped tunnel pipe by using finite element software.

Background technique

Tunnel pipes are widely used in aerospace, aviation, machinery and other industrial sectors. With the advancement of science and technology, the role and importance of tunnel pipes are increasing. There are many forms of tunnel tubes, which are divided into C, U, S, etc. according to the wave form. Among them, the C-type tunnel tube is currently widely used in the aerospace field, and the size and structure parameters of the C-type tunnel tube include wall thickness, wave height, and wave distance. Different sizes and structural parameters have different effects on the strength and stability of the C-shaped tunnel pipe.

ANSYS software has powerful calculation and post-processing functions, which simplifies the generation and analysis of finite element models, data processing and result analysis after completion.

At present, the common analysis types for finite element analysis of tunnel pipe strength and stability include ultimate load analysis, eigenvalue buckling analysis and nonlinear buckling analysis. There are many size parameters of the C-shaped tunnel pipe. When performing finite element analysis on the C-shaped tunnel pipe with different structural sizes, the analysis process is cumbersome and the repetitive workload is large. And analysts need to master a certain basis of finite element analysis.

Contents of the invention

In view of the above existing problems, the present invention provides a method for analyzing the strength and stability of a C-shaped tunnel pipe using finite element software. Based on ultimate load analysis, eigenvalue buckling analysis and nonlinear buckling analysis methods, use APDL language in ANSYS to write corresponding algorithm programs, combine VB language to carry out secondary development of ANSYS software, and obtain software for finite element analysis of C-shaped tunnel pipes , input the size parameters of the C-shaped tunnel pipe into the software for strength and stability analysis, and directly obtain the corresponding maximum external pressure load calculation results, which provides a new analysis method for the finite element analysis of the C-shaped tunnel pipe. The method is simple, practical and in line with objective reality. At the same time, it facilitates the structural design of the tunnel pipe.

During the loading process of the C-shaped tunnel pipe, the plastic zone continues to expand. When the load increases to a certain limit value, the C-shaped tunnel pipe undergoes plastic flow. This state is called the plastic limit state, and the corresponding load is called "ultimate load". ". A sufficiently large external pressure is applied to the C-shaped tunnel pipe to make it enter the plastic limit state and obtain the corresponding limit load.

The eigenvalue buckling analysis refers to the appearance of the second equilibrium state of the structure under the external load. What is solved in the derivation is a problem of solving eigenvalues, so it is called eigenvalue buckling analysis. The critical load value is obtained by applying an external pressure per unit load to the tunnel tube.

Nonlinear buckling analysis considers geometric nonlinearity and material nonlinearity, so as to analyze the nonlinear instability of the structure. Geometric nonlinearity is the imposition of initial imperfections in the calculation to change the initial shape of the structure. When analyzing the C-shaped tunnel pipe, 0.1 times the initial defect is applied, and the ideal elastic-plastic curve material model is used for analysis. The critical load value when the structure buckles occurs is obtained by nonlinear buckling analysis.

A method for analyzing the strength and stability of a C-shaped tunnel pipe using finite element software. The basic carrier of the method is a software designed for the analysis and design of the strength and stability of a C-shaped tunnel pipe. Meta-analysis module and result output module. The flow chart of the software is shown in Figure 1.

The path setting module is used to set the ANSYS startup path and the project saving path;

The parameter setting module is used to input the parameters required for the analysis software to run, including the structural parameters of the C-shaped tunnel pipe, material properties and design conditions.

The finite element analysis module performs finite element analysis according to the input parameters of the C-shaped tunnel pipe, including ultimate load analysis, eigenvalue buckling analysis and nonlinear buckling analysis.

The result output module extracts and displays the cloud image of the finite element analysis results and the corresponding maximum external pressure load value.

Compared with prior art, the beneficial effect of the present invention is:

1. The present invention uses the APDL language in ANSYS to write the algorithm program for the finite element analysis of the strength and stability of the C-shaped tunnel pipe, and combines the VB language to carry out secondary development of the ANSYS software, providing a new method for the finite element analysis of the C-shaped tunnel pipe. The analysis method is simple, practical and in line with objective reality. At the same time, it is convenient for the structural design of the tunnel pipe;

2. When performing finite element analysis on C-shaped tunnel pipes of different structural sizes, the present invention simplifies the analysis process and shortens the calculation time.

Description of drawings

Fig. 1 is a software flow chart of the present invention;

Fig. 2 is the startup setting interface of the specific embodiment of the present invention;

Fig. 3 is the parameter setting interface of the specific embodiment of the present invention;

Fig. 4 is the ultimate load analysis interface of a specific embodiment of the present invention;

Fig. 5 is the eigenvalue buckling analysis interface of a specific embodiment of the present invention;

Fig. 6 is a nonlinear buckling analysis interface of a specific embodiment of the present invention.

Detailed ways

In order to make the objects and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the examples.

As shown in Figure 2, the purpose of the startup setup is to invoke the ANSYS program and set the working directory. Specific operation: Click the menu <Settings>, a dialog box will pop up, set the ANSYS startup path through the first browse button, and set the project save path through the second browse button.

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

(1) Input structural parameters, material properties and design conditions through the parameter setting window, as shown in Figure 3.

(2) Click the ultimate load analysis button to enter the ultimate load analysis interface, as shown in Figure 4. Enter the external pressure load value in the applied load box, click the analyze button, and click the display result button after the calculation is completed.

(3) Click the eigenvalue buckling analysis button to enter the eigenvalue buckling analysis interface, as shown in Figure 5. After the calculation is completed, click the Display Result button to display the eigenvalue buckling analysis result graph.

(4) Click the nonlinear buckling analysis button to enter the nonlinear buckling analysis interface, as shown in Figure 6. After the calculation is completed, click the Display Result button to display the nonlinear buckling analysis result graph.

Based on the ultimate load analysis, eigenvalue buckling analysis and nonlinear buckling analysis methods, the corresponding algorithm program is written by using the APDL language in ANSYS, and the secondary development of ANSYS software is carried out in combination with VB language.

During the loading process of the structure, the plastic zone continues to expand. When the load increases to a certain limit value, the structure undergoes plastic flow. This state is called the plastic limit state, and the corresponding load is called the "ultimate load". A sufficiently large external pressure is applied to the C-shaped tunnel pipe to make it enter the plastic limit state and obtain the corresponding limit load.

The eigenvalue buckling analysis refers to the appearance of the second equilibrium state of the structure under the external load. What is solved in the derivation is a problem of solving eigenvalues, so it is called eigenvalue buckling analysis. The critical load value is obtained by applying an external pressure per unit load to the tunnel tube.

Nonlinear buckling analysis considers geometric nonlinearity and material nonlinearity, so as to analyze the nonlinear instability of the structure. Geometric nonlinearity is the imposition of initial imperfections in the calculation to change the initial shape of the structure. When analyzing the C-shaped tunnel pipe, 0.1 times the initial defect is applied, and the ideal elastic-plastic curve material model is used for analysis. The critical load value when the structure buckles occurs is obtained by nonlinear buckling analysis.

The eigenvalue load value is generally higher than the nonlinear load value. This is because the eigenvalue load value ignores the influence of geometric nonlinearity on the structure in the calculation, so the eigenvalue load value is not conservative and is usually not used in engineering. The limit load value is close to the nonlinear load and smaller than the eigenvalue load, indicating that when the structural strength is insufficient, the stiffness has a margin.

Claims (4)

1. a kind of using finite element analysis software C-shaped tunneltron intensity and the method for stability, C-shaped tunneltron is in loading procedure In, plastic zone constantly expands, and when load increases to a certain limiting value, Plastic Flow occurs for C-shaped tunneltron, and this state is known as Plastic limit state, corresponding load are known as " ultimate load "；To C-shaped tunneltron apply a sufficiently large external pressure, make its into Enter plastic limit state, obtains corresponding ultimate load；

Eigenvalue Buckling Analysis refers to structure under external load function, second equilibrium state occurs；What is solved in derivation is one The problem of a solution characteristic value, therefore referred to as Eigenvalue Buckling Analysis；The external pressure for applying specific loading to tunneltron, to obtain Critical load value；

Nonlinear buckling analysis considers geometrical non-linearity, material nonlinearity, to carry out Nonlinear Instability analysis to structure；Geometry Non-linear is to apply initial imperfection when calculating, to change the original shape of structure；Apply 0.1 times when to the analysis of C-shaped tunneltron Initial imperfection, analyzed using ideal elastic-plastic curved material model；Structure is obtained using nonlinear buckling analysis Critical load value when buckling；

It is characterized by: the underlying carrier of this method is the software for C-shaped tunneltron intensity and Stability Analysis and Design, this point Analysing software includes path setup module, parameter setting module, finite element analysis module and result output module；

Path setup module, the path that setting ANSYS starts path and project saves；

Parameter setting module, input analysis software required parameter when running, including C-shaped tunneltron structural parameters, material category Property and design condition；

Finite element analysis module carries out finite element analysis, including limit load analysis, spy according to the C-shaped tunneltron parameter of input Value indicative buckling analysis and nonlinear buckling analysis；

As a result output module extracts simultaneously explicit finite element analysis result cloud atlas and corresponding maximum external pressure load value.

2. a kind of C-shaped tunneltron intensity according to claim 1 and Finite element analysis of stability software, it is characterised in that: Based on limit load analysis, Eigenvalue Buckling Analysis and nonlinear buckling analysis method, write with APDL language in ANSYS Corresponding algorithm routine carries out secondary development to ANSYS software in conjunction with VB language；

During loading, plastic zone constantly expands structure, and when load increases to a certain limiting value, plasticity stream occurs for structure Dynamic, this state is known as plastic limit state, and corresponding load is known as " ultimate load "；One is applied enough to C-shaped tunneltron Big external pressure, makes it into plastic limit state, obtains corresponding ultimate load；

Eigenvalue Buckling Analysis refers to structure under external load function, second equilibrium state occurs；What is solved in derivation is one The problem of a solution characteristic value, therefore referred to as Eigenvalue Buckling Analysis；The external pressure for applying specific loading to tunneltron, to obtain Critical load value；

Nonlinear buckling analysis considers geometrical non-linearity, material nonlinearity, to carry out Nonlinear Instability analysis to structure；Geometry Non-linear is to apply initial imperfection when calculating, to change the original shape of structure；Apply 0.1 times when to the analysis of C-shaped tunneltron Initial imperfection, analyzed using ideal elastic-plastic curved material model；Structure is obtained using nonlinear buckling analysis Critical load value when buckling.

3. a kind of C-shaped tunneltron intensity according to claim 1 and Finite element analysis of stability software, it is characterised in that:

Characteristic value load value is generally higher than non-linear load value, this is because to have ignored geometry in calculating non-for characteristic value load value Linearly to the influence of structure, therefore characteristic value load value is not guarded partially, is not used usually in engineering；Ultimate load value with it is non-thread Property load it is close and be less than characteristic value load, illustrate when structural strength deficiency, rigidity has allowance.

4. a kind of analysis system using finite element analysis software C-shaped tunneltron intensity and stability according to claim 1 System, it is characterised in that:

The purpose of starting setting is to call ANSYS program and working directory is arranged；Concrete operations: menu<setting>, pop-up are clicked Dialog box is arranged ANSYS by first navigation button and starts path, and project is arranged by second navigation button and saves road Diameter；

(1) pass through parameter setting window input structure parameter, material properties and design condition；

(2) it clicks limit load analysis button and enters limit load analysis interface；External pressure load value is inputted in applying load frame, Analysis button is clicked, display results button is clicked after the completion of to be calculated；

(3) click feature value buckling analysis button enters Eigenvalue Buckling Analysis interface；Display result is clicked after the completion of to be calculated Button shows Eigenvalue Buckling Analysis result figure；

(4) it clicks nonlinear buckling analysis button and enters nonlinear buckling analysis interface；Display result is clicked after the completion of to be calculated Button shows nonlinear buckling analysis result figure.