A method for testing and simulating contact stress at the interface of a bladed disk structure

Abstract

This invention discloses a method for testing and simulating the contact stress at the interface of an impeller structure. The method mainly includes measuring the contact pressure at the interface of a rotating, full-circumference impeller structure and simulating the contact pressure at the interface of a static, single-sector impeller structure. The measurement of the contact pressure at the interface of a rotating, full-circumference impeller structure includes a rotating test bench, a full-circumference impeller test piece, and a thin-film sensor. The simulation of the contact pressure at the interface of a static, single-sector impeller structure mainly includes an electric cylinder drive system, a single-sector impeller test piece, a drive system support frame, and a thin-film sensor. This method is primarily used to simulate the contact pressure distribution characteristics at the interface of a rotating, full-circumference impeller structure under static conditions. This invention achieves real-time measurement of the contact pressure distribution at the interface of an impeller structure under both static and rotating conditions, providing a testing technique for the design and optimization of engine impeller structures.

Description

Technical Field

[0001] This invention relates to the field of mechanical measurement technology for engine bladed disk structures, specifically to a method for testing and simulating contact stress at the connection interface of a bladed disk structure. Background Technology

[0002] Engine bladed disk structures (such as those in aero engines and gas turbines) typically contain numerous connection interfaces (e.g., tenons / mortises, ribs / dampers, shoulders / shoulders, and blade crowns / crowns). The contact characteristics of these interfaces significantly influence the overall dynamic characteristics of the engine, severely limiting performance improvements. Measuring the contact stress distribution at the connection interfaces of rotating bladed disks under real-world operating conditions makes it possible to perform high-precision simulations of rotating bladed disk tests using static single-sector bladed disk experiments. Furthermore, static tests are generally less costly and yield more accurate results. Therefore, it is necessary to measure the contact stress at the connection interfaces of bladed disk structures under both static and rotating conditions.

[0003] The connection interfaces of bladed disk structures typically have complex geometries, and the bladed disk system is constantly vibrating during high-speed rotation. This makes measuring the contact pressure at the connection interfaces, especially the contact pressure distribution at the connection interfaces of rotating bladed disk structures, particularly difficult. Currently, there are few mechanical measurement methods for bladed disk structures that can accurately measure the contact stress distribution at the connection interfaces, and even fewer methods for measuring the contact stress distribution at the connection interfaces under rotating conditions. Therefore, most existing methods cannot meet the requirements for measuring the contact stress at the connection interfaces of bladed disk structures.

[0004] In summary, there is an urgent need for a method to measure the contact stress at the interface of the engine bladed disk structure that meets the above requirements and can be used to measure the contact stress at the interface of the rotating engine bladed disk structure. Summary of the Invention

[0005] The purpose of this invention is to provide a method for testing and simulating the contact stress at the interface of a bladed disk structure connection, in order to solve the problem that existing methods cannot accurately measure the contact stress at the interface of a bladed disk structure connection, and to meet the needs of measuring the contact stress at the interface of a rotating engine bladed disk structure connection.

[0006] To achieve the above objectives, the present invention provides a method for testing and simulating the contact stress at the connection interface of a bladed disk structure, the specific steps of which are as follows:

[0007] S1. When installing the blades onto the wheel disk, simultaneously install the thin-film sensor onto the connection interface. Then, fix the blade disk structure after completing the full circumference installation, and sequentially connect the power and signal lines of the thin-film sensor, encoder, and slip ring.

[0008] S2, start the rotating test bench, gradually increase the speed of the bladed disk structure to the target speed required for measurement, and at the same time use the encoder to obtain the real-time speed of the bladed disk and the thin film sensor to obtain the contact pressure distribution of the bladed disk structure connection interface at the corresponding speed.

[0009] S3, two, one and two elastic ropes are symmetrically fixed on both sides of the blade root, front and back and top of the blade, respectively, to provide loads in three translational and three rotational directions of the blade.

