Method for simulating rolling wear volume of cam forming surface based on combination of multiple subroutines

Abstract

To simulate a rolling wear volume of a cam forming surface based on a combination of multiple subroutines, in an actual rolling wear volume simulation technology for a cam capable of eliminating interference from plastic deformation data.SOLUTION: The present invention comprises: establishing a cam-roller rolling contact wear model for a rolling contact state between a cam and a roller; combining it with secondary development of a umeshmotion subroutine and a ufield subroutine to complete simulation of cam wear volume transmission and an accumulation process due to rolling wear, and acquiring a rolling net wear volume distribution cloud map that eliminates the influence of factors such as metal plastic deformation and residual stress; and performing the secondary development in PYTHON (registered trademark) to depict a wear volume of a cam-roller contact node and further accurately calculate change in a cam wear volume.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of marine diesel engines and to a technology for evaluating cam-roller wear failures and performance in marine diesel engines, and more particularly to a method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines, taking into account the cam-roller rolling contact usage state. [Background technology]

[0002] Marine diesel engine cams experience surface wear during operation, which not only reduces the engine's operating efficiency and performance but also impacts its service life. Therefore, predicting the service life of diesel engine cams under wear conditions is important for marine diesel engine inspection, repair, and maintenance. Existing mechanical workpiece wear performance simulation software, typically ANSYS and ABAQUS, typically uses Archard theory to develop a wear displacement distribution cloud map using a secondary development of the umeshmotion subroutine, and then analyzes the change in wear depth through the displacement result cloud map. However, because the displacement cloud map results from the wear finite element simulation are affected by both the workpiece's plastic deformation and wear depth, it is not possible to obtain an indicator of the actual wear volume of the cam forming surface.

[0003] Therefore, new technical solutions are needed to solve this problem. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of existing technology by providing a finite element simulation method for the rolling wear volume of a cam forming surface based on a combination of multiple subroutines, taking into account the cam-roller rolling contact usage state. Specifically, this method combines two sub-subroutines, the umeshmotion subroutine and the ufield subroutine of ABAQUS, to eliminate the effects of plastic deformation and residual stress, and accumulates and transmits the changes in wear volume based on the Archard wear model in the form of field variables to obtain a wear volume distribution cloud map that only takes into account the actual wear volume of the material. Data is then extracted from the wear volume ODB file using Python programming to obtain the wear volume results for different cam-roller contact nodes.

[0005] The technical solution is as follows: To achieve the above object, the present invention provides a method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines, which includes the following steps:

[0006] S1, for the rolling contact condition between the cam and the roller, establish the rolling contact wear model of the cam and the roller.

[0007] S2, by combining the secondary development of the umeshmotion subroutine and the ufield subroutine, the simulation of the cam wear volume transmission and accumulation process caused by rolling wear is completed, and the rolling net wear volume distribution cloud map is obtained, eliminating the influence of factors such as metal plastic deformation and residual stress.

[0008] S3, the wear volume of the cam-roller contact node is plotted by secondary development in Python, and the change in the cam wear volume is further accurately calculated.

[0009] Furthermore, the method for establishing the cam and roller rolling contact wear model in step S1 involves introducing the cam and roller model into the ABAQUS software, setting simulation parameters based on the actual working state of the cam, providing material parameters for the cam and roller, and setting two analysis steps: the first analysis step for realizing the load loading of the model working state, and the second analysis step for realizing the rotation of the cam and roller, thereby generating contact fatigue and wear on the working forming surface. Next, the load and rotation speed for the interaction between the cam and roller are created, mesh division is performed, appropriate element types are selected, and finally the work task is created.

[0010] In the runtime program of the ABAQUS software, the element stiffness matrix including the geometric attributes, material properties and integration algorithm of the elements is defined, the material attributes of 40Cr are given, the interaction is set, the magnitude of the load is defined, a table program controller is added to set the load amplitude, and the geometric model of the cam-roller contact wear is established.

