Test method for the stiffness of vehicle door sheet metal panels

Abstract

The present invention discloses a method for testing the stiffness of a vehicle door sheet metal panel, belonging to the field of vehicle inspection technology. The testing method comprises providing a test specimen comprising a vehicle door sheet metal panel; selecting a plurality of panel stiffness test points on the vehicle door sheet metal panel of the test specimen; performing a hammer test on the positions of the plurality of panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point; performing data processing on the origin vibration acceleration response results of each panel stiffness test point; and evaluating the stiffness of the vehicle door sheet metal panel based on the data processing results. The testing method can evaluate the stiffness of the vehicle door sheet metal panel at different frequencies to improve the quality of the vehicle door closing sound, reduce driving noise inside the vehicle, and enhance the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle detection, and in particular to a method for testing the stiffness of a vehicle door sheet metal panel. Background Art

[0002] The door system is the most frequently used component in automotive products, and its performance has a great impact on the entire vehicle. The stiffness test of door sheet metal is an important part of vehicle design.

[0003] The testing methods for door sheet metal panels in related technologies mainly include the dent resistance test method (static load loading test) and the overall bending-torsion stiffness test method (static load loading test), etc., all of which analyze the static stiffness of the door sheet metal panels (that is, the pressing stiffness perceptible to car users), but cannot evaluate the stiffness of the door sheet metal panels at different frequencies, and thus cannot determine whether the stiffness of the door sheet metal panels at different frequencies meets the standards, which will affect the vehicle's door closing sound quality and the driving noise inside the car, reducing the user experience.

[0004] Therefore, how to provide a test method for the stiffness of vehicle door sheet metal panels that can evaluate the stiffness of vehicle door sheet metal panels at different frequencies to improve the quality of vehicle door closing sound, reduce driving noise inside the vehicle, and improve user experience has become an urgent problem that needs to be solved. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a method for testing the stiffness of a vehicle door sheet metal panel that overcomes the above problems or at least partially solves the above problems. The method can evaluate the stiffness of a vehicle door sheet metal panel at different frequencies to improve the quality of the vehicle door closing sound, reduce the driving noise inside the vehicle, and improve the user experience.

[0006] In one aspect, a method for testing the stiffness of a vehicle door sheet metal panel is provided, the method comprising:

[0007] Providing a test sample including a door sheet metal panel;

[0008] Selecting a plurality of panel stiffness test points on the door sheet metal panel of the test sample;

[0009] Performing a hammer test on the plurality of panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point;

[0010] Performing data processing on the origin vibration acceleration response results of each panel stiffness test point;

[0011] The stiffness of the door sheet metal panel is evaluated based on the data processing result.

[0012] Optionally, the selecting of a plurality of panel stiffness test points on the door sheet metal panel of the test sample includes:

[0013] Nine panel stiffness test points are selected on the door sheet metal panel using a nine-square grid method;

[0014] The nine panel stiffness test points are marked.

[0015] Optionally, the nine panel stiffness test points are selected on the door sheet metal panel using a nine-square grid method, including:

[0016] Determining the center point of the door sheet metal panel as the center panel stiffness test point;

[0017] With the central panel stiffness test point as the center, eight panel stiffness test points are selected around the central panel stiffness test point, and the eight panel stiffness test points and the central panel stiffness test point are arranged in a 3×3 matrix.

[0018] Optionally, performing a hammer test on the plurality of panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point includes:

[0019] An acceleration sensor is provided at each panel stiffness test point;

[0020] Within the set bandwidth frequency range, at least five hammer tests are performed on each panel stiffness test point, and the corresponding acceleration sensor is used to test the origin vibration acceleration response of each hammer test until at least five sets of origin vibration acceleration response results are obtained for each panel stiffness test point.

[0021] Optionally, the testing method further includes:

[0022] A hammer test is performed on the plurality of panel stiffness test points under a set environment, wherein the set environment is an environment where the noise level does not exceed 50 dB.

[0023] Optionally, the data processing of the origin vibration acceleration response result of each panel stiffness test point includes:

[0024] Taking an average value of at least five groups of origin vibration acceleration response results of each panel stiffness test point;

[0025] According to the average value of the origin vibration acceleration response results of each panel stiffness test point, a stiffness and frequency relationship curve of each panel stiffness test point is obtained.

[0026] Optionally, the evaluating the stiffness of the door sheet metal panel according to the data processing result includes:

[0027] Comparing the stiffness and frequency relationship curve of each panel stiffness test point with the target curve to determine whether the stiffness of each panel stiffness test point reaches the target value;

[0028] If the stiffness of any of the panel stiffness test points does not reach the target value, it is evaluated that the stiffness of the door sheet metal panel does not meet the standard.

[0029] Optionally, before performing the hammer test on multiple panel stiffness test points within the set bandwidth frequency range, the testing method further includes:

[0030] The surface of the vehicle door sheet metal panel of the test sample is pretreated to remove dirt on the surface of the vehicle door sheet metal panel.

[0031] Optionally, the test sample is a door assembly or a complete vehicle.

[0032] Optionally, when the test sample is a vehicle door assembly, before performing a hammer test on multiple panel stiffness test points within a set bandwidth frequency range, the test method further includes:

[0033] The vehicle door assembly is hoisted by using elastic ropes.

[0034] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0035] An embodiment of the present invention provides a method for testing the stiffness of a vehicle door sheet metal panel. This method selects multiple panel stiffness test points on a test sample's door sheet metal panel, then performs hammer impact tests on these test points within a set bandwidth frequency range. The origin vibration acceleration response of each panel stiffness test point is measured, and finally, the origin vibration acceleration response results of each panel stiffness test point are processed. Based on the data processing results, the stiffness of the vehicle door sheet metal panel can be evaluated. This testing method can evaluate the stiffness of a vehicle door sheet metal panel at different frequencies to determine whether the stiffness of the vehicle door sheet metal panel meets the standard at different frequencies. This can improve the quality of the vehicle door closing sound, reduce driving noise inside the vehicle, and enhance the user experience.

[0036] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0038] Figure 1 This is a flow chart of a method for testing the stiffness of a vehicle door sheet metal panel provided by an embodiment of the present invention;

[0039] Figure 2 This is a flow chart of a method for testing the stiffness of a door sheet metal panel of a vehicle door assembly provided by an embodiment of the present invention;

[0040] Figure 3 1 is a schematic diagram of the positions of panel stiffness test points provided by an embodiment of the present invention;

[0041] Figure 4 1 is a schematic diagram of a first unit force acceleration response-frequency curve provided by an embodiment of the present invention;

[0042] Figure 5 1 is a schematic diagram of a second unit force acceleration response-frequency curve provided by an embodiment of the present invention;

[0043] Figure 6 1 is a schematic diagram of a third unit force displacement response-frequency curve provided by an embodiment of the present invention;

[0044] Figure 7 is a schematic diagram of a fourth stiffness-frequency curve provided by an embodiment of the present invention;

[0045] Figure 8 