Multi-angle high-temperature high-low cycle fatigue test device and method for blade front edge simulation piece

Abstract

The invention discloses a multi-angle high-temperature high-low cycle fatigue test device and method for a front edge simulation piece of a blade. A fatigue testing machine and a vibration fatigue loading device in the device are located on the same horizontal plane; the upper end, the lower end and the side face of the simulation piece clamp are in sliding connection with the upper portion and the lower portion of the fatigue testing machine and the vibration fatigue loading device through the vibration and stretching decoupling mechanism, and the simulation piece centering adjusting assembly is arranged on the vibration and stretching decoupling mechanism. The method comprises the following steps: installing a blade front edge simulation piece on a simulation piece clamp; a simulation piece centering adjusting assembly is installed on the vibration and stretching decoupling mechanism; inputting a test index into the control system, and carrying out a high-temperature high-low cycle fatigue test on the blade front edge simulation piece until the number of vibration cycles is completed; and adjusting the test angle of the blade front edge simulation piece, and repeating the operation. According to the invention, composite loading of low-frequency high-stress low-cycle load along the spanwise direction of the blade and high-frequency low-stress high-cycle vibration load vertical to the blade is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of material and structure fatigue testing, and in particular relates to a high-temperature and high- and low-cycle fatigue testing device and method for a blade leading edge simulation component at multiple angles. Background Art

[0002] With the rapid development of modern national defense industry, science and technology, machine manufacturing and instrument manufacturing, the requirements for machine parts and their structures are becoming higher and higher, such as safety, volume and weight, etc., especially in aviation gas turbine engines, such requirements are more prominent. The damage to engines and blades in service is mostly due to the dynamic load, which causes fatigue cracks in parts and then continues to expand. At the same time, due to the high service temperature of the engine, the blades suffer fatigue fracture prematurely, which in turn endangers flight safety.

[0003] In actual operation, aircraft engine blades are mainly subjected to loads in two directions. One is the low-frequency and high-stress low-cycle load along the blade span direction generated when the blade rotates at high speed, and the other is the high-frequency and low-stress high-cycle vibration load perpendicular to the blade caused by the uneven and unstable flow field in the environment. Studies have shown that the fatigue failure of engine blades is mostly caused by high- and low-cycle composite fatigue failure caused by superimposing high-cycle loads on the peak value of low-cycle loads. In high- and low-cycle composite fatigue, low-cycle loads play a leading role in the initiation of material cracks due to their high stress level, and are also the main cause of steady-state crack expansion. High-cycle loads have a small stress amplitude but a high frequency. The superposition of low-cycle loads with high-cycle loads will significantly accelerate the expansion rate of material cracks, thereby reducing the fatigue life of the blades. Therefore, in the process of studying the life of various aircraft engine blades, it is particularly necessary to consider the role of blades under high- and low-cycle composite fatigue loads in order to reflect the damage process of blades in actual service loads and more accurately predict the life of blades.

[0004] One of the effective ways to prevent blade fatigue failure is to improve the fatigue resistance of components. Improving the fatigue performance of materials and designing fatigue-resistant structures are the main aspects of improving the fatigue resistance of components. This requires a large amount of fatigue test data of materials and structures. Therefore, it is urgent to develop a high-temperature, high- and low-cycle fatigue test device and method for blade leading edge simulation parts at multiple angles. The fatigue testing machine is combined with a vibration table to provide high- and low-cycle composite fatigue strength for the blades. On this basis, the life of the blades is tested to provide safe and reliable working guarantees for aircraft engines.

[0005] The existing blade high and low cycle composite fatigue testing machines are aimed at the blade root area where the stress is relatively large. However, due to the different vibration forms, stress may also be generated at the leading edge of the blade. Moreover, most of these testing machines adopt forced vibration. Due to the gap between the top rod and the sample, the energy transfer rate is not high, and it is difficult to damage the sample. The frequency of forced vibration is also difficult to meet the requirements. In addition, after these testing machines fix the sample, the angle of the sample cannot be adjusted, and the test results are not comprehensive.

[0006] The invention patent with application publication number CN112082886A discloses a small high-low cycle composite fatigue in-situ testing machine that provides orthogonal loading. The low-frequency drive unit of the testing machine uses the inverse piezoelectric effect of the piezoelectric drive group to generate an axial drive load, which is amplified by the load transfer mechanism and then transferred to the test piece to provide it with an axial low-frequency tensile and compressive fatigue load; the high-frequency drive unit relies on the dielectric elastomer to generate high-frequency vibrations to provide the test piece with a vertical high-frequency vibration fatigue load; the force sensor monitors the axial force of the test piece, and the displacement sensor monitors the vibration frequency and vertical displacement. This technical solution is not suitable for high-low cycle composite fatigue loading of blade leading edge feature simulation parts, and the vibration mode is forced vibration. Due to contact problems, efficient energy transfer and high-frequency load application are difficult. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a high-temperature and high-low cycle fatigue test device for a blade leading edge simulation piece at a multi-angle, including a fatigue testing machine, a vibration fatigue loading device, a heating device, a simulation piece fixture, a vibration and tensile decoupling mechanism, and a simulation piece centering adjustment component. The fatigue testing machine and the vibration fatigue loading device are placed on the same horizontal plane, and the upper and lower ends and sides of the simulation piece fixture are slidingly connected to the upper and lower sides of the fatigue testing machine and the vibration fatigue loading device through the vibration and tensile decoupling mechanism, respectively. The simulation piece centering adjustment component is arranged on the vibration and tensile decoupling mechanism, and the heating device is fixed on the fatigue testing machine and surrounded by the outer side of the blade leading edge simulation piece.

