Simplified evaluation method and device for structural fatigue damage, medium and product

Abstract

The invention discloses a simplified evaluation method and device for structural fatigue damage, a medium and a product, and relates to the technical field of fatigue damage evaluation.The method comprises the steps that load history data and geometric structure data of a to-be-evaluated structure are obtained; performing rain flow analysis on the load history data to obtain rain flow result data of typical loads; the rain flow result data comprises a load change amplitude and a corresponding change frequency; calculating a load fluctuation range according to the rain flow result data based on a fatigue damage linear superposition method; obtaining the maximum equivalent stress change amplitude of the to-be-evaluated structure according to the load fluctuation range and the geometric structure data; and determining the fatigue life of the to-be-evaluated structure based on a general fatigue life evaluation method according to the maximum equivalent stress change amplitude. According to the invention, through a calculation thought of equivalent conversion, simplified and efficient structure fatigue damage evaluation is realized through one-time calculation.

Description

Technical Field

[0001] The present application relates to the technical field of fatigue damage evaluation, and in particular to a simplified evaluation method, equipment, medium and product for structural fatigue damage. Background Art

[0002] Fatigue loads often need to be considered in structural design calculations. In actual structural service, fatigue loads are often non-uniform and non-uniform and change over time. Sometimes, in order to evaluate the fatigue performance of a structure, a large number of load step analysis and calculations are required. Existing structural fatigue damage evaluation methods are time-consuming and inefficient. Solving engineering problems usually requires efficient solutions first. Summary of the invention

[0003] The purpose of this application is to provide a simplified evaluation method, equipment, medium and product for structural fatigue damage, which can realize simplified and efficient structural fatigue damage evaluation.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a simplified evaluation method for structural fatigue damage, the simplified evaluation method for structural fatigue damage comprising:

[0006] Obtain load history data and geometric structure data of the structure to be evaluated;

[0007] Performing rain flow analysis on the load history data to obtain rain flow result data; the rain flow result data includes: load change amplitude and corresponding change times;

[0008] Based on the fatigue damage linear superposition method, the load fluctuation range is calculated according to the rain flow result data;

[0009] According to the load fluctuation range and the geometric structure data, obtaining the maximum equivalent stress variation amplitude of the structure to be evaluated;

[0010] According to the maximum equivalent stress variation amplitude and based on a general fatigue life evaluation method, the fatigue life of the structure to be evaluated is determined.

[0011] Optionally, the calculation formula for the load fluctuation range is:

[0012]

[0013] Where n is the number of changes, m is the exponential constant, Δp equ is the load fluctuation range, N i is the fluctuation number of the i-th load, △P i is the fluctuation range of the ith load.

[0014] Optionally, according to the maximum equivalent stress variation amplitude, based on a general fatigue life evaluation method, determining the fatigue life of the structure to be evaluated specifically includes:

[0015] Obtaining a fatigue design curve of the structure to be evaluated;

[0016] Calculating the allowable number of service cycles of the structure to be evaluated according to the maximum equivalent stress variation amplitude and the fatigue design curve;

[0017] The fatigue service factor of the structure to be evaluated is calculated according to the allowable number of use cycles.

[0018] Optionally, calculating the fatigue service coefficient of the structure to be evaluated according to the allowable number of use cycles specifically includes:

[0019] The reciprocal of the allowable number of use cycles is taken to obtain the fatigue use coefficient of the structure to be evaluated.

[0020] Optionally, the load history data is: pressure or temperature data.

[0021] Optionally, obtaining the maximum equivalent stress variation amplitude of the structure to be evaluated according to the load fluctuation range and the geometric structure data specifically includes:

[0022] The maximum equivalent stress variation amplitude of the structure to be evaluated is obtained by using finite element modeling software according to the load fluctuation range and the geometric structure data.

[0023] Optionally, after determining the fatigue life of the structure to be evaluated according to the maximum equivalent stress variation amplitude based on a general fatigue life evaluation method, the method further includes:

[0024] Prepare simplified structural fatigue evaluation report.

[0025] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the simplified evaluation methods for structural fatigue damage described above.

