Vibration durability test method and system for excavator fuel tank

Abstract

The present invention discloses a method and system for vibration durability testing of excavator fuel tanks. The method comprises adding water to the fuel tank; and conducting a vibration durability test of the fuel tank according to the corresponding relationship between the liquid level and the vibration durability test time, as determined based on the damage equivalence principle. The present invention uses water instead of fuel for durability testing, thereby resolving fire safety hazards. Furthermore, the real-time changes in the liquid level are simplified by conducting the vibration durability test at multiple liquid levels of varying heights, simplifying the test plan, making it more feasible, and reducing testing costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering machinery, and in particular relates to a vibration durability test method and system for an excavator fuel tank. Background Art

[0002] The fuel tank is a key component of the excavator's power system. Its performance, including the structural strength and life of the tank, will directly affect the normal operation of the excavator. The fuel tank is prone to vibration fatigue damage under the combined effects of fluid-solid coupling between the tank and the oil and the vibration load of the operating conditions. Therefore, it is necessary to conduct fluid-solid coupling vibration durability tests on the fuel tank during the design phase to ensure its sufficient safety and life.

[0003] The structural dynamics of a fuel tank change due to fluid-structure interaction within the tank. Different oil levels within the tank result in different vibration modes and response stresses within the tank structure. Therefore, when conducting fuel tank durability tests, the effect of the oil level must be considered to accurately verify the tank's lifespan.

[0004] The existing fuel tank vibration bench test scheme mainly takes into account the continuous changes in oil under actual operating conditions. It uses the oil supply system to realize the empty and full cycle of the fuel tank liquid level while conducting the vibration durability test of the fuel tank.

[0005] Existing technical solutions achieve continuous changes in the oil level within the fuel tank under operating conditions, enabling accurate prediction of the tank's lifespan. However, this also requires the fuel supply system to cycle the tank's level between empty and full levels during the endurance test, complicating the testing process. Fuel is also injected into the fuel tank during the endurance test. Because fuel is a flammable liquid, this poses a safety hazard during long-term endurance tests, making it highly susceptible to accidents. Summary of the Invention

[0006] In response to the above problems, the present invention proposes a vibration durability test method and system for an excavator fuel tank, which can achieve a more convenient and safer fuel tank vibration fatigue durability test while ensuring test accuracy.

[0007] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0008] In a first aspect, the present invention provides a vibration durability test method for an excavator fuel tank, comprising:

[0009] Add water to the fuel tank;

[0010] The vibration durability test of the fuel tank is carried out according to the corresponding relationship between the liquid level height and the vibration durability test time obtained based on the damage equivalence principle.

[0011] Optionally, the liquid level is h j The vibration endurance test time t that needs to be carried out j for:

[0012] t j =(D 水ji D 水ij ) -1 D 水ji D 油i T1

[0013] Among them, D 水ij The liquid level height h at the i crack risk point on the fuel tank under the water filling condition is j The total damage value under the condition of 水ji D 水ij The transpose of D 油i is the total damage value of i cracking risk points during an empty and full cycle under the fuel filling condition, T1 is the data collection time under different liquid level heights under the water filling condition, and T1 is a constant.

[0014] Optionally, the liquid level h j and durability time t j The corresponding relationship between them is obtained through the following steps:

[0015] Identify the crack risk points of the fuel tank and attach strain gauges to the identified crack risk points;

[0016] When the fuel tank is filled with fuel, the time domain strain spectrum ε of i cracking risk points during an empty and full fuel cycle is collected by strain gauges. i ;

[0017] The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ;

[0018] Replace the fuel in the fuel tank with water and collect the strain spectrum ε of the i cracking risk point under different liquid level heights ij ;

[0019] The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case;

[0020] Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ;

[0021] According to the damage equivalence principle, the total damage value D of i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h j The vibration endurance test time t that needs to be carried out j .

[0022] Optionally, identifying the cracking risk points of the fuel tank and attaching strain gauges to the identified cracking risk points includes:

[0023] Perform modal analysis on the fuel tank and select locations with greater strain energy as crack risk points in the fuel tank structure;

[0024] Paste strain gauges at the crack risk points.