[0008] Preferably, the fatigue testing machine includes a fixed base, a fixed top plate, a support column, a force transmission shaft and a concave force transmission arm, the fatigue testing machine is placed perpendicular to a horizontal plane, and the fixed base is fixed on the horizontal plane; four support columns are vertically arranged between the fixed base and the fixed top plate, the force transmission shaft and the concave force transmission arm are vertically arranged in sequence above the fixed base, and the force transmission shaft and the concave force transmission arm are vertically arranged in sequence below the fixed top plate, and the upper and lower concave force transmission arms are arranged opposite to each other.

[0009] In any of the above schemes, it is preferred that the vibration fatigue loading device includes a fixed platform, an arc-shaped bracket, a vibration table, and a vibration connector, the fixed platform is fixed on a horizontal plane, the arc-shaped bracket is arranged on the fixed platform, the vibration table is horizontally placed on the arc-shaped bracket, and the table top of the vibration table faces one side of the fatigue testing machine, the vibration connector is vertically arranged at the center of the table top of the vibration table, and the ribs on both sides and the bottom of the vibration connector are fixedly connected to the table top of the vibration table by bolts.

[0010] In any of the above schemes, it is preferred that the heating device includes a heating tube, a fixing rod, and a heating coil, the heating tube is composed of two semi-cylinders, the side of the heating tube is fixed to the support column by the two fixing rods, and the heating coil is arranged in the gap between the inner and outer walls of the heating tube.

[0011] In any of the above schemes, it is preferred that the simulation part fixture includes a Y-shaped fixture seat, an angle rotating part, an angle fixing part, and a tightening nut, and the middle part of the simulation part fixture clamps the blade leading edge simulation part; the Y-shaped fixture seat is composed of a horizontal plate, an inclined plate and a square block, a first boss is arranged on the outside of one end of the angle rotating part, and a first internal thread is arranged on the inside of the other end, an external thread is arranged on the outside of the angle fixing part, and a second boss is arranged on one end of the tightening nut, and a second internal thread is arranged on the other end.

[0012] The clamping section of the blade leading edge simulation component is installed at one end of the angle rotating component where the first internal thread is set, and the clamping section cooperates with the first internal thread; the second internal thread inside the tightening nut cooperates with the external thread outside the angle fixing component, and the second boss inside the tightening nut is clamped with the first boss outside the angle rotating component.

[0013] In any of the above schemes, it is preferred that a plurality of cross-distributed trapezoidal grooves and trapezoidal bosses are circumferentially arranged on the first boss of the angle rotating member, and a plurality of cross-distributed trapezoidal grooves and trapezoidal bosses are circumferentially arranged on the end face of the angle fixing member; the trapezoidal groove on the first boss of the angle rotating member cooperates with the trapezoidal boss on the end face of the angle fixing member, and the trapezoidal boss on the first boss of the angle rotating member cooperates with the trapezoidal groove on the end face of the angle fixing member.

[0014] In any of the above schemes, it is preferred that the trapezoidal groove and the trapezoidal boss have the same shape and size, that is, the angle formed by the two inclined surfaces of the trapezoidal groove is 15°, the depth of the trapezoidal groove is 5mm, and the height of the trapezoidal groove is 3.5-4.5 times its depth; the angle formed by the two inclined surfaces of the trapezoidal boss is 15°, the thickness of the trapezoidal boss is 5mm, and the height of the trapezoidal boss is 3.5-4.5 times its thickness.

[0015] In any of the above schemes, it is preferred that the vibration and stretching decoupling mechanism includes a vertical stretching guide rail, two vertical stretching sliders, four transverse vibration guide rails, and four transverse vibration sliders; one of the vertical stretching guide rails is fixed to the vibration connector by bolts, and the two vertical stretching sliders are respectively arranged at both ends of the vertical stretching guide rail, and slide vertically on the vertical stretching guide rail; the four transverse vibration guide rails are respectively fixed to the open ends of the concave force transmission arms by bolts, and the four transverse vibration sliders are respectively arranged on the four transverse vibration guide rails, and slide horizontally on the transverse vibration guide rails.

[0016] The two vertical stretching sliders are connected to the corresponding square blocks of the Y-shaped clamp seat through bolts, and the four horizontal vibration sliders are connected to the corresponding horizontal plates of the Y-shaped clamp seat through bolts.

[0017] In any of the above schemes, it is preferred that the simulation part centering adjustment component includes a vertical limit rod, a transverse limit rod, a limit block, and a fixing buckle; the limit blocks are respectively arranged at both ends of one of the vertical stretching guide rails, the vertical limit rods are respectively arranged between the two vertical stretching sliders and the corresponding limit blocks, and the two ends of the vertical limit rods are respectively fixed by the fixing buckles; the limit blocks are respectively arranged at both ends of the four transverse vibration guide rails, the transverse limit rods are respectively arranged between the four transverse vibration sliders and the corresponding limit blocks, and the two ends of the transverse limit rods are respectively fixed by the fixing buckles.

[0018] The present invention also provides a method for testing a blade leading edge simulation piece at multiple angles at high temperature and at low cycle fatigue. Using any of the above-mentioned devices for testing a blade leading edge simulation piece at multiple angles at high temperature and at low cycle fatigue, the method comprises the following steps in order:

[0019] Step 1: Assemble the fatigue testing machine, vibration fatigue loading device, simulation fixture, vibration and tensile decoupling mechanism together according to the design requirements to form a high-temperature and high-low cycle fatigue test device for the leading edge simulation of the blade at multiple angles, and debug the test device to ensure that it can be used normally during the test;

