Vibration reduction performance comprehensive evaluation method for helicopter

Abstract

The invention belongs to the field of helicopter vibration control, and relates to a vibration reduction performance comprehensive evaluation method for a helicopter. The method comprises the following steps: calculating the simulation vibration reduction efficiency eta < call > after a helicopter adopts vibration reduction measures through calculation and analysis of vibration reduction performance; through the test of the vibration reduction performance, calculating the test vibration reduction efficiency eta test after the helicopter adopts the vibration reduction measures; and according to the simulation vibration reduction efficiency eta < call > and the test vibration reduction efficiency eta < test >, comprehensive evaluation of the vibration reduction performance is carried out.

Description

Technical Field

[0001] The invention belongs to the field of helicopter vibration control and relates to a vibration reduction performance comprehensive evaluation method for a helicopter. Background Art

[0002] The key direct manifestation of helicopter dynamics problems is vibration, and the vibration level is an important indicator for measuring the advancement of helicopters. This indicator is not only related to the comfort of pilots, but also a key factor in ensuring structural safety. The vibration problem has always plagued and accompanied the development and progress of helicopters. Helicopter vibration and control are eternal topics in helicopter development. More than 40% of helicopter accidents are related to vibration. Excessive vibration of helicopters will lead to frequent failures of onboard equipment, seriously reducing the battlefield attendance rate, and the high vibration level will prevent the weapon fire control system itself and the pilot from locking the target in time to carry out precise strikes, reducing combat effectiveness. Summary of the invention

[0003] Purpose of the invention: Various vibration control measures are important means to reduce helicopter vibration, so it is necessary to comprehensively evaluate the vibration reduction performance in order to select appropriate vibration control measures in a targeted manner.

[0004] Technical solution:

[0005] A comprehensive evaluation method for vibration reduction performance of a helicopter is provided, comprising:

[0006] Through the calculation and analysis of vibration reduction performance, the simulated vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated calculate ;

[0007] Through the vibration reduction performance test, the test vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated test ;

[0008] According to the simulation vibration reduction efficiency η calculate And the test vibration reduction efficiency η test , conduct a comprehensive evaluation of the vibration reduction performance.

[0009] Furthermore, the calculation formula for the vibration reduction efficiency η of the comprehensive evaluation vibration reduction measures is:

[0010] η=k1×η calculate +k2×η test ;

[0011] Among them, k1 and k2 are proportional coefficients.

[0012] Furthermore, k1+k2=1.

[0013] Furthermore, through the calculation and analysis of vibration reduction performance, the simulated vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated. calculate ,include:

[0014] Establish a helicopter dynamics finite element model, and randomly select N preliminary positions of evaluation points in the dynamics finite element model;

[0015] The dynamic finite element model is calculated to obtain the response of N evaluation points. According to the actual vibration reduction needs, the convex optimization algorithm is used to select the final positions of n evaluation points representing the vibration response of the whole machine from the N evaluation points.

[0016] Apply an exciting force to the center of the hub on the helicopter dynamics model and calculate the initial response of the final position of n evaluation points

[0017] Apply the same exciting force to the dynamic finite element model, implement vibration reduction measures on the model, and calculate the vibration reduction response of the final position of n evaluation points

[0018] Calculate the simulated vibration reduction efficiency η based on the initial response and the response after vibration reduction calculate .

[0019] Furthermore,

[0020] Furthermore, through the vibration reduction performance test, the experimental vibration reduction efficiency η of the helicopter after adopting the vibration reduction measures is calculated. test ,include:

[0021] Establish a simulation test rig similar to helicopter dynamics;

[0022] Install n vibration sensors on the simulation test bench, and keep the installation positions consistent with the final positions of the n evaluation points;

[0023] Apply the same exciting force as the dynamic finite element model at a similar position on the simulation test bench, and test the initial vibration response of the installation position through n vibration sensors.

[0024] Apply the same exciting force at similar positions on the simulation test bench, implement the same vibration reduction measures as the dynamic finite element model, and test the vibration response of the installation position after vibration reduction through n vibration sensors.

[0025] According to the initial vibration response and the vibration response after vibration reduction, the test vibration reduction efficiency η is calculated. calculate .

