Calculation method of service life of carrier-based aircraft landing gear structure based on sinking rate

Abstract

The present invention discloses a method for calculating the service life of a carrier aircraft landing gear structure based on a sinking rate, comprising: obtaining a stress spectrum according to a first measured load spectrum of the landing gear structure; using a rain flow counting method to count the first measured load spectrum to obtain the stress amplitude and mean corresponding to each level of load of the first measured load spectrum; correcting the fatigue load spectrum of the landing gear structure according to the stress amplitude and mean of the first measured load spectrum; and correcting the predicted service life of the landing gear structure after each take-off and landing according to the fatigue load spectrum, the sinking rate of the carrier aircraft and the damage coefficient corresponding to the sinking rate. The influence of the sinking rate on the damage of the carrier aircraft landing gear structure is taken into account in the calculation of the service life of the landing gear structure, which improves the calculation accuracy of the service life of the carrier aircraft landing gear structure and can provide useful assistance for risk assessment, life determination and life extension of the carrier aircraft landing gear structure.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft structure health monitoring, and in particular to a method for calculating the service life of a carrier-based aircraft landing gear structure based on a sinking rate. Background Art

[0002] At present, the service life of an aircraft during its service period is based on the aircraft calendar life, flight hours and aircraft take-off and landing times as the aircraft life standards, and the first of the three is taken as the aircraft service life. For carrier-based aircraft, due to the large number of take-off and landing training in daily use, the take-off and landing times of the aircraft are consumed significantly faster than the calendar life and flight hours. In addition, in the calculation of the take-off and landing life consumption of carrier-based aircraft, one take-off and landing of a carrier-based aircraft on the ship is equivalent to two take-offs and landings on land, which accelerates the consumption of the take-off and landing times of the carrier-based aircraft.

[0003] During the take-off and landing process of carrier-based aircraft, the landing gear structure is the key structural part that bears the fatigue load of take-off and landing, especially during the high sinking rate landing process, the damage of the landing gear structure is the most serious. Due to the limited space on the aircraft carrier deck, carrier-based aircraft need to adopt a fixed-point landing method when landing, and the sinking rate can reach 6m / s, which is twice that of land-based aircraft. The impact energy experienced by the landing gear structure will reach 4 times that of land-based aircraft. In addition, due to the high difficulty of carrier-based aircraft landing and the many factors affecting carrier-based aircraft landing, heavy landings with a sinking rate higher than 6m / s sometimes occur when the aircraft lands, increasing the risk of damage to the landing gear structure. However, the current calculation of the service life consumption of the landing gear structure of carrier-based aircraft does not take into account the influence of the sinking rate. It is only in the special case of a carrier-based aircraft with a sinking rate close to or higher than 6m / s that the risk is reduced by strengthening the inspection of the damage to the landing gear structure and other measures. However, the calculation of the take-off and landing life of the structure is still expressed in terms of 1 take-off and landing number. This calculation method is obviously inconsistent with the structural damage to the landing gear caused by a heavy landing.

[0004] Therefore, how to conduct an accurate safety risk assessment on the carrier-based aircraft landing gear structure in order to extend the service life of the carrier-based aircraft landing gear structure has become an urgent problem to be solved. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a method for calculating the service life of a carrier-based aircraft landing gear structure based on the sinking rate, so as to solve the problem that the risk assessment results and life determination and extension of the carrier-based aircraft landing gear structure obtained by the safety risk assessment of the carrier-based aircraft landing gear structure in the prior art are not accurate enough.

[0006] An embodiment of the present invention provides a method for calculating the service life of a carrier aircraft landing gear structure based on a sinking rate, comprising:

[0007] obtaining a stress spectrum according to a first measured load spectrum of the landing gear structure;

[0008] The first measured load spectrum is counted by using a rain flow counting method to obtain stress amplitudes and mean values ​​corresponding to each level of load in the first measured load spectrum;

[0009] Correcting the fatigue load spectrum of the landing gear structure according to the stress amplitude and mean value of the first measured load spectrum;

[0010] According to the fatigue load spectrum, the sinking rate of the carrier-based aircraft and the damage coefficient corresponding to the sinking rate, the predicted service life of the landing gear structure after each take-off and landing is corrected.