[0020] Step 2: Install the blade leading edge simulation part on the simulation part fixture according to the design requirements. First, loosen the tightening nut from the external thread on the outside of the angle fixing part, and remove the angle rotating part; secondly, install the clamping sections at both ends of the blade leading edge simulation part on one end of the first internal thread of the angle rotating part, so that the clamping section and the first internal thread cooperate with each other, and tighten and fix; then combine one end of the first boss of the angle rotating part at both ends of the blade leading edge simulation part with its corresponding angle fixing part, so that the trapezoidal groove and the trapezoidal boss on the first boss of the angle rotating part cooperate with the trapezoidal boss and the trapezoidal groove on the end face of the angle fixing part, and ensure that the plane where the test section of the blade leading edge simulation part is located is parallel to the table surface of the vibration table. At this time, the angle of the blade leading edge simulation part is 0 degrees; finally, clamp the second boss inside the tightening nut with the first boss outside the angle rotating part, and at the same time, match the second internal thread inside the tightening nut with the external thread outside the angle fixing part, and tighten and fix;

[0021] Step 3: Install the simulation component centering adjustment component on the vibration and tension decoupling mechanism according to the design requirements. First, install a vertical limit rod between the two vertical tension sliders and their corresponding limit blocks, and fix them with a fixing buckle; then install a transverse limit rod between the two transverse vibration sliders located above the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle; finally, install a transverse limit rod between the two transverse vibration sliders located below the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle. At this time, the blade leading edge simulation component is in a centered state in both the vertical and horizontal directions;

[0022] Step 4: According to the design requirements, surround the heating cylinder of the heating device on the outside of the blade leading edge simulation part, then open all the fixing buckles on the vibration and tension decoupling mechanism, and remove all the vertical limit rods and transverse limit rods;

[0023] Step 5: Input the required indicators in the control system according to the design requirements, including heating temperature, tensile load, vibration loading frequency, vibration loading output, and vibration cycle number; start the control system and enter the high-temperature and high-low cycle fatigue test process of the blade leading edge simulation parts at multiple angles until the vibration cycle number is completed; during the entire test process, the vertical tensile guide rail and the vertical tensile slider provide vertical vertical degrees of freedom and transmit the tensile load applied by the fatigue testing machine, and the lateral vibration guide rail and the lateral vibration slider provide horizontal lateral degrees of freedom and transmit the vibration load applied by the vibration table, and the two cooperate to achieve the decoupling of the vibration load and the tensile load;

[0024] Step six: During the high-temperature and high-and low-cycle fatigue tests of the blade leading edge simulation at multiple angles, after completing the number of vibration cycles, if the blade leading edge simulation is broken, it is necessary to replace it with a new blade leading edge simulation and repeat steps two to five to test the newly installed blade leading edge simulation. In step two, adjust the matching angles between the trapezoidal grooves and trapezoidal bosses of the angle rotating part and the trapezoidal bosses and trapezoidal grooves of the angle fixing part as needed to ensure that the plane where the test section of the blade leading edge simulation is located forms a certain angle with the surface of the vibration table. At this time, this angle is the adjustment angle of the blade leading edge simulation.

[0025] If the blade leading edge simulation is not broken, there is no need to replace it with a new one. Repeat steps 2 to 5 to continue testing with the unbroken blade leading edge simulation. In step 2, adjust the matching angles between the trapezoidal grooves and trapezoidal bosses of the angle rotating part and the trapezoidal bosses and trapezoidal grooves of the angle fixing part as needed to ensure that the plane where the test section of the blade leading edge simulation is located forms a certain angle with the surface of the vibration table. At this time, this angle is the adjustment angle of the blade leading edge simulation.

[0026] In the present invention, the vibration table adopts Sushi DC-600-6 electric vibration test system, which can provide a frequency of 5-5000Hz, a rated sinusoidal thrust of 5.88KN, and a maximum load of 200Kg. The fatigue test machine adopts the Siddens fatigue test machine, which can provide a maximum dynamic and static test force of ±50KN, a maximum system displacement of not less than ±75mm, and a frequency of 0.1-30Hz. The fatigue test machine is equipped with a high-temperature heating furnace. During the test, the high-temperature heating furnace can be directly used, or the heating device of the present invention can be used.

[0027] The fatigue testing machine provides a low-frequency, high-stress, low-cycle load along the span direction of the blade in the simulation test system. The Y-shaped fixture seat is connected to the lateral vibration guide rail through a lateral vibration slider. The lateral vibration guide rail is fixedly connected to the concave force transmission arm of the fatigue testing machine. The concave force transmission arm is further connected to the force transmission shaft. The load applied by the fatigue testing machine is transmitted to the blade leading edge simulation part through the force transmission shaft and the concave force transmission arm.

[0028] The vibration table provides a high-frequency, low-stress, high-cycle vibration load perpendicular to the blade in the simulation test system. The Y-shaped fixture seat is connected to the vertical stretching guide rail through a vertical stretching slider. The vertical stretching guide rail is connected to the vibration table through a vibration connector. The vibration table generates a high-frequency, low-stress, high-cycle vibration load perpendicular to the blade, and is transmitted to the blade leading edge simulation part by the vibration connector.

[0029] The blade leading edge simulation part is in the shape of a strip, with the middle part being the test section and the two ends being the clamping sections. The test section is in the shape of a dumbbell with a small longitudinal cross-section, and the clamping section is in the shape of a cylinder. An external thread is arranged on the clamping section, and the two side surfaces of the test section are respectively connected to the two side surfaces of the clamping section by a set of arc surface transitions.

[0030] The high-temperature and low-cycle fatigue test device and method for the blade leading edge simulation part at multiple angles of the present invention have the following beneficial effects:

[0031] (1) The present invention solves the problem of applying different directions and different stress loads in a high-temperature, high-low-cycle composite fatigue test system based on a vibration table and a fatigue testing machine for a blade leading edge feature simulation part; the fatigue testing machine and the vibration table are used to achieve the low-frequency, high-stress, low-cycle load along the blade span and the high-frequency, low-stress, high-cycle vibration load perpendicular to the blade required during the test.