[0026] Furthermore,

[0027] Beneficial effects: The present invention proposes a comprehensive evaluation method for the vibration reduction performance of helicopters. The vibration reduction performance of helicopter vibration reduction measures is comprehensively evaluated through calculation and testing, providing more comprehensive support for the demonstration of helicopter vibration reduction measures indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a flow chart of a comprehensive evaluation method for vibration reduction performance of helicopters.

[0029] Figure 2 Schematic diagram of the dynamic finite element model.

[0030] Figure 3 This is a schematic diagram of the structure of the simulation test bench. DETAILED DESCRIPTION

[0031] The present invention provides a comprehensive evaluation method for vibration reduction performance of a helicopter, such as Figure 1 As shown, including:

[0032] The first step is to calculate and analyze the vibration reduction performance. The convex optimization algorithm is used to obtain the best position of the evaluation point and calculate the vibration reduction efficiency of the helicopter after the vibration reduction measures are taken. The specific method is as follows:

[0033] 1) Establish a helicopter dynamics finite element model and select N evaluation points on the platform for preliminary selection (select the main structures such as the main frame beam, skin, floor, etc. of the whole aircraft to establish the whole aircraft dynamics finite element model, in which the airborne products are replaced by mass points and bound to the actual installation position of the whole aircraft finite element model);

[0034] 2) Calculate the response of the dynamic finite element model to obtain the responses of the N evaluation points selected in 1), and select the final positions of n evaluation points representing the vibration response of the whole machine by using a convex optimization algorithm according to the actual vibration reduction needs;

[0035] 3) Apply the exciting force at the center of the hub on the helicopter dynamics model and calculate the initial response of the final position of the n evaluation points selected in 2)

[0036] 4) Apply the same exciting force as in 3) to the model, implement vibration reduction measures on the model, and calculate the vibration reduction response of the final position of the n evaluation points selected in 2)

[0037] 5) Calculate the vibration reduction efficiency according to the following formula:

[0038]

[0039] The second step is to test the vibration reduction performance. By establishing a test bench similar to helicopter dynamics, we can carry out the vibration reduction performance test and test the vibration reduction efficiency of the test bench after adopting vibration reduction measures. The specific method is as follows:

[0040] 1') Establish a simulation test bench similar to helicopter dynamics. The simulation test bench is designed according to the main frame beam structure of the helicopter and has the same dynamic characteristics as the helicopter, and can simulate the complex vibration environment of the helicopter;

[0041] 2') Install n vibration sensors on the simulation test bench, and the installation positions are similar to the final positions of the evaluation points selected in the first step 2);

[0042] 3') Apply the same exciting force as in step 3) at a similar position on the simulation test bench, and test the initial vibration response of the installation position through n vibration sensors in 2').

[0043] 4') Apply the same exciting force as in step 3) at a similar position on the simulation test bench, and implement the same vibration reduction measures as in step 4) to test the vibration response of the installation position after vibration reduction through n vibration sensors in step 2').

[0044] 5') Calculate the vibration reduction efficiency according to the following formula:

[0045]

[0046] The third step is the comprehensive evaluation of vibration reduction performance. Through the calculation and analysis of vibration reduction performance and the test results, the vibration reduction efficiency of the vibration reduction measures is comprehensively evaluated according to the following formula, where k1+k2=1.

[0047] η=k1×η calculate +k2×η test

[0048] Example description:

[0049] Take the vibration reduction capability of a certain type of machine active vibration control system as an example.

[0050] The first step is the calculation and analysis of vibration reduction performance.

[0051] 1) Establishment Figure 2 The dynamic finite element model was used to select 12 evaluation points for preliminary location selection;

[0052] 2) Perform response calculation on the dynamic finite element to obtain the responses of 10 evaluation points. According to the needs of the active vibration control system, 6 points (1, 2, 5, 6, 7, and 8) are selected as the final positions of the evaluation points.

[0053] Evaluation points 1 2 3 4 5 6 7 8 9 10 response 1.127 1.088 0.246 0.172 0.938 0.747 1.089 1.150 0.224 0.147

[0054] 3) Exciting force (0N, 0N, 1000N) is applied to the center of the hub on the helicopter dynamics model, and the initial response of the final position of the evaluation point is calculated as follows.

