Aviation equipment accelerated life test method under multi-stress coupling condition

Abstract

The invention belongs to the field of aviation equipment test, and particularly relates to an aviation equipment accelerated life test method under a multi-stress coupling condition, which comprises the following steps of: 1, carrying out life simulation on aviation equipment under the action of each single stress environment; 2, according to the life simulation result in the step 1, determining an influence factor between each stress and the damage amount of the aviation equipment; 3, establishing a nonlinear cumulative damage model based on influence factors; and 4, evaluating the service life of the aviation equipment under the multi-stress coupling action according to the nonlinear cumulative damage model. According to the invention, the sensitivity of different stresses to failure is considered, the accelerated life test under the multi-stress coupling condition is realized, the accuracy of the accelerated life test result is improved, and the test cost is reduced at the same time.

Description

Technical Field

[0001] The invention belongs to the field of aviation equipment testing, and in particular relates to an aviation equipment accelerated life test method under multi-stress coupling conditions. Background Art

[0002] At present, aviation equipment exists everywhere in the fields of storage, transportation, and use, from tropical to cold zones, from plains to plateaus, from oceans to space, etc., and the various natural environments and induced environments encountered are becoming more and more numerous, more and more complex, and more and more severe. The coupling failure problem caused by the combined action of two, three, four or even multiple environmental factors has become the main cause of damage and even failure of aviation equipment. To obtain aviation equipment life data under multi-stress coupling conditions, the evaluation method and the test method are currently commonly used. The two methods that are more commonly used in the evaluation method are competitive failure and linear cumulative damage method. The test method mainly involves building a test room, setting up multiple stress conditions, and conducting equivalent accelerated tests on the life of aviation equipment on site.

[0003] Competitive failure is the simplest method to evaluate the life of aviation equipment under multi-stress conditions. The competitive failure theory believes that the failure of a product is caused by a main failure mechanism, thus ignoring other minor failure mechanisms. The stress corresponding to the main failure mechanism is the main stress that causes product failure. This method only needs to determine the main failure mechanism of the product when evaluating the life of the product under multiple stresses, thereby converting the life prediction under multiple stresses into a single stress (principal stress) life prediction problem. Although this method is simple and convenient, it still has great limitations in actual engineering use. In actual engineering applications, in many cases, the failure of a product is caused by multiple stresses, there is no particularly obvious principal stress, or there are multiple principal stresses at the same time. At this time, the principle of competitive failure is no longer applicable.

[0004] The linear cumulative damage method can effectively make up for the limitations of competitive failure. The linear cumulative damage method is proposed based on the linear cumulative damage theory, which assumes that damage is linearly accumulated. As long as the life of each stress under the action of each stress alone is known, the life of the product under the action of multiple stress coupling can be calculated. However, in actual engineering, under multiple stress conditions, there is a mutual coupling effect between the stresses. When the same failure mode is caused, the total damage is not the linear superposition of the damage when each stress acts alone, but there is a certain coupling relationship. The existing methods, whether it is the competitive failure principle or the linear superposition principle, cannot consider the coupling relationship between different stresses, nor can they consider the sensitivity of different stresses to failure. This limitation can no longer meet the life assessment needs of aviation equipment under multiple stress coupling. In addition, although the test method can accurately obtain the life of aviation equipment under multiple stress conditions, it is time-consuming and labor-intensive, and the cost is high when setting up the laboratory, preparing stress conditions, and conducting field tests. Therefore, an accelerated life test method for aviation equipment under multiple stress coupling conditions is proposed to solve the above problems. Summary of the invention

[0005] To solve the above problems, the present invention provides an accelerated life test method for aviation equipment under multi-stress coupling conditions, which takes into account the sensitivity of different stresses to failure, realizes accelerated life testing under multi-stress coupling conditions, improves the accuracy of accelerated life test results, and reduces test costs.

[0006] The technical solution of the present invention is an accelerated life test method for aviation equipment under multi-stress coupling conditions, comprising the following steps: Step 1, performing life simulation on aviation equipment under each single stress environment; Step 2, according to the life simulation results of step 1, determine the influencing factors between various stresses and the damage amount of aviation equipment; Step 3, establishing a nonlinear cumulative damage model based on influence factors; Step 4: Evaluate the life of aviation equipment under multi-stress coupling based on the nonlinear cumulative damage model.

[0007] In an optional implementation, step 1 performs life simulation on aviation equipment under each single stress environment, specifically including: Step 1.1, conduct actual working stress simulation analysis of aviation equipment under a single stress environment; Step 1.2, perform life simulation of aviation equipment based on stress simulation analysis results.