[0032] (2) The present invention adjusts the test angle of the blade leading edge simulation part by designing trapezoidal grooves and trapezoidal bosses on the angle rotating part and the angle fixing part; at the same time, a simulation part centering adjustment component is set on the vibration and tension decoupling mechanism to ensure that the blade leading edge simulation part is in a centered state in the horizontal and vertical directions before the test starts.

[0033] (3) The vibration and tension decoupling mechanism of the present invention prevents the two force-applying elements from interfering with each other. That is, when the blade leading edge simulation part is subjected to horizontal vibration loading, the horizontal vibration loading behavior cannot affect the force-applying element (fatigue testing machine) of vertical tension loading. When the blade leading edge simulation part is subjected to vertical tension loading, the vertical tension loading behavior cannot affect the force-applying element (vibration table) of horizontal vibration loading.

[0034] (4) The present invention simulates the lateral load and longitudinal load encountered by the leading edge of the blade during service by means of a vibration table and a fatigue testing machine. On this basis, the life of the blade can be tested, thus providing safe and reliable working guarantee for the aircraft engine.

[0035] (5) The present invention is mainly aimed at the simulation parts of the leading edge characteristics of the blade. However, by replacing different simulation parts, the structural characteristics of different parts of the blade can be simulated. It has high universality and can be widely used in high-temperature and high- and low-cycle fatigue loading tests and fatigue performance evaluation of engineering materials and structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of a preferred embodiment of a high-temperature high-low cycle fatigue test device for a blade leading edge simulation member at multiple angles according to the present invention;

[0037] Figure 2 for Figure 1Another schematic diagram of the overall structure of the test device in the embodiment shown (the heating device is not shown);

[0038] Figure 3 for Figure 1 A schematic structural diagram of a fatigue testing machine in the illustrated embodiment;

[0039] Figure 4 for Figure 1 A schematic structural diagram of a vibration fatigue loading device in the illustrated embodiment;

[0040] Figure 5 for Figure 1 A schematic structural diagram of a heating device in the illustrated embodiment;

[0041] Figure 6 for Figure 1 A schematic diagram of the structure of the simulation fixture in the illustrated embodiment;

[0042] Figure 7 for Figure 1 A schematic structural diagram of a Y-shaped fixture seat in a simulation fixture of the illustrated embodiment;

[0043] Figure 8 for Figure 1 A schematic diagram of the structure of an angle rotating member in a simulation member fixture of the illustrated embodiment;

[0044] Fig. 9 for Figure 1 A schematic diagram of the structure of an angle fixing member in a simulation member fixture of the illustrated embodiment;

[0045] Fig.10 for Figure 1 A schematic diagram of the structure of tightening a nut in a simulation fixture of the illustrated embodiment;

[0046] Fig.11 for Figure 1 A schematic structural diagram of the vibration and stretching decoupling mechanism in the illustrated embodiment;

[0047] Fig.12 for Figure 1 A front view of the vibration and tension decoupling mechanism in the illustrated embodiment;

[0048] Fig.13 for Figure 1 A schematic structural diagram of a simulation component centering adjustment assembly (arranged on a vertical stretching guide rail) in the illustrated embodiment;

[0049] Fig.14 for Figure 1 A schematic diagram of the structure of the simulation component centering adjustment assembly (arranged on the transverse stretching guide rail) in the illustrated embodiment;

[0050] Fig.15 for Figure 1A schematic diagram of the structure of a blade leading edge simulation component in the illustrated embodiment.

[0051] Notes in the figure:

[0052] 1- fatigue testing machine, 101- fixed base, 102- fixed top plate, 103- support column, 104- force transmission shaft, 105- concave force transmission arm;

[0053] 2-vibration fatigue loading device, 201-fixed platform, 202-arc bracket, 203-vibration table, 204-vibration connector;

[0054] 3-heating device, 301-heating cylinder, 302-fixing rod;

[0055] 4-simulation fixture, 401-Y-shaped fixture seat, 402-angle rotating member, 403-angle fixing member, 404-tightening nut, 405-horizontal plate, 406-inclined plate, 407-square block, 408-first boss, 409-first internal thread, 410-external thread, 411-second boss, 412-second internal thread, 413-trapezoidal groove, 414-trapezoidal boss;

[0056] 5- vibration and stretching decoupling mechanism, 501- vertical stretching guide rail, 502- vertical stretching slider, 503- transverse vibration guide rail, 504- transverse vibration slider;

[0057] 6-simulation part centering adjustment assembly, 601-vertical limit rod, 602-lateral limit rod, 603-limit block, 604-fixing buckle; 7-blade leading edge simulation part, 701-test section, 702-clamping section, 703-arc surface. DETAILED DESCRIPTION

[0058] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0059] like Figure 1-2 As shown, according to a preferred embodiment of the multi-angle high-temperature and high-low cycle fatigue test device of the blade leading edge simulation part of the present invention, it includes a fatigue testing machine 1, a vibration fatigue loading device 2, a heating device 3, a simulation part fixture 4, a vibration and tensile decoupling mechanism 5, and a simulation part centering adjustment component 6. The fatigue testing machine 1 and the vibration fatigue loading device 2 are placed on the same horizontal plane, and the upper and lower ends and the side surfaces of the simulation part fixture 4 are slidingly connected to the upper and lower sides of the fatigue testing machine 1 and the vibration fatigue loading device 2 through the vibration and tensile decoupling mechanism 5, respectively. The simulation part centering adjustment component 6 is arranged on the vibration and tensile decoupling mechanism 5, and the heating device 3 is fixed on the fatigue testing machine 1 and surrounded by the outer side of the blade leading edge simulation part 7.

