Abrasion loss prediction method of wind driven generator main shaft coating corrosion working condition

Abstract

The invention relates to a method for predicting the abrasion loss of a coating corrosion working condition of a wind driven generator spindle. The method mainly solves the technical problem that complex mechanical and physical changes in the wear process cannot be considered in a traditional prediction method. The wear loss prediction method comprises the following steps: step 1, establishing a finite element numerical model of a friction pair; 2, setting materials and boundary conditions; step 3, carrying out grid division; step 4, carrying out grid redrawing and grid deformation superposition by using an ALE adaptive grid technology; 5, a UMESHMOTION subprogram is written; 6, a coating abrasion theoretical formula under the corrosion working condition is constructed; 7, writing the wear theoretical formula into a UMESHMOTION subprogram, and carrying out secondary development on the subprogram, and 8, inserting the subprogram obtained through secondary development into a working module, and carrying out wear loss calculation; and 9, carrying out data extraction on the ODB file subjected to finite element calculation in the step 8, and obtaining key parameters such as contact surface pressure change and total abrasion loss in the abrasion process of the coating friction pair.

Description

Technical Field

[0001] The invention belongs to the technical field of predicting mechanical friction and wear, and specifically relates to a method for predicting the wear amount of a wind turbine main shaft coating (zinc spraying / galvanizing, etc.) under corrosion conditions. Background Art

[0002] With the rapid development of industrial technology, coatings have been widely used in the fields of industry and science and technology, especially in offshore wind turbines. Due to extreme conditions such as high salt spray, high humidity and corrosive atmosphere, the connecting parts are extremely susceptible to corrosion. The application of anti-corrosion and wear-resistant coatings is the key to preventing the failure of transmission connection friction pairs. The corrosion and wear performance of the coating directly affects the service life and stability of the whole machine. Therefore, it is of great significance to predict the wear amount of the main shaft coating (zinc spraying / galvanizing, etc.) under corrosive conditions.

[0003] There are many methods for evaluating the wear performance of materials, including theoretical calculation, statistical analysis and experimental evaluation. Theoretical calculation usually uses simplified theoretical formulas for evaluation, which often cannot accurately predict the durability in actual use. Experimental evaluation is time-consuming, labor-intensive and costly, and cannot fully consider the complex mechanical and physical changes in the wear process. Statistical analysis infers the wear performance under other working conditions by statistics of historical data and test results, which is severely limited by the quality and quantity of data collection.

[0004] Traditional wear prediction methods have certain limitations in accuracy, cost and applicability, especially under coating technology and complex working conditions, it is difficult to achieve accurate prediction and real-time analysis. In order to further improve the accuracy and effectiveness of wear prediction of wind turbine main shaft coating under complex working conditions, it is of great significance to invent a wear prediction method for wind turbine main shaft coating corrosion conditions. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problems of inaccuracy, time-consuming, high cost, low applicability and inability to consider the complex mechanical and physical changes in the wear process in traditional prediction methods, and to provide a method for predicting the wear amount of wind turbine main shaft coating (zinc spraying / galvanizing, etc.) under corrosion conditions.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for predicting the wear amount of a wind turbine main shaft coating under corrosion conditions comprises the following steps:

[0008] Step 1: Establish a finite element numerical model of the friction pair. Based on the ABAQUS finite element software, establish a finite element numerical model of the friction pair with a coating. The simple model is modeled through CAE of ABAQUS, and the complex model is modeled in Solidworks or UG professional modeling software, and imported into the assembly module of ABAQUS through the association program; according to the actual contact mode of the friction pair, establish the wear area between the contact surfaces;

[0009] Step 2: Set materials and boundary conditions, define the basic parameters of Young's modulus, density, and Poisson's ratio of the friction ball, substrate, and coating; set the finite element analysis step, apply load data to the finite element numerical model of the friction pair, and define the interaction between the coating friction pair;

[0010] Step 3: Mesh division: define the mesh properties as hexahedral units, set the global size and mesh curvature of the friction pair finite element numerical model mesh according to the accuracy requirements, and refine the mesh of the wear area established in step 1 to further ensure the accuracy of wear calculation;

[0011] Step 4: Use ALE adaptive mesh technology to redraw the ALE mesh and superimpose mesh deformation to achieve real-time update of the mesh of the friction pair finite element numerical model;

[0012] Step 5: Write the UMESHMOTION subroutine to define the corrosion wear coefficient, sliding speed and corrosion coefficient of the coating friction pair; obtain the coordinates of the nodes in the wear area through the subroutine, calculate the node sliding distance, and obtain the contact pressure of the nodes in the wear area;