[0011] Optionally, acquiring the stress spectrum according to the first measured load spectrum of the landing gear structure includes:

[0012] Determine the key fatigue parts of carrier-based aircraft landing gear during take-off and landing;

[0013] Obtain the load-time curve of the key fatigue parts;

[0014] The stress analysis and calculation are performed on the key fatigue parts, and the load spectrum of the key fatigue parts is converted into a stress spectrum.

[0015] Optionally, the load spectrum is counted using a rain flow counting method to obtain stress amplitudes and mean values ​​corresponding to each level of load in the stress spectrum, including:

[0016] Rotate the load spectrum by 90° so that a peak or valley of the load spectrum is used as the starting point, with the vertical axis representing time and the horizontal axis representing load;

[0017] Make the rain flow start from the starting point and the inside of each peak / valley;

[0018] Make the rain flow fall vertically at the next peak / valley until it stops when a peak / valley value greater in absolute value than the starting point appears on the other side of the vertical axis;

[0019] In the process of any rain flow, when the rain flow meets the rain flow flowing down from above, it stops flowing, forming a rain flow cycle;

[0020] The irregular random load spectrum obtained by actual measurement is simplified into several cyclic load spectra by the rain flow counting method, and the stress amplitude and mean value of each cycle are recorded.

[0021] Optionally, the fatigue load spectrum of the landing gear structure is corrected according to the stress amplitude and the mean value of the first measured load spectrum, including:

[0022] The Gerber model is used to correct the fatigue load spectrum.

[0023] Optionally, it also includes:

[0024] Calculate the first cumulative damage of the landing gear structure under the repeated action of fatigue load according to the stress amplitude and mean value;

[0025] The total damage suffered by the landing gear structure during a take-off and landing process is obtained according to the number of cycles of each stress level in the load spectrum suffered by the landing gear structure during a take-off and landing process and the number of failure cycles under the independent action of each stress level.

[0026] Optionally, the predicted service life of the landing gear structure after each take-off and landing is corrected according to the fatigue load spectrum, the sinking rate of the carrier aircraft and the damage coefficient corresponding to the sinking rate, including:

[0027] Obtain the average load spectrum of the landing gear structure under the average sinking rate of the carrier-based aircraft;

[0028] Obtaining a second measured load spectrum of the landing gear structure under a high sinking rate of the carrier-based aircraft;

[0029] Calculate the average cumulative damage corresponding to the average load spectrum;

[0030] calculating a second accumulated damage corresponding to a second measured load spectrum;

[0031] The equivalent fatigue life coefficient of the landing gear structure at different sinking rates is calculated based on the average cumulative damage and the second cumulative damage.

[0032] Optionally, perform stress analysis and calculation on the key fatigue parts, and convert the load spectrum of the key fatigue parts into a stress spectrum, including:

[0033] Obtain the axial force, bending moment and torque of the landing gear structure;

[0034] According to the axial force, bending moment and torque, the maximum nominal equivalent stress of the fatigue-critical section of the landing gear structure is obtained.

[0035] Optionally, the equivalent fatigue life coefficient is a ratio of the accumulated fatigue damage at the current sinking rate to the average accumulated damage.

[0036] Optionally, it also includes:

[0037] The fatigue life is calculated based on the peak load fluctuation at the moment of carrier-based aircraft landing and impact.

[0038] Beneficial effects of the embodiments of the present invention:

[0039] The embodiment of the present invention proposes a method for calculating the service life of a carrier-based aircraft landing gear structure based on the sinking rate, which takes the influence of the sinking rate on the damage of the carrier-based aircraft landing gear structure into consideration in the calculation of the service life of the landing gear structure, thereby improving the calculation accuracy of the service life of the carrier-based aircraft landing gear structure, and can provide useful assistance for risk assessment, life determination and life extension of the carrier-based aircraft landing gear structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0041] Figure 1 A flow chart of a method for calculating the service life of a carrier aircraft landing gear structure based on a sinking rate in Embodiment 1 of the present invention is shown;