[0010] S4, the other ends of the above eight elastic ropes are respectively fixed to eight high-precision electric cylinders in order to provide the required tension for the ropes;

[0011] S5, the tension of each elastic rope is adjusted sequentially by electric cylinder, and the displacement and tension of the electric cylinder are recorded in real time. At the same time, the real-time pressure distribution of the thin film sensor is obtained through the data processing system.

[0012] S6. The deviation between the static and rotating pressure distributions at the connection interface obtained by the thin-film sensor is calculated using the least squares method. Then, the displacements of each electric cylinder are further adjusted according to the deviation to finally obtain a static pressure distribution with the required deviation. At this point, the static pressure distribution at the connection interface measured by the thin-film sensor can be approximately considered to be the same as that in the rotating state.

[0013] Preferably, in step S1, the thin-film sensors should be installed circumferentially to ensure the overall dynamic balance of the impeller structure during high-speed rotation, and priority should be given to ensuring the number of thin-film sensor channels connected for measurement.

[0014] Preferably, in step S2, since the high-speed rotating impeller is in a state of constant vibration, the number of cycles and the sampling frequency should be ensured to obtain the most stable contact pressure fluctuation distribution curve possible.

[0015] Preferably, in step S5, the top electric cylinder should be driven to stretch the elastic rope, and then the four elastic ropes on the side should be driven one by one in the direction of blade torsion, so as to reduce the matching time required for the electric cylinder to obtain the comprehensive motion.

[0016] Preferably, in step S6, the contact pressure distribution obtained by the thin-film sensor is the pressure at many points, so the least squares method deals with the deviation of the contact pressure distribution under rotating and static conditions.

[0017] Compared with the prior art, the technical solution proposed in this application has the following beneficial effects: it can obtain the contact pressure distribution at the connection interface of the bladed disk structure at different speeds, which is something that most existing bladed disk measurement methods cannot achieve. Obtaining this distribution can provide experimental data support for the design and optimization of engine bladed disk structure, which is of great significance.

[0018] This invention enables the approximation of rotating full-cycle bladed disk operating conditions using static single-sector bladed disk conditions. Existing static single-sector bladed disk tests mostly only involve bottom clamping or top tensile loading, failing to simulate the combined tensile and torsional motion of a real bladed disk, resulting in significant discrepancies with actual conditions and unreliable test results. Based on real rotating contact pressure data, this invention utilizes eight elastic ropes to highly replicate the contact state of the rotating bladed disk structure's connection interfaces, thus possessing greater engineering practical value.

[0019] By using a thin-film sensor to measure the pressure distribution at the interface, as many pressure distribution points at the interface as possible can be obtained, and the non-uniform pressure distribution characteristics at the interface can be captured.

[0020] The blades' translational and rotational degrees of freedom are controlled by a composite of eight elastic ropes, which theoretically can reproduce the contact state of the blade disk connection interface under any working condition. Attached Figure Description

[0021] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figure 1 This is a schematic diagram of a method for testing and simulating contact stress at the interface of a bladed disk structure.

[0023] Figure 2 Schematic diagram of the test bench for rotating bladed disk structure;

[0024] Figure 3 This is a schematic diagram of the bladed disk structure;

[0025] Figure 4 A schematic diagram of the thin-film sensor installation;

[0026] Figure 5 This is a schematic diagram of a static simulation bladed disk test bench;

[0027] Figure 6 Schematic diagram of static analog driver layout; Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described and discussed below with reference to the accompanying drawings. Obviously, what is described here is only a part of the examples of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0029] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] This invention provides a method for testing and simulating the contact stress at the connection interface of a bladed disk structure, the specific steps of which are as follows:

[0032] S1. When installing the blades onto the wheel disk, simultaneously install the thin-film sensor onto the connection interface. Then, fix the blade disk structure after completing the full circumference installation, and sequentially connect the power and signal lines of the thin-film sensor, encoder, and slip ring.

