Design and experimental method of characteristic simulation parts of CMC guide blade body-edge plate connection area
By comprehensively considering the simulation component design and experimental methods of CMC turbine guide blade blade body-edge plate connection, the problem of insufficient blade connection strength is solved, efficient strength analysis and failure mode research is achieved, simplifying the test process and reducing costs.
Patent Information
- Application Number
- CN202410250301.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-05
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2044-03-05
AI Technical Summary
The connection part of the CMC turbine guide blade body-edge plate has the problem of insufficient connection strength under the action of high aerodynamic load, resulting in the risk of failure.
The design method of CMC turbine-steered blade body-edge plate connection simulation component that comprehensively considers the blade manufacturing process, geometric characteristics and load consistency is adopted. By establishing a full-size macro-geometric model, finite element heat transfer and strength simulation, feature simulation component design and Experiment, obtain the load-bearing capacity and failure mode of the connection structure, and optimize the blade connection form.
The full-size test is simplified, cost and efficiency is reduced, the blade stress characteristics are reflected in the hazardous cross-sectional stress, avoiding the diversity and high cost problems in traditional methods, and the blade connection strength and failure mode can be studied.
Smart Images
Figure CN118194637B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aircraft engine turbine blades, and in particular relates to a design and experimental method of a characteristic simulation part of a CMC guide blade blade body-edge plate connection area. Background Art
[0002] Ceramic matrix composites (CMC) are an important candidate material for the hot end components of high-performance aircraft engines due to their high temperature resistance, corrosion resistance, low density, and excellent mechanical properties. Applying CMC to turbine guide vanes and turbine rotor blades can maximize the advantages of CMC's high temperature resistance, thereby significantly improving the performance of the engine.
[0003] Turbine guide blades are subjected to the impact of high-temperature airflow during service and are the components that are most severely subjected to thermal loads in aircraft engines. At the same time, with the continuous improvement of the thrust-to-weight ratio of the new generation of engines, the aerodynamic load on the surface of the blade body is also increasing. Therefore, there is a risk of failure at the blade-edge plate connection. It is an important part of aircraft engine development to obtain the strength reliability of turbine guide blades by conducting simulated aerodynamic load tests in high-temperature environments.
[0004] At present, the blade-edge plate connection can be roughly divided into two types: assembly type and integrated type. The assembly type connection is typically pinned, and the integrated type connection means that the blade and the edge plate are folded from the same piece of fiber cloth. It can be seen that the assembly type connection has the disadvantage of fiber discontinuity, while the integrated type connection has the defect that the blade-edge plate connection is prone to defects caused by fiber cloth flanging or yarn addition. Therefore, the connection area between the blade and the edge plate has connection strength problems under high aerodynamic loads, which is prone to failure risks and is a failure risk area for CMC turbine guide vanes.
[0005] Therefore, it is necessary to carry out the design and verification of the blade-edge plate connection simulation parts that comprehensively consider the process, geometry, and load consistency with the complete blade to support the design of CMC turbine guide vanes. Summary of the invention
[0006] The technical problem to be solved by the present invention is that the connection strength of the blade body-edge plate connection of the CMC turbine guide blade is insufficient under high aerodynamic loads. A design method for a CMC turbine guide blade blade body-edge plate connection simulation part that comprehensively considers the blade manufacturing process, geometric characteristics, and load consistency is provided, and a design and experimental method for a CMC guide blade blade body-edge plate connection area characteristic simulation part is proposed to obtain the load-bearing capacity and failure mode type of the connection structure.