[0008] In an optional embodiment, step 1.1 specifically includes: Step 1.1.1, establish a three-dimensional model of aviation equipment; Step 1.1.2, import the three-dimensional model of the aviation equipment into the stress analysis software, and perform actual working stress simulation analysis of the aviation equipment under each single stress environment according to the stress environment profile.

[0009] In an optional embodiment, the stress analysis software is finite element software.

[0010] In an optional embodiment, step 1.2 specifically includes: The stress simulation analysis results are input into the life prediction model in the life prediction software to perform life simulation of aviation equipment.

[0011] In an optional implementation, step 2 determines the influencing factors between various stresses and the amount of damage to the aviation equipment based on the life simulation results of step 1, specifically including: Step 2.1: Collect aviation equipment damage data for each stress environment and corresponding historical period ;in, For the The set of damage amounts corresponding to each stress in a long time series is: is the number of time series, , Indicates The stress in The damage amount corresponding to the time series is is the number of stresses; Step 2.2, according to the damage data of aviation equipment, the correlation between each stress and the damage amount is calculated based on the grey correlation algorithm, and the influencing factors between each stress and the damage amount of aviation equipment are determined; Step 2.2.1, using the grey correlation algorithm to standardize the aviation equipment damage data, and calculating the incremental sequence of the aviation equipment damage data based on the standardization result; Step 1: Standardize the data using the following formula:

[0012] Step 2, calculate the sequence difference by the following formula,

[0013] Step 3, calculate the minimum difference by the following formula and maximum difference ,

[0014] in, , ; Step 2.2.2, calculate the correlation coefficient between each stress and damage amount in the corresponding historical period according to the grey correlation algorithm, including calculating the correlation coefficient by the following formula ,

[0015] in, , ; Step 2.2.3, take the average of the correlation coefficients between each stress and the damage amount, which is the influence factor, including calculating the influence factor by the following formula ,

[0016] in, Indicates The influencing factor of stress is , .

[0017] In an optional implementation, step 3 establishes a nonlinear cumulative damage model based on the influence factor, specifically including establishing a nonlinear cumulative damage model of the following formula:

[0018] in, To control the parameters, .

[0019] In an optional implementation, after step 3 of establishing the nonlinear cumulative damage model based on the influence factor, the method further includes: The equivalent accelerated life test of aviation equipment was carried out under multi-stress coupling conditions. According to the test data, the nonlinear cumulative damage model was corrected by the following formula:

[0020] in, is the error between the experimental measurement value and the predicted value of the nonlinear cumulative damage model.

[0021] The invention provides an accelerated life test method for aviation equipment under multi-stress coupling conditions. Compared with the prior art, the invention has the following beneficial effects: determining the influence factors between each stress and the damage amount of aviation equipment, and based on the nonlinear cumulative damage model of the influence factors, evaluating the life of aviation equipment under multi-stress coupling according to the nonlinear cumulative damage model. The invention describes the coupling relationship between different stresses based on the principle of nonlinear superposition, and characterizes the contribution of different stresses to failure by introducing the parameter of the influence factor. When evaluating the life of aviation equipment under multi-stress coupling, the coupling relationship between different stresses can be considered, and the sensitivity of different stresses to failure can be reflected, thereby improving the accuracy of the accelerated life test results. The invention establishes a nonlinear cumulative damage model. After one-time modeling, the calculation of the life of aviation equipment under multi-stress coupling conditions can be directly realized in the subsequent process, eliminating the need for laboratory construction, shortening the test time, and greatly reducing the test cost. In addition, when establishing the nonlinear cumulative damage model, the life simulation of aviation equipment under a single stress environment is performed, and the equivalent accelerated life test of aviation equipment is performed under multi-stress coupling conditions. The nonlinear cumulative damage model is corrected according to the test data to ensure the accuracy of the nonlinear cumulative damage model. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic flow chart of an accelerated life test method for aviation equipment under multi-stress coupling conditions provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] In view of the fact that neither the competitive failure principle nor the linear superposition principle can consider the coupling relationship between different stresses, nor the sensitivity of different stresses to failure, and this limitation can no longer meet the problem of life assessment needs of aviation equipment under multi-stress coupling, the present invention provides an accelerated life test method for aviation equipment under multi-stress coupling conditions, determines the influence factors between each stress and the damage amount of aviation equipment, and evaluates the life of aviation equipment under multi-stress coupling according to the nonlinear cumulative damage model based on the influence factor. The coupling relationship between different stresses is explained based on the nonlinear superposition principle, and the contribution of different stresses to failure is characterized by introducing the influence factor parameter. When evaluating the life of aviation equipment under multi-stress coupling, it can not only consider the coupling relationship between different stresses, but also reflect the sensitivity of different stresses to failure, thereby improving the accuracy of the accelerated life test results.