[0042] Figure 2 A schematic diagram of a rain flow counting method in an embodiment of the present invention is shown;

[0043] Figure 3 A force analysis diagram of a carrier aircraft landing gear structure in an embodiment of the present invention is shown;

[0044] Figure 4 A landing gear structure load spectrum according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0046] The embodiment of the present invention provides a method for calculating the service life of a carrier aircraft landing gear structure based on a sinking rate, such as Figure 1 As shown, including:

[0047] Step S1, obtaining a stress spectrum according to a first measured load spectrum of the landing gear structure.

[0048] In this embodiment, the load spectrum is processed and converted into a stress spectrum, so that the stress condition of the landing gear structure is quantified into data.

[0049] Step S2: using a rain flow counting method to count the first measured load spectrum, and obtaining stress amplitudes and mean values ​​corresponding to each level of load in the first measured load spectrum.

[0050] Step S3, correcting the fatigue load spectrum of the landing gear structure according to the stress amplitude and mean value of the first measured load spectrum.

[0051] The fatigue load spectrum is determined by the fatigue stress amplitude and mean value. Usually, the average stress of the fatigue load on the structure is not zero. According to the positive and negative values ​​of the fatigue stress mean value, the fatigue load can be divided into tensile mean stress and compressive mean stress. Among them, the tensile mean stress will reduce the fatigue life of the material, while the compressive mean stress is beneficial to the fatigue life of the material. Therefore, in order to consider the influence of the mean stress on the fatigue life of the material, the fatigue load spectrum is usually corrected using the mean stress correction model. Currently, commonly used correction models include the Goodman model, the Gerber model, the Soderberg model, etc. In this embodiment, the load spectrum is corrected using the Gerber model.

[0052] Step S4, correcting the predicted service life of the landing gear structure after each take-off and landing according to the fatigue load spectrum, the sinking rate of the carrier-based aircraft and the damage coefficient corresponding to the sinking rate.

[0053] Usually, the landing gear structure's take-off and landing times are based on the average aircraft sinking rate V m In this embodiment, the measured load spectra of the landing gear structure at the average sinking rate and the high sinking rate are used respectively, and the cumulative damage of the structure at different sinking rates and the corresponding damage coefficient are calculated through the above steps. After the equivalent fatigue damage coefficient of the landing gear structure at different sinking rates is obtained, during the use of the carrier-based aircraft, the service life of the landing gear structure after each take-off and landing can be corrected according to the sinking rate, so as to achieve the purpose of accurately calculating the service life of the carrier-based aircraft landing gear structure.

[0054] As an optional implementation, step S1 includes:

[0055] Determine the key fatigue parts of carrier-based aircraft landing gear during take-off and landing.

[0056] Obtain the load-time history curve of the key fatigue parts.

[0057] The stress analysis and calculation are performed on the key fatigue parts, and the load spectrum of the key fatigue parts is converted into a stress spectrum.

[0058] During the take-off and landing process of carrier-based aircraft, the landing gear structure is the key structural component that bears the take-off and landing fatigue load, especially during the high sink rate landing process, the damage to the landing gear structure is the most serious. During the service of a certain type of carrier-based aircraft, due to mission requirements, it is often used for shipboard take-off and landing training and land-based simulated landing training, and the take-off and landing life of the carrier-based aircraft landing gear structure is consumed too quickly.

[0059] Usually, the impact of sink rate is not considered in the calculation process of landing gear service life, but in actual use, too high sink rate poses a serious threat to the structure. Therefore, taking the sink rate into account in the service life calculation will help to accurately calculate the service life of the landing gear structure and provide assistance for structural risk assessment and life extension.

[0060] As an optional implementation, Figure 2 As shown, step S2 includes:

[0061] The load spectrum is rotated 90° so that a peak or valley value of the load spectrum is used as the starting point. The vertical axis represents time and the horizontal axis represents load.

[0062] Make the rain flow start from the starting point and the inside of each peak / valley.

