Tire assembly modal test method

Abstract

The invention provides a tire assembly modal test method, and belongs to the technical field of tire acoustics. According to the tire assembly modal test method, the modal parameters of the tire can be analyzed by measuring the modal shape of each order of the tire, and data support is provided for acoustic development of the tire. The test is suitable for passenger car tires and minibus tires (LT / RV). And the frequency response function represents the relation between steady-state output and input of the test system under the given frequency. The relation specifically refers to a function relation between the ratio of the output amplitude to the input amplitude and the input frequency and a function relation between the output phase difference and the input phase difference and the input frequency. Therefore, the test method is simplified, the test process is standardized, the test efficiency is improved, and various data of the tire can be quickly subjected to experimental acquisition, so that whether the tire is qualified or not can be known, and the product improvement direction can be well determined in the subsequent tire production.

Description

Technical Field

[0001] The present application relates to the field of tire acoustics, and in particular, to a tire assembly modal testing method. Background Art

[0002] The tire assembly is the tire. The tire is a circular elastic rubber product that is grounded and rolled on various vehicles or machines. It is usually installed on a metal rim, which can support the vehicle body, buffer external impact, achieve contact with the road surface and ensure the driving performance of the vehicle. Tires are often used under complex and harsh conditions. They are subjected to various deformations, loads, forces, and high and low temperature effects when driving, so they must have high load-bearing performance, traction performance, and buffering performance. At the same time, they are also required to have high wear resistance and flexibility resistance, as well as low rolling resistance and heat generation.

[0003] Tire NVH refers to the noise, vibration and harshness generated by the tire when it interacts with the vehicle and the road.

[0004] As the only component of the vehicle that interacts with the road, the performance of the tire has a direct impact on the comfort and safety of the vehicle. NVH characteristics are one of the important indicators to measure tire quality. It involves the noise, vibration and roughness generated by the tire during use. These factors not only affect driving comfort, but also the handling stability of the vehicle and the riding experience of the passengers. Therefore, the NVH performance of the tire is one of the key factors to be considered in automobile design and manufacturing. The NVH performance of the tire is affected by many factors, including the structural design of the tire, material selection, and interaction with the road. In order to improve the NVH performance of the tire, manufacturers will take a series of technical measures, such as optimizing the tire pattern design, using high-performance materials, and reducing noise and vibration through advanced manufacturing processes. In addition, the NVH performance of the tire is also an important part of the automobile NVH system, and is closely related to other components of the vehicle such as the engine and exhaust system. In summary, the research and optimization of the NVH performance of the tire is of great significance to improving the comfort, safety and user satisfaction of the whole vehicle. Therefore, the tire needs to be tested for performance before leaving the factory.

[0005] At present, there is no unified test method in the industry and no national standard test method has been promulgated. The test methods of various automobile and tire companies are different, and the measurement data and judgment criteria are different. As a result, the test data cannot be converted and compared to determine whether the product is qualified or not, and the direction of product improvement cannot be determined well. Summary of the invention

[0006] In order to remedy the above shortcomings, the present application provides a tire assembly modal test method, which aims to improve the problem that the test methods of automobile and tire companies are different, the measurement data and judgment criteria are different, resulting in the inability to convert and compare the test data to determine whether the product is qualified or not, and the inability to determine the direction of product improvement.

[0007] The present application provides a tire assembly modal test method, comprising the following steps:

[0008] Step 1: Adjust the tire pressure to half-load pressure, use elastic rope to suspend the tire, and ensure that the cylinder modal evaluation frequency of the system composed of the tire assembly and elastic rope is less than 3Hz;

[0009] Step 2: Arrange the measuring equipment at the center of the tire tread;

[0010] Step 3: Data model establishment:

[0011] Step 4: Use the mobile force hammer method to excite, select a rubber hammer head, hammer each measuring point in the radial direction in turn, and obtain the frequency response function of each measuring point. The coherence function should be no less than 0.95 during the test;

[0012] Step 5: Perform modal analysis on the measured frequency response function and calculate the first 6 modal vibration shapes, focusing on the frequencies of the first-order rigid body mode and elastic body mode vibration shapes;

[0013] Step 6: Data display, convert the frequency response function curve and modal vibration shape into a data model for display. Among them, by measuring the vibration shape of each medium mode of the tire and analyzing its modal parameters, data support is provided for the development of tire acoustics. This test is suitable for passenger car tires and van tires (LT / RV). Frequency response function: The frequency response function characterizes the relationship between the steady-state output and input of the test system at a given frequency. This relationship specifically refers to the functional relationship between the ratio of the output and input amplitudes and the input frequency, and the functional relationship between the output and input phase difference and the input frequency. Mode: The natural vibration characteristics of the structure, such as natural frequency, damping ratio and vibration shape. In turn, the test method is simplified, the test process is standardized, and the test efficiency is improved, so that various data of the tire can be quickly collected experimentally, so that it can be understood whether the tire is qualified, so that the product improvement direction can be well determined in the subsequent tire production.