[0060] like Figure 3 As shown, the fatigue testing machine 1 includes a fixed base 101, a fixed top plate 102, a support column 103, a force transmission shaft 104 and a concave force transmission arm 105. The fatigue testing machine 1 is placed perpendicular to a horizontal plane, and the fixed base 101 is fixed on the horizontal plane; four support columns 103 are vertically arranged between the fixed base 101 and the fixed top plate 102, the force transmission shaft 104 and the concave force transmission arm 105 are vertically arranged in sequence above the fixed base 101, and the force transmission shaft 104 and the concave force transmission arm 105 are vertically arranged in sequence below the fixed top plate 102, and the upper and lower concave force transmission arms 105 are arranged opposite to each other.

[0061] like Figure 4 As shown, the vibration fatigue loading device 2 includes a fixed platform 201, an arc bracket 202, a vibration table 203, and a vibration connector 204. The fixed platform 201 is fixed on a horizontal plane, the arc bracket 202 is arranged on the fixed platform 201, the vibration table 203 is horizontally placed on the arc bracket 202, and the table top of the vibration table 203 faces one side of the fatigue testing machine 1, and the vibration connector 204 is vertically arranged at the center of the table top of the vibration table 203. The ribs on both sides and the bottom of the vibration connector 204 are fixedly connected to the table top of the vibration table 203 by bolts.

[0062] like Figure 5 As shown, the heating device 3 includes a heating tube 301, a fixing rod 302, and a heating coil. The heating tube 301 is composed of two semi-cylinders. The side of the heating tube 301 is fixed to the support column 103 through the two fixing rods 302. The heating coil is set in the gap between the inner and outer walls of the heating tube 301.

[0063] like Figure 6-10 As shown, the simulation component fixture 4 includes a Y-shaped fixture seat 401, an angle rotating component 402, an angle fixing component 403, and a tightening nut 404. The middle part of the simulation component fixture 4 clamps the blade leading edge simulation component 7; the Y-shaped fixture seat 401 is composed of a horizontal plate 405, an inclined plate 406 and a square block 407. The first boss 408 is arranged on the outside of one end of the angle rotating component 402, and the first internal thread 409 is arranged on the inside of the other end. The external thread 410 is arranged on the outside of the angle fixing component 403. The second boss 411 is arranged on one end of the tightening nut 404, and the second internal thread 412 is arranged on the other end.

[0064] The clamping section of the blade leading edge simulation part 7 is installed at one end of the angle rotating part 402 where the first internal thread 409 is set, and the clamping section cooperates with the first internal thread 409; the second internal thread 412 inside the tightening nut 404 cooperates with the external thread 410 outside the angle fixing part 403, and the second boss 411 inside the tightening nut 404 is clamped with the first boss 408 outside the angle rotating part 402.

[0065] A plurality of cross-distributed trapezoidal grooves 413 and trapezoidal bosses 414 are circumferentially arranged on the first boss 408 of the angle rotating member 402, and a plurality of cross-distributed trapezoidal grooves 413 and trapezoidal bosses 414 are circumferentially arranged on the end face of the angle fixing member 403; the trapezoidal grooves 413 on the first boss 408 of the angle rotating member 402 cooperate with the trapezoidal bosses 414 on the end face of the angle fixing member 403, and the trapezoidal bosses 414 on the first boss 408 of the angle rotating member 402 cooperate with the trapezoidal grooves 413 on the end face of the angle fixing member 403.

[0066] The trapezoidal groove and the trapezoidal boss have the same shape and size, that is, the angle formed by the two inclined surfaces of the trapezoidal groove is 15°, the depth of the trapezoidal groove is 5mm, and the height of the trapezoidal groove is 3.5-4.5 times its depth; the angle formed by the two inclined surfaces of the trapezoidal boss is 15°, the thickness of the trapezoidal boss is 5mm, and the height of the trapezoidal boss is 3.5-4.5 times its thickness.

[0067] like Figure 11-12 As shown, the vibration and stretching decoupling mechanism 5 includes a vertical stretching guide rail 501, two vertical stretching sliders 502, four transverse vibration guide rails 503, and four transverse vibration sliders 504; one of the vertical stretching guide rails 501 is fixed to the vibration connector 204 by bolts, and the two vertical stretching sliders 502 are respectively arranged at both ends of the vertical stretching guide rail 501, and slide vertically on the vertical stretching guide rail 501; the four transverse vibration guide rails 503 are respectively fixed to the open ends of the concave force transmission arms 105 by bolts, and the four transverse vibration sliders 504 are respectively arranged on the four transverse vibration guide rails 503, and slide horizontally on the transverse vibration guide rails 503.

[0068] The two vertical stretching sliders 502 are connected to the corresponding square blocks 407 of the Y-shaped clamp seat 401 through bolts, and the four horizontal vibration sliders 504 are connected to the corresponding horizontal plates 405 of the Y-shaped clamp seat 401 through bolts.

[0069] like Figure 13-14As shown, the simulation part centering adjustment component 6 includes a vertical limit rod 601, a transverse limit rod 602, a limit block 603, and a fixing buckle 604; the limit blocks 603 are respectively arranged at both ends of one of the vertical stretching guide rails 501, the vertical limit rods 601 are respectively arranged between the two vertical stretching sliders 502 and their corresponding limit blocks 603, and the two ends of the vertical limit rod 601 are respectively fixed by the fixing buckles 604; the limit blocks 603 are respectively arranged at both ends of the four transverse vibration guide rails 503, the transverse limit rods 602 are respectively arranged between the four transverse vibration sliders 504 and their corresponding limit blocks 603, and the two ends of the transverse limit rod 602 are respectively fixed by the fixing buckles 604.

[0070] like Fig.15 As shown, the blade leading edge simulation part 7 is in the shape of a strip, the middle part of which is a test section 701, and the two ends are clamping sections 702. The test section 701 is in the shape of a dumbbell with a smaller longitudinal cross-section, and the clamping section 702 is in the shape of a cylinder. The clamping section 702 is provided with an external thread, and the two side surfaces of the test section 701 are respectively transitionally connected with the two side surfaces of the clamping section 702 by a group of arc surfaces 703.

