A method and apparatus for designing rapid vibration fatigue test specimens

Abstract

This disclosure relates to the field of aerospace materials technology, and in particular to a rapid vibration fatigue specimen design method and apparatus. It addresses the problems in existing vibration fatigue specimen design technologies, such as long design cycles, high costs, component frequencies exceeding the excitation frequency range of the vibration test bench, or the need for multiple rounds of optimization and iterative design. This disclosure first designs a reference specimen, and then uses the principle of dynamic similarity to rapidly design a vibration fatigue specimen that is simultaneously applicable to the geometric characteristics of the component and the excitation frequency range of the vibration test bench, i.e., determining the specific scaling factor required for the reference specimen. This disclosure only requires the pre-designed reference specimen to rapidly design a vibration fatigue specimen that is simultaneously applicable to the geometric characteristics of the component and the excitation frequency range of the vibration test bench, making better use of existing resources. Compared to the best existing technologies, it improves specimen design efficiency and has the advantages of high speed and strong applicability.

Description

Technical Field

[0001] This disclosure relates to the field of aerospace materials technology, and in particular to a method and apparatus for designing rapid vibration fatigue test specimens. Background Technology

[0002] Aerospace materials refer to all kinds of materials used in aircraft and their power plants, accessories, and instruments. They are one of the decisive factors in the development of aerospace engineering technology, and aerospace materials science is also a pioneering branch of materials science. Aerospace materials possess excellent resistance to high and low temperatures, as well as aging and corrosion resistance, enabling them to adapt to the space environment. Each generation of materials leads to a new generation of equipment; aerospace materials are the technological foundation for enabling aerospace products to achieve their expected performance, lifespan, and reliability. The fatigue strength of materials is an important basis for component selection and strength-life assessment; however, currently, the mechanical property data of many materials used in engineering projects are incomplete.

[0003] In both military and civilian mechanical engineering, high-frequency vibration testing is commonly used to assess the fatigue strength of materials. High-frequency vibration testing utilizes testing equipment to generate alternating inertial forces with cyclic loading characteristics at a frequency of approximately 1000Hz, which are applied to fatigue specimens. This method can satisfy the requirements for studying the fatigue performance of metallic materials in service under high-frequency, low-amplitude, and high-cyclic environmental conditions. To obtain the fatigue limit of materials, there are three main engineering methods: the first is to customize material blanks and then fabricate specimens according to standards for vibration fatigue testing; the second method is to directly use existing parts for vibration fatigue testing; and the third method also involves designing dedicated vibration fatigue specimens based on the structural characteristics of the components for testing.

[0004] All three methods in the existing technology have shortcomings:

[0005] The method of customizing blanks and making samples has drawbacks such as long cycle time and high cost.

[0006] Second, vibration fatigue test specimens are made using existing parts. Some of these parts have frequencies that exceed the excitation frequency range of the vibration test bench (usually below 3000Hz), and stress concentration may also exist on the existing parts, leading to inaccurate test results.

[0007] Third, designing dedicated vibration fatigue specimens based on the structural characteristics of existing parts requires multiple rounds of optimization in fatigue specimen design to avoid stress concentration. Furthermore, fatigue specimens need to be redesigned according to the different structures of the parts, resulting in high work repetition.

[0008] In summary, existing vibration fatigue specimen designs either have long cycles and high costs, or the component frequencies exceed the excitation frequency range of the vibration test bench and there may be stress concentration phenomena that lead to inaccurate test results, or require multiple rounds of optimization and iterative design. Summary of the Invention

[0009] To address the aforementioned problems, this disclosure provides a rapid vibration fatigue specimen design method and apparatus. This method solves the issues in existing vibration fatigue specimen design, such as long design cycles and high costs, component frequencies exceeding the excitation frequency range of the vibration testing bench, potential stress concentration leading to inaccurate test results, and the need for multiple rounds of optimization and iterative design. This disclosure utilizes existing components to rapidly design vibration fatigue specimens, reducing design cycle and cost, improving the accuracy of test results, and minimizing the number of design iterations.