[0026] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the simplified evaluation methods for structural fatigue damage described above.

[0027] In a fourth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the simplified evaluation methods for structural fatigue damage described above.

[0028] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0029] The present application provides a simplified evaluation method, equipment, medium and product for structural fatigue damage, the method comprising: obtaining load history data and geometric structure data of the structure to be evaluated; performing rainflow analysis on the load history data to obtain rainflow result data; the rainflow result data comprises: load variation amplitude and corresponding variation times; based on the fatigue damage linear superposition method, calculating the load fluctuation range according to the rainflow result data; obtaining the maximum equivalent stress variation amplitude of the structure to be evaluated according to the load fluctuation range and the geometric structure data; determining the fatigue life of the structure to be evaluated according to the maximum equivalent stress variation amplitude based on the general fatigue life evaluation method. The present application adopts the calculation idea of ​​equivalent conversion, does not need to perform a large number of analysis and calculation of multiple load steps, and only needs to calculate the load fluctuation range through the rainflow result data once, so as to realize simplified and efficient structural fatigue damage evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is an application environment diagram of a simplified evaluation method for structural fatigue damage in one embodiment of the present application;

[0032] Figure 2 A schematic flow chart of a simplified evaluation method for structural fatigue damage provided in one embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] Fatigue loads often need to be taken into account in structural design calculations. In the actual service process of the structure, fatigue loads are often non-uniform, non-uniform, and change over time. Sometimes, in order to evaluate the fatigue performance of the structure, a large number of multiple load step analysis and calculations are required, which is time-consuming and inefficient. At present, the solution to engineering problems usually requires efficient solutions first, although the accuracy of one step may be sacrificed. In view of the low efficiency of the evaluation calculation under the current engineering fatigue load, based on theoretical derivation and analysis, the analysis method proposed in this application can be calculated through the equivalent conversion calculation idea, and it is proposed to achieve simplified and efficient evaluation of structural fatigue evaluation through one calculation, based on the fatigue damage life equivalence and linear accumulation principles.

[0036] The disadvantage of the prior art is that it is inefficient. To address the low efficiency, this application proposes an equivalent calculation method to replace the multiple calculation method of the prior art.

[0037] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] The simplified evaluation method for structural fatigue damage provided in the embodiments of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the load history data and geometric structure data to be processed to the server 104. After receiving the load history data and geometric structure data to be processed, the server 104 performs rain flow analysis on the load history data to obtain rain flow result data; the rain flow result data includes: load change amplitude and the corresponding number of changes; based on the fatigue damage linear superposition method, the load fluctuation range is calculated according to the rain flow result data; according to the load fluctuation range and the geometric structure data, the maximum equivalent stress change amplitude of the structure to be evaluated is obtained; according to the maximum equivalent stress change amplitude, based on the general fatigue life evaluation method, the fatigue life of the structure to be evaluated is determined. The server 104 can feedback the obtained fatigue life to the terminal 102. In addition, in some embodiments, the simplified evaluation method of structural fatigue damage can also be implemented independently by the server 104 or the terminal 102. For example, the terminal 102 can directly process the load history data and geometric structure data to be processed, or the server 104 can obtain the load history data and geometric structure data to be processed from the data storage system for processing.

[0039] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0040] In an exemplary embodiment, Figure 2 As shown, a simplified evaluation method for structural fatigue damage is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used as an example to illustrate the method, which includes the following steps S1 to S5. Among them:

[0041] S1. Obtain load history data and geometric structure data of the structure to be evaluated.

[0042] The data and information collected in this embodiment include detailed geometric dimensions of the structure to be evaluated (geometric structure data of the structure to be analyzed can be repeatedly generated on a computer), typical time history data of the load fluctuation range (data on the change of loads such as pressure and temperature over time).

[0043] The structures to be evaluated include all types of situations that may be encountered in engineering and may be subjected to changing loads during their service life.

[0044] For example, for a pressure vessel that is subjected to changes in pressure and temperature during use, load history data refers to the real-time specific data of pressure or temperature within a certain time range.

[0045] S2. Perform rain flow analysis on the load history data to obtain rain flow result data; the rain flow result data includes: load change amplitude and corresponding change times.