[0026] Figure 1 FIG. 1 is a flow chart of an accelerated life test method for aviation equipment under multi-stress coupling conditions provided by an embodiment of the present invention. Figure 1 As shown, the method includes the following steps.

[0027] Step 1: Perform life simulation on aviation equipment under each single stress environment.

[0028] First, the aviation equipment is modeled, including the stress simulation model and the life prediction simulation model. Secondly, according to the stress simulation model, each single environmental stress is input respectively to simulate the actual working stress size of the aviation equipment under the action of each different environmental stress; finally, the stress simulation results are input into the life prediction simulation model respectively to evaluate the life of the aviation equipment under the action of a single stress. Specifically, the following steps are included.

[0029] Step 1.1, conduct actual working stress simulation analysis of aviation equipment under a single stress environment.

[0030] Step 1.1.1, build a three-dimensional model of aviation equipment.

[0031] Step 1.1.2, import the three-dimensional model of the aviation equipment into the stress analysis software, and perform actual working stress simulation analysis of the aviation equipment under each single stress environment according to the stress environment profile.

[0032] In an optional embodiment, the stress analysis software is finite element software, which may be any one of Ansys, Abaqus, Fluent, or other finite element software.

[0033] Step 1.2, perform life simulation of aviation equipment based on stress simulation analysis results.

[0034] The stress simulation analysis results are input into the life prediction model in the life prediction software to perform life simulation of aviation equipment.

[0035] It should be noted that life prediction is a method based on damage volume physics. Exemplarily, life prediction software includes CALCE PWA.

[0036] Step 2: According to the life simulation results of step 1, determine the influencing factors between various stresses and the damage amount of aviation equipment.

[0037] Step 2.1, collect aviation equipment damage data for each stress environment and the corresponding historical period.

[0038] First, various stress environment data and aviation equipment damage data in the corresponding historical period are collected to provide data support for the subsequent calculation of influencing factors.

[0039] The collected aviation equipment damage data is ;in, For the The set of damage amounts corresponding to each stress in a long time series is: is the number of time series, , Indicates The stress in The damage amount corresponding to the time series is is the number of stresses.

[0040] Step 2.2, according to the stress failure data, the correlation between each stress and the damage amount is calculated based on the grey correlation algorithm, and the influencing factors between each stress and the damage amount of the aviation equipment are determined.

[0041] Step 2.2.1, using the grey correlation algorithm to standardize the aviation equipment damage data, and calculating the incremental sequence of the aviation equipment damage data based on the standardization result; Step 1: Standardize the data using the following formula:

[0042] Step 2, calculate the sequence difference by the following formula,

[0043] Step 3, calculate the minimum difference by the following formula and maximum difference ,

[0044] in, , ; Step 2.2.2, calculate the correlation coefficient between each stress and damage amount in the corresponding historical period according to the grey correlation algorithm, including calculating the correlation coefficient by the following formula ,

[0045] in, , ; Step 2.2.3, take the average of the correlation coefficients between each stress and the damage amount, which is the influence factor, including calculating the influence factor by the following formula ,

[0046] in, Indicates The influencing factor of stress is , .

[0047] In this step, the grey correlation algorithm is first used to standardize the damage data of aviation equipment, and the incremental sequence of the damage data of aviation equipment is calculated based on the standardization result; then the correlation coefficient between each stress and the damage amount in the corresponding historical period is calculated according to the grey correlation algorithm; finally, the average of the correlation coefficients between each stress and the damage amount is taken, which is the influence factor. It can be seen that the influence factor reflects the sensitivity of different stresses to the damage amount.

[0048] Step 3: Establish a nonlinear cumulative damage model based on influence factors.

[0049] This embodiment starts from the definition of damage and establishes a nonlinear cumulative damage model to show the coupling relationship between damages caused by different stresses. Through deduction, the expression of the established nonlinear cumulative damage model is as follows:

[0050] in, To control the parameters, .

[0051] At the same time, an equivalent accelerated life test is carried out on aviation equipment under multi-stress coupling conditions, and the nonlinear cumulative damage model is corrected by the following formula based on the test data.

[0052]

[0053] in, is the error between the experimental measurement value and the predicted value of the nonlinear cumulative damage model.

[0054] In this embodiment, the nonlinear cumulative damage model is modified according to the influence factor to characterize the different contributions of different stresses to the damage amount.