[0010] A method for designing rapid vibration fatigue test specimens, the method comprising:

[0011] Design a general reference specimen for vibration fatigue testing with a first natural frequency of W;

[0012] Select the components that need to be subjected to vibration fatigue testing, preliminarily determine the sample cutting scheme, and according to the principle of dynamic similarity, scale the reference sample proportionally according to the existing component cutting scheme to obtain the design sample, so that the first natural frequency of the design sample is within the excitation frequency range of the vibration test bench. The design sample is the vibration fatigue sample.

[0013] Furthermore, the reference specimens designed for vibration fatigue testing include:

[0014] The reference specimen includes: a clamping section, a narrow waist section, and a counterweight section;

[0015] By adjusting the structural dimensions of the counterweight section and the narrow waist section, the maximum point of the first-order bending vibration stress of the specimen is made to fall at the narrow neck of the narrow waist section, which is the vibration fatigue initiation point.

[0016] During the test, the sample is fixed on the vibration table by the clamping section.

[0017] Furthermore, the sample cutting plan is determined, including:

[0018] Based on the engine blade disk and gear web model, while ensuring that the vibration frequency falls within the excitation frequency range of the excitation table, the disk and web structure are utilized to the maximum extent. The scaling dimensions are determined based on the reference specimen, the geometric dimensions of the fatigue specimen are determined, and the cutting scheme is determined.

[0019] Furthermore, based on the material of the designed specimen and the material of the reference specimen, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference specimen, the first natural frequency of the designed specimen is obtained.

[0020] By selecting an appropriate geometric similarity ratio, the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is then called a vibration fatigue specimen.

[0021] Furthermore, based on the principle of kinetic similarity, when enlarging or reducing the reference specimen, the geometric similarity ratio A between the target design specimen and the reference specimen is first set. l =λ, where λ is the ratio of the size of the design specimen to that of the reference specimen, and λ is a positive number;

[0022] The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of their material density and elastic modulus are A. ρ and A E ;

[0023] Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as

[0024] Furthermore, after designing the test specimen and determining the material, based on the geometric characteristics of the part and the excitation frequency range of the vibration test bench, the specific magnification or reduction factor required for the reference specimen is determined, that is, the specific value of λ is determined, where λ is a positive number.

[0025] Furthermore, the designed specimen and the reference specimen have the same stress distribution; the stress similarity ratio is the elastic modulus similarity ratio A. σ =A E ;

[0026] The excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

[0027] Furthermore, based on the material and geometric characteristics of the components, the design of the test specimens utilizes similarity relationships to quickly obtain vibration fatigue test specimens that are compatible with the structural geometry and the excitation frequency range of the vibration table.

[0028] A rapid vibration fatigue specimen design device, the device comprising:

[0029] The reference design unit is used to design a general reference specimen for vibration fatigue testing, with a first-order natural frequency of W.

[0030] The specimen design unit is used to select the components that need to be subjected to vibration fatigue testing, preliminarily determine the specimen cutting scheme, and obtain the design specimen by scaling the reference specimen proportionally according to the existing component cutting scheme based on the principle of dynamic similarity. The first natural frequency of the design specimen is within the excitation frequency range of the vibration test bench. The design specimen is the vibration fatigue specimen.

[0031] Furthermore, based on the material of the designed specimen and the material of the reference specimen, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference specimen, the first natural frequency of the designed specimen is obtained.

[0032] Based on the similarity of the material mechanical properties between the designed specimen and the reference specimen, an appropriate geometric similarity ratio is selected so that the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is the vibration fatigue specimen.

[0033] Furthermore, based on the principle of kinetic similarity, when enlarging or reducing the reference specimen, the geometric similarity ratio A between the target design specimen and the reference specimen is first set. l =λ, where λ is the ratio of the size of the design specimen to that of the reference specimen, and λ is a positive number;

[0034] The material of the designed specimen is different from that of the reference specimen, therefore the similarity ratios of the material density and elastic modulus are Aρ and AE, respectively.

[0035] Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as

[0036] Furthermore, based on the geometric characteristics of the part, the material, and the excitation frequency range of the vibration test bench, the specific magnification or reduction factor required for the reference specimen is determined, that is, the specific value of λ is determined, where λ is a positive number.

[0037] Furthermore, the designed specimen and the reference specimen have the same stress distribution; the stress similarity ratio is the elastic modulus similarity ratio A. σ =A E ;

[0038] The excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

[0039] Furthermore, based on the geometric characteristics and materials of the components, fatigue specimens with first-order natural frequencies that meet the requirements of the excitation table can be quickly designed.