[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:
[0008] The design and experimental method of the characteristic simulation part of the CMC guide blade blade-edge plate connection area include the following steps:
[0009] Step 1: Establish a full-scale real structure macro-geometry model of the CMC turbine guide blade;
[0010] Step 2: Assign anisotropic thermal / mechanical performance parameters to the macro-geometric model, conduct finite element heat transfer and strength simulation of the CMC turbine guide blades under specified working conditions, and obtain the stress distribution and potential failure mode of the macro-geometric model;
[0011] Step 3: Based on finite element heat transfer and strength simulation, the high stress area in the macro-geometric model, i.e., the blade-edge plate connection area, is selected as the research object;
[0012] Step 4: Keep the main features of the research object unchanged, simplify and remove the secondary features, and obtain the characteristic simulation part of the blade body-edge plate connection area of the CMC turbine guide blade;
[0013] Step 5: Assign anisotropic thermal / mechanical performance parameters to the characteristic simulation part, select an assessment area for the characteristic simulation part in the finite element software, and apply concentrated force load to the assessment area to simulate the stress distribution and failure behavior of the characteristic simulation part in a high temperature environment;
[0014] Step 6: Adjust the load size and angle direction applied to the characteristic simulation part so that the test temperature, stress distribution and failure mode of the loading condition of the test area of the characteristic simulation part under the concentrated force load are the same or similar to the test temperature, stress distribution and failure mode of the corresponding area of the full-size macro model, and then determine the conversion relationship between the loading mode of the characteristic simulation part and the loading mode of the full-size macro model. Under this conversion relationship, the stress distribution of the characteristic simulation part is consistent with the stress distribution of the dangerous area of the full-size macro model under the service condition.
[0015] Step 7: Conduct static strength tests on characteristic simulation parts in high temperature environments to obtain failure behaviors of characteristic simulation parts under concentrated force loads.
[0016] Step 8: Convert the loading mode of the characteristic simulation part into the loading mode of the full-size macro model through the conversion relationship, and obtain the failure behavior of the blade-edge plate connection area of the full-size macro model under the action of concentrated force load.
[0017] To optimize the technical solution, the present invention is further improved as follows:
[0018] In step 1, the full-scale real structure macro-geometry model of the CMC turbine guide vane includes the blade profile, upper and lower edge plates, and cooling structure features.
[0019] In step 2, the anisotropic thermal / mechanical performance parameters of the macro-geometric model include thermal conductivity, thermal expansion coefficient, material density, elastic modulus and Poisson's ratio.
[0020] In step 2, the specified working condition is the actual service condition of the CMC turbine guide blade. Under the service condition, the CMC turbine guide blade is subjected to the combined effects of thermal load and aerodynamic load.
[0021] In step 4, the main features of the research object include blade shape features and blade body-lower edge plate connection features, and the secondary features include upper edge plate and cooling structure.
[0022] The cooling structure comprises air film holes and trailing edge slits of the CMC turbine guide blades.
[0023] The anisotropic thermal / mechanical parameters in step five are exactly the same as those in step two.
[0024] In step five, the concentrated force load is applied perpendicularly to the area where the surface of the CMC turbine guide blade body contacts the front end of the static strength test electric cylinder actuator, and the area is approximately circular in shape.
[0025] In step six, the load applied to the characteristic simulation part is adjusted to be within the load range that the static strength test electric cylinder can provide.
[0026] In step eight, the macroscopic full-size turbine guide blade connection form is optimized based on the failure behavior of the blade-edge plate connection area of the full-size macroscopic model under the action of concentrated force load. The optimization of the macroscopic full-size turbine guide blade connection form includes adjusting the ceramic matrix composite material weaving scheme, changing the fiber volume fraction and porosity.
[0027] The beneficial effects of the present invention are as follows: compared with the traditional CMC turbine blade strength analysis method, the present invention avoids the disadvantage of too high cost of full-scale specimen testing, and also avoids the inefficiency of multiple examples and multiple models caused by the diversity of blade-edge plate connection processes. The present invention simplifies the full-scale model characteristics based on the stress distribution characteristics of the full-scale CMC turbine guide blades under service conditions, and the characteristic simulation parts of the blade-edge plate connection area of the designed CMC turbine guide blade can reflect the stress characteristics of the full-scale blade in the dangerous section, is not limited by the blade-edge plate connection process, and has a simple structure, and the cost of manufacturing, processing and testing is low. Therefore, a certain number of static strength tests of blade simulation parts can be carried out to study the connection strength and failure mode type of the blade-edge plate connection part of the CMC turbine guide blade. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1It is a schematic diagram of the design and experimental method flow of the characteristic simulation parts of the blade body-edge plate connection area of the CMC guide blade;
[0029] Figure 2 It is the front view of the geometric model of the feature simulation part at different angles;
[0030] Figure 3 It is a top view of the geometric model of the feature simulation part;
[0031] Figure 4 It is a schematic diagram when the feature simulation retains the secondary features;
[0032] Figure 5 It is a schematic diagram of the feature simulation after simplification and removal of minor features;
[0033] Figure 6 It is a line graph of stress magnitude of a full-size CMC turbine guide blade and a characteristic simulation along the same path;
[0034] Figure 7 It is a schematic diagram of the test loading of characteristic simulation parts. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.