[0011] Furthermore, the specific process for completing the calculation of the cam wear volume due to rolling wear using the umeshmotion subroutine in step S2 is to edit the umeshmotion subroutine, introduce the umeshmotion subroutine into the simulation model through self-adaptive mesh control, obtain the contact pressure and sliding distance in the cam rolling process in the umeshmotion subroutine through the utility routines GETNODETOELEMCONN and GETVRMAVGATNODE, import them into the Archard wear model, calculate the local wear volume, and output the wear volume through iteration.

[0012] Furthermore, the Archard wear model calculates the local wear depth by the Archard wear formula, and multiplies the local wear depth by the wear contact width and the local wear path to obtain the local wear volume. The wear formula is as follows:

number

number

[0013] Furthermore, the specific process of completing the transmission and accumulation of the cam wear volume due to rolling wear through the ufield subroutine in step S2 is to first select the pre-defined field variable of FV in the analysis step module, then declare the field variable in the ufield subroutine, and accumulate the wear volume obtained by umeshmotion through the field variable, that is, to transmit and accumulate the value of the node's field variable, which functions when starting to solve the incremental step, participates in the iterative solution process of the implicit analysis, and obtains the field variable cloud map and odb result file of the net wear volume according to the Archard wear model.

[0014] Furthermore, in step S2, the ufield subroutine is called, and the keyword ufield is added after the node set of the self-adaptive mesh control. * Add field, user, number=2, and press Enter to add the node set name for self-adaptive mesh control. At the same time, open the predefined field variable for wear volume (FV) in the field output.

[0015] Furthermore, step S3 specifically involves secondary development using Python language to write a plug-in to extract node coordinates from the post-processed cloud map, connect the nodes on the wear forming surface of the cam to draw a closed line loop, extract the coordinates of these nodes along the wear direction after wear, extract the wear node data before and after wear, generate an Excel table, and obtain the wear volume change data of different contact nodes on the cam forming surface.

[0016] Furthermore, execution of the ABAQUS software program includes sequentially defining initial conditions, initiating an analysis step, and initiating an incremental step, and applying the umeshmotion and ufield subroutines in the incremental step.

[0017] Furthermore, the calling order and method of the umeshmotion subroutine and the ufield subroutine in the incremental step is as follows: at the end of each incremental step, the umeshmotion subroutine is called; if kmeshsweep=1, the mesh is swept once to obtain the relative sliding distance, which is then input into the Archard wear model formula written in Fortran to generate the increment of wear volume; at the start of the next incremental step, the ufield subroutine is executed, which transfers and accumulates the wear volume generated at the end of the previous incremental step, and forms the output of the net wear volume variable through the subroutine dialogue.

[0018] This invention uses the improved technology of finite element secondary development technology to establish a simulation method for the actual wear volume of the cam forming surface, and extracts the accumulated wear volume of the nodes on the cam-roller contact surface, thereby obtaining the change discipline pattern of the cam wear volume more accurately and intuitively.

[0019] In the umeshmotion subroutine of the present invention, the utility routine GETNODETOELEMCONN establishes the connection between the node and the element, and then the number of the element connected to the node can be obtained. The utility routine GETVRMAVGATNODE obtains the average value of the parameter value of the element at the node, and obtains the contact pressure and sliding distance. The implicit element analysis in the subroutine is mainly solved by incremental step iterative calculation.

[0020] This invention first establishes a cam-roller rolling contact wear model using ABAQUS software, sets the vertical upward motion contact load at the center of the roller, assigns rotational boundary conditions to the cam and roller, and simultaneously releases the roller's degree of freedom in the y direction. Sets the friction coefficient of the cam-roller contact forming surface, and sets two analysis steps: the first analysis step for realizing the Hertzian contact load load and the second step for realizing the relative rolling contact between the cam and roller. The umeshmotion subroutine based on Archard wear theory is compiled to realize the displacement of the mesh nodes due to friction on the cam surface. The ufield subroutine outputs the post-processed wear volume, and realizes the transmission and accumulation of wear volume through field variables. Secondary development is carried out using the Python language to access the field variable FV distribution cloud map of the wear volume and extract the coordinate changes of the wear volume distribution cloud map.