[0063] Make the rain flow fall vertically at the next peak / valley until it stops when a peak / valley value greater in absolute value than the starting point appears on the other side of the vertical axis.

[0064] During the flow of any rain flow, when the rain flow meets the rain flow flowing down from above, it stops flowing, forming a rain flow cycle.

[0065] The irregular random load spectrum obtained by actual measurement is simplified into several cyclic load spectra by the rain flow counting method, and the stress amplitude and mean value of each cycle are recorded.

[0066] The rain flow counting method is a method widely used in structural fatigue design and failure assessment. It can simplify the irregular random load spectrum obtained from actual measurement into several cyclic loads, thus facilitating the calculation of the fatigue life of the structure.

[0067] As an optional implementation, step S3 includes:

[0068] The Gerber model is used to correct the fatigue load spectrum.

[0069] In this embodiment, the Gerber model formula is:

[0070]

[0071] In the formula, σ a is the stress amplitude, σ ae is the mean stress, σ m is the equivalent stress amplitude, σ b is the tensile strength of the material.

[0072] As an optional implementation, it also includes:

[0073] Based on the stress amplitude and mean, the first cumulative damage of the landing gear structure under the repeated action of fatigue load is calculated.

[0074] The total damage suffered by the landing gear structure during a take-off and landing process is obtained according to the number of cycles of each stress level in the load spectrum suffered by the landing gear structure during a take-off and landing process and the number of failure cycles under the independent action of each stress level.

[0075] In this embodiment, after obtaining the stress amplitude and mean after structural correction, the fatigue life of the structure can be calculated by the fatigue damage criterion. The Miner fatigue damage criterion is a fatigue life calculation method widely used in engineering. It has the characteristics of simple form and convenience for engineering calculation. This article adopts the Miner criterion to calculate the fatigue life of the carrier-based aircraft landing gear structure. The Miner criterion believes that when the structure is repeatedly subjected to fatigue loads, each cyclic load will cause certain damage to the structure, and the damage is linearly accumulated. When the damage accumulates to a certain extent, it will lead to structural failure and destruction.

[0076] If the damage to the structure caused by each fatigue load cycle is:

[0077]

[0078] Then the cumulative damage caused to the structure by n fatigue load cycles is:

[0079]

[0080] Since the fatigue load on the carrier-based aircraft landing gear structure is a multi-level load with variable amplitude and variable mean, the total damage to the structure during a take-off and landing is:

[0081]

[0082] Where n ij N is the number of cycles of each stress level in the load spectrum of the landing gear structure during a take-off and landing process. ij is the number of failure cycles under each stress level alone, and D is the total structural damage.

[0083] As an optional implementation, step S4 includes:

[0084] Obtain the average load spectrum of the landing gear structure at the average sinking rate of the aircraft.

[0085] The second measured load spectrum of the landing gear structure under the high sink rate of the aircraft is obtained.

[0086] Calculate the average accumulated damage corresponding to the average load spectrum.

[0087] A second accumulated damage corresponding to the second measured load spectrum is calculated.

[0088] The equivalent fatigue life coefficient of the landing gear structure at different sinking rates is calculated based on the average cumulative damage and the second cumulative damage.

[0089] In this embodiment, the average load spectrum at the average sink rate is compared with the second measured load spectrum at the high sink rate, and the linear relationship between the four is obtained through the corresponding cumulative damage analysis, so as to determine the equivalent fatigue life coefficient at different sink rates, and the equivalent fatigue life coefficient is used as one of the parameters of the predicted service life model of the landing gear structure.

[0090] As an optional implementation, the stress analysis and calculation of the key fatigue parts are performed to convert the load spectrum of the key fatigue parts into a stress spectrum, including:

[0091] Obtain the axial force, bending moment and torque of the landing gear structure;

[0092] According to the axial force, bending moment and torque, the maximum nominal equivalent stress of the fatigue-critical section of the landing gear structure is obtained.