[0033] S2, start the rotating test bench, gradually increase the speed of the bladed disk structure to the target speed required for measurement, and at the same time use the encoder to obtain the real-time speed of the bladed disk and the thin film sensor to obtain the contact pressure distribution of the bladed disk structure connection interface at the corresponding speed.

[0034] S3, two, one and two elastic ropes are symmetrically fixed on both sides of the blade root, front and back and top of the blade, respectively, to provide loads in three translational and three rotational directions of the blade.

[0035] S4, the other ends of the above eight elastic ropes are respectively fixed to eight high-precision electric cylinders in order to provide the required tension for the ropes;

[0036] S5, the tension of each elastic rope is adjusted sequentially by electric cylinder, and the displacement and tension of the electric cylinder are recorded in real time. At the same time, the real-time pressure distribution of the thin film sensor is obtained through the data processing system.

[0037] S6. The deviation between the static and rotating pressure distributions at the connection interface obtained by the thin-film sensor is calculated using the least squares method. Then, the displacements of each electric cylinder are further adjusted according to the deviation to finally obtain a static pressure distribution with the required deviation. At this point, the static pressure distribution at the connection interface measured by the thin-film sensor can be approximately considered to be the same as that in the rotating state.

[0038] In step S1, the thin-film sensors should be installed uniformly around the circumference to ensure the overall dynamic balance of the impeller structure during high-speed rotation, and priority should be given to ensuring the number of channels connected to the thin-film sensors used for measurement.

[0039] In step S2, since the high-speed rotating impeller is in a state of constant vibration, the number of cycles and the sampling frequency should be ensured in order to obtain the most stable contact pressure fluctuation distribution curve possible.

[0040] In step S5, the top electric cylinder should be driven to stretch the elastic rope, and then the four elastic ropes on the side should be driven one by one in the direction of blade torsion, so as to reduce the matching time required for the electric cylinder to obtain the overall motion.

[0041] In step S6, the contact pressure distribution obtained by the thin-film sensor is the pressure at many points, so the least squares method deals with the deviation of the contact pressure distribution under rotating and static conditions.

[0042] For details, see Figures 1 to 6 A method for testing and simulating contact stress at the interface of a bladed disk structure includes measuring the contact pressure at the interface of a rotating, full-circumference bladed disk structure and simulating the contact pressure at the interface of a static, single-sector bladed disk structure. The measuring of the contact pressure at the interface of the rotating, full-circumference bladed disk structure includes a rotating test bench, installation of the full-circumference bladed disk structure, installation of a thin-film sensor at the interface, and measurement of the contact pressure distribution at the rotating bladed disk interface. The thin-film sensor is uniformly installed at the interface between the blade and the disk to record the contact pressure distribution at the interface of the rotating bladed disk structure in real time. The simulation of the contact pressure at the interface of the static, single-sector bladed disk structure mainly includes the installation of the static, single-sector bladed disk structure, the layout and installation of multiple electric cylinder drive systems, and the simulation of the contact pressure at the interface of the rotating bladed disk structure.

[0043] Thin-film sensors are uniformly installed circumferentially between the connection interfaces of the rotating full-circumference bladed disk structure to acquire the contact pressure distribution of the connection interfaces under the corresponding bladed disk rotation speed in real time. The thin-film sensors are installed between all connection interfaces of the measured sector, and the uniformity of adhesion and the integrity of the contact interface coverage should be ensured during installation to guarantee the accuracy and comprehensiveness of the measurement results.

[0044] In the static single-sector bladed disk structure connection interface contact pressure simulation, after the electric cylinder moves and generates a load applied to the blade, the contact pressure distribution of the bladed disk structure connection interface will change accordingly. Therefore, it is necessary to calculate the deviation between the connection interface contact pressure and the rotational state at a certain moment in the static test, and further adjust the electric cylinder stroke accordingly. Finally, the connection interface contact pressure distribution error corresponding to the static test converges to a reasonable range.