[0036] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.
[0037] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.
[0038] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or units (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" / "several" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.
[0039] like Figure 1 As shown, the present invention discloses a CMC guide blade blade body-edge plate connection area characteristic simulation part design and experimental method, comprising the following steps:
[0040] Step 1: Create a full-size real model of the CMC turbine guide blade in the 3D modeling software. Take a certain type of 2D plain-ply CMC turbine guide blade as an example. The blade body and the edge plate are connected by a pin plate, and the preform fiber is discontinuous in this connection area. Its cooling structure is that the leading edge of the blade body, the blade basin, and the back of the blade are densely distributed with air film holes, and a non-continuous slit is set at the trailing edge of the blade, and a spoiler column structure is provided. The lower edge plate is provided with bolt holes for connecting with other components;
[0041] Step 2: Import the drawn full-size model into the finite element software, and assign it the macroscopic anisotropic thermal / mechanical performance parameters of the two-dimensional plain weave scheme, including thermal conductivity, thermal expansion coefficient, density, elastic modulus and Poisson's ratio, and define the unit main direction of the model according to its weaving method and the yarn direction; carry out flow heat transfer calculation in the fluid analysis software according to the boundary conditions under the service condition of this type of blade, and obtain the temperature distribution and pressure distribution of the CMC turbine guide blade under the service condition, and export the calculation results and assign them to the blade surface as the boundary condition input to obtain the stress distribution of the CMC turbine guide blade;
[0042] Step 3: The high stress area of this type of blade is located at the connection between the blade body and the lower edge plate. The stress in this area is mainly tensile load on the blade basin side and mainly compressive load on the back side. The load reaches the maximum value at the leading edge. Therefore, the connection area between the blade body and the lower edge plate is selected as the research object;
[0043] Step 4: Based on the characteristics of the research object selected in step 3, simplify and modify the full-size model of the blade obtained in step 1. The upper edge plate is not the focus of the research, so it can be removed by trimming the body. The cooling structure of the blade does not affect the stress distribution in the assessment area, so it can be ignored in the characteristic simulation part. Therefore, the air film holes on the surface of the blade body can be removed by deleting the surface in the modeling software, and the cooling structure of the trailing edge can also be deleted. Based on the existing blade shape, a curve connection is carried out at the trailing edge, and then the connection between the blade basin and the blade back is realized at the trailing edge. In this way, the characteristic simulation parts are preliminarily obtained, such as Figure 4 As shown;
[0044] Step 5: Import the designed feature simulation parts into the finite element software, assign them macro equivalent anisotropic thermal / mechanical performance parameters according to step 2, and define their unit main directions; according to the temperature distribution of the blade body-edge plate connection of the full-size blade obtained in step 3, set the corresponding simulation temperature in the finite element software to ensure the consistency of temperature distribution. Select a quasi-circular area on the blade basin side that is consistent with the shape of the front end of the actuator, apply a concentrated force load perpendicular to the surface to the area, obtain the stress distribution level of the blade body-edge plate connection area, and compare it with the stress level of the dangerous area of the full-size blade model.
[0045] By optimizing the load size and load angle, the stress distribution in the connection area of the characteristic simulation part in the warp direction is finally obtained to be similar to that of the full-size part.
[0046] Step 6: Adjust the load size and angle direction applied to the characteristic simulation part so that the test temperature, stress distribution and failure mode of the loading condition of the test area of the characteristic simulation part under concentrated force load are similar to those of the corresponding area of the full-size macro model, and then determine the loading condition of the simulation part. Under this loading method, the stress distribution of the characteristic simulation part is consistent with the stress distribution of the dangerous area of the full-size macro model under service conditions.
[0047] Step 7: According to the loading position determined in step 5, design a static strength test of the CMC turbine guide vane simulation. The test method is similar to the Chinese patent CN113640140A "Ceramic Matrix Composite Turbine Guide Vane High Temperature Biaxial Strength Tester and Method", both of which use electric cylinder loading, but the CMC turbine guide vane simulation designed in the present invention does not contain an upper edge plate, so it is only necessary to carry out uniaxial loading on the blade basin side or biaxial loading on both sides of the blade basin and blade back for the simulation, and the loading position and loading angle must be consistent with the loading area and angle finally obtained in step 5. The entire test process can be heated to the specified temperature by a quartz lamp or other heating device. The electric cylinder loading process needs to be carried out slowly, and DIC is used during the loading process or DVC is used for the test piece after the test to collect the deformation of the test piece.
