CN110194282B - Airplane wheel brake vibration testing method applying vibration measurement technology - Google Patents
Airplane wheel brake vibration testing method applying vibration measurement technology Download PDFInfo
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- CN110194282B CN110194282B CN201910531906.9A CN201910531906A CN110194282B CN 110194282 B CN110194282 B CN 110194282B CN 201910531906 A CN201910531906 A CN 201910531906A CN 110194282 B CN110194282 B CN 110194282B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64F—GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR
- B64F5/00—Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for
- B64F5/60—Testing or inspecting aircraft components or systems
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
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- Aviation & Aerospace Engineering (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The utility model provides a system for measuring simulation aircraft brake wheel vibration process can be used to measure the vibration acceleration of aircraft wheel structure subassembly under different operating modes to better understand the mechanism of vibration intensity and production and the influence that probably causes the system in the aircraft braking process. The experimental platform based on the inertial table realizes the arrangement of the airplane wheel assembly and the brake device, applies the landing load of the airplane through the flywheel, and then measures the vibration acceleration of the airplane wheel assembly through the acceleration sensor, the signal conditioner and the signal collector to obtain vibration data of a hub, a carbon disc, a brake torque cylinder, a torque cylinder and the like, wherein the vibration data comprises displacement and acceleration time-domain curves and is used for analyzing the vibration characteristics of the airplane wheel.
Description
Technical Field
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology, and belongs to the technical field of airplane testing.
Background
The detection of the aircraft wheel brake device needs to be verified through a large number of tests to ensure the brake efficiency and the structural reliability, and meanwhile, the detection needs to be completed by continuously adjusting parameters and different control methods. If the test is completed by taking off and landing of the actual airplane, the cost is greatly increased, and the test period is too long. And the inertia test bed can simulate the flight conditions of the airplane such as actual braking, landing and takeoff loads and the like in the landing, takeoff, running and other processes. Therefore, the relevant test verification work of the airplane wheel brake device is generally completed through an inertia test bed in the industry. Therefore, the performance of the airplane wheel and the antiskid system is detected, and a basis is provided for new product development and improvement of the existing products.
The demand for greater and greater production efficiency, as well as economic considerations in design, requires machines to operate at higher speeds and the use of large quantities of lightweight construction materials. These trends increase the likelihood of machine resonance during operation, while decreasing system reliability. Therefore, in order to secure a sufficient safety margin, it is necessary to test the vibration characteristics of the mechanical structure. Any observed change in natural frequency or other vibration characteristics often indicates that the machine system has failed or requires timely maintenance.
In many applications, it is desirable to determine whether a structure or machine can withstand a particular vibration environment. A structure or machine system is considered to be able to withstand such a particular vibration environment without damage if it still achieves the intended goal after vibration testing in that particular environment.
By measuring characteristics of the vibration system input and output, it is helpful to identify the mass, stiffness and damping of the system. However, to date, no relevant reports have been made on measuring the braking vibration of the wheels of an aircraft.
Disclosure of Invention
The invention solves the problems: the system for simulating the vibration process of the braking airplane wheel of the airplane by measuring is provided for the first time, the airplane wheel vibration condition of the airplane braking under the working conditions of overload landing, takeoff stopping, normal landing and the like is simulated, and the vibration acceleration value measurement of the airplane wheel assembly is realized.
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology, which is developed based on a system for measuring and simulating the brake vibration process of an airplane;
the system for measuring and simulating the brake vibration process of the airplane comprises:
the inertia test bed consists of a motor, a drum wheel, a bracket and a drum wheel main shaft, wherein the bracket is used for placing the wheel, and the drum wheel is used for providing braking energy; the motor is used for driving the drum wheel;
the measuring device comprises an acceleration sensor, a dynamic signal conditioner and a data acquisition unit, wherein the acceleration sensor is connected with components in the airplane wheel and the dynamic signal conditioner, and the dynamic signal conditioner is connected with the data acquisition unit;
during the test, firstly, the drum wheel is driven to rotate by the alternating current or direct current motor, then the driving motor controls the airplane wheel and the drum wheel to contact with each other to complete the airplane brake model process, the digital information under the brake working condition is obtained by the measuring device, and the digital information is analyzed to obtain the test result; the digital information comprises displacement and acceleration time domain curves of each airplane wheel assembly in the braking process; the test result comprises vibration displacement values and acceleration values of all components of the airplane wheel; the accuracy and the applicability of the airplane wheel dynamic model are verified by comparing the goodness of fit between the acceleration curve and the displacement curve of each part of the airplane wheel obtained by simulating the airplane wheel dynamic model and the experimental curve.