[0040] This disclosure first designs a reference specimen, and then uses the principle of dynamic similarity to quickly design a vibration fatigue specimen that is suitable for the geometric features of the parts and the excitation frequency range of the vibration test bench, that is, to determine the specific magnification or reduction factor required for the reference specimen.

[0041] This disclosure allows for the rapid design of vibration fatigue specimens that are compatible with the geometric features of the components and the excitation frequency range of the vibration test bench, based solely on a pre-designed reference specimen. It makes better use of existing resources and improves the design efficiency of the specimens compared to the best existing technology, offering advantages such as speed and strong applicability.

[0042] This method has been verified to be feasible through simulation analysis using commercial software. Furthermore, it has been applied in the vibration fatigue test of accessory transmission gears of a certain type of engine. It uses existing scrapped gears to quickly design and process fatigue specimens, improving the utilization rate of parts or scrap. The test obtained the vibration fatigue limit of four types of gears made of different materials, providing a reliable basis for troubleshooting vibration fatigue faults of gears in this type of engine.

[0043] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart illustrating the method of an embodiment of this disclosure;

[0046] Figure 2 This is a schematic diagram of the apparatus according to an embodiment of the present disclosure;

[0047] Figure 3 This is a schematic diagram of a reference sample according to an embodiment of this disclosure. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0049] In the field of aerospace materials, vibration is a common form of motion in engineering structures and an important cause of fatigue failure in engineering structures and materials. Therefore, vibration fatigue testing is an important testing method to obtain the fatigue performance of materials and structural components under vibration conditions.

[0050] To obtain the fatigue limit of a material, there are three engineering methods: the first is to customize a material blank and then make a test specimen according to the standard for vibration fatigue testing; the second is to directly use existing parts for vibration fatigue testing; the third method also involves designing a special vibration fatigue test specimen based on the structural characteristics of the parts.

[0051] All three methods in the existing technology have shortcomings:

[0052] The method of customizing blanks and making samples has drawbacks such as long cycle time and high cost.

[0053] 2. Vibration fatigue specimens are made using existing parts, some of which have frequencies that exceed the excitation frequency range of the vibration test bench (usually below 3000Hz). The frequency of the parts exceeding the excitation frequency range of the vibration test bench and the stress concentration phenomenon that may lead to inaccurate test results are also present.

[0054] Third, designing dedicated vibration fatigue specimens based on the structural characteristics of existing parts requires multiple rounds of optimization in fatigue specimen design to avoid stress concentration. Furthermore, fatigue specimens need to be redesigned according to the different structures of the parts, resulting in high work repetition.

[0055] Therefore, this disclosure proposes a method and apparatus for designing rapid vibration fatigue specimens, including a method for designing rapid vibration fatigue specimens and an apparatus for designing rapid vibration fatigue specimens.

[0056] This disclosure solves the problems in existing vibration fatigue specimen design, such as long design cycles and high costs, component frequencies exceeding the excitation frequency range of the vibration test bench, stress concentration that may lead to inaccurate test results, and the need for multiple rounds of optimization and iterative design. This disclosure utilizes existing components to quickly design vibration fatigue specimens, reducing design cycle and cost, improving the accuracy of test results, and reducing the number of iterative design rounds.

[0057] like Figure 1 As shown, this disclosure provides a method for designing rapid vibration fatigue test specimens, the method comprising:

[0058] Design a reference specimen and determine its material and first natural frequency.

[0059] Select the components that need to undergo vibration fatigue testing, determine the materials, and determine a preliminary sample cutting plan based on the geometric characteristics of the components;

[0060] The design specimen is obtained by scaling the reference specimen proportionally according to the existing component cutting scheme, so that the first natural frequency of the design specimen is within the excitation frequency range of the vibration test bench.

[0061] In practice, a reference specimen is first designed. Then, using the principle of dynamic similarity, a vibration fatigue specimen suitable for both the geometric characteristics of the components and the excitation frequency range of the vibration test bench is quickly designed, thus determining the specific scaling factor required for the reference specimen. Compared to existing technologies, this reduces the design cycle and cost, and minimizes the number of design iterations.

