A rotor system safety design method under lateral impact-rubbing load excitation

Abstract

The present application belongs to the technical field of aero-engine rotor dynamics, and particularly relates to a rotor system safety design method under lateral impact-collision load excitation, comprising: judging whether collision occurs through deformation characteristic analysis of the rotor system under lateral impact, and if collision occurs, performing dynamic response analysis of the rotor system under lateral impact-collision load excitation, if collision does not occur, performing supporting dynamic load analysis during the lateral impact process, judging whether instability occurs and whether the supporting structure is damaged or destroyed, and then performing instability safety design of the rotor system under lateral impact-collision load excitation from three aspects of improving elastic supporting stiffness, designing supporting damping energy dissipation structure and increasing blade-casing clearance; performing supporting structure safety design from three aspects of designing supporting amplitude limiting structure, designing rotor collision amplitude limiting structure and designing supporting buffer damping structure. The present application solves the problems of rotor instability and supporting structure damage or destruction under lateral impact-collision load excitation.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine rotor dynamics technology, specifically relating to a safety design method for rotor systems under lateral impact-rubbing load excitation. Background Technology

[0002] When an aircraft lands or lands on a ship, due to the aircraft's own mass inertia, the main landing gear will be subjected to huge transient impact loads from the ground. The impact loads are transmitted from the main landing gear to the fuselage, causing modal vibrations of the fuselage and wing structures.

[0003] Currently, the heavy payload requirements of modern advanced heavy transport aircraft mean they face increasingly severe impact loads during landing. Simultaneously, the development and application of high-aspect-ratio aircraft and the demand for high structural efficiency in aircraft design are driving wing structures towards ultra-thin and ultra-large designs, resulting in decreasing wing stiffness. Therefore, unlike previous small and medium-sized transport aircraft, heavy transport aircraft often experience large-amplitude, low-frequency modal vibrations in their wing structures during landing due to lateral impact loads.

[0004] Engineering practice shows that under lateral impact loads, the aero-engine rotor system will also be subjected to lateral impact loads along with the vibration of the wing structure. This can lead to severe rubbing between the rotor and the casing structure, and induce rotor instability and damage or destruction of the support structure, seriously affecting the safe operation of the rotor system.

[0005] For extreme operating conditions of aero-engine rotor systems, relevant patents have proposed structural solutions to ensure the safety of the rotor-support system. For example, patent application CN116201637A proposes an aero-engine and its support structure with metal rubber for the extreme condition of blade loss in a high-bypass turbofan engine; patent application CN116357404A proposes a braking structure to prevent turbine overspeed after a low-pressure rotor shaft breakage in an aero-engine. However, none of the above patents have proposed a rotor system safety design solution for lateral impact-rubbing load excitation environments.

[0006] Therefore, there is an urgent need for a safety design method for rotor systems under transverse impact-rubbing load excitation environment. This method should be developed from the perspective of forward design of rotor structure dynamics to solve the safety problems of rotor instability and damage or destruction of support structure under transverse impact-rubbing load. Summary of the Invention

[0007] To address the safety issues of rotor instability and support structure damage or failure under lateral impact-rub load excitation in current aero-engine rotor systems, this invention provides a safety design method for rotor systems under lateral impact-rub load excitation.

[0008] This invention is achieved by providing a safety design method for a rotor system under lateral impact-rubbing load excitation, comprising the following steps: S1: Deformation characteristics analysis and rubbing judgment of rotor system under transverse impact load: Based on the deformation characteristics, determine whether the blades and casing in the rotor system will rub against each other. If rubbing will occur, proceed to step S2; if rubbing will not occur, proceed to step S3. S2: Dynamic response analysis and instability safety design of rotor system under transverse impact-rubbing load excitation: Based on the time-varying characteristics of the displacement response at the rotor system support, determine whether the rotor system will become unstable. If instability will occur, perform instability safety design of rotor system under transverse impact-rubbing load excitation. If instability will not occur, proceed to step S3. S3: Analysis of dynamic load on the support under transverse impact load of the rotor system and safety design of the support structure: Based on the characteristics of the change of the amplitude of the dynamic load on the support over time, determine whether the support structure will be damaged or destroyed. If damage or destruction will occur, conduct safety design of the support structure under transverse impact. If no damage or destruction will occur, complete the safety design of the rotor system under transverse impact-rubbing load excitation.