[0014] In a specific implementation manner, in step 2, the measuring equipment includes a data collector, a force hammer collector and an acceleration sensor.

[0015] In a specific implementation scheme, in step 2, the data collector uses a signal acquisition front-end device to collect signals. The device should have at least 2 acquisition channels, such as LMS 8-channel, Head8-channel, BBM PAK 16 / 32-channel data collector, and a hammer collector. A hammer is used to collect input signals. A rubber hammer head is used to ensure that it can effectively stimulate a response within 500 Hz. An accelerometer sensor is used to collect response signals, such as a PCB unidirectional or tridirectional acceleration sensor.

[0016] In a specific embodiment, in step 2, the measured data is a physical quantity, and the measured physical quantity includes

[0017] The force applied by the hammer to the tire (N);

[0018] Acceleration measured at the response point (m / s2).

[0019] In a specific embodiment, in step 2, the temperature of the test environment is between 10°C and 25°C.

[0020] In a specific implementation scheme, in step 2, the various data settings of the data acquisition software of the measuring device are:

[0021] Bandwidth: 512Hz;

[0022] Frequency resolution: 0.25Hz;

[0023] Reference windowReference wi ndow:Force windowForce;

[0024] Response window: Exponential window;

[0025] Average number of times: 5 times;

[0026] Frequency response function estimation: H1;

[0027] No weighting;

[0028] Save FRF and Coherence data.

[0029] In a specific embodiment, in step 3, the data model establishment includes the following steps:

[0030] Step 3.1: Geometry model establishment;

[0031] Step 3.2: Hammer method modal test process: Impact test i ng module usage;

[0032] Step 3.3: Modal analysis part: Use of Time MDOF module.

[0033] In a specific embodiment, in step 3.2, the module use of Impact testing includes the following steps:

[0034] Step 3.2.1: Channel settings;

[0035] Step 3.2.2: Hammer the oscilloscope;

[0036] Step 3.2.3: Hammer setting;

[0037] Step 3.2.4: Measure;

[0038] Step 3.2.5: Data verification.

[0039] In a specific embodiment, in step 3.3, the module use of Time MDOF includes the following steps:

[0040] Step 3.3.1: Modal test data selection;

[0041] Step 3.3.2: Select bandwidth;

[0042] Step 3.3.3: Select the pole;

[0043] Step 3.3.4: Calculate the mode shape;

[0044] Step 3.3.5: Modal fitting;

[0045] Step 3.3.6: Modal verification of the first-order vibration mode.

[0046] In a specific embodiment, in step 6, the data model displayed is 6 vibration modes.

[0047] Beneficial effects: By measuring the modal vibration shapes of each order of the tire and analyzing its modal parameters, data support is provided for the acoustic development of the tire. This test is applicable to passenger car tires and van tires (LT / RV). Frequency response function: The frequency response function characterizes the relationship between the steady-state output and input of the test system at a given frequency. This relationship specifically refers to the functional relationship between the ratio of the output and input amplitudes and the input frequency, and the functional relationship between the output and input phase difference and the input frequency. Mode: The natural vibration characteristics of the structure, such as natural frequency, damping ratio and vibration shape. This simplifies the test method, standardizes the test process, improves the test efficiency, and enables rapid experimental collection of various data of the tire, so as to understand whether the tire is qualified, so as to facilitate the subsequent determination of the product improvement direction in tire production. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a structural block diagram of a tire assembly modal test method provided in an embodiment of the present application;

[0050] Figure 2 Establish a model diagram for the Geometry model provided in the implementation mode of this application;

[0051] Figure 3 A diagram showing the steps of using the Impact testing module provided in the implementation mode of the present application;

[0052] Figure 4 A diagram showing the steps of using the Time MDOF module according to an embodiment of the present application;

[0053] Figure 5 A data display model diagram provided for an implementation method of this application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0055] See also Figure 1-Figure 5 The present application provides a tire assembly modal test method, comprising the following steps:

[0056] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5, Step 1: Adjust the tire pressure to half-load pressure. Specifically, if there are two tire pressures for half-load, use the higher tire pressure. Use elastic ropes to suspend the tire to ensure that the cylinder modal evaluation rate of the system composed of the tire assembly and the elastic rope is lower than 3Hz; Step 2: Arrange the measuring equipment at the center of the tire tread. Specifically, measure the radial acceleration response of the tire, with at least 10 measuring points; Step 3: Data model establishment: Step 4: Use the mobile force hammer method to excite, select a rubber hammer head, and hammer each measuring point in turn to obtain the frequency response function of each measuring point. The coherence function should be no less than 0.95 during the test; Step 5: Perform modal analysis on the measured frequency response function, calculate the first 6 modal vibration shapes, and focus on the frequency of the first-order rigid body mode and elastic body mode vibration shape; Step 6: Data display, convert the frequency response function curve and modal vibration shape into a data model for display. Among them, by measuring the vibration shape of each intermediate mode of the tire and analyzing its modal parameters, data support is provided for tire acoustic development. This test is applicable to tires for passenger cars and vans (LT / RV). Frequency response function: The frequency response function characterizes the relationship between the steady-state output and input of the test system at a given frequency. This relationship specifically refers to the functional relationship between the ratio of the output and input amplitudes and the input frequency, and the functional relationship between the output and input phase difference and the input frequency. Mode: The natural vibration characteristics of the structure, such as natural frequency, damping ratio and vibration mode. This simplifies the test method, standardizes the test process, improves the test efficiency, and enables rapid experimental collection of various tire data, so as to understand whether the tire is qualified, so as to facilitate the subsequent determination of product improvement directions in tire production.

[0057] In this embodiment, in step 2, the measuring equipment includes a data collector, a hammer collector and an acceleration sensor. In step 2, the data collector uses a signal acquisition front-end device to collect signals. The device should have at least 2 acquisition channels, such as LMS 8-channel, Head 8-channel, BBM PAK 16 / 32-channel data collector, and a hammer collector. A hammer is used to collect input signals. A rubber hammer head is used to ensure that the response within 500Hz can be effectively stimulated. An accelerometer sensor is used to collect response signals, such as a PCB unidirectional or tridirectional acceleration sensor. In step 2, the measured data is a physical quantity, and the measured physical quantities include the force (N) applied by the hammer to the tire; the acceleration (m / s2) measured at the response point. In step 2, the temperature of the test environment is between 10°C and 25°C.

[0058] In the specific settings, in step 2, the various data settings of the data acquisition software of the measuring equipment are: Bandwidth: 512Hz; Frequency resolution: 0.25Hz; Reference window: Force window; Response window: Exponential window; Average times: 5 times; Frequency response function estimation: H1; Unweighted; Save FRF and Coherence data.

[0059] In this embodiment, in step 3, the data model establishment includes the following steps:

[0060] See also Figure 2 , Step 3.1: Geometry model establishment;

[0061] Refer to 3, Step 3.2: Hammer Method Modal Testing Process: Impact Testing Module Usage;

[0062] See also Figure 4 , Step 3.3: Modal analysis part: Use of Time MDOF module.

[0063] See also Figure 3 In step 3.2, the use of the Impact testing module includes the following steps: Step 3.2.1: Channel setting: Step 3.2.2: Hammer oscilloscope; Step 3.2.3: Hammer setting; Step 3.2.4: Measurement; Step 3.2.5: Data verification.

[0064] See also Figure 4 In step 3.3, the module usage of Time MDOF includes the following steps:

[0065] Step 3.3.1: Modal test data selection; Step 3.3.2: Select bandwidth; Step 3.3.3: Select poles; Step 3.3.4: Calculate modal vibration shape; Step 3.3.5: Modal fitting; Step 3.3.6: Modal verification of first-order vibration shape.

[0066] See also Figure 5 ,In step 6, 6 data models are displayed, and the vibration frequencies of the 6 models are 84.29Hz, 101.45Hz, 130.0Hz, 154.34Hz, 179.71Hz, and 205.25Hz respectively.