The invention relates to a method for testing the brake vibration of an airplane wheel by applying a vibration measurement technology; the application range of the measuring system is airplane wheel braking.
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology; the measuring structure in the measuring system is a component of a wheel, and the component of the wheel is selected from at least one of a hub, a cylinder seat, a torsion cylinder and a carbon disc (comprising a pressing disc, a movable disc, a static disc and a pressure-bearing disc).
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology; in the measuring system, the braking condition of the airplane is selected from at least one of normal landing, takeoff stopping and overload landing.
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology; in the measuring system, the working temperature of an accelerator sensor is between-40 ℃ and +120 ℃, the measuring range is +/-200 g, the frequency range is 0.7-11000Hz, and the weight is less than 20g.
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology; in the measuring system, the used brake device is a carbon brake disc.
The invention relates to an airplane wheel brake vibration testing method applying a vibration measurement technology; in the measuring system, the hub material is LD10, and the torsion cylinder material is ZG30Cr18Mn12Si2N.
The invention takes an inertia test bed as a basic platform; the support of the inertial platform is used for supporting the airplane wheel, the motor is used for applying rotating speed to the drum wheel to simulate landing energy of the airplane, the motor is driven to enable the airplane wheel and the drum wheel to be in contact with each other, and the braking process of the model airplane is started; in the experiment process under different working conditions, the measuring personnel are far away from the experiment equipment to ensure the safety; an acceleration sensor in the measuring equipment is directly connected with the airplane wheel assembly in a magnet adsorption or gluing mode, then a signal is input to a dynamic signal conditioner and then to a signal collector, and finally data transmission is connected with a computer; the dynamic signal conditioner has the functions of amplifying the measuring signal and filtering noise.
Drawings
FIG. 1 is a schematic diagram of a vibration experiment system.
Fig. 2 is a physical diagram of a vibration experiment system.
Fig. 3 is a graph of axial vibration acceleration of the traveling cylinder block in embodiment 1.
Fig. 4 is a graph of the acceleration of the dynamic response analysis of a vibrating aircraft wheel in the cylinder block axial direction 2~3 second time period.
Figure 5 cylinder block radial vibration acceleration curve.
FIG. 6 cylinder block radial 2~3 second time period vibration acceleration profile.
Fig. 7 is a torque barrel axial vibration acceleration curve.
Fig. 8 is a plot of vibration acceleration for a time period 2~3 seconds for a torque barrel shaft.
FIG. 9 is a graph of axial vibration acceleration of a compaction disk.
FIG. 10 is a plot of the acceleration of vibration of the compression disc in the axial direction 3~4 seconds.
Fig. 11 is a graph of axial simulated vibration acceleration for a torsion cylinder.
Fig. 12 is a graph of simulated vibration acceleration for a torque barrel axis 2~3 seconds.
In fig. 1, 1 is a driving motor, 2 is a bracket, 3 is an aircraft wheel, 4 is a drum, 5 is an alternating current or direct current motor, and 6 is a drum main shaft.
It can be seen from fig. 2 that the present invention has been designed and passed through practical experiments.
Fig. 3-6 show the axial and radial vibration acceleration curves of the cylinder block, when the brake pressure is in an ascending state, the amplitude of the axial vibration acceleration is stabilized at 0.5g, and the amplitude of the radial vibration acceleration is stabilized at 1.2g.
Fig. 7 and 8 show axial vibration acceleration curves of the torsion cylinder of the airplane wheel, and it can be seen that the amplitude of the vibration acceleration of the torsion cylinder is stabilized near 0.4g, and is small compared with the axial vibration of the static disc and the cylinder seat; at the moment when the braking process is just started, the maximum acceleration value is only 3.6g. Comparing the brake pressure curve, it can be seen that when the brake pressure is stable after 8 seconds, the vibration amplitude of the torsion tube is reduced by a small amount.
It can be seen from fig. 9 and 10 that the amplitude of the axial vibration acceleration of the stationary disk is in a steady state and is reduced by a small amplitude during the process of gradually increasing the braking torque.
11, 12 bit simulation torsion cylinder vibration acceleration curve, contrast experiment curve, under the condition of acceleration vibration maximum amplitude, moment stable region amplitude, curve change, etc., the experiment and simulation result is close, the error is not more than 0.1g basically; the simulation result of the system dynamic equation is accurate and reliable, and the method is suitable for analyzing the vibration characteristics of the airplane wheel.