[0021] Compared with the prior art, the present invention obtains a cam actual rolling wear volume simulation technology that eliminates the interference of plastic deformation data, and can simulate the cam wear volume indicator, improving the simulation effect and providing beneficial effects that are of important guiding significance in the optimization of cam forming lines and processes for diesel engines. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a simulation flowchart of a finite element simulation model in the present invention. [Figure 2]FIG. 2 is a geometric model diagram of the rolling contact between the cam and the roller in this embodiment. [Figure 3] FIG. 10 is a schematic diagram of the operation principle of a subroutine in an incremental step in this embodiment. [Figure 4] 10 is a wear volume cloud map of the cam in the case of rolling contact in this embodiment. [Figure 5] FIG. 10 is a diagram illustrating an extracted wear volume of a node on a cam forming surface in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be further described below in combination with drawings and specific examples. However, it should be understood that these examples are only for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention. After reading the present invention, modifications to various equivalent forms of the present invention by those skilled in the art are all included in the scope defined by the appended claims of this application.

[0024] As shown in Figure 1, the present invention provides a method for simulating rolling wear volume of a cam forming surface based on a combination of multiple subroutines. The method includes the following steps:

[0025] S1, for the rolling contact condition between the cam and the roller, establish the rolling contact wear model of the cam and the roller.

[0026] Step S1 specifically involves importing the cam and roller model into the ABAQUS software, setting simulation parameters based on the actual working state of the cam, providing material parameters for the cam and roller, and setting two analysis steps: the first analysis step for realizing the load load of the model working state, and the second analysis step for realizing the rotation of the cam and roller, which will cause contact fatigue and wear on the working forming surfaces. Next, we create the load and rotation speed for the interaction between the cam and roller, segment the mesh, select element types, and finally create the work task.

[0027] In the runtime program of the ABAQUS software, the element stiffness matrix including the geometric attributes, material properties and integration algorithm of the elements is defined, the material attributes of 40Cr are given, the interaction is set, the magnitude of the load is defined, a table program controller is added to set the load amplitude, and the geometric model of the cam-roller contact wear is established.

[0028] The rolling contact wear model between the cam and the roller obtained in this example is shown in FIG.

[0029] S2, combined with the secondary development of the umeshmotion subroutine and the ufield subroutine, completes the simulation of the cam wear volume transmission and accumulation process caused by rolling wear, and obtains the rolling net wear volume distribution cloud map that eliminates the influence of factors such as metal plastic deformation and residual stress.

[0030] The specific process of completing the calculation of the cam wear volume due to rolling wear using the umeshmotion subroutine is to edit the umeshmotion subroutine, introduce the umeshmotion subroutine into the simulation model through self-adaptive mesh control, obtain the contact pressure and sliding distance in the cam rolling process in the umeshmotion subroutine through the utility routines GETNODETOELEMCONN and GETVRMAVGATNODE, import them into the Archard wear model, obtain the local wear volume, and output the wear volume through iteration.

[0031] The Archard wear model calculates the local wear depth by the Archard wear formula, and then multiplies the local wear depth by the wear contact width and the local wear path to obtain the local wear volume. The wear formula is as follows:

number

number

[0032] The specific process of completing the transmission and accumulation of the cam wear volume due to rolling wear through the ufield subroutine is to first select the predefined field variable of FV in the analysis step module, then declare the field variable in the ufield subroutine, and accumulate the wear volume obtained by umeshmotion through the field variable, that is, to transmit and accumulate the value of the node's field variable, which functions when starting to solve the incremental step, participates in the iterative solution process of the implicit analysis, and obtains the field variable cloud map and odb result file of the net wear volume according to the Archard wear model.