[0046] In this embodiment, the load history data is analyzed by rain flow analysis with the help of relevant software (MATLAB or other special software) or self-programming program to determine the load change amplitude Δp i And the corresponding number of changes N i Among them, these loads may be specific parameters such as operating internal pressure and operating temperature; loads that change on the structure to be evaluated can also be called important loads. After the rainflow analysis, subsequent steps can also be performed only on important loads.

[0047] S3. Based on the fatigue damage linear superposition method, the load fluctuation range is calculated according to the rain flow result data.

[0048] In this embodiment, based on the principle of equal fatigue service coefficient and the principle of linear superposition of fatigue damage, the load fluctuation range is calculated in combination with the rain flow result data. The calculation formula is:

[0049]

[0050] Where n is the number of changes, m is the exponential constant, Δp equ is the load fluctuation range (equivalent load fluctuation range), N i is the fluctuation number of the i-th load, △P i is the fluctuation range of the i-th load, where, due to multiple calculations, the final Δp equ It is a fluctuation range.

[0051] The specific process of calculating the load fluctuation range is as follows:

[0052] Step (1): Consider load fluctuation Δp i Elastic relationship with the amplitude of structural stress changes.

[0053] Step (2): Consider the relationship between the amplitude of structural stress variation and the allowable fluctuation range.

[0054] Step (3): Based on steps (1) and (2), determine the relationship between the allowable fluctuation range and the load fluctuation range.

[0055] Step (4): Based on step (3), according to the principle of linear superposition of fatigue cumulative coefficient, determine the cumulative service factor of the structure under the action of repeated load fluctuations and the load fluctuation Δp i and the fluctuation frequency N i The relationship between .

[0056] Step (5): Based on step (4), according to the principle of equal fatigue cumulative coefficients, determine the relationship between the fatigue service coefficient under the equivalent load and the cumulative service coefficient of the structure under the cumulative load fluctuation.

[0057] Step (6): Based on step (5), the fluctuation frequency corresponding to the equivalent load fluctuation range is taken as 1, and the relationship between the equivalent load and the previous load fluctuations and the fluctuation frequency is determined, that is:

[0058]

[0059] S4. Obtaining a maximum equivalent stress variation amplitude of the structure to be evaluated according to the load fluctuation range and the geometric structure data.

[0060] In this embodiment, the maximum equivalent stress variation amplitude of the structure to be evaluated under the load fluctuation range is calculated with the help of relevant software. According to mature finite element analysis structural software, such as Ansys, through finite element modeling, the calculation input conditions include the realization of the geometric model and the application of the equivalent load fluctuation range, and the calculation output result is the equivalent stress fluctuation range on the structure.

[0061] S5. Determine the fatigue life of the structure to be evaluated according to the maximum equivalent stress variation amplitude and based on a general fatigue life evaluation method.

[0062] Specifically, it includes: obtaining the fatigue design curve of the structure to be evaluated; calculating the allowable number of use cycles of the structure to be evaluated according to the maximum equivalent stress variation amplitude and the fatigue design curve; and calculating the fatigue use coefficient of the structure to be evaluated according to the allowable number of use cycles. The reciprocal of the allowable number of use cycles is the fatigue use coefficient of the structure to be evaluated.

[0063] In this embodiment, the fatigue design curve or calculation formula in the relevant standard is used to calculate the allowable number of cycles of the structure according to different selections of the material of the structure to be evaluated. The calculation can be performed by looking up a table, an illustration, or by a given relationship between the stress amplitude and the allowable number of cycles. The selection of the curve can be combined with the type of structural material selected in the design analysis standard. The horizontal axis of the curve is the allowable number of cycles, and the vertical axis is half of the equivalent stress fluctuation range obtained by the analysis software in the previous step.

[0064] Finally, a simplified structural fatigue evaluation report is compiled based on the calculation results.

[0065] The simplified structural fatigue evaluation report includes:

[0066] 1: Brief introduction of the structure to be evaluated.

[0067] 2: Determine the load history and the process and data for future expected usage.

[0068] 3: Software-based rainflow analysis process and data for load history.