[0062] like Figure 1 As shown, this disclosure first designs a vibration fatigue reference specimen based on existing components, then selects an appropriate design specimen material, and finally scales the design specimen proportionally to the existing components to obtain the design specimen, so that the first natural frequency of the design specimen is within the excitation frequency range of the vibration test bench. At this time, the design specimen is the vibration fatigue specimen.

[0063] In practice, vibration test benches have a limited range of excitation frequencies and can accommodate a limited number of geometrically specific components. Therefore, it is necessary to design specimens that meet the requirements of the vibration test bench. The fatigue limit data of the designed specimen is measured, and then the fatigue limit data of the reference specimen is calculated using the corresponding formulas.

[0064] In this embodiment, the first natural frequency of the design sample is obtained based on the material of the design sample and the material of the reference sample, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference sample.

[0065] By selecting an appropriate geometric similarity ratio, the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is then called a vibration fatigue specimen.

[0066] In practical implementation, this disclosure can quickly obtain the required design specimen based on the principle of kinetic similarity.

[0067] In particular, the design specimen can be made of a different material than the reference specimen, allowing for the faster design of specimens of appropriate size for components made of different materials.

[0068] In this embodiment, based on the principle of dynamic similarity, the reference sample is enlarged or reduced. First, the geometric similarity ratio Al = λ between the target design sample and the reference sample is set, where λ is the ratio of the size of the design sample and the reference sample, and λ is a positive number.

[0069] The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of their material density and elastic modulus are Aρ and A, respectively. E ;

[0070] Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as

[0071] In this embodiment, after designing the sample and determining the material, the specific magnification or reduction factor of the reference sample is determined based on the geometric characteristics of the part and the excitation frequency range of the vibration test bench, that is, the specific value of λ is determined, where λ is a positive number.

[0072] In practice, the material of the test specimen is first determined, and then the specific magnification or reduction factor of the reference specimen is determined based on the geometric characteristics of the part and the excitation frequency range of the vibration test bench.

[0073] In this embodiment, the designed specimen and the reference specimen have the same stress distribution, and the stress similarity ratio is the elastic modulus similarity ratio A. σ =A E .

[0074] In practice, since the designed specimen and the reference specimen are enlarged or reduced proportionally in terms of geometric dimensions, so that they have the same stress distribution, the fatigue limit of the specimen can be accurately obtained.

[0075] In this embodiment, the excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

[0076] In practice, the excitation frequency of the vibration test bench is the same as the first natural frequency of the design specimen, which can make the design specimen resonate with the vibration test bench to test the fatigue limit of the material under test.

[0077] In this embodiment, the design of the test specimen is based on the material and geometric characteristics of the components, and the similarity relationship is used to quickly obtain a vibration fatigue test specimen that is adapted to the structural geometric characteristics and the vibration table excitation frequency range.

[0078] In practice, the material of the component is determined, and the sample cutting scheme is determined based on the geometric characteristics of the component. The design sample is obtained by scaling the cutting scheme proportionally. One component can be processed into multiple fatigue samples, which makes great use of existing components or scrapped parts, speeds up the design process, and shortens the test cycle.

[0079] like Figure 2 As shown, this disclosure provides a rapid vibration fatigue specimen design device, the device comprising:

[0080] The reference design unit is used to design a general reference specimen for vibration fatigue testing and calculate its first natural frequency as W.

[0081] The specimen design unit is used to select the components that need to be subjected to vibration fatigue testing, preliminarily determine the specimen cutting scheme, and obtain the design specimen by scaling the reference specimen proportionally according to the existing component cutting scheme based on the principle of dynamic similarity. The first natural frequency of the design specimen is within the excitation frequency range of the vibration test bench. The design specimen is the vibration fatigue specimen.

[0082] In specific implementation, such as Figure 2 As shown, the apparatus disclosed herein includes a reference design unit for designing a reference specimen and a specimen design unit for designing a test specimen. The reference specimen is as follows: Figure 3 As shown.

[0083] In this embodiment, the first natural frequency of the design sample is obtained based on the material of the design sample and the material of the reference sample, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference sample.

[0084] Based on the similarity of the material mechanical properties between the designed specimen and the reference specimen, an appropriate geometric similarity ratio is selected so that the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is the vibration fatigue specimen.