[0048] Step 8: Based on the failure mode obtained from the simulation, optimize the macro full-size turbine guide vane connection form.
[0049] The optimization of the macro full-size turbine guide blade connection form includes but is not limited to the adjustment of the ceramic matrix composite weaving scheme, the change of the fiber volume fraction and the porosity, etc. Through the above adjustments, the optimal macro full-size turbine guide blade connection form is obtained under the predetermined blade weight, volume and other boundary conditions.
[0050] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.
Claims
1. Design and experimental method of characteristic simulation parts of CMC guide blade blade-edge plate connection area, characterized in that: The following steps are involved: Step 1: Establish a full-scale real structure macro-geometry model of the CMC turbine guide blade; Step 2: Assign anisotropic thermal / mechanical performance parameters to the macro-geometric model, conduct finite element heat transfer and strength simulation of the CMC turbine guide blades under specified working conditions, and obtain the stress distribution and potential failure mode of the macro-geometric model; Step 3: Based on finite element heat transfer and strength simulation, the high stress area in the macro-geometric model, i.e., the blade-edge plate connection area, is selected as the research object; Step 4: Keep the main features of the research object unchanged, simplify and remove the secondary features, and obtain the characteristic simulation part of the blade body-edge plate connection area of the CMC turbine guide blade; Step 5: Assign anisotropic thermal / mechanical performance parameters to the characteristic simulation part, select an assessment area for the characteristic simulation part in the finite element software, and apply concentrated force load to the assessment area to simulate the stress distribution and failure behavior of the characteristic simulation part in a high temperature environment; Step 6: Adjust the load size and angle direction applied to the characteristic simulation part so that the test temperature, stress distribution and failure mode of the loading condition of the test area of the characteristic simulation part under the concentrated force load are the same or similar to the test temperature, stress distribution and failure mode of the corresponding area of the full-size macro model, and then determine the conversion relationship between the loading mode of the characteristic simulation part and the loading mode of the full-size macro model. Under this conversion relationship, the stress distribution of the characteristic simulation part is consistent with the stress distribution of the dangerous area of the full-size macro model under the service condition. Step 7: Conduct static strength tests on characteristic simulation parts in high temperature environments to obtain failure behaviors of characteristic simulation parts under concentrated force loads. Step 8: Convert the loading mode of the characteristic simulation part into the loading mode of the full-size macro model through the conversion relationship, and obtain the failure behavior of the blade-edge plate connection area of the full-size macro model under the concentrated force load; In step 2, the specified working condition is the actual service working condition of the CMC turbine guide blade, under which the CMC turbine guide blade is subjected to the combined action of thermal load and aerodynamic load; In step 4, the main characteristics of the research object include blade shape characteristics and blade body-lower edge plate connection characteristics, and the secondary characteristics include upper edge plate and cooling structure; The anisotropic thermal / mechanical parameters in step five are exactly the same as those in step two.
2. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: In step 1, the full-scale real structure macro-geometry model of the CMC turbine guide vane includes the blade profile, upper and lower edge plates, and cooling structure features.
3. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: In step 2, the anisotropic thermal / mechanical performance parameters of the macro-geometric model include thermal conductivity, thermal expansion coefficient, material density, elastic modulus and Poisson's ratio.
4. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: The cooling structure comprises air film holes and trailing edge slits of the CMC turbine guide blades.
5. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: In step five, the concentrated force load is applied perpendicularly to the area where the surface of the CMC turbine guide blade body contacts the front end of the static strength test electric cylinder actuator, and the area is approximately circular in shape.
6. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: In step six, the load applied to the characteristic simulation part is adjusted to be within the load range that the static strength test electric cylinder can provide.
7. The CMC guide blade blade-edge plate connection area characteristic simulation component design and experimental method according to claim 1, characterized in that: In step eight, the macroscopic full-size turbine guide blade connection form is optimized based on the failure behavior of the blade-edge plate connection area of the full-size macroscopic model under the action of concentrated force load. The optimization of the macroscopic full-size turbine guide blade connection form includes adjusting the ceramic matrix composite material weaving scheme, changing the fiber volume fraction and porosity.