[0009] Preferably, step S1 specifically includes: S1.1: Deformation characteristics of the rotor system under lateral impact load: Establish an equivalent mechanical model of the rotor system, without considering the rubbing between the blades and the casing, apply a lateral impact load at the support structure as the basic excitation, simulate the load environment of the rotor system during landing or ship landing, and analyze the lateral displacement of the blade tips of the blades corresponding to each stage of the rotor disk. S1.2: Determine whether the rotor system will rub against each other: Based on the blade-casing clearance under the actual working state of the engine during landing or ship landing, determine whether the blade and casing will rub against each other by measuring the relative size of the lateral displacement of the blade tip of the blade corresponding to each stage of the rotor disk and the corresponding blade-casing clearance. If rubbing will occur, proceed to step S2; if rubbing will not occur, proceed to step S3.

[0010] Preferably, step S2 specifically includes: S2.1: Dynamic response analysis of rotor system under transverse impact-rubbing load excitation; Based on step S1, it is determined that the blades and casing will rub against each other. Considering the rubbing effect between the blades and casing, the displacement response at the rotor system support point changes with time. S2.2: Determine whether the rotor system will become unstable; after being subjected to lateral impact-rubbing load excitation, assume the period corresponding to the rotor system's rotation frequency is... T Based on the moment of impact t Starting from 0, in t 0 tot 0+20 T Extracting the peak displacement response of the rotor system within the time interval A 20 The peak value of the steady-state response before the collision occurs. A 0 is the baseline, when A 20 / A When 0 ≥ 1.2, the rotor system is considered to be unstable, and step S2.3 is performed; when A 20 / A When 0 < 1.2, it is assumed that the rotor system will not become unstable, and step S3 is performed; S2.3: Rotor system instability safety design under lateral impact-rubbing load excitation, including: ST1: Improve the stiffness of the elastic support; ST2: Design a support damping energy dissipation structure; ST3: Increase blade-casing clearance.

[0011] Further preferably, in step S2.3, when designing the rotor system's instability safety under lateral impact-rubbing load excitation, step ST1 is performed first: increasing the elastic support stiffness. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST2 is performed: designing the support damping energy dissipation structure. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST3 is performed: increasing... Blade-casing clearance; After the design is completed, repeat steps S1.1 and S1.2. In step S1.2, if it is determined that the blade and casing will not rub against each other, proceed to step S3. If it is determined that the blade and casing will rub against each other, repeat steps S2.1 and S2.2. In step S2.2, if it is determined that the rotor system will not become unstable, proceed to step S3. If it is determined that the rotor system will become unstable, repeat step S3: increase the blade-casing clearance; repeat steps S1.1, S1.2, S2.1 and S2.2 until it is determined that the rotor system will not become unstable or the blade and casing will not rub against each other, then proceed to step S3.

[0012] Preferably, step S3 specifically includes: S3.1: Analysis of dynamic load on the support during the transverse impact process; Based on step S1, determine that the blade and casing will not rub against each other, or based on step S2, determine that the rotor system will not become unstable under the excitation of transverse impact-rubbing load, and analyze the characteristics of the change of the amplitude of the support dynamic load over time. S3.2: Determine whether the support structure will be damaged or destroyed; if the maximum value of the dynamic load amplitude of the support is greater than or equal to the maximum safe load that the support structure can withstand, it is considered that the support structure will be damaged or destroyed, and proceed to step S3.3; if the maximum value of the dynamic load amplitude of the support is less than the maximum safe load that the support structure can withstand, it is considered that the support structure will not be damaged or destroyed, and the safety design of the rotor system under transverse impact-rubbing load excitation is completed. S3.3: Safety design of support structure under lateral impact, including: ST4: Design a support and limiting structure; ST5: Design of rotor rubbing and limiting structure; ST6: Design a support, buffer, and damping structure.

[0013] Further preferably, in step S3.3, when designing the safety of the support structure under lateral impact, step ST4 is performed first: designing the support limiting structure. After completing the design, steps S3.1 and S3.2 are repeated. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed; if it is determined that the support structure will be damaged or destroyed, step ST5 is performed: designing the rotor rubbing limiting structure. After completing the design, steps S3.1 and S3.2 are repeated. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed. If the structure will not be damaged or destroyed, the safety design of the rotor system under transverse impact-rubbing load excitation is completed. If it is determined that the support structure will be damaged or destroyed, proceed to step ST6: design the support buffer damping structure. After completing the design, repeat steps S3.1 and S3.2. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, the safety design of the rotor system under transverse impact-rubbing load excitation is completed. If it is determined that the support structure will be damaged or destroyed, repeat step ST6: design the support buffer damping structure until it is determined that the support structure will not be damaged or destroyed.