[0055] Evaluation points 1 2 5 6 7 8 Initial Response 0.259 0.250 0.216 0.172 0.250 0.264

[0056] 4) Apply the same exciting force as in 3) to the model, and enable the active vibration control system to start vibration control. The post-vibration reduction response of the final position of the evaluation point is calculated as follows.

[0057] Evaluation points 1 2 5 6 7 8 Response after vibration reduction 0.091 0.063 0.065 0.060 0.138 0.127

[0058] 5) Calculate the vibration reduction efficiency as follows:

[0059]

[0060] The second step is to test the vibration reduction performance.

[0061] Establish a simulation test bench similar to helicopter dynamics such as Figure 3 shown.

[0062] Install n vibration sensors on the simulation test bench, and the installation positions are similar to the final positions of the evaluation points selected in step 2);

[0063] Apply the same exciting force as in step 3) at a similar position on the simulation test bench, and test the initial vibration response of the installation position by n vibration sensors in 2) as follows;

[0064] Evaluation points 1 2 5 6 7 8 Initial Response 0.285 0.225 0.207 0.181 0.213 0.317

[0065] Apply the same exciting force as in step 3) at a similar position of the simulation test bench, and enable the active vibration control system to start vibration control. The vibration response after vibration reduction at the installation position tested by n vibration sensors in 2) is as follows;

[0066] Evaluation points 1 2 5 6 7 8 Initial Response 0.057 0.068 0.083 0.101 0.047 0.078

[0067] The vibration reduction efficiency is calculated as follows:

[0068]

[0069] The third step is the comprehensive evaluation of vibration reduction performance.

[0070] η=0.3×η calculate +0.7×η test =66.4%

[0071] After comprehensive evaluation, the vibration active control system has a vibration reduction efficiency of 66.4%.

Claims

1. A comprehensive evaluation method for vibration reduction performance of a helicopter, characterized in that: include: Through the calculation and analysis of vibration reduction performance, the simulated vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated calculate ; Through the vibration reduction performance test, the test vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated test ; According to the simulation vibration reduction efficiency η calculate And the test vibration reduction efficiency η test , conduct a comprehensive evaluation of the vibration reduction performance.

2. The method according to claim 1, characterized in that The calculation formula for the vibration reduction efficiency η of the comprehensive evaluation vibration reduction measures is: η=k1×η calculate +k2×η test ; Among them, k1 and k2 are proportional coefficients.

3. The method according to claim 2, characterized in that k1+k2=1.

4. The method according to claim 1, characterized in that: Through the calculation and analysis of vibration reduction performance, the simulated vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated calculate ,include: Establish a helicopter dynamics finite element model, and randomly select N preliminary positions of evaluation points in the dynamics finite element model; The dynamic finite element model is calculated to obtain the response of N evaluation points. According to the actual vibration reduction needs, the convex optimization algorithm is used to select the final positions of n evaluation points representing the vibration response of the whole machine from the N evaluation points. Apply an exciting force to the center of the hub on the helicopter dynamics model and calculate the initial response of the final position of n evaluation points Apply the same exciting force to the dynamic finite element model, implement vibration reduction measures on the model, and calculate the vibration reduction response of the final position of n evaluation points Calculate the simulated vibration reduction efficiency η based on the initial response and the response after vibration reduction calculate .

5. The method according to claim 4, characterized in that 6. The method according to claim 1, characterized in that Through the vibration reduction performance test, the test vibration reduction efficiency η of the helicopter after adopting vibration reduction measures is calculated test ,include: Establish a simulation test rig similar to helicopter dynamics; Install n vibration sensors on the simulation test bench, and keep the installation positions consistent with the final positions of the n evaluation points; Apply the same exciting force as the dynamic finite element model at a similar position on the simulation test bench, and test the initial vibration response of the installation position through n vibration sensors. Apply the same exciting force at similar positions on the simulation test bench, implement the same vibration reduction measures as the dynamic finite element model, and test the vibration response of the installation position after vibration reduction through n vibration sensors. According to the initial vibration response and the vibration response after vibration reduction, the test vibration reduction efficiency η is calculated. calculate .

7. The method according to claim 6, characterized in that 8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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