[0025] Optionally, when the fuel tank is filled with fuel, the time domain strain spectrum ε of i cracking risk points within an empty and full cycle of fuel is collected by strain gauges. i include:

[0026] Install the fuel tank on the vibration test bench, fill the tank with fuel, and conduct a vibration test on the fuel tank;

[0027] During the vibration test, the fuel is tested through the fuel supply system to test the empty and full cycle of the fuel tank, and the strain spectrum ε of i cracking risk points within the empty and full cycle time T0 is collected synchronously. i .

[0028] Optionally, the vibration endurance test time t required for different liquid level conditions is j The calculation formula is:

[0029] t j =β j T1

[0030] Among them, β j The liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

[0031] Optionally, when the fuel tank is filled with fuel, the total damage value D of the i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The mathematical expression corresponding to the same total damage value produced by the time endurance test is:

[0032] D 水ij β j =D 油i

[0033] Among them, β j The liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

[0034] In a second aspect, the present invention provides an excavator fuel tank vibration durability test system, comprising a strain gauge, a water injection module, and an oil injection module;

[0035] Each strain gauge is attached to the crack risk point of the fuel tank;

[0036] Use the oil filling module to fill the fuel tank with fuel, and use the strain gauge to collect the time domain strain spectrum ε of i cracking risk points during an empty and full cycle of the fuel. i ;

[0037] The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ;

[0038] Use the water injection module to add water to the fuel tank and collect the strain spectrum ε of the i cracking risk point under different liquid level heights ij ;

[0039] The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case;

[0040] Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ;

[0041] According to the damage equivalence principle, the total damage value D of i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h j The vibration endurance test time t that needs to be carried out j .

[0042] Optionally, the liquid level is h j The vibration endurance test time t that needs to be carried out j for:

[0043] t j =(D 水ji D 水ij ) -1 D 水ji D油i T1

[0044] Among them, D 水jj The i crack risk points on the fuel tank are at a liquid level of h j The total damage value under the condition of 水ji D 水i The transpose of D 油i is the total damage value of i cracking risk points within an empty and full cycle time, T1 is the data acquisition time under water filling conditions and different liquid level heights, and T1 is a constant.

[0045] Optionally, the vibration endurance test time t required for different liquid level conditions is j The calculation formula is:

[0046] t j =β j T1

[0047] Among them, β j The liquid level is h j In this case, the number of cycles is compared with the data acquisition time T1;

[0048] When the fuel tank is filled with fuel, the total damage value D of the i cracking risk point 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The mathematical expression corresponding to the same total damage value produced by the time endurance test is:

[0049] D 水ij β j =D 油i .

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention uses water instead of fuel to carry out the durability test, which can solve the fire safety hazard; and simplifies the real-time change of the liquid level into a plurality of liquid levels at different heights to carry out the vibration durability test, which simplifies the test plan, makes the test plan more feasible, and reduces the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0053] Figure 1The figure is a flow chart of a vibration durability test method for an excavator fuel tank according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, not as limitations. Therefore, other examples of the exemplary embodiments may also include different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0056] In the description of the present invention, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0057] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0058] The application principle of the present invention is described in detail below with reference to the accompanying drawings.

[0059] Example 1

[0060] An embodiment of the present invention provides a vibration durability test method for an excavator fuel tank, comprising the following steps:

[0061] (1) Add water to the fuel tank;

[0062] (2) According to the corresponding relationship between the liquid level height and the vibration durability test time obtained based on the damage equivalence principle, the vibration durability test of the fuel tank is carried out; specifically, the liquid level height is h j The vibration endurance test time t that needs to be carried out j for:

[0063] t j =(D 水ji D 水ij ) -1 D 水ji D 油i T1

[0064] Among them, D 水ij The liquid level height h at the i crack risk point on the fuel tank under the water filling condition is j The total damage value under the condition of 水ji D 水ij The transpose of D 油i is the total damage value of i cracking risk points during an empty and full cycle under the oil filling condition, and T1 is the data collection time under different liquid level heights under the water filling condition (T1 is a constant, that is, the data collection time is the same under different liquid level heights).