[0033] Call the ufield subroutine and add the keyword after the node set for self-adaptive mesh control. * Add field, user, number=2, and press Enter to add the node set name for self-adaptive mesh control. At the same time, open the predefined field variable for wear volume (FV) in the field output.

[0034] Execution of the ABAQUS software program involves sequentially defining initial conditions, initiating an analytical step, and initiating an incremental step, where the umeshmotion and ufield subroutines are applied in the incremental step.

[0035] As shown in Figure 3, the calling order and method of the umeshmotion subroutine and ufield subroutine in each incremental step is as follows: at the end of each incremental step, the umeshmotion subroutine is called; if kmeshsweep=1, the mesh is swept once to obtain the relative sliding distance, which is then input into the Archard wear model formula written in Fortran to generate the increment of wear volume; and at the start of the next incremental step, the ufield subroutine is executed, which transfers and accumulates the wear volume generated at the end of the previous incremental step, forming the output of the net wear volume variable through subroutine interaction. The wear volume cloud map of the cam for rolling contact in this embodiment is specifically shown in Figure 4.

[0036] As shown in Figure 5, secondary development was carried out using Python language to write a plugin to extract node coordinates from the post-processed cloud map, connect the nodes on the wear-forming surface of the cam to draw a closed line loop, extract the coordinates of these nodes along the wear direction after wear, extract the wear node data before and after wear, and generate an Excel table to obtain the wear volume change data of different contact nodes on the cam forming surface.

[0037] This embodiment further provides a system for simulating rolling wear volume of a cam forming surface based on a combination of multiple subroutines, the system comprising a network interface, a memory, and a processor, the network interface being used for transmitting and receiving signals in the process of transmitting and receiving information with other external network elements, the memory being used for storing computer program instructions executable by the processor, and the processor being used for performing the steps of the consensus method when executing the computer program instructions.

[0038] This embodiment further provides a computer storage medium that stores a computer program and, when executed by a processor, can implement the steps of the above-described method. The computer storage medium is considered to be tangible and non-transitory. Non-limiting examples of non-transitory, tangible computer storage media include non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital tape, hard drives, and optical storage media (CDs, DVDs, or Blu-ray discs)). A computer program includes processor-executable instructions stored on at least one non-transitory, tangible computer storage medium. A computer program may also include or depend on stored data. A computer program may include a basic input / output system (BIOS) that interacts with hardware in a special-purpose computer, device driver programs that interact with specific devices in a special-purpose computer, one or more operating systems, user application programs, background services, background application programs, and the like.

[0039] Those skilled in the art should understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may adopt an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining hardware and software. Furthermore, the present application may adopt the form of a computer program product embodied in one or more computer-usable storage media (including, but not limited to, magnetic disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0040] The present application will be described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, whereby the instructions executed by the processor of the computer or other programmable data processing device generate an apparatus for implementing the function(s) specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0041] These computer program instructions may be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, whereby the instructions stored in the computer-readable memory produce an article of manufacture that includes an instruction apparatus that implements the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0042] These computer program instructions may be loaded into a computer or other programmable data processing device and cause the computer or other programmable device to execute a series of operational steps to produce a computer-implemented process, whereby the instructions executed on the computer or programmable device provide steps for implementing the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

Claims

1. Step S1: establishing a cam-roller rolling contact wear model for the rolling contact state between the cam and the roller; Step S2: combine the secondary development of the umeshmotion subroutine and the ufield subroutine to complete the simulation of the cam wear volume transfer and accumulation process due to rolling wear, and obtain a rolling net wear volume distribution cloud map that eliminates the influence of factors such as metal plastic deformation and residual stress; A method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines, characterized by including step S3 of secondary development in Python to plot the wear volume of the cam roller contact node, and further accurately calculating the change in the cam wear volume.