[0013] Step 6: Construct the theoretical formula of coating wear under corrosion conditions;

[0014] Step 7, write the wear theory formula constructed in step 6 into the UMESHMOTION subroutine in step 5, perform secondary development of the subroutine, calculate the wear depth. When performing secondary development of the subroutine, it is also necessary to define the wear direction in the subroutine, assign the calculated wear depth to the nodes in the wear area, offset the nodes in the wear direction, and finally obtain the wear depth of each node in the wear area;

[0015] Step 8: Insert the UMESHMOTION subroutine obtained by secondary development into the working module, analyze it through finite element software, and calculate the wear amount;

[0016] Step 9: Extract data from the ODB file calculated by finite element in step 8 to obtain the contact surface pressure change during the wear process of the coated friction pair, the wear cloud map of the wear area, the wear amount change in each incremental step, and the total wear amount.

[0017] Furthermore, in the step 4, when the ALE adaptive grid is used, the grid refinement unit of the wear area is controlled.

[0018] Furthermore, the theoretical formula for coating wear under corrosion conditions constructed in step 6 is:

[0019]

[0020] Where: h i is the total wear depth of the ith increment, h i–1 is the total wear depth of the i-th–1th increment, dh i is the wear depth of the ith increment, K is the corrosion wear coefficient, P is the contact pressure, H is the surface hardness of the friction pair, and v is the sliding speed.

[0021] The beneficial effects of the present invention are:

[0022] The present invention simulates the real wear behavior of the coating by constructing a finite element numerical model of the friction pair under the corrosion condition. The simulation process realizes the grid update and accurate wear amount prediction of the coating during the wear process by using ALE adaptive grid technology and UMESHMOTION subroutine secondary development technology. At the same time, the contact pressure change of the coating during the wear process is monitored, and the wear behavior of the main shaft coating of the wind turbine generator under the corrosion condition is intuitively analyzed, solving the technical problems of inaccurate, time-consuming, high cost, low applicability of the traditional prediction method, and inability to consider the complex mechanical and physical changes in the wear process, which is of great significance to improving the efficiency of coating research and development and reducing research and development costs. Compared with the background technology, the present invention has higher accuracy and prediction ability, and can accurately predict the advantages of the life and performance of the coating (zinc spraying / galvanizing, etc.) under the corrosion condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flow chart of an embodiment of the present invention;

[0024] Figure 2 is a finite element numerical model of the friction pair of an embodiment of the present invention;

[0025] Figure 3 is the ALE adaptive grid model of an embodiment of the present invention;

[0026] Figure 4 is a wear morphology diagram of the coating according to an embodiment of the present invention;

[0027] Figure 5 It is a diagram of pressure variation in the coating wear area according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example

[0030] like Figure 1 As shown, a method for predicting the wear amount of a wind turbine main shaft coating (zinc spraying / galvanizing, etc.) under corrosion conditions in this embodiment includes the following steps:

[0031] Step 1: Establish a finite element numerical model of the friction pair. Based on the ABAQUS finite element software, establish a finite element numerical model of the friction pair with a coating. The simple model is modeled through CAE of ABAQUS, and the complex model is modeled in Solidworks or UG professional modeling software, and imported into the assembly module of ABAQUS through the association program; according to the actual contact mode of the friction pair, establish the wear area between the contact surfaces;

[0032] For step 1, specifically, the model in this embodiment is relatively simple and is directly modeled in ABAQUS CAE, as shown in the attached Figure 2 As shown, the friction ball diameter is: D=6mm, the base material size is: 20mm×10mm×3mm, the zinc spray coating size is: 20mm×10mm×0.2mm, the bottom of the friction ball contacts the top of the coating, and a wear area is established on the contact surface.

[0033] Step 2: Set materials and boundary conditions, define the basic parameters of Young's modulus, density, and Poisson's ratio of the friction ball, substrate, and coating; set the finite element analysis step, apply load data to the finite element numerical model of the friction pair, and define the interaction between the coating friction pair;

[0034] For step 2, specifically, the friction ball material in the embodiment is Si3N4, the substrate material is 34CrNiMo6, and the coating is treated by zinc spraying, wherein the density of Si3N4 is: 3.12g / cm 3 , Young's modulus: 300GPa, Poisson's ratio: 0.3; Density of 34CrNiMo6: 7.85g / cm 3 , Young's modulus: 210GPa, Poisson's ratio: 0.3; density of zinc spray coating 6.2g / cm 3 , Young's modulus 108Gpa, Poisson's ratio 0.25. Set two analysis steps, the first step is used to apply load, and the second step is used to apply reciprocating displacement. Apply loads of 10N, 15N, and 20N respectively, set the friction ball as a rigid body, apply reciprocating displacement, the displacement amplitude is 5mm, the frequency is 2Hz, and the displacement direction is adjacent Figure 2 The v direction.