[0045] When the thin-film sensor is installed at the connection interface of the rotating full-circumference bladed disk structure, priority should be given to installing the thin-film sensor at all corresponding connection interfaces of the bladed disk to ensure the balance of the bladed disk during high-speed rotation. Since the connection channels of the slip ring are limited, when actually connecting the signal lines, the signals of the thin-film sensor should be acquired at uniform intervals, and then the average value of the pressure distribution of multiple sensors should be taken. When installing the thin-film sensor, the consistency of the installation position and calibration orientation of the circumferential connection interface of the rotating bladed disk and the connection interface of the static single-sector bladed disk should be ensured as much as possible to ensure the one-to-one correspondence of the signal point positions.

[0046] In the static single-sector bladed disk structure connection interface contact pressure simulation, when calculating the deviation between the static test connection interface pressure distribution and the rotating state pressure distribution, the sum of squares of the pressure deviations at corresponding locations can be used as an evaluation index. The allowable final convergence deviation range needs to be selected according to specific requirements.

[0047] Pressure measurement sensors and their installation locations and quantities, actuators that apply force during static simulation and their layout, the shape of the measured component, and the geometry of the connection interface all exhibit various deformable structures.

[0048] The aforementioned circumferential bladed disk structure installation (e.g.) Figure 3The process involves mounting the full-circumference blade 601 onto the impeller 602. The thin-film sensor installation refers to mounting the thin-film sensors 603 and 604 between the tenon interfaces 605 and 606 and the mortise interfaces 607 and 608 corresponding to the blade 601 and impeller 602, respectively, forming a one-to-one correspondence. The acquisition of the contact pressure distribution at the connection interface refers to mounting the impeller structure 6 onto a rotating test bench. The rotating test bench mainly includes a base 8, an electrical control cabinet 1, a coupling 2, a rotating shaft 4, bearing seats 3 and 5, the impeller structure 6, and a slip ring 7. In actual operation, the electrical control cabinet 1 drives the rotating shaft 4 to rotate on the bearing seats 3 and 5 via the coupling 2, thereby driving the impeller structure 6 to rotate. The slip ring 7 mainly provides a test channel for the thin-film sensors 603 and 604 mounted on the impeller structure 6. The thin-film sensors 603 and 604 rotate on the impeller structure... The contact pressure distribution at the blade disk structure connection interfaces 607 and 608 is measured in real time during rotation. The static single-sector blade disk structure connection interface contact pressure simulation includes steps such as static single-sector blade disk structure installation, thin-film sensor installation, and elastic rope drive. The static single-sector blade disk structure installation refers to installing the blade 16 on the single-sector disk base 11. The thin-film sensor installation is similar to the thin-film sensor installation for measuring the contact pressure at the connection interface of the rotating full-circumference blade disk structure. The elastic rope drive refers to using high-precision linear electric cylinders 131, 141, 151, 171, 181, 191, 201, and 211 corresponding to the elastic rope system 11-15 and 17-21 to drive the elastic rope to generate tension, thereby applying the load to the blade 16. The elastic rope system includes a high-precision linear electric cylinder XX1, a force sensor XX2, and an elastic rope XX3 (e.g., Figure 6 The elastic ropes are installed on the support frame 12. The specific number and layout of the ropes need to be determined according to the shape of the blades and the connection form of the blade disk (whether it includes the connecting interface such as the blade crown and shoulder).