[0067] Working principle of the tire assembly modal test method:

[0068] Step 1: Adjust the tire pressure to half-load pressure. Specifically, if there are two tire pressures for half-load, use the higher tire pressure. Use elastic ropes to suspend the tire to ensure that the cylinder modal evaluation rate of the system composed of the tire assembly and the elastic rope is lower than 3Hz; Step 2: Arrange the measurement equipment at the center of the tire tread. Specifically, measure the radial acceleration response of the tire, with at least 10 measurement points; Step 3: Establish the data model: Step 4: Use the mobile force hammer method to excite, select a rubber hammer head, and hammer each measurement point in turn to obtain the frequency response function of each measurement point. The coherence function should be no less than 0.95 during the test; Step 5: Perform modal analysis on the measured frequency response function, calculate the first 6 modal vibration modes, and focus on the frequency of the first-order rigid body mode and elastic body mode vibration mode; Step 6: Data display, convert the frequency response function curve and modal vibration mode into a data model for display. Among them, by measuring the vibration mode of each intermediate mode of the tire and analyzing its modal parameters, data support is provided for tire acoustic development. This test is applicable to tires for passenger cars and vans (LT / RV). Frequency response function: The frequency response function characterizes the relationship between the steady-state output and input of the test system at a given frequency. This relationship specifically refers to the functional relationship between the ratio of the output and input amplitudes and the input frequency, and the functional relationship between the output and input phase difference and the input frequency. Mode: The natural vibration characteristics of the structure, such as natural frequency, damping ratio and vibration mode. This simplifies the test method, standardizes the test process, improves the test efficiency, and enables rapid experimental collection of various tire data, so as to understand whether the tire is qualified, so as to facilitate the subsequent determination of product improvement directions in tire production.

[0069] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

Claims

1. A tire assembly modal test method, characterized in that: The following steps are involved: Step 1: Adjust the tire pressure to half-load pressure, use elastic rope to suspend the tire, and ensure that the cylinder modal evaluation frequency of the system composed of the tire assembly and elastic rope is less than 3Hz; Step 2: Arrange the measuring equipment at the center of the tire tread; Step 3: Data model establishment: Step 4: Use the mobile force hammer method to excite, select a rubber hammer head, hammer each measuring point in the radial direction in turn, and obtain the frequency response function of each measuring point. The coherence function should be no less than 0.95 during the test; Step 5: Perform modal analysis on the measured frequency response function and calculate the first 6 modal vibration shapes, focusing on the frequencies of the first-order rigid body mode and elastic body mode vibration shapes; Step 6: Data display, convert the frequency response function curve and mode vibration shape into a data model for display.

2. A tire assembly modal test method according to claim 1, characterized in that: In step 2, the measuring equipment includes a data collector, a force hammer collector and an acceleration sensor.

3. A tire assembly modal test method according to claim 2, characterized in that: In step 2, the data collector uses the signal acquisition front-end device to collect signals. The device should have at least 2 acquisition channels, such as LMS 8-channel, Head8-channel, BBM PAK 16 / 32-channel data collector, and hammer collector. A hammer is used to collect input signals. A rubber hammer head is used to ensure that it can effectively stimulate a response within 500Hz. An accelerometer sensor is used to collect response signals, such as a PCB unidirectional or triaxial accelerometer.

4. A tire assembly modal test method according to claim 2, characterized in that: In step 2, the measured data are physical quantities, including The force applied by the hammer to the tire (N); Acceleration measured at the response point (m / s2).

5. A tire assembly modal test method according to claim 1, characterized in that: In step 2, the temperature of the test environment is between 10°C and 25°C.

6. A tire assembly modal test method according to claim 1, characterized in that: In step 2, the various data settings of the data acquisition software of the measurement equipment are: Bandwidth: 512Hz; Frequency resolution: 0.25Hz; Reference window: Force window; Response window: Exponential window; Average number of times: 5 times; Frequency response function estimation: H1; No weighting; Save FRF and Coherence data.

7. A tire assembly modal test method according to claim 1, characterized in that: In step 3, the data model establishment includes the following steps: Step 3.1: Geometry model establishment; Step 3.2: Hammer method modal testing process: Use of impact testing modules; Step 3.3: Modal analysis part: Use of Time MDOF module.

8. A tire assembly modal test method according to claim 7, characterized in that: In step 3.2, the module usage for Impact testing includes the following steps: Step 3.2.1: Channel settings; Step 3.2.2: Hammer the oscilloscope; Step 3.2.3: Hammer setting; Step 3.2.4: Measure; Step 3.2.5: Data verification.

9. A tire assembly modal test method according to claim 7, characterized in that: In step 3.3, the use of the Time MDOF module includes the following steps: Step 3.3.1: Modal test data selection; Step 3.3.2: Select bandwidth; Step 3.3.3: Select the pole; Step 3.3.4: Calculate the mode shape; Step 3.3.5: Modal fitting; Step 3.3.6: Modal verification of the first-order vibration mode.

10. A tire assembly modal test method according to claim 1, characterized in that: In step 6, the data model displayed is 6 vibration modes.

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