[0085] In this embodiment, based on the principle of kinetic similarity, the reference sample is enlarged or reduced, and the geometric similarity ratio A between the target design sample and the reference sample is first set. l =λ, where λ is the ratio of the size of the design specimen to that of the reference specimen, and λ is a positive number;

[0086] The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of their material density and elastic modulus are A. ρ and A E ;

[0087] Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as

[0088] In this embodiment, after designing the sample and determining the material, the specific magnification or reduction factor of the reference sample is determined based on the geometric characteristics of the part, the material, and the excitation frequency range of the vibration test bench, that is, the specific value of λ is determined, where λ is a positive number.

[0089] In this embodiment, the designed specimen and the reference specimen have the same stress distribution, and the stress similarity ratio is the elastic modulus similarity ratio A. σ =A E ;

[0090] The excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

[0091] In this embodiment, fatigue specimens with first-order natural frequencies that meet the requirements of the excitation table are quickly designed based on the material and geometric characteristics of the components.

[0092] This disclosure allows for the rapid design of vibration fatigue specimens that are compatible with the geometric features of the components and the excitation frequency range of the vibration test bench, based solely on a pre-designed reference specimen. It makes better use of existing resources and improves the design efficiency of the specimens compared to the best existing technology, offering advantages such as speed and strong applicability.

[0093] To enable those skilled in the art to better understand this disclosure, the principles of this disclosure are explained as follows:

[0094] The fatigue limit refers to the maximum stress value that a material can withstand without failure after an infinite number of stress cycles; it is also known as the endurance limit. The fatigue limit of a material is an inherent property of the material itself and varies depending on the cyclic characteristics, the form of specimen deformation, and the environment in which the material is subjected. It must be determined through fatigue testing. The determination requires several smooth, small-sized specimens and is conducted on a specialized fatigue testing machine.

[0095] Fatigue limit is a crucial physical quantity in materials science, representing a material's ability to withstand cyclic stress. It refers to the maximum stress value that a material can withstand after an infinite number of stress cycles without failure; it is also known as the endurance limit.

[0096] This disclosure consists of the following steps:

[0097] 1) Design a vibration fatigue specimen, referred to in this disclosure as the reference specimen, with a first natural frequency of W.

[0098] 2) Based on the principle of kinetic similarity, when enlarging or reducing the reference specimen, first set the geometric similarity ratio A between the target design specimen and the reference specimen. l =λ, λ>0.

[0099] 3) The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of the material density and elastic modulus are Aρ and A, respectively. E .

[0100] 4) Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as The excitation frequency of the vibration test bench is also Furthermore, the designed specimen and the reference specimen have the same stress distribution, and the stress similarity ratio is the elastic modulus similarity ratio A. σ =A E .

[0101] 5) Based on the geometric characteristics of the part and the excitation frequency range of the test bench, determine the specific magnification or reduction factor required for the reference specimen, that is, determine the specific value of λ.

[0102] Through the above steps, based on the pre-designed reference specimen, a vibration fatigue test specimen that is suitable for both the geometric characteristics of the parts and the excitation frequency range of the vibration test bench can be quickly designed using the principle of dynamic similarity.

[0103] This method has been verified to be feasible through simulation analysis using commercial software. Furthermore, it has been applied in the vibration fatigue test of accessory transmission gears of a certain type of engine. It uses existing scrapped gears to quickly design and process fatigue specimens, improving the utilization rate of parts or scrap. The test obtained the vibration fatigue limit of four types of gears made of different materials, providing a reliable basis for troubleshooting vibration fatigue faults of gears in this type of engine.

[0104] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for designing rapid vibration fatigue test specimens, characterized in that, The method includes: The reference specimen designed for vibration fatigue testing has a first-order natural frequency of W. Select the components that need to be subjected to vibration fatigue testing, determine the specimen cutting scheme, and according to the principle of dynamic similarity, scale the reference specimen proportionally according to the existing component cutting scheme to obtain the design specimen, so that the first natural frequency of the design specimen is within the excitation frequency range of the vibration test bench. The design specimen is the vibration fatigue specimen. Specifically, this includes: obtaining the first natural frequency of the design specimen based on the material of the design specimen and the material of the reference specimen, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference specimen. Based on the principle of kinetic similarity, when enlarging or reducing the reference specimen, the geometric similarity ratio between the target design specimen and the reference specimen is first set. , where λ is the ratio of the size of the design specimen to that of the reference specimen, and λ is a positive number; The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of the material density and elastic modulus are respectively... and ; Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as ; By selecting an appropriate geometric similarity ratio, the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is then called a vibration fatigue specimen.