[0014] In a further preferred embodiment, in step S3.2, the maximum safe load that the supporting structure can withstand is the allowable dynamic load determined by strength calculation or test calibration based on the allowable stress of the supporting structure material, connection or contact boundary conditions, load transfer path and safety factor.

[0015] Compared with the prior art, the advantages of the present invention are as follows: This invention addresses the safety issues of aero-engine rotor systems under lateral impact-rubbing load excitation. It addresses rotor system instability safety design under lateral impact-rubbing load excitation by improving elastic support stiffness, designing support damping energy dissipation structures, and increasing blade-casing clearance. Furthermore, it addresses support structure safety design under lateral impact by designing support limiting structures, rotor rubbing limiting structures, and support buffer damping structures. This invention solves the problems of rotor instability and support structure damage or failure under lateral impact-rubbing load excitation. Attached Figure Description

[0016] Figure 1 This is a simplified diagram of a typical aero-engine rotor structure in an embodiment of the present invention; Figure 2 A simplified flowchart of a rotor system safety design method under transverse impact-rubbing load excitation provided by the present invention; Figure 3 This is a simplified lateral impact load curve for landing or shipboarding in an embodiment of the present invention; Figure 4 This is a deformation feature diagram of the rotor system under lateral impact in an embodiment of the present invention; Figure 5 This is a characteristic diagram of the displacement response of the rotor front support point under transverse impact-rubbing load excitation as a function of time in an embodiment of the present invention. Figure 6 This is a characteristic diagram of the rotor front support displacement response over time after increasing the elastic support stiffness in an embodiment of the present invention; Figure 7 This is a diagram of the support damping energy dissipation structure at the rotor front support point in an embodiment of the present invention; Figure 8 This is a characteristic diagram of the rotor front support displacement response over time after designing the support damping energy dissipation structure in this embodiment of the invention; Figure 9 This is a characteristic diagram of the variation of the amplitude of the dynamic load on the support during the lateral impact process of the rotor system in an embodiment of the present invention over time; Figure 10 This is a diagram of the support and limiting structure of the rotor front support point in an embodiment of the present invention; Figure 11 This is a characteristic diagram of the variation of the dynamic load amplitude of the support over time during the lateral impact process of the rotor system after designing the support limiting structure in this embodiment of the invention; Figure 12 This is a diagram of the rotor friction limiting structure at the rotor front support point in an embodiment of the present invention; Figure 13 This is a characteristic diagram of the variation of the amplitude of the dynamic load on the rotor system during the lateral impact process in an embodiment of the present invention after designing the rotor rubbing limiting structure; Figure 14This is a diagram of the support, buffer, and damping structure at the rotor's front support point in an embodiment of the present invention. Figure 15 This is a characteristic diagram of the variation of the amplitude of the dynamic load on the rotor system during the lateral impact process after designing the support buffer damping structure in this embodiment of the invention. The components are as follows: 1. Rotor front journal; 2. Rotor front support; 3. First and second stage compressor components; 4. Third stage compressor bladed disk; 5. Fifth and sixth stage compressor components; 6. Compressor rear sealing plate; 7. Compressor rear drum; 8. Turbine front sealing plate; 9. Turbine bladed disk; 10. Rotor rear journal; 11. Rotor rear support; 21. Front bearing housing; 22. Reversible squirrel cage elastic support; 23. Metal rubber damping mounting base; 24. Elastic positioning circlip; 25. Metal rubber damping structure; 26. Front ball bearing; 27. Metal rubber damping mounting base limiting structure; 28. Support structure rubbing ring; 29. ​​Rotor structure rubbing ring; 30. Metal rubber buffer damping structure. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0018] like Figure 1 As shown, a typical aero-engine rotor system includes: rotor front journal 1, rotor front support 2, first and second stage compressor components 3, third stage compressor bladed disk 4, fifth and sixth stage compressor components 5, compressor rear sealing disk 6, compressor rear drum 7, turbine front sealing disk 8, turbine bladed disk 9, rotor rear journal 10, and rotor rear support 11.