2. The method for establishing the rolling contact wear model between the cam and the roller in step S1 is as follows: The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as claimed in claim 1, characterized in that the cam and roller model is introduced into the ABAQUS software, simulation parameters are set by referring to the actual working state of the cam, material parameters of the cam and roller are given, and two analysis steps are set: a first analysis step to realize the load loading of the model working state and a second analysis step to realize the rotation of the cam and roller, thereby generating contact fatigue and wear of the working forming surface, then creating the load and rotation speed for the interaction between the cam and roller, dividing the mesh, selecting element types, and finally creating the working task.

3. The specific process of completing the calculation of the cam wear volume due to rolling wear by the umeshmotion subroutine in step S2 is as follows: The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as claimed in claim 1, characterized in that: a umeshmotion subroutine is compiled; the umeshmotion subroutine is introduced into the simulation model through self-adaptive mesh control; the contact pressure and sliding distance in the cam rolling process are obtained in the umeshmotion subroutine through utility routines GETNODETOELEMCONN and GETVRMAVGATNODE, and they are imported into the Archard wear model to determine the local wear volume, and the wear volume is output by iteration.

4. The Archard wear model calculates the local wear depth using the Archard wear formula, and multiplies the local wear depth by the wear contact width and the local wear path to obtain the local wear volume. The wear formula is as follows: [Equation 5] where t is time, ΔN is the number of rolling turns, p(x, t) is the contact stress, and K ｌ is the friction coefficient, δ(x, t) is the relative sliding distance, Δh(x, t) is the wear depth increment, [Equation 6] Δv(x, t) is the wear volume, and d ｗｅａｒ 4. The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines according to claim 3, wherein: s(x, t) is the wear contact width; and s(x, t) is the relative rolling path.

5. 4. The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as claimed in claim 3, characterized in that the specific process of completing the transmission and accumulation of the cam wear volume due to rolling wear by the ufield subroutine in step S2 is to first select a pre-defined field variable of FV in the analysis step module, then declare the field variable in the ufield subroutine, and accumulate the wear volume obtained by umeshmotion through the field variable, that is, to transmit and accumulate the value of the nodal field variable, which functions when starting to solve the incremental step, participates in the iterative solution process of implicit analysis, and obtains the field variable cloud map and the odb result file of the net wear volume according to the Archard wear model.

6. In step S2, the subroutine ufield is called, and the keyword ufield is added after the node set of the self-adaptive mesh control. ＊ The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as claimed in claim 5, characterized in that: field, user, number=2 is added, the node set name of the self-adaptive mesh control is added by pressing the Enter key, and at the same time, the pre-defined field variable of the wear volume is opened in the field output.

7. The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as described in claim 1, characterized in that step S3 specifically involves using Python language for secondary development, editing a plug-in to extract node coordinates from the post-processed cloud map, connecting nodes on the wear forming surface of the cam to draw closed line loops, extracting the coordinates of these nodes along the wear direction after wear, extracting wear node data before and after wear, generating an Excel table, and obtaining wear volume change data of different contact nodes on the cam forming surface.

8. 3. The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines as described in claim 2, wherein the execution of the ABAQUS software program sequentially includes defining initial conditions, starting an analysis step, and starting an incremental step, and the umeshmotion subroutine and the ufield subroutine are applied in the incremental step.

9. 9. The method for simulating the rolling wear volume of a cam forming surface based on a combination of multiple subroutines according to claim 8, characterized in that the calling order and method of the umeshmotion subroutine and the ufield subroutine in the incremental steps are as follows: at the end of each incremental step, the umeshmotion subroutine is called; if kmeshsweep=1, the mesh is swept once to obtain the relative sliding distance, which is then input into the Archard wear model formula written in Fortran language to generate the increment of wear volume; and at the start of the next incremental step, the ufield subroutine is executed to transfer and accumulate the wear volume generated at the end of the previous incremental step, and form the output of the net wear volume variable through subroutine dialogue.

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