[0035] Step 3: Mesh division: define the mesh properties as hexahedral units, set the global size and mesh curvature of the friction pair finite element numerical model mesh according to the accuracy requirements, and refine the mesh of the wear area established in step 1 to further ensure the accuracy of wear calculation;

[0036] For step three, specifically, the friction pair finite element numerical model established in the embodiment is reasonably divided into structures, the mesh attribute is defined as the C3D8R regular hexahedron reduced integral mesh type, and the mesh is refined in the wear area.

[0037] Step 4: Use ALE adaptive mesh technology to redraw the ALE mesh and superimpose mesh deformation to achieve real-time update of the mesh of the friction pair finite element numerical model;

[0038] In the step 4, when the ALE adaptive grid is used, the grid refinement unit of the wear area is controlled.

[0039] Step 5: Write the UMESHMOTION subroutine to define the corrosion wear coefficient, sliding speed and corrosion coefficient of the coating friction pair; obtain the coordinates of the nodes in the wear area through the subroutine, calculate the node sliding distance, and obtain the contact pressure of the nodes in the wear area;

[0040] For step five, specifically, some basic parameters such as the wear coefficient of the friction pair wear_k, the total slip distance L, the slip speed v, etc. are set in the embodiment program, and the coordinates of the nodes in the wear area are obtained: current_x, current_y, current_z, the node slip distance is calculated, and the contact pressure of the nodes in the wear area is obtained.

[0041] Step 6: Construct the wear theory formula of coating under corrosion conditions;

[0042] The theoretical formula for coating wear under corrosion conditions constructed in step 6 is:

[0043]

[0044] Where: h i is the total wear depth of the ith increment, h i–1 is the total wear depth of the i-th–1th increment, dh i is the wear depth of the ith increment, K is the corrosion wear coefficient, P is the contact pressure, H is the surface hardness of the friction pair, and v is the sliding speed.

[0045] Step 7, write the wear theory formula constructed in step 6 into the UMESHMOTION subroutine in step 5, perform secondary development of the subroutine, calculate the wear depth. When performing secondary development of the subroutine, it is also necessary to define the wear direction in the subroutine, assign the calculated wear depth to the nodes in the wear area, offset the nodes in the wear direction, and finally obtain the wear depth of each node in the wear area;

[0046] Step 8: Insert the UMESHMOTION subroutine obtained by secondary development into the working module, analyze it through finite element software, and calculate the wear amount;

[0047] Step 9: Extract data from the ODB file calculated by finite element in step 8 to obtain the contact surface pressure change during the wear process of the coated friction pair, the wear cloud map of the wear area, the wear amount change in each incremental step, and the total wear amount.

[0048] The derivation of the theoretical formula for coating wear under corrosion conditions in step 6 is: by introducing the corrosion coefficient k c Considering the influence of corrosive media on the wear of the friction pair surface, a wear theory formula is constructed, which is as follows: when the contact area ΔA and the time increment dt are infinitely small, the differential form of the wear volume and wear depth is:

[0049]

[0050] Where: dV is the wear volume when the actual contact area is A, dh is the wear depth in dt time, k c is the corrosion coefficient, k is the wear coefficient, W is the load, A is the actual contact area, L is the total sliding distance, H is the hardness of the friction pair surface, P is the contact pressure, and v is the sliding speed;

[0051] In order to facilitate data processing and simulation calculation, all coefficients are simplified to the corrosion wear coefficient K, and the following is obtained:

[0052]

[0053] Where: p is the benchmark unit load, d is the unit sliding distance, ΔW is the wear volume, and V is the friction pair volume, all of which are obtained from the corrosion wear benchmark test;

[0054] An automatic variable increment technique is used to calculate the wear depth. The wear depth dh of the ith increment can be obtained from equation (4): i for:

[0055]

[0056] dh max Defined as the maximum wear increment at the i-th increment, then the wear depth of the i-th increment must be less than the maximum wear depth at this increment, then a new increment dt is defined in To meet:

[0057]

[0058] As wear progresses, the contact area of ​​the friction pair increases and the contact pressure of the contact surface decreases. Therefore, the total wear depth h of the i-th increment isi for:

[0059]

[0060] Where: h i is the total wear depth of the ith increment; h i–1 is the total wear depth of the i-th–1th increment; dh i is the wear depth of the ith increment. The derived formula (8) is the coating wear theory formula (1).