[0019] The rotor system adopts a 1-0-1 support scheme, with the front support point 2 of the rotor located on the front journal 1 of the rotor and the rear support point 11 of the rotor located on the rear journal 10 of the rotor.

[0020] The rotor front journal 1, the first and second stage compressor components 3, the third stage compressor bladed disk 4, and the fifth and sixth stage compressor components 5 are connected by a flange-bolt structure via a locating joint to form the compressor assembly. The turbine front sealing disc 8, the rotor rear journal 10, and the turbine bladed disk 9 are connected by a flange-bolt structure via a locating joint to form the turbine assembly. The fifth and sixth stage compressor components 5, the compressor rear drum 7, and the compressor rear sealing disc 6 are connected by a flange-bolt structure via a locating joint. The turbine front sealing disc 8 and the compressor rear drum 7 are connected by a flange-bolt structure via a locating joint, thereby transmitting the axial force and torque generated by the turbine assembly forward to the compressor assembly.

[0021] like Figure 2 As shown, the present invention provides a rotor system safety design method under transverse impact-rubbing load excitation, comprising the following steps: S1: Deformation characteristics analysis and rubbing assessment of the rotor system under lateral impact load, specifically: S1.1: Deformation characteristics of the rotor system under lateral impact load: Establish an equivalent mechanical model of the rotor system, without considering the rubbing between the blades and the casing, apply a lateral impact load at the support structure as the basic excitation, simulate the load environment of the rotor system during landing or ship landing, and analyze the lateral displacement of the blade tips of the blades corresponding to each stage of the rotor disk. S1.2: Determine whether the rotor system will rub against each other: Based on the blade-casing clearance under the actual working state of the engine during landing or ship landing, determine whether the blade and casing will rub against each other by measuring the relative size of the lateral displacement of the blade tip of the blade corresponding to each stage of the rotor disk and the corresponding blade-casing clearance. If rubbing will occur, proceed to step S2; if rubbing will not occur, proceed to step S3.

[0022] S2: Dynamic response analysis of rotor system under lateral impact-rubbing load excitation and rotor system instability safety design. Specifically: S2.1: Dynamic response analysis of rotor system under transverse impact-rubbing load excitation; Based on step S1, it is determined that the blades and casing will rub against each other. Considering the rubbing effect between the blades and casing, the displacement response at the rotor system support point changes with time. S2.2: Determine whether the rotor system will become unstable; after being subjected to lateral impact-rubbing load excitation, assume the period corresponding to the rotor system's rotation frequency is... T Based on the moment of impact t Starting from 0, in t 0 to t 0+20 T Extracting the peak displacement response of the rotor system within the time interval A 20 The peak value of the steady-state response before the collision occurs. A0 is the baseline, when A 20 / A When 0 ≥ 1.2, the rotor system is considered to be unstable, and step S2.3 is performed; when A 20 / A When 0 < 1.2, it is assumed that the rotor system will not become unstable, and step S3 is performed; S2.3: Rotor system instability safety design under lateral impact-rubbing load excitation, including: ST1: Improve the stiffness of the elastic support; ST2: Design a support damping energy dissipation structure; ST3: Increase blade-casing clearance.

[0023] Specifically, in step S2.3, when designing the rotor system's instability safety under lateral impact-rubbing load excitation, step ST1 is first performed: increasing the elastic support stiffness. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST2 is performed: designing the support damping energy dissipation structure. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST3 is performed: adding blades. Blade-casing clearance; After completing the design, repeat steps S1.1 and S1.2. In step S1.2, if it is determined that the blade and casing will not rub against each other, proceed to step S3. If it is determined that the blade and casing will rub against each other, repeat steps S2.1 and S2.2. In step S2.2, if it is determined that the rotor system will not become unstable, proceed to step S3. If it is determined that the rotor system will become unstable, then repeat step S3: increase the blade-casing clearance; repeat steps S1.1, S1.2, S2.1 and S2.2 until it is determined that the rotor system will not become unstable or the blade and casing will not rub against each other, then proceed to step S3.