[0065] In a specific implementation of the embodiment of the present invention, the liquid level height h j and durability time t j The corresponding relationship between them is obtained through the following steps:

[0066] Identify the crack risk points of the fuel tank and attach strain gauges to the identified crack risk points;

[0067] When the fuel tank is filled with fuel, the time domain strain spectrum ε of i cracking risk points during an empty and full fuel cycle is collected by strain gauges. i ;

[0068] The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ;

[0069] Replace the fuel in the fuel tank with water and collect the strain spectrum ε of the i cracking risk point under different liquid level heightsij ;

[0070] The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case;

[0071] Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ;

[0072] According to the damage equivalence principle, when the fuel tank is filled with fuel, the total damage value D of the i cracking risk point is: 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h j The vibration endurance test time t that needs to be carried out j .

[0073] The step of identifying the cracking risk points of the fuel tank and attaching strain gauges to the identified cracking risk points includes:

[0074] Perform modal analysis on the fuel tank and select locations with greater strain energy as crack risk points in the fuel tank structure;

[0075] Paste strain gauges at the crack risk points.

[0076] Under the condition that the fuel tank is filled with fuel, the time domain strain spectrum ε of i cracking risk points within an empty and full cycle of fuel is collected by strain gauges. i include:

[0077] Install the fuel tank on the vibration test bench, fill the tank with fuel, and conduct a vibration test on the fuel tank;

[0078] During the vibration test, the fuel is tested through the fuel supply system to test the empty and full cycle of the fuel tank, and the strain spectrum ε of i cracking risk points within the empty and full cycle time T0 is collected synchronously. i .

[0079] Vibration durability test time t required under different liquid level conditions j The calculation formula is:

[0080] t j =β j T1

[0081] Among them, β jThe liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

[0082] The total damage value D of the i cracking risk points 油i Under the condition of adding water to the fuel tank, the fuel tank is j The mathematical expression corresponding to the total damage value produced by the t-time endurance test is:

[0083] D 水ij β j =D 油i .

[0084] The following combination Figure 1 A specific implementation method is described in detail for the durability test method in the embodiment of the present invention.

[0085] The vibration durability test method for excavator fuel tanks provided by the present invention is an equivalent method for fatigue damage in fuel tank vibration fatigue durability tests. The test accuracy is consistent with that of existing technical solutions. Specifically, it includes the following steps:

[0086] Step 100: Identify the crack risk points of the fuel tank structure through simulation analysis and attach strain gauges to the identified risk points:

[0087] A modal analysis was conducted on the fuel tank, and locations with greater strain energy were selected as cracking risk points of the fuel tank structure. Strain gauges were affixed to the cracking risk points in preparation for strain testing in the subsequent vibration durability tests under different working conditions.

[0088] Step 200: Under the fuel tank filling condition, collect the time domain strain spectrum ε of i cracking risk points during one empty and full fuel cycle i :

[0089] The fuel tank is installed on the vibration test bench, fuel is added to the tank, and the vibration test of the fuel tank is carried out. During the vibration test, the fuel passes through the fuel supply system to test the empty and full cycle of the tank liquid level. During the test, the strain spectrum ε of i cracking risk points within the empty and full cycle time T0 is collected. i .

[0090] Step 300: The strain spectrum ε of i cracking risk points in an empty and full cycle time T0 collected in step 200 under the fuel filling state is converted into i Converted into the total damage value D of i cracking risk points 油i .

[0091] Step 400: Replace the fuel in the fuel tank with water and collect the strain spectra ε of i cracking risk points under different liquid level heights ij :

[0092] Replace the fuel in the fuel tank with water, adjust the liquid in the tank to a certain height through the fuel supply system, and perform a vibration test on the fuel tank while keeping the liquid level constant. Collect the strain spectra of i cracking risk points at this height. The collection time for each liquid level is T1. Adjust the liquid level and use the same method to collect the strain spectra of i cracking risk points. Collect a total of j groups of strain spectra of i cracking risk points at different liquid level heights, and obtain the strain spectrum ε of i cracking risk points at j different liquid level heights. ij , ε ij There are i cracking risk points at a liquid level of h j Test strain spectrum under the condition of .

[0093] Step 500: The strain spectra ε of i cracking risk points under different liquid level conditions collected in step 400 are ij Converted into the total damage value D of the cracking risk point 水ij , D 水ij There are i cracking risk points at a liquid level of h j The total damage value in this case.