[0071] This embodiment also provides a method for testing high-temperature and low-cycle fatigue of a blade leading edge simulation piece at multiple angles. Using the above-mentioned high-temperature and low-cycle fatigue testing device for a blade leading edge simulation piece at multiple angles, the method includes the following steps in order:

[0072] Step 1: Assemble the fatigue testing machine, vibration fatigue loading device, simulation fixture, vibration and tensile decoupling mechanism together according to the design requirements to form a high-temperature and high-low cycle fatigue test device for the leading edge simulation of the blade at multiple angles, and debug the test device to ensure that it can be used normally during the test;

[0073] Step 2: Install the blade leading edge simulation part on the simulation part fixture according to the design requirements. First, loosen the tightening nut from the external thread on the outside of the angle fixing part, and remove the angle rotating part; secondly, install the clamping sections at both ends of the blade leading edge simulation part on one end of the first internal thread of the angle rotating part, so that the clamping section and the first internal thread cooperate with each other, and tighten and fix; then combine one end of the first boss of the angle rotating part at both ends of the blade leading edge simulation part with its corresponding angle fixing part, so that the trapezoidal groove and the trapezoidal boss on the first boss of the angle rotating part cooperate with the trapezoidal boss and the trapezoidal groove on the end face of the angle fixing part, and ensure that the plane where the test section of the blade leading edge simulation part is located is parallel to the table surface of the vibration table. At this time, the angle of the blade leading edge simulation part is 0 degrees; finally, clamp the second boss inside the tightening nut with the first boss outside the angle rotating part, and at the same time, match the second internal thread inside the tightening nut with the external thread outside the angle fixing part, and tighten and fix;

[0074] Step 3: Install the simulation component centering adjustment component on the vibration and tension decoupling mechanism according to the design requirements. First, install a vertical limit rod between the two vertical tension sliders and their corresponding limit blocks, and fix them with a fixing buckle; then install a transverse limit rod between the two transverse vibration sliders located above the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle; finally, install a transverse limit rod between the two transverse vibration sliders located below the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle. At this time, the blade leading edge simulation component is in a centered state in both the vertical and horizontal directions;

[0075] Step 4: According to the design requirements, surround the heating cylinder of the heating device on the outside of the blade leading edge simulation part, then open all the fixing buckles on the vibration and tension decoupling mechanism, and remove all the vertical limit rods and transverse limit rods;

[0076] Step 5: Input the required indicators in the control system according to the design requirements, including heating temperature, tensile load, vibration loading frequency, vibration loading output, and vibration cycle number; start the control system and enter the high-temperature and high-low cycle fatigue test process of the blade leading edge simulation parts at multiple angles until the vibration cycle number is completed; during the entire test process, the vertical tensile guide rail and the vertical tensile slider provide vertical vertical degrees of freedom and transmit the tensile load applied by the fatigue testing machine, and the lateral vibration guide rail and the lateral vibration slider provide horizontal lateral degrees of freedom and transmit the vibration load applied by the vibration table, and the two cooperate to achieve the decoupling of the vibration load and the tensile load;

[0077] Step six: During the high-temperature and high-and low-cycle fatigue tests of the blade leading edge simulation at multiple angles, after completing the number of vibration cycles, if the blade leading edge simulation is broken, it is necessary to replace it with a new blade leading edge simulation and repeat steps two to five to test the newly installed blade leading edge simulation. In step two, adjust the matching angles between the trapezoidal grooves and trapezoidal bosses of the angle rotating part and the trapezoidal bosses and trapezoidal grooves of the angle fixing part as needed to ensure that the plane where the test section of the blade leading edge simulation is located forms a certain angle with the surface of the vibration table. At this time, this angle is the adjustment angle of the blade leading edge simulation.

[0078] If the blade leading edge simulation is not broken, there is no need to replace it with a new one. Repeat steps 2 to 5 to continue testing with the unbroken blade leading edge simulation. In step 2, adjust the matching angles between the trapezoidal grooves and trapezoidal bosses of the angle rotating part and the trapezoidal bosses and trapezoidal grooves of the angle fixing part as needed to ensure that the plane where the test section of the blade leading edge simulation is located forms a certain angle with the surface of the vibration table. At this time, this angle is the adjustment angle of the blade leading edge simulation.

[0079] In this embodiment, the vibration table adopts Sushi DC-600-6 electric vibration test system, which can provide a frequency of 5-5000Hz, a rated sinusoidal thrust of 5.88KN, and a maximum load of 200Kg. The fatigue test machine adopts the Siddens fatigue test machine, which can provide a maximum dynamic and static test force of ±50KN, a maximum system displacement of not less than ±75mm, and a frequency of 0.1-30Hz. The fatigue test machine is equipped with a high-temperature heating furnace. During the test, the high-temperature heating furnace can be directly used, or the heating device of this embodiment can be used.

[0080] The fatigue testing machine provides a low-frequency, high-stress, low-cycle load along the span direction of the blade in the simulation test system. The Y-shaped fixture seat is connected to the lateral vibration guide rail through a lateral vibration slider. The lateral vibration guide rail is fixedly connected to the concave force transmission arm of the fatigue testing machine. The concave force transmission arm is further connected to the force transmission shaft. The load applied by the fatigue testing machine is transmitted to the blade leading edge simulation part through the force transmission shaft and the concave force transmission arm.

[0081] The vibration table provides a high-frequency, low-stress, high-cycle vibration load perpendicular to the blade in the simulation test system. The Y-shaped fixture seat is connected to the vertical stretching guide rail through a vertical stretching slider. The vertical stretching guide rail is connected to the vibration table through a vibration connector. The vibration table generates a high-frequency, low-stress, high-cycle vibration load perpendicular to the blade, and is transmitted to the blade leading edge simulation part by the vibration connector.