[0024] S3: Analysis of dynamic load on rotor system supports under lateral impact loads and safety design of support structures. Specifically: S3.1: Analysis of dynamic load on the support during the transverse impact process; Based on step S1, determine that the blade and casing will not rub against each other, or based on step S2, determine that the rotor system will not become unstable under the excitation of transverse impact-rubbing load, and analyze the characteristics of the change of the amplitude of the support dynamic load over time. S3.2: Determine whether the support structure will be damaged or destroyed; if the maximum value of the dynamic load amplitude of the support is greater than or equal to the maximum safe load that the support structure can withstand, it is considered that the support structure will be damaged or destroyed, and proceed to step S3.3; if the maximum value of the dynamic load amplitude of the support is less than the maximum safe load that the support structure can withstand, it is considered that the support structure will not be damaged or destroyed, and the safety design of the rotor system under transverse impact-rubbing load excitation is completed; the maximum safe load that the support structure can withstand is the allowable dynamic load determined by strength calculation or test calibration based on the allowable stress of the support structure material, connection or contact boundary conditions, load transfer path and safety factor. S3.3: Safety design of support structure under lateral impact, including: ST4: Design a support and limiting structure; ST5: Design of rotor rubbing and limiting structure; ST6: Design a support, buffer, and damping structure.

[0025] Specifically, in step S3.3, when designing the safety of the support structure under lateral impact, step ST4 is first performed: designing the support limiting structure. After completing the design, steps S3.1 and S3.2 are repeated. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed; if it is determined that the support structure will be damaged or destroyed, step ST5 is performed: designing the rotor rubbing limiting structure. After completing the design, steps S3.1 and S3.2 are repeated. In step S3.2, if it is determined that the support structure will be damaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed. If the support structure is determined to be undamaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed. If it is determined that the support structure will be damaged or destroyed, proceed to step ST6: design the support buffer damping structure. After completing the design, repeat steps S3.1 and S3.2. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, the safety design of the rotor system under lateral impact-rubbing load excitation is completed. If it is determined that the support structure will be damaged or destroyed, repeat step ST6: design the support buffer damping structure until it is determined that the support structure will not be damaged or destroyed.

[0026] The following detailed description of the above-mentioned rotor system safety design method under transverse impact-rubbing load excitation will be provided through specific embodiments.

[0027] S1. Deformation characteristics analysis and rubbing judgment of rotor system under lateral impact load.

[0028] like Figure 3 As shown, in this embodiment, the lateral impact load during landing or shipboarding is simplified to a half-sine pulse with an action time of 11ms and a maximum overload absolute value of 10g.

[0029] The deformation characteristics of the rotor system under the aforementioned lateral impact load are as follows: Figure 4 As shown, the lateral displacement of the blade tip of the blade corresponding to the first-stage compressor blade disk is 0.56 mm, and the lateral displacement of the blade tip of the blade corresponding to the turbine blade disk is 0.52 mm.

[0030] Considering that the blade-casing clearance between the first-stage compressor blades and the casing is 0.3 mm during landing or shipboard landing, and the blade-casing clearance between the turbine blades and the casing is 0.35 mm during landing, and that the maximum lateral deformation at the first-stage compressor blade disk and the turbine blade disk is greater than the corresponding blade-casing clearance, it is determined that the blades and casing will rub against each other, and a dynamic response analysis is performed under lateral impact-rubbing load excitation.

[0031] S2. Dynamic response analysis of rotor system under transverse impact-rubbing load excitation and instability safety design of rotor system.

[0032] like Figure 5 As shown, considering the friction between the blades and the casing, the embodiment takes the rotor front support displacement response as an example to analyze the variation characteristics of the rotor front support displacement response with time. It can be seen that the amplitude of the rotor front support displacement response increases from 0.23 mm at 0.45 s to 1.26 mm at 0.52 s. During the process from 0.45 s to 0.52 s, the amplitude of the rotor front support displacement response continuously increases with time. Within 20 rotor rotation cycles, the amplitude of the rotor front support displacement response is more than or equal to 1.2 times that before being subjected to the impact-friction load excitation. Therefore, it is determined that the rotor system has become unstable under the combined action of lateral impact-friction load excitation. The following safety design for rotor system instability under lateral impact-friction load excitation is then performed: First, increase the stiffness of the elastic support. Considering the current rotor front support stiffness is 2×10⁻⁶... 7 N / m, rotor rear support stiffness is 3×10 7 N / m, therefore, increasing the elastic support stiffness increases the rotor front support stiffness to 4×10 N / m. 7 N / m, the rotor rear support stiffness is increased to 6×10 N / m. 7 The N / m value was calculated, and the dynamic response analysis under lateral impact-rubbing load excitation was performed again.