[0093] In this embodiment, if Figure 3 As shown in Figure 1, the load spectrum obtained by actual measurement also needs to be converted into a stress spectrum by performing stress analysis on the landing gear structure. During the take-off and landing process of a carrier-based aircraft, the outer cylinder of the landing gear strut is a key fatigue-weak part. Stress analysis is performed on it and the load spectrum is converted into a stress spectrum. Figure 3 The axial force F, bending moment M and torque T of the mid-landing gear can be obtained by the following formula:

[0094] F=F y -P y

[0095]

[0096] T=F x ·c

[0097] The maximum nominal equivalent stress of the fatigue-dangerous section of the landing gear can be obtained from the fourth strength theory:

[0098]

[0099] in,

[0100]

[0101]

[0102] Where A is the fatigue hazardous cross-sectional area of ​​the landing gear, W z is the section bending modulus, W p is the section torsional modulus.

[0103] According to the above calculation process, the load spectrum of the landing gear structure can be converted into a stress spectrum. After the stress spectrum is obtained, it is counted using the rain flow counting method to obtain the stress amplitude and stress mean of each level of the stress spectrum.

[0104] As an optional implementation, the equivalent fatigue life coefficient is the ratio of the cumulative fatigue damage at the current sinking rate to the average cumulative damage.

[0105] In this embodiment, the calculation formula of the equivalent fatigue life coefficient of the landing gear structure at different sinking rates is:

[0106]

[0107] Where, γ is the damage coefficient of landing gear structure sinking rate; D v is the cumulative damage of the landing gear structure under different sinking rates; D m is the cumulative damage to the landing gear structure at the average sinking rate.

[0108] As an optional implementation, it also includes:

[0109] Fatigue life calculation is performed on the peak load fluctuation at the moment of aircraft landing impact.

[0110] The load spectrum of a carrier-based aircraft takeoff and landing consists of two loads: landing and takeoff. The load spectrum of the landing gear structure is usually obtained by actual measurement of aircraft takeoff and landing. In order to obtain the service life of the landing gear structure under different sinking rates, it is necessary to measure the load of the carrier-based aircraft landing gear structure under different sinking rates to obtain its load spectrum. The typical load spectrum of the landing gear is as follows: Figure 4 As shown. By analyzing the load spectrum of carrier-based aircraft take-off and landing, it can be found that the influence of sinking rate on the load spectrum of landing gear structure is mainly due to the different peak loads at the moment of landing impact, while the load spectra of the subsequent taxiing section and take-off section are basically the same. Therefore, in order to simplify the calculation, the load spectrum under different sinking rates is simplified, assuming that the cumulative damage of the taxiing section is consistent, and only the peak load fluctuation at the moment of landing impact is calculated for fatigue life.

[0111] The embodiment of the present invention is Figure 4 Taking the load spectrum as an example, the service life of the landing gear structure is predicted. The stress amplitude and stress mean of each load level are shown in Table 1.

[0112] Table 1 Stress amplitude and mean value of each level of stress spectrum

[0113]

[0114] The Gerber model is used to correct the stress amplitude and mean of each level of stress spectrum, and then the cumulative fatigue damage of the landing gear structure during a take-off and landing process is calculated according to the Miner damage criterion. The stress concentration factor of the landing gear structure is taken as 3, and the material of the fatigue weak part of the landing gear is 30CrMnSiNi2A steel. According to the SN fatigue life curve of 30CrMnSiNi2A steel obtained from the table, the number of load cycles and cumulative fatigue damage of the landing gear structure under different sinking rates are calculated. The fatigue life and damage values ​​of each level of load under the average sinking rate are shown in Table 1, and the fatigue life and damage values ​​of the landing gear structure under different sinking rates are shown in Table 2.

[0115] Table 2 Fatigue life and damage value of landing gear structure at different sinking rates

[0116]

[0117] Taking the cumulative fatigue damage of the landing gear at the average sinking rate as a benchmark, the equivalent fatigue life coefficient of the landing gear structure at different sinking rates is obtained by using the above embodiment, as shown in Table 2. As can be seen from Table 2, when the sinking rate of the carrier-based aircraft reaches 6m / s, the cumulative fatigue damage of its landing gear structure in one take-off and landing reaches 2.22 times that of the average sinking rate. Therefore, when the carrier-based aircraft lands at a sinking rate of 6m / s, the take-off and landing life of its landing gear structure should be recorded as 2.22 times.