[0094] Step 600: Calculate the vibration endurance test time required for each liquid level condition when the fuel tank is filled with water.

[0095] The solution of the present invention adopts the method of adding water and carrying out durability tests at different liquid level heights. To this end, it is necessary to calculate the durability time required for each liquid level height. j The liquid level is h j The vibration endurance test time that needs to be carried out.

[0096] t j =β j T1

[0097] Among them, β j The liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

[0098] According to the damage equivalence principle, the total damage value D of the cracking risk point calculated in step 300 is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, that is:

[0099] D 水ij β j =D 油i

[0100] Further calculate the liquid level height h jThe vibration endurance test time t that needs to be carried out j for:

[0101] t j =(D 水ji D 水ij ) -1 D 水ji D 油i T1

[0102] Step 700: Under the condition of adding water, the liquid level height h calculated in step 600 is calculated. j and durability time t j The team carried out vibration durability tests on fuel tanks.

[0103] Example 2

[0104] The present invention provides a vibration durability test system for an excavator fuel tank, comprising a strain gauge, a water injection module and an oil injection module;

[0105] Each strain gauge is attached to the crack risk point of the fuel tank;

[0106] Use the oil filling module to fill the fuel tank with fuel, and use the strain gauge to collect the time domain strain spectrum ε of i cracking risk points during an empty and full cycle of the fuel. i ;

[0107] The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ;

[0108] Use the water injection module to add water to the fuel tank and collect the strain spectrum ε of the i cracking risk point under different liquid level heights ij ;

[0109] The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case;

[0110] Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ;

[0111] According to the damage equivalence principle, the total damage value D of i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h jThe vibration endurance test time t that needs to be carried out j .

[0112] Optionally, the liquid level is h j The vibration endurance test time t that needs to be carried out j for:

[0113] t j =(D 水ji D 水ij ) -1 D 水ji D 油i T1

[0114] Among them, D 水ij The i crack risk points on the fuel tank are at a liquid level of h j The total damage value under the condition of 水ji D 水 The transpose of D 油i is the total damage value of i cracking risk points within an empty and full cycle time, T1 is the data acquisition time under water filling conditions and different liquid level heights, and T1 is a constant.

[0115] Optionally, the vibration endurance test time t required for different liquid level conditions is j The calculation formula is:

[0116] t j =β j T1

[0117] Among them, β j The liquid level is h j In this case, the number of cycles is compared with the data acquisition time T1;

[0118] When the fuel tank is filled with fuel, the total damage value D of the i cracking risk point 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The mathematical expression corresponding to the same total damage value produced by the time endurance test is:

[0119] D 水ij β j =D 油i .

[0120] In summary, the present invention uses water instead of fuel to conduct durability tests: fuel is a flammable liquid, and there are fire safety hazards in long-term durability tests. Using water instead of fuel to conduct durability tests can solve the fire safety hazards. At the same time, the present invention simplifies the real-time changes in the liquid level into a plurality of liquid levels at different heights to conduct vibration durability tests: the empty and full cycles of the liquid level require the fuel tank to continuously pump out and return oil through the oil supply system when conducting the vibration durability test. During the entire durability test, the oil supply system must work synchronously and in real time, and the test plan is complicated. By simplifying the test plan, the real-time changes in the liquid level are simplified to a plurality of liquid levels at different heights to conduct vibration durability tests. This makes it unnecessary for the oil supply system to work synchronously and in real time during the vibration durability test, and only serves to adjust the liquid level during the test.