[0033] Figure 6The variation characteristics of the rotor front support displacement response over time after increasing the elastic support stiffness are shown. It can be seen that the amplitude of the rotor front support displacement response continues to increase with time, from 0.19 mm at 0.45 s to 0.92 mm at 0.52 s. Within 20 rotor rotation cycles, the amplitude of the rotor front support displacement response is more than 1.2 times greater than the amplitude before the impact-rubbing load excitation. The rotor system still experienced instability under the combined effect of lateral impact-rubbing load excitation; therefore, it is necessary to redesign the rotor system's instability safety under lateral impact-rubbing load excitation.

[0034] Furthermore, a support damping energy dissipation structure was designed.

[0035] Figure 7 The support damping energy dissipation structure designed for the rotor front support point in this embodiment is shown. The rotor front support point 2 and the support damping energy dissipation structure mainly include: front bearing housing 21, folding squirrel cage elastic support 22, metal rubber damping mounting base 23, elastic positioning ring 24, metal rubber damping structure 25, and front ball bearing 26.

[0036] The outer ring of the front ball bearing 26 is positioned with the retractable squirrel cage elastic support 22 via a stop fit. The retractable squirrel cage elastic support 22 is positioned with the front bearing housing 21 via a flange fit and is fastened with bolts. The outer flange of the metal rubber damping mounting base 23 is positioned with the retractable squirrel cage elastic support 22 via a flange fit and is fastened with bolts. The metal rubber damping structure 25 and the metal rubber damping mounting base 23 are interference-fitted and fixed by elastic positioning rings 24 on both sides to prevent axial movement of the metal rubber damping structure 25, thereby providing damping and dissipating vibration energy during the lateral impact-rubbing process of the rotor system.

[0037] Figure 8 The variation characteristics of the rotor front support displacement response over time after designing the damping energy dissipation structure are shown. During the period from 0.3s to 0.35s, the rotor system is subjected to a lateral impact, resulting in rotor-casing rubbing. During the period from 0.35s to 0.6s, the amplitude of the rotor front support displacement response continuously decreases with increasing time. The amplitude of the rotor front support displacement response is less than 1.2 times the amplitude of the displacement response before the impact-rubbing load excitation. Therefore, it is determined that the rotor system did not become unstable under the lateral impact-rubbing load excitation, thus completing the rotor system instability safety design under lateral impact-rubbing load excitation.

[0038] S3. Analysis of dynamic load on the rotor system under lateral impact load and safety design of the support structure.

[0039] like Figure 9As shown, after completing the rotor system instability safety design under lateral impact-rubbing load excitation, the dynamic load of the support during the lateral impact process of the rotor system is analyzed. It can be seen that the maximum amplitude of the support dynamic load is 9216N, while the maximum safe load that the support structure can withstand in this embodiment is 4500N. Therefore, it is determined that the support structure will be damaged or destroyed, and a safety design for the support structure under lateral impact is required. First, design the support and limiting structure. Figure 10 The diagram illustrates a support limiting structure designed for the rotor front support point in this embodiment, which further incorporates a metal-rubber damping mounting base limiting structure 27 based on the support damping energy dissipation structure design. The metal-rubber damping mounting base limiting structure 27 restricts the deformation of the reciprocating squirrel cage elastic support 22, thereby reducing the maximum impact load on the reciprocating squirrel cage elastic support 22.

[0040] Figure 11 The diagram illustrates the variation of the dynamic load amplitude of the rotor system under lateral impact during the design of the support limiting structure. It shows that the maximum value of the dynamic load amplitude decreases from the initial 9216 N to 6034 N, but it is still greater than the maximum safe load of 4500 N that the support structure can withstand. Therefore, it is determined that the support structure will be damaged or destroyed, and safety design of the support structure under lateral impact is still required.

[0041] Furthermore, a rotor rubbing limiting structure was designed. Figure 12 The rotor rubbing limiting structure designed for the rotor front support point in this embodiment is shown. It mainly consists of a support structure rubbing ring 28 and a rotor structure rubbing ring 29. The rotor structure rubbing ring 29 is assembled on the rotor front journal 1 together with the front ball bearing 26. The gap between the support structure rubbing ring 28 and the rotor structure rubbing ring 29 is smaller than the gap of the grate sealing structure. When the rotor system is subjected to lateral impact load, the support structure rubbing ring 28 and the rotor structure rubbing ring 29 come into contact, sharing the impact load on the reciprocating squirrel cage elastic support 22, thereby reducing the maximum value of the support dynamic load amplitude and protecting the support structure.