[0118] By utilizing the equivalent fatigue damage coefficient of the landing gear structure at different sinking rates, during the use of carrier-based aircraft, the service life of the landing gear structure after each take-off and landing can be corrected according to the sinking rate, so as to achieve the purpose of accurately calculating the service life of the carrier-based aircraft landing gear structure.

[0119] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate, characterized in that: include: obtaining a stress spectrum according to a first measured load spectrum of the landing gear structure; Using a rain flow counting method to count the first measured load spectrum, and obtaining stress amplitudes and mean values ​​corresponding to each level of load in the first measured load spectrum; Correcting the fatigue load spectrum of the landing gear structure according to the stress amplitude and mean value of the first measured load spectrum; The predicted service life of the landing gear structure after each take-off and landing is corrected according to the fatigue load spectrum, the sinking rate of the carrier aircraft and the damage coefficient corresponding to the sinking rate, including: Obtaining an average load spectrum of the landing gear structure at an average sinking rate of the carrier-based aircraft; Acquiring a second measured load spectrum of the landing gear structure under a high sinking rate of the carrier aircraft; calculating an average accumulated damage corresponding to the average load spectrum; calculating a second accumulated damage corresponding to the second measured load spectrum; The equivalent fatigue life coefficient of the landing gear structure at different sinking rates is calculated according to the average cumulative damage and the second cumulative damage; the equivalent fatigue life coefficient is the ratio of the cumulative fatigue damage at the current sinking rate to the average cumulative damage.

2. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 1, characterized in that: Obtaining a stress spectrum according to a first measured load spectrum of the landing gear structure includes: Determining the fatigue critical parts of the carrier-based aircraft landing gear during the take-off and landing phases; Obtaining a load-time curve of the fatigue critical part; The stress analysis and calculation are performed on the fatigue critical part, and the load spectrum of the fatigue critical part is converted into the stress spectrum.

3. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 1, characterized in that: The load spectrum is counted by using the rain flow counting method to obtain the stress amplitude and mean value corresponding to each level of load of the stress spectrum, including: The load spectrum is rotated 90 degrees, so that a peak value or a valley value of the load spectrum is used as a starting point, the vertical axis represents time, and the horizontal axis represents load; Make the rain flow start from the starting point and the inner side of each peak value / the valley value; Make the rain flow fall vertically at the next peak / valley until a peak / valley value greater in absolute value than the starting point appears on the other side of the vertical axis and stops; During the flow of any of the rain flows, when the rain flow meets the rain flow flowing down from above, the rain flow stops flowing, thus forming a rain flow cycle; The irregular random load spectrum obtained by actual measurement is simplified into a number of cyclic load spectra by the rain flow counting method, and the stress amplitude and mean value of each cycle are recorded.

4. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 3, characterized in that: The method further comprises: modifying the fatigue load spectrum of the landing gear structure according to the stress amplitude and the mean value of the first measured load spectrum, comprising: The fatigue load spectrum is corrected using the Gerber model.

5. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 4, characterized in that: Also includes: calculating, according to the stress amplitude and the mean value, a first cumulative damage of the landing gear structure under repeated action of a fatigue load; The total damage suffered by the landing gear structure during the take-off and landing process is obtained according to the number of cycles of each stress level in the load spectrum suffered by the landing gear structure during the take-off and landing process and the number of failure cycles under the independent action of each stress level.

6. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 2, characterized in that: Performing force analysis and calculation on the fatigue critical part, and converting the load spectrum of the fatigue critical part into the stress spectrum, includes: Obtaining the axial force, bending moment and torque of the landing gear structure; The maximum nominal equivalent stress of a fatigue-critical section of the landing gear structure is obtained according to the axial force, the bending moment and the torque.

7. The method for calculating the service life of a carrier aircraft landing gear structure based on sinking rate according to claim 1, characterized in that: Also includes: The fatigue life is calculated according to the peak load fluctuation at the moment of landing and impact of the carrier-based aircraft.

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