[0121] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0122] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A vibration durability test method for an excavator fuel tank, characterized in that: include: Add water to the fuel tank; Conduct vibration durability tests on fuel tanks based on the corresponding relationship between the liquid level and the vibration durability test time obtained based on the damage equivalence principle; The liquid level is h j The vibration endurance test time t that needs to be carried out j for: t j =(D 水ji D 水ij )D 水ji D 油i T1 Among them, D 水ij The liquid level height h at the i crack risk point on the fuel tank under the water filling condition is j The total damage value under the condition of 水ji D 水ij The transpose of D 油i is the total damage value of i cracking risk points during an empty and full cycle under fuel filling condition, T1 is the data collection time under water filling condition at different liquid level heights, and T1 is a constant; Liquid level h j and durability time t j The corresponding relationship between them is obtained through the following steps: Identify the crack risk points of the fuel tank and attach strain gauges to the identified crack risk points; When the fuel tank is filled with fuel, the time domain strain spectrum ε of i cracking risk points during an empty and full fuel cycle is collected by strain gauges. i ; The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ; Replace the fuel in the fuel tank with water and collect the strain spectrum ε of the i cracking risk point under different liquid level heights ij ; The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case; Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ; According to the damage equivalence principle, the total damage value D of i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h j The vibration endurance test time t that needs to be carried out j .

2. The vibration durability test method for an excavator fuel tank according to claim 1, characterized in that: The identifying of the cracking risk points of the fuel tank and attaching strain gauges to the identified cracking risk points includes: Perform modal analysis on the fuel tank and select locations with greater strain energy as crack risk points in the fuel tank structure; Paste strain gauges at the crack risk points.

3. The vibration durability test method for an excavator fuel tank according to claim 1, characterized in that: Under the condition of fuel tank filling, the time domain strain spectrum ε of i cracking risk points within one empty and full fuel cycle is collected by strain gauge. i include: Install the fuel tank on the vibration test bench, fill the tank with fuel, and conduct a vibration test on the fuel tank; During the vibration test, the fuel is tested through the fuel supply system to test the empty and full cycle of the fuel tank, and the strain spectrum ε of i cracking risk points within the empty and full cycle time T0 is collected synchronously. i .

4. The vibration durability test method for an excavator fuel tank according to claim 1, characterized in that: Vibration durability test time t required under different liquid level conditions j The calculation formula is: t j =β j T1 Among them, β j The liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

5. The vibration durability test method for an excavator fuel tank according to claim 1, characterized in that: When the fuel tank is filled with fuel, the total damage value D of the i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The mathematical expression corresponding to the same total damage value produced by the time endurance test is: D 水ij b j =D 油i Among them, β j The liquid level is h j The number of cycles in each case compared to the data acquisition time T1.

6. An excavator fuel tank vibration durability test system, characterized in that: Includes strain gauge, water injection module and oil injection module; Each strain gauge is attached to the crack risk point of the fuel tank; Use the oil filling module to fill the fuel tank with fuel, and use the strain gauge to collect the time domain strain spectrum ε of i cracking risk points during an empty and full cycle of the fuel. i ; The time domain strain spectrum ε i Converted into the total damage value D of i cracking risk points 油i ; Use the water injection module to add water to the fuel tank and collect the strain spectrum ε of the i cracking risk point under different liquid level heights ij ; The strain spectrum ε of the i cracking risk point under different liquid level heights ij Converted into the total damage value D of i cracking risk points 水ij , D 水ij There are i cracking risk points at a liquid level of h j Total damage value in the case; Calculate the vibration endurance test time t required for the fuel tank under water filling conditions and different liquid level heights j ; According to the damage equivalence principle, the total damage value D of i cracking risk points is 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The total damage value produced by the time endurance test is the same, and the liquid level height is h j The vibration endurance test time t that needs to be carried out j ; The liquid level is h j The vibration endurance test time t that needs to be carried out j for: t j =(D 水ji D 水ij ) -1 D 水ji D 油i T1 Among them, D 水ij The i crack risk points on the fuel tank are at a liquid level of h j The total damage value under the condition of 水ji D 水ij The transpose of D 油i is the total damage value of i cracking risk points within an empty and full cycle time, T1 is the data acquisition time under water filling conditions and different liquid level heights, and T1 is a constant.

7. The excavator fuel tank vibration durability test system according to claim 6, characterized in that: Vibration durability test time t required under different liquid level conditions j The calculation formula is: t j =β j T1 Among them, β j The liquid level is h j In this case, the number of cycles is compared with the data acquisition time T1; When the fuel tank is filled with fuel, the total damage value D of the i cracking risk point 油i Under the condition of adding water to the fuel tank, the fuel tank is j Carry out j The mathematical expression corresponding to the same total damage value produced by the time endurance test is: D 水ij b j =D 油i 。

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