[0042] Figure 13 The diagram illustrates the variation of the dynamic load amplitude of the support during the lateral impact process of the rotor system after the design of the rotor rubbing limiting structure. It can be seen that the maximum value of the dynamic load amplitude decreases from the initial 9216N to 4786N, but it is still greater than the maximum safe load of 4500N that the support structure can withstand. Therefore, it is determined that the support structure will be damaged or destroyed, and safety design of the support structure under lateral impact is still required.

[0043] Furthermore, a support, buffer, and damping structure was designed. Figure 14The support buffer damping structure designed for the front support point of the rotor in this embodiment is shown. A metal rubber buffer damping structure 30 is designed between the reciprocating squirrel cage elastic support 22 and the outer ring of the front ball bearing 26 to absorb lateral impact loads and reduce the modal vibration generated by the lateral impact of the rotor system.

[0044] Figure 15 The variation characteristics of the dynamic load amplitude of the rotor system under lateral impact during the design of the support buffer damping structure are shown. It can be seen that the maximum value of the dynamic load amplitude of the support decreases from the initial 9216N to 2047N. The dynamic load amplitude of the support decreases and is less than the maximum safe load of 4500N that the support structure can withstand. Therefore, it is determined that the support structure will not be damaged or destroyed, and the safety design of the support structure under lateral impact is completed.

[0045] After analyzing the deformation characteristics and judging the rubbing situation of the rotor system under the lateral impact load, analyzing the dynamic response of the rotor system under the lateral impact-rubbing load excitation and designing the instability safety of the rotor system, and analyzing the dynamic load of the support during the lateral impact process of the rotor system and designing the safety of the support structure, the safety design of the rotor system under the lateral impact-rubbing load excitation was finally completed.

Claims

1. A method for safety design of a rotor system under transverse impact-rubbing load excitation, characterized in that, Includes the following steps: S1: Deformation characteristics analysis and rubbing judgment of rotor system under transverse impact load: Based on the deformation characteristics, determine whether the blades and casing in the rotor system will rub against each other. If rubbing will occur, proceed to step S2; if rubbing will not occur, proceed to step S3. S2: Dynamic response analysis and instability safety design of the rotor system under lateral impact-rubbing load excitation: Based on the time-varying characteristics of the displacement response at the rotor system's support points, determine whether the rotor system will become unstable. If instability is likely, perform instability safety design for the rotor system under lateral impact-rubbing load excitation; if instability is not likely, proceed to step S3; specifically including: S2.1: Dynamic response analysis of rotor system under transverse impact-rubbing load excitation; Based on step S1, it is determined that the blades and casing will rub against each other. Considering the rubbing effect between the blades and casing, the displacement response at the rotor system support point changes with time. S2.2: Determine whether the rotor system will become unstable; after being subjected to lateral impact-rubbing load excitation, assume the period corresponding to the rotor system's rotation frequency is... T Based on the moment of impact t Starting from 0, in t 0 to t 0+20 T Extracting the peak displacement response of the rotor system within the time interval A 20 The peak value of the steady-state response before the collision occurs. A 0 is the baseline, when A 20 / A When 0 ≥ 1.2, the rotor system is considered to be unstable, and step S2.3 is performed; when A 20 / A When 0 < 1.2, it is assumed that the rotor system will not become unstable, and step S3 is performed; S2.3: Rotor system instability safety design under lateral impact-rubbing load excitation, including: ST1: Improve the stiffness of the elastic support; ST2: Design a support damping energy dissipation structure; ST3: Increase blade-casing clearance; S3: Rotor System Lateral Impact Load Analysis and Support Structure Safety Design: Based on the time-varying characteristics of the support dynamic load amplitude, determine whether the support structure will be damaged or destroyed. If damage or destruction is expected, perform the support structure safety design under lateral impact. If no damage or destruction is expected, complete the rotor system safety design under lateral impact-rubbing load excitation. Specifically, this includes: S3.1: Analysis of dynamic load on the support during the transverse impact process; Based on step S1, determine that the blade and casing will not rub against each other, or based on step S2, determine that the rotor system will not become unstable under the excitation of transverse impact-rubbing load, and analyze the characteristics of the change of the amplitude of the support dynamic load over time. S3.2: Determine whether the support structure will be damaged or destroyed; if the maximum value of the dynamic load amplitude of the support is greater than or equal to the maximum safe load that the support structure can withstand, it is considered that the support structure will be damaged or destroyed, and proceed to step S3.3; if the maximum value of the dynamic load amplitude of the support is less than the maximum safe load that the support structure can withstand, it is considered that the support structure will not be damaged or destroyed, and the safety design of the rotor system under transverse impact-rubbing load excitation is completed. S3.3: Safety design of support structure under lateral impact, including: ST4: Design a support and limiting structure; ST5: Design of rotor rubbing and limiting structure; ST6: Design a support, buffer, and damping structure.