[0055] This embodiment proposes a nonlinear superposition principle to explain the coupling relationship between different stresses, and at the same time introduces an influence factor parameter to characterize the contribution of different stresses to failure. When evaluating the life of aviation equipment under multi-stress coupling, it can not only take into account the coupling relationship between different stresses, but also reflect the sensitivity of different stresses to failure, thereby improving the accuracy of accelerated life test results.

[0056] Step 4: Evaluate the life of aviation equipment under multi-stress coupling based on the nonlinear cumulative damage model.

[0057] This embodiment establishes a nonlinear cumulative damage model. After the model is built once, the life of the aviation equipment under multi-stress coupling conditions can be directly calculated subsequently, which saves the need to build a laboratory, shortens the test time, and greatly reduces the test cost. In addition, when establishing the nonlinear cumulative damage model, the life of the aviation equipment under a single stress environment is simulated, and an equivalent accelerated life test is performed on the aviation equipment under multi-stress coupling conditions. The nonlinear cumulative damage model is corrected according to the test data to ensure the accuracy of the nonlinear cumulative damage model.

[0058] The above disclosure is only a preferred embodiment of the present invention, but the present invention is not limited thereto. Any non-creative changes that can be thought of by a person skilled in the art, as well as several improvements and modifications made without departing from the principle of the present invention, should fall within the protection scope of the present invention.

Claims

1. The accelerated life test method for aviation equipment under multi-stress coupling conditions is characterized by: The following steps are involved: Step 1, performing life simulation on aviation equipment under each single stress environment; Step 2, according to the life simulation results of step 1, determine the influencing factors between various stresses and the damage amount of aviation equipment; Step 3, establishing a nonlinear cumulative damage model based on influence factors; Step 4: Evaluate the life of aviation equipment under multi-stress coupling based on the nonlinear cumulative damage model.

2. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 1, characterized in that: Step 1 is to simulate the life of aviation equipment under each single stress environment, including: Step 1.1, conduct actual working stress simulation analysis of aviation equipment under a single stress environment; Step 1.2, perform life simulation of aviation equipment based on stress simulation analysis results.

3. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 2, characterized in that: Step 1.1 specifically includes: Step 1.1.1, establish a three-dimensional model of aviation equipment; Step 1.1.2, import the three-dimensional model of the aviation equipment into the stress analysis software, and perform actual working stress simulation analysis of the aviation equipment under each single stress environment according to the stress environment profile.

4. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 3, characterized in that: Stress analysis software is finite element software.

5. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 2, characterized in that: Step 1.2 specifically includes: The stress simulation analysis results are input into the life prediction model in the life prediction software to perform life simulation of aviation equipment.

6. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 1, characterized in that: Step 2: According to the life simulation results of step 1, determine the influencing factors between each stress and the damage amount of aviation equipment, including: Step 2.1: Collect aviation equipment damage data for each stress environment and corresponding historical period ;in, For the The set of damage amounts corresponding to each stress in a long time series is: is the number of time series, , Indicates The stress in The damage amount corresponding to the time series is is the number of stresses; Step 2.2, according to the damage data of aviation equipment, the correlation between each stress and the damage amount is calculated based on the grey correlation algorithm, and the influencing factors between each stress and the damage amount of aviation equipment are determined; Step 2.2.1, using the grey correlation algorithm to standardize the aviation equipment damage data, and calculating the incremental sequence of the aviation equipment damage data based on the standardization result; Step 1: Standardize the data using the following formula: Step 2, calculate the sequence difference by the following formula, Step 3, calculate the minimum difference by the following formula and maximum difference , in, , ; Step 2.2.2, calculate the correlation coefficient between each stress and damage amount in the corresponding historical period according to the grey correlation algorithm, including calculating the correlation coefficient by the following formula , in, , ; Step 2.2.3, take the average of the correlation coefficients between each stress and the damage amount, which is the influence factor, including calculating the influence factor by the following formula , in, Indicates The influencing factor of stress is , .

7. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 1, characterized in that: Step 3 establishes a nonlinear cumulative damage model based on the influence factor, specifically including establishing a nonlinear cumulative damage model of the following formula: in, To control the parameters, .

8. The method for accelerated life test of aviation equipment under multi-stress coupling conditions according to claim 7, characterized in that: After establishing the nonlinear cumulative damage model based on the influence factor in step 3, it also includes: The equivalent accelerated life test of aviation equipment was carried out under multi-stress coupling conditions. According to the test data, the nonlinear cumulative damage model was corrected by the following formula: in, is the error between the experimental measurement value and the predicted value of the nonlinear cumulative damage model.

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