2. The rapid vibration fatigue specimen design method according to claim 1, characterized in that, The reference specimens designed for vibration fatigue testing include: The reference specimen includes: a clamping section, a narrow waist section, and a counterweight section; By adjusting the structural dimensions of the counterweight section and the narrow waist section, the maximum point of the first-order bending vibration stress of the specimen is made to fall at the narrow neck of the narrow waist section, which is the vibration fatigue initiation point. During the test, the sample is fixed on the vibration table by the clamping section.

3. The rapid vibration fatigue specimen design method according to claim 1, characterized in that, Determine the specimen cutting plan, including: Based on the engine blade disk and gear web model, and ensuring that the vibration frequency falls within the excitation frequency range of the excitation table, the scaling dimensions are determined according to the reference specimen, the geometric dimensions of the fatigue specimen are determined, and the cutting scheme is determined.

4. The rapid vibration fatigue specimen design method according to claim 1, characterized in that, After designing the test specimen and determining the material, based on the geometric characteristics of the part and the excitation frequency range of the vibration test bench, determine the specific magnification or reduction factor required for the reference specimen, that is, determine the specific value of λ, where λ is a positive number.

5. The rapid vibration fatigue specimen design method according to claim 1, characterized in that, The stress similarity ratio between the designed specimen and the reference specimen is the same as the elastic modulus similarity ratio. ; The excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

6. A method for designing rapid vibration fatigue test specimens according to any one of claims 1-5, characterized in that, Based on the material and geometric characteristics of the components, the design of the test specimens utilizes similarity relationships to quickly obtain vibration fatigue test specimens that are compatible with the structural geometry and the excitation frequency range of the shaking table.

7. A rapid vibration fatigue specimen design device, characterized in that, The device includes: The reference design unit is used to design a general reference specimen for vibration fatigue testing, with a first-order natural frequency of W. The sample design unit is used to select the components that need to be subjected to vibration fatigue testing, preliminarily determine the sample cutting scheme, and obtain the design sample by scaling the reference sample proportionally according to the existing component cutting scheme based on the principle of dynamic similarity, so that the first natural frequency of the design sample is within the excitation frequency range of the vibration test bench. The design sample is the vibration fatigue sample. The specimen design unit is specifically used to: obtain the first natural frequency of the designed specimen based on the material of the designed specimen and the material of the reference specimen, the similarity ratio of their material density, elastic modulus, and geometric similarity, as well as the first natural frequency of the reference specimen. Based on the principle of kinetic similarity, when enlarging or reducing the reference specimen, the geometric similarity ratio between the target design specimen and the reference specimen is first set. , where λ is the ratio of the size of the design specimen to that of the reference specimen, and λ is a positive number; The material of the designed specimen is different from that of the reference specimen; therefore, the similarity ratios of the material density and elastic modulus are respectively... and ; Based on the principle of dynamic similarity, the natural frequency similarity ratio between the designed sample and the reference sample is obtained. That is, the first-order natural frequency of the designed sample is obtained as ; By selecting an appropriate geometric similarity ratio, the first natural frequency of the designed specimen is within the excitation frequency range of the vibration test bench. The designed specimen is then called a vibration fatigue specimen.

8. The rapid vibration fatigue specimen design device according to claim 7, characterized in that, Based on the geometric characteristics of the part, the material, and the excitation frequency range of the vibration test bench, determine the specific magnification or reduction factor required for the reference specimen, that is, determine the specific value of λ, where λ is a positive number.

9. The rapid vibration fatigue specimen design device according to claim 7, characterized in that, The stress similarity ratio between the designed specimen and the reference specimen is the same as the elastic modulus similarity ratio. ; The excitation frequency of the vibration test bench is the same as the first natural frequency of the designed specimen.

10. A rapid vibration fatigue specimen design device according to any one of claims 7-9, characterized in that, Based on the material and geometric characteristics of the components, fatigue specimens with first-order natural frequencies that meet the requirements of the excitation table can be designed quickly.

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