[0049] When using the testing and simulation methods of this application, firstly, the contact pressure measurement method of the rotating full-circumference bladed disk structure connection interface is used to obtain the pressure distribution at the connection interface at different rotational speeds using a thin-film sensor. Then, in the static single-sector bladed disk structure connection interface contact pressure simulation process, each electric cylinder system is driven separately, and the contact pressure distribution at the static connection interface is obtained simultaneously using a thin-film sensor. Subsequently, the sum of squares of the contact pressure deviations at each measuring point of the thin-film sensor under rotating and static conditions is calculated. Then, the pressure distribution at the interface under static conditions is fine-tuned by each electric cylinder drive system until the pressure distribution error obtained under static and rotating conditions meets the experimental requirements. At this point, the contact pressure measured at the static single-sector bladed disk structure connection interface can be approximately considered as the contact pressure at the rotating bladed disk structure connection interface under actual working conditions. When using the contact pressure measurement method of this application, the appropriate bladed disk rotation speed and thin-film sensor arrangement in the rotating full-circumference bladed disk structure connection interface contact pressure measurement should be selected according to the needs. In addition, the number and layout of the electric cylinder drive system in the static single-sector bladed disk structure connection interface contact pressure simulation should also be selected, mainly depending on the shape of the blades and whether they include blade crowns, shoulders, and other bladed disk connection interfaces.

[0050] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, nor to combinations thereof. Those skilled in the art can make various changes, modifications, or combinations within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for testing and simulating contact stress at the interface of a bladed disk structure, characterized in that, The specific steps are as follows: S1. When installing the blades onto the wheel disk, simultaneously install the thin-film sensor onto the connection interface. Then, fix the blade disk structure after completing the full circumference installation, and sequentially connect the power and signal lines of the thin-film sensor, encoder, and slip ring. S2, start the rotating test bench, gradually increase the speed of the bladed disk structure to the target speed required for measurement, and at the same time use the encoder to obtain the real-time speed of the bladed disk and the thin film sensor to obtain the contact pressure distribution of the bladed disk structure connection interface at the corresponding speed. S3, two, one and two elastic ropes are symmetrically fixed on both sides of the blade root, front and back and top of the blade, respectively, to provide loads in three translational and three rotational directions of the blade. S4, the other ends of the above eight elastic ropes are respectively fixed to eight high-precision electric cylinders in order to provide the required tension for the ropes; S5, the tension of each elastic rope is adjusted sequentially by the electric cylinder, and the displacement and tension of the electric cylinder are recorded in real time. At the same time, the real-time pressure distribution of the thin film sensor is obtained through the data processing system. S6. The deviation between the static and rotating pressure distributions at the connection interface obtained by the thin-film sensor is calculated using the least squares method. Then, the displacements of each electric cylinder are further adjusted according to the deviation to finally obtain a static pressure distribution with the required deviation. At this point, the static pressure distribution at the connection interface measured by the thin-film sensor can be approximately considered to be the same as that in the rotating state.

2. The method for testing and simulating contact stress at the connection interface of a bladed disk structure according to claim 1, characterized in that, In step S1, the thin-film sensors should be installed uniformly around the circumference to ensure the dynamic balance of the entire bladed disk structure during high-speed rotation, and priority should be given to ensuring the number of channels connected to the thin-film sensors used for measurement.

3. The method for testing and simulating contact stress at the connection interface of a bladed disk structure according to claim 1, characterized in that, In step S2, since the high-speed rotating impeller is in a state of constant vibration, the number of cycles and the sampling frequency should be ensured in order to obtain the most stable contact pressure fluctuation distribution curve possible.

4. The method for testing and simulating contact stress at the connection interface of a bladed disk structure according to claim 1, characterized in that, In step S5, the top electric cylinder should be driven to stretch the elastic rope, and then the four elastic ropes on the side should be driven one by one in the direction of blade torsion, so as to reduce the matching time required for the electric cylinder to obtain the comprehensive motion.

5. The method for testing and simulating contact stress at the connection interface of a bladed disk structure according to claim 1, characterized in that, In step S6, the contact pressure distribution obtained by the thin-film sensor is the pressure at many points, so the least squares method deals with the deviation of the contact pressure distribution under rotating and static conditions.

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