[0082] The high-temperature, high-low-cycle fatigue test device and method for the blade leading edge simulation of the present embodiment have the following beneficial effects: (1) It solves the problem of applying different directions and different stress loads in the high-temperature, high-low-cycle composite fatigue test system based on the vibration table and the fatigue test machine, and realizes the low-frequency, high-stress, low-cycle load along the blade span and the high-frequency, low-stress, high-cycle vibration load perpendicular to the blade required during the test by using the fatigue test machine and the vibration table. (2) The test angle of the blade leading edge simulation is adjusted by designing a trapezoidal groove and a trapezoidal boss on the angle rotating member and the angle fixing member; at the same time, by setting a simulation member centering adjustment component on the vibration and tension decoupling mechanism, it is ensured that the blade leading edge simulation is in the center state in both the horizontal and vertical directions before the test starts. (3) The vibration and tension decoupling mechanism prevents the two force-applying elements from interfering with each other, that is, when the blade leading edge simulation is subjected to horizontal vibration loading, the horizontal vibration loading behavior cannot affect the force-applying element (fatigue test machine) of the vertical tension loading, and when the blade leading edge simulation is subjected to vertical tension loading, the vertical tension loading behavior cannot affect the force-applying element (vibration table) of the horizontal vibration loading. (4) The vibration table and fatigue testing machine are used to simulate the lateral and longitudinal loads encountered by the leading edge of the blade during service. On this basis, the life of the blade can be tested, providing safe and reliable operation guarantee for aircraft engines.

[0083] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0084] It is not difficult for those skilled in the art to understand that the high-temperature and low-cycle fatigue test device and method for the multi-angle blade leading edge simulation of the present invention include any combination of the invention content and specific implementation methods of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles. Features: It includes a fatigue testing machine, a vibration fatigue loading device, a heating device, a simulation part fixture, a vibration and tensile decoupling mechanism, and a simulation part centering adjustment component. The fatigue testing machine and the vibration fatigue loading device are placed on the same horizontal plane. The upper and lower ends and the side surfaces of the simulation part fixture are slidably connected to the upper and lower parts of the fatigue testing machine and the vibration fatigue loading device respectively through the vibration and tensile decoupling mechanism. The simulation part centering adjustment component is arranged on the vibration and tensile decoupling mechanism. The heating device is fixed on the fatigue testing machine and surrounded by the outer side of the blade leading edge simulation part.

2. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 1, Features: The fatigue testing machine includes a fixed base, a fixed top plate, a support column, a force transmission shaft and a concave force transmission arm. The fatigue testing machine is placed perpendicular to a horizontal plane, and the fixed base is fixed on the horizontal plane. Four support columns are vertically arranged between the fixed base and the fixed top plate, the force transmission shaft and the concave force transmission arm are vertically arranged in sequence above the fixed base, and the force transmission shaft and the concave force transmission arm are vertically arranged in sequence below the fixed top plate, and the upper and lower concave force transmission arms are arranged opposite to each other.

3. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 2, Features: The vibration fatigue loading device includes a fixed platform, an arc-shaped bracket, a vibration table, and a vibration connector. The fixed platform is fixed on a horizontal plane, the arc-shaped bracket is arranged on the fixed platform, the vibration table is horizontally placed on the arc-shaped bracket, and the table top of the vibration table faces one side of the fatigue testing machine. The vibration connector is vertically arranged at the center of the table top of the vibration table, and the ribs on both sides and the bottom of the vibration connector are fixedly connected to the table top of the vibration table by bolts.

4. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 3, Features: The heating device comprises a heating cylinder, a fixing rod and a heating coil. The heating cylinder is composed of two semi-cylinders. The side of the heating cylinder is fixed to the supporting column by the two fixing rods. The heating coil is arranged in the gap between the inner and outer walls of the heating cylinder.

5. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 4, Features: The simulation fixture comprises a Y-shaped fixture seat, an angle rotating member, an angle fixing member, and a tightening nut, and the middle part of the simulation fixture clamps the blade leading edge simulation member; the Y-shaped fixture seat is composed of a horizontal plate, an inclined plate, and a square block, a first boss is arranged on the outside of one end of the angle rotating member, and a first internal thread is arranged on the inside of the other end, an external thread is arranged on the outside of the angle fixing member, and a second boss is arranged on one end of the tightening nut, and a second internal thread is arranged on the other end; The clamping section of the blade leading edge simulation component is installed at one end of the angle rotating component where the first internal thread is set, and the clamping section cooperates with the first internal thread; the second internal thread inside the tightening nut cooperates with the external thread outside the angle fixing component, and the second boss inside the tightening nut is clamped with the first boss outside the angle rotating component.

6. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 5, Features: A plurality of cross-distributed trapezoidal grooves and trapezoidal bosses are circumferentially arranged on the first boss of the angle rotating member, and a plurality of cross-distributed trapezoidal grooves and trapezoidal bosses are circumferentially arranged on the end face of the angle fixing member; the trapezoidal groove on the first boss of the angle rotating member cooperates with the trapezoidal boss on the end face of the angle fixing member, and the trapezoidal boss on the first boss of the angle rotating member cooperates with the trapezoidal groove on the end face of the angle fixing member.

7. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 6, Features: The trapezoidal groove and the trapezoidal boss have the same shape and size, that is, the angle formed by the two inclined surfaces of the trapezoidal groove is 15°, the depth of the trapezoidal groove is 5mm, and the height of the trapezoidal groove is 3.5-4.5 times its depth; the angle formed by the two inclined surfaces of the trapezoidal boss is 15°, the thickness of the trapezoidal boss is 5mm, and the height of the trapezoidal boss is 3.5-4.5 times its thickness.

8. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 7, Features: The vibration and stretching decoupling mechanism comprises a vertical stretching guide rail, two vertical stretching sliders, four transverse vibration guide rails, and four transverse vibration sliders; one vertical stretching guide rail is fixed to the vibration connector by bolts, and two vertical stretching sliders are respectively arranged at both ends of the vertical stretching guide rail and vertically slide on the vertical stretching guide rail; four transverse vibration guide rails are respectively fixed to the open ends of the concave force transmission arms by bolts, and four transverse vibration sliders are respectively arranged on the four transverse vibration guide rails and horizontally slide on the transverse vibration guide rails; The two vertical stretching sliders are connected to the corresponding square blocks of the Y-shaped clamp seat through bolts, and the four horizontal vibration sliders are connected to the corresponding horizontal plates of the Y-shaped clamp seat through bolts.

9. The high-temperature and low-cycle fatigue test device for blade leading edge simulation parts at multiple angles according to claim 8, Features: The simulation part centering adjustment component includes a vertical limit rod, a transverse limit rod, a limit block, and a fixing buckle; the limit blocks are respectively arranged at both ends of one vertical stretching guide rail, the vertical limit rod is respectively arranged between the two vertical stretching sliders and the corresponding limit blocks, and the two ends of the vertical limit rod are respectively fixed by the fixing buckles; the limit blocks are respectively arranged at both ends of the four transverse vibration guide rails, the transverse limit rod is respectively arranged between the four transverse vibration sliders and the corresponding limit blocks, and the two ends of the transverse limit rod are respectively fixed by the fixing buckles.

10. A high-temperature and low-cycle fatigue test method for blade leading edge simulation parts at multiple angles. Features: The high-temperature and low-cycle fatigue test device for the blade leading edge simulation member at multiple angles using any one of claims 1 to 9 comprises the following steps in chronological order: Step 1: Assemble the fatigue testing machine, vibration fatigue loading device, simulation fixture, vibration and tensile decoupling mechanism together according to the design requirements to form a high-temperature and high-low cycle fatigue test device for the leading edge simulation of the blade at multiple angles, and debug the test device to ensure that it can be used normally during the test; Step 2: Install the blade leading edge simulation part on the simulation part fixture according to the design requirements. First, loosen the tightening nut from the external thread on the outside of the angle fixing part, and remove the angle rotating part; secondly, install the clamping sections at both ends of the blade leading edge simulation part on one end of the first internal thread of the angle rotating part, so that the clamping section and the first internal thread cooperate with each other, and tighten and fix; then combine one end of the first boss of the angle rotating part at both ends of the blade leading edge simulation part with its corresponding angle fixing part, so that the trapezoidal groove and the trapezoidal boss on the first boss of the angle rotating part cooperate with the trapezoidal boss and the trapezoidal groove on the end face of the angle fixing part, and ensure that the plane where the test section of the blade leading edge simulation part is located is parallel to the table surface of the vibration table. At this time, the angle of the blade leading edge simulation part is 0 degrees; finally, clamp the second boss inside the tightening nut with the first boss outside the angle rotating part, and at the same time, match the second internal thread inside the tightening nut with the external thread outside the angle fixing part, and tighten and fix; Step 3: Install the simulation component centering adjustment component on the vibration and tension decoupling mechanism according to the design requirements. First, install a vertical limit rod between the two vertical tension sliders and their corresponding limit blocks, and fix them with a fixing buckle; then install a transverse limit rod between the two transverse vibration sliders located above the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle; finally, install a transverse limit rod between the two transverse vibration sliders located below the simulation component fixture and their corresponding limit blocks, and fix them with a fixing buckle. At this time, the blade leading edge simulation component is in a centered state in both the vertical and horizontal directions; Step 4: According to the design requirements, surround the heating cylinder of the heating device on the outside of the blade leading edge simulation part, then open all the fixing buckles on the vibration and tension decoupling mechanism, and remove all the vertical limit rods and transverse limit rods; Step 5: Input the required indicators in the control system according to the design requirements, including heating temperature, tensile load, vibration loading frequency, vibration loading output, and vibration cycle number; start the control system and enter the high-temperature and high-low cycle fatigue test process of the blade leading edge simulation parts at multiple angles until the vibration cycle number is completed; during the entire test process, the vertical tensile guide rail and the vertical tensile slider provide vertical vertical degrees of freedom and transmit the tensile load applied by the fatigue testing machine, and the lateral vibration guide rail and the lateral vibration slider provide horizontal lateral degrees of freedom and transmit the vibration load applied by the vibration table, and the two cooperate to achieve the decoupling of the vibration load and the tensile load; Step 6: During the high-temperature and high-and low-cycle fatigue tests of the blade leading edge simulation parts at multiple angles, after the number of vibration cycles is completed, if the blade leading edge simulation part is broken, it is necessary to replace the new blade leading edge simulation part, and repeat the operations of steps 2 to 5 to test the newly installed blade leading edge simulation part. In step 2, the matching angles between the trapezoidal grooves and the trapezoidal bosses of the angle rotating part and the trapezoidal bosses and the trapezoidal grooves of the angle fixing part are adjusted as needed to ensure that the plane where the test section of the blade leading edge simulation part is located forms a certain angle with the table surface of the vibration table. At this time, the angle is the adjustment angle of the blade leading edge simulation part; If the blade leading edge simulation is not broken, there is no need to replace it with a new one. Repeat steps 2 to 5 to continue testing with the unbroken blade leading edge simulation. In step 2, adjust the matching angles between the trapezoidal grooves and trapezoidal bosses of the angle rotating part and the trapezoidal bosses and trapezoidal grooves of the angle fixing part as needed to ensure that the plane where the test section of the blade leading edge simulation is located forms a certain angle with the surface of the vibration table. At this time, this angle is the adjustment angle of the blade leading edge simulation.

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