2. The method for safety design of a rotor system under transverse impact-rubbing load excitation according to claim 1, characterized in that, Step S1 specifically includes: S1.1: Deformation characteristics of the rotor system under lateral impact load: Establish an equivalent mechanical model of the rotor system, without considering the rubbing between the blades and the casing, apply a lateral impact load at the support structure as the basic excitation, simulate the load environment of the rotor system during landing or ship landing, and analyze the lateral displacement of the blade tips of the blades corresponding to each stage of the rotor disk. S1.2: Determine whether the rotor system will rub against each other: Based on the blade-casing clearance under the actual working state of the engine during landing or ship landing, determine whether the blade and casing will rub against each other by measuring the relative size of the lateral displacement of the blade tip of the blade corresponding to each stage of the rotor disk and the corresponding blade-casing clearance. If rubbing will occur, proceed to step S2; if rubbing will not occur, proceed to step S3.

3. The rotor system safety design method under transverse impact-rubbing load excitation according to claim 1, characterized in that, In step S2.3, when designing the rotor system's instability safety under lateral impact-rubbing load excitation, step ST1 is first performed: increasing the elastic support stiffness. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST2 is performed: designing the support damping energy dissipation structure. After completing the design, steps S2.1 and S2.2 are repeated. In step S2.2, if it is determined that the rotor system will not become unstable, step S3 is performed; if it is determined that the rotor system will become unstable, step ST3 is performed: adding blades... Casing clearance; After completing the design, repeat steps S1.1 and S1.

2. In step S1.2, if it is determined that the blades and casing will not rub against each other, proceed to step S3. If it is determined that the blades and casing will rub against each other, repeat steps S2.1 and S2.

2. In step S2.2, if it is determined that the rotor system will not become unstable, proceed to step S3. If it is determined that the rotor system will become unstable, then repeat step S3: increase the blade-casing clearance; repeat steps S1.1, S1.2, S2.1 and S2.2 until it is determined that the rotor system will not become unstable or that the blades and casing will not rub against each other, then proceed to step S3.

4. The rotor system safety design method under transverse impact-rubbing load excitation according to claim 1, characterized in that, In step S3.3, when designing the safety of the support structure under lateral impact, first proceed to step ST4: design the support limiting structure. After completing the design, repeat steps S3.1 and S3.

2. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, complete the rotor system safety design under lateral impact-rubbing load excitation; if it is determined that the support structure will be damaged or destroyed, proceed to step ST5: design the rotor rubbing limiting structure. After completing the design, repeat steps S3.1 and S3.

2. In step S3.2, if it is determined that the support structure will not be damaged or destroyed, complete the rotor system safety design under lateral impact-rubbing load excitation. If damage or failure occurs, complete the rotor system safety design under transverse impact-rubbing load excitation; if it is determined that the support structure will be damaged or failed, proceed to step ST6: design the support buffer damping structure; after completing the design, repeat steps S3.1 and S3.2; in step S3.2, if it is determined that the support structure will not be damaged or failed, complete the rotor system safety design under transverse impact-rubbing load excitation; if it is determined that the support structure will be damaged or failed, repeat step ST6: design the support buffer damping structure, until it is determined that the support structure will not be damaged or failed.

5. The rotor system safety design method under transverse impact-rubbing load excitation according to claim 1, characterized in that, In step S3.2, the maximum safe load that the supporting structure can withstand is the allowable dynamic load determined by strength calculation or test calibration based on the allowable stress of the supporting structure material, connection or contact boundary conditions, load transfer path and safety factor.

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