Detailed Description
Example 1
The vibration experiment system is shown in figure 2, wherein an airplane wheel to be measured is arranged on an inertia table bracket, then a drum wheel is driven to rotate through an alternating current or direct current motor, braking energy is applied, and the driving motor controls the airplane wheel and the drum wheel to contact with each other to complete the airplane braking model process; and an acceleration sensor and the surface of the wheel structure are installed, in the braking process, the acceleration sensor transmits a measured electric signal to a signal conditioning device for amplification and filtering, then the measured electric signal is transmitted to a signal acquisition device, and finally the measured electric signal is displayed through a computer end to finish the vibration acceleration measuring process of the structure.
(1) Rotating speed of the inertia wheel: 0 to 2500 rpm.
(2) Outputting energy: minimum: 2.0 MJ; maximum: 80 MJ; energy (indication) precision: plus or minus 1.0 percent.
(3) Weight of the airplane wheel: 70Kg.
(4) The cylinder base test results are shown in fig. 3, 4, 5, 6.
Fig. 3-6 show the axial and radial vibration acceleration curves of the cylinder block, where the amplitude of the axial vibration acceleration is stabilized at 0.5g and the amplitude of the radial vibration acceleration is stabilized at 1.2g when the brake pressure is in a rising state.
(5) The torque tube test results are shown in fig. 7 and 8.
Fig. 7 and 8 show the axial vibration acceleration curves of the torsion cylinder of the airplane wheel, and it can be seen that the amplitude of the vibration acceleration of the torsion cylinder is stabilized around 0.4g, and is small compared with the axial vibration of the static disc and the cylinder seat. At the moment when the braking process is just started, the maximum acceleration value is only 3.6g. Comparing the brake pressure curve, it can be seen that when the brake pressure is stable after 8 seconds, the vibration amplitude of the torsion tube is reduced by a small amount.
(6) The results of the compression disc test are shown in fig. 9 and 10.
It can be seen from fig. 9 and 10 that the amplitude of the axial vibration acceleration of the stationary disk is in a steady state and is reduced by a small amplitude during the process of gradually increasing the braking torque.
(7) The simulation results are compared with the experimental results, see fig. 11 and 12.
In the vibration acceleration curve of the torsion cylinder in the simulation of fig. 11 and 12, compared with an experimental curve, under the conditions of the maximum amplitude of the vibration of the acceleration, the amplitude of a torque stable region, curve change and the like, the experimental result and the simulation result are close, and the error basically does not exceed 0.1g. The simulation result of the system dynamic equation is accurate and reliable, and the method is suitable for analyzing the vibration characteristics of the airplane wheel.
Claims (8)
1. The method for testing the brake vibration of the airplane wheel by applying the vibration measurement technology is characterized by comprising the following steps of: the method is based on the development of a system for measuring and simulating the braking vibration process of an airplane;
the system for measuring and simulating the brake vibration process of the airplane comprises:
the inertia test bed consists of a driving motor, a drum wheel, a bracket and a drum wheel main shaft, wherein the bracket is used for placing the wheel, and the drum wheel is used for providing braking energy; the drum wheel is driven to rotate by an alternating current or direct current motor, braking energy is applied, and the driving motor controls the airplane wheel and the drum wheel to contact with each other to complete the airplane braking model process;
the measuring device comprises an acceleration sensor, a dynamic signal conditioner and a data acquisition unit, wherein the acceleration sensor is connected with components in the airplane wheel and the dynamic signal conditioner, and the dynamic signal conditioner is connected with the data acquisition unit;
during the test, firstly, the drum wheel is driven to rotate by the alternating current or direct current motor, then the driving motor controls the airplane wheel and the drum wheel to contact with each other to complete the airplane brake model process, the digital information under the brake working condition is obtained by the measuring device, and the digital information is analyzed to obtain the test result; the digital information comprises displacement and acceleration time domain curves of each airplane wheel assembly in the braking process; the test result comprises vibration displacement values and acceleration values of all components of the airplane wheel; the accuracy and the applicability of the airplane wheel dynamic model are verified by comparing the matching degree of the acceleration curve and the displacement curve of each part of the airplane wheel obtained by simulating the airplane wheel dynamic model with the experimental curve.
2. The method for testing the braking vibration of the airplane wheel by applying the vibration measurement technology of claim 1; the method is characterized in that: the application range of the measuring system is airplane brake.
3. The method for testing the braking vibration of the airplane wheel by applying the vibration measurement technology of claim 1; the method is characterized in that: in the test method, the test structure is a component of the airplane wheel, and the component of the airplane wheel is selected from at least one of a hub, a cylinder seat, a torsion cylinder and a carbon disk; the carbon disc comprises at least one of a pressing disc, a movable disc, a static disc and a pressure-bearing disc.