[0069] 4: Determine the load fluctuation range process and data based on the simplified method proposed in this application.

[0070] 5: Determine the process and data of the maximum equivalent stress change amplitude under the load fluctuation range.

[0071] 6: Based on the general fatigue life evaluation method, the process and data for determining the fatigue life of the structure.

[0072] The present embodiment provides a simplified evaluation method for structural fatigue damage, firstly obtaining load history data and geometric structure data of the structure to be evaluated; performing rainflow analysis on the load history data to obtain rainflow result data; the rainflow result data includes: load variation amplitude and corresponding variation times; based on the fatigue damage linear superposition method, calculating the load fluctuation range according to the rainflow result data; obtaining the maximum equivalent stress variation amplitude of the structure to be evaluated according to the load fluctuation range and the geometric structure data; determining the fatigue life of the structure to be evaluated according to the maximum equivalent stress variation amplitude based on the general fatigue life evaluation method. The present application adopts the calculation idea of ​​equivalent conversion, and does not need to perform a large number of analysis and calculation of multiple load steps. It can realize simplified and efficient structural fatigue damage evaluation by only calculating the load fluctuation range through the rainflow result data.

[0073] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 3 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a simplified evaluation method for structural fatigue damage is implemented.

[0074] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0075] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0076] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0077] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0078] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0079] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0080] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0081] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A simplified evaluation method for structural fatigue damage, characterized in that: The simplified evaluation method for structural fatigue damage includes: Obtain load history data and geometric structure data of the structure to be evaluated; Performing rain flow analysis on the load history data to obtain rain flow result data; the rain flow result data includes: load change amplitude and corresponding change times; Based on the fatigue damage linear superposition method, the load fluctuation range is calculated according to the rain flow result data; According to the load fluctuation range and the geometric structure data, obtaining the maximum equivalent stress variation amplitude of the structure to be evaluated; According to the maximum equivalent stress variation amplitude and based on a general fatigue life evaluation method, the fatigue life of the structure to be evaluated is determined.

2. The simplified evaluation method for structural fatigue damage according to claim 1, characterized in that: The calculation formula for the load fluctuation range is: Where n is the number of changes, m is the exponential constant, Δp equ is the load fluctuation range, N i is the fluctuation number of the i-th load, △P i is the fluctuation range of the ith load.

3. The simplified evaluation method for structural fatigue damage according to claim 1, characterized in that: According to the maximum equivalent stress variation amplitude, based on the general fatigue life evaluation method, the fatigue life of the structure to be evaluated is determined, specifically including: Obtaining a fatigue design curve of the structure to be evaluated; Calculating the allowable number of service cycles of the structure to be evaluated according to the maximum equivalent stress variation amplitude and the fatigue design curve; The fatigue service factor of the structure to be evaluated is calculated according to the allowable number of use cycles.

4. The simplified evaluation method for structural fatigue damage according to claim 3, characterized in that: Calculating the fatigue service factor of the structure to be evaluated according to the allowable number of use cycles specifically includes: The reciprocal of the allowable number of use cycles is taken to obtain the fatigue use coefficient of the structure to be evaluated.

5. The simplified evaluation method for structural fatigue damage according to claim 1, characterized in that: The load history data is: pressure or temperature data.

6. The simplified evaluation method for structural fatigue damage according to claim 1, characterized in that: According to the load fluctuation range and the geometric structure data, the maximum equivalent stress variation amplitude of the structure to be evaluated is obtained, specifically including: The maximum equivalent stress variation amplitude of the structure to be evaluated is obtained by using finite element modeling software according to the load fluctuation range and the geometric structure data.

7. The simplified evaluation method for structural fatigue damage according to claim 1, characterized in that: After determining the fatigue life of the structure to be evaluated according to the maximum equivalent stress variation amplitude based on a general fatigue life evaluation method, the method further includes: Prepare simplified structural fatigue evaluation report.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the simplified evaluation method for structural fatigue damage according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the simplified evaluation method for structural fatigue damage according to any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the simplified evaluation method for structural fatigue damage according to any one of claims 1 to 7 is implemented.

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