[0061] The wear prediction values ​​and experimental comparison values ​​of the coating (zinc spraying) friction pair in this embodiment are shown in Table 1.

[0062] Table 1 Comparison of wear prediction and experimental values ​​of coating friction pairs

[0063]

[0064] By attaching Figure 4 Wear morphology and adhesion of coating (zinc spraying) Figure 5 It can be seen from the pressure change that the wear amount prediction method of the wind turbine main shaft coating (zinc spraying / galvanizing, etc.) under corrosion conditions proposed in the present invention can observe the wear behavior and wear mark morphology of the coating during the wear process, and can also analyze the dynamic changes of the contact pressure during the wear process. Analysis of the predicted wear values ​​of the coating (zinc spraying) friction pair and the experimental comparison values ​​in Table 1 shows that this method can well predict the wear amount of the friction pair during the wear process and meet the accuracy requirements.

[0065] The above embodiments are only descriptions of the preferred methods of the invention, and are not intended to limit the scope of the invention. Without departing from the design spirit of the invention, various modifications and improvements made to the technical solutions of the invention by ordinary technicians in this field should fall within the protection scope of the claims of the invention.

Claims

1. A method for predicting the wear amount of wind turbine main shaft coating corrosion conditions, characterized in that: The following steps are involved: Step 1: Establish a finite element numerical model of the friction pair. Based on the ABAQUS finite element software, establish a finite element numerical model of the friction pair with a coating. The simple model is modeled through CAE of ABAQUS, and the complex model is modeled in Solidworks or UG professional modeling software, and imported into the assembly module of ABAQUS through the association program; according to the actual contact mode of the friction pair, establish the wear area between the contact surfaces; Step 2: Set materials and boundary conditions, define the basic parameters of Young's modulus, density, and Poisson's ratio of the friction ball, substrate, and coating; set the finite element analysis step, apply load data to the finite element numerical model of the friction pair, and define the interaction between the coating friction pair; Step 3: Mesh division: define the mesh properties as hexahedral units, set the global size and mesh curvature of the friction pair finite element numerical model mesh according to the accuracy requirements, and refine the mesh of the wear area established in step 1 to further ensure the accuracy of wear calculation; Step 4: Use ALE adaptive mesh technology to redraw the ALE mesh and superimpose mesh deformation to achieve real-time update of the mesh of the friction pair finite element numerical model; Step 5: Write the UMESHMOTION subroutine to define the corrosion wear coefficient, sliding speed and corrosion coefficient of the coating friction pair; obtain the coordinates of the nodes in the wear area through the subroutine, calculate the node sliding distance, and obtain the contact pressure of the nodes in the wear area; Step 6: Construct the theoretical formula of coating wear under corrosion conditions; Step 7, write the wear theory formula constructed in step 6 into the UMESHMOTION subroutine in step 5, perform secondary development of the subroutine, calculate the wear depth. When performing secondary development of the subroutine, it is also necessary to define the wear direction in the subroutine, assign the calculated wear depth to the nodes in the wear area, offset the nodes in the wear direction, and finally obtain the wear depth of each node in the wear area; Step 8: Insert the UMESHMOTION subroutine obtained by secondary development into the working module, analyze it through finite element software, and calculate the wear amount; Step 9: Extract data from the ODB file calculated by finite element in step 8 to obtain the contact surface pressure change during the wear process of the coated friction pair, the wear cloud map of the wear area, the wear amount change in each incremental step, and the total wear amount.

2. The wear amount prediction method of the wind turbine main shaft coating under corrosion conditions according to claim 1 is characterized in that: In the step 4, when the ALE adaptive grid is used, the grid refinement unit of the wear area is controlled.

3. The wear amount prediction method of the wind turbine main shaft coating under corrosion conditions according to claim 1 is characterized in that: The theoretical formula for coating wear under corrosion conditions constructed in step 6 is: Where: h i is the total wear depth of the ith increment, h i–1 is the total wear depth of the i-th–1th increment, dh i is the wear depth of the ith increment, K is the corrosion wear coefficient, P is the contact pressure, H is the surface hardness of the friction pair, and v is the sliding speed.

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