4. The method for testing the brake vibration of the airplane wheel by applying the vibration measurement technology according to the claim 1; the method is characterized in that: the digital information comprises displacement and acceleration time domain curves of each airplane wheel assembly in the braking process; each airplane wheel assembly comprises a cylinder base, a pressing disc and a cylinder base.
5. The method for testing the braking vibration of the airplane wheel by applying the vibration measurement technology of claim 1; the method is characterized in that: in the test method, the brake working condition of the airplane is selected from at least one of normal landing, takeoff stopping and overload landing.
6. The method for testing the braking vibration of the airplane wheel by applying the vibration measurement technology of claim 1; the method is characterized in that: in the test method, the working temperature of the accelerator sensor is-40 ℃ to +120 ℃, the measuring range is +/-200 g, the frequency range is 0.7-11000Hz, and the weight is less than 20g.
7. The method for testing the braking vibration of the airplane wheel by applying the vibration measurement technology of claim 1; the method is characterized in that: in the test method, the used brake device is a carbon brake disc.
8. The method for testing the brake vibration of the airplane wheel by applying the vibration measurement technology according to the claim 1; the method is characterized in that: in the testing method, the hub material is LD10 aluminum alloy, and the torsion cylinder material is ZG30Cr18Mn12Si2N heat-resistant steel.
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| CN117909659B (en) * | 2024-03-20 | 2024-05-14 | 中国空气动力研究与发展中心超高速空气动力研究所 | Method and device for processing aerodynamic force signals of balance in wind tunnel dynamic test of variant aircraft |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4101985A1 (en) * | 1991-01-24 | 1992-07-30 | Domarkas Andrew | Test for irregularities of cooperative elements, esp. gears - involves computation of sum of acoustic emissions superimposed at fixed phase w.r.t. relevant outputs of accelerometer |
| CA2230202A1 (en) * | 1998-02-23 | 1999-08-23 | Yvon Rancourt | Dynamometer |
| JP2004352191A (en) * | 2003-05-30 | 2004-12-16 | Aruze Corp | Wheel supporting mechanism for aircraft |
| CN101000238A (en) * | 2007-01-17 | 2007-07-18 | 北京航空航天大学 | Plane wheel space displacement measuring system of landing gear lowering shock test |
| CN102121846A (en) * | 2010-11-30 | 2011-07-13 | 中南大学 | Method and device for testing vibration effect of multi-combination hydraulic long pipeline system |
| CN103803098A (en) * | 2014-02-13 | 2014-05-21 | 西安航空制动科技有限公司 | Airplane wheel speed simulation device |
| CN105138805A (en) * | 2015-09-29 | 2015-12-09 | 中国航空工业集团公司沈阳飞机设计研究所 | Load simulation method for cataplane landing gear |
| CN105480431A (en) * | 2014-10-11 | 2016-04-13 | 中国航空工业集团公司西安飞机设计研究所 | Method for avoiding excessive vibration of undercarriage in overhead state |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103553695B (en) * | 2013-10-23 | 2015-01-21 | 中南大学 | Carbon-ceramic composite brake disc and preparation method thereof |
-
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Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4101985A1 (en) * | 1991-01-24 | 1992-07-30 | Domarkas Andrew | Test for irregularities of cooperative elements, esp. gears - involves computation of sum of acoustic emissions superimposed at fixed phase w.r.t. relevant outputs of accelerometer |
| CA2230202A1 (en) * | 1998-02-23 | 1999-08-23 | Yvon Rancourt | Dynamometer |
| JP2004352191A (en) * | 2003-05-30 | 2004-12-16 | Aruze Corp | Wheel supporting mechanism for aircraft |
| CN101000238A (en) * | 2007-01-17 | 2007-07-18 | 北京航空航天大学 | Plane wheel space displacement measuring system of landing gear lowering shock test |
| CN102121846A (en) * | 2010-11-30 | 2011-07-13 | 中南大学 | Method and device for testing vibration effect of multi-combination hydraulic long pipeline system |
| CN103803098A (en) * | 2014-02-13 | 2014-05-21 | 西安航空制动科技有限公司 | Airplane wheel speed simulation device |
| CN105480431A (en) * | 2014-10-11 | 2016-04-13 | 中国航空工业集团公司西安飞机设计研究所 | Method for avoiding excessive vibration of undercarriage in overhead state |
| CN105138805A (en) * | 2015-09-29 | 2015-12-09 | 中国航空工业集团公司沈阳飞机设计研究所 | Load simulation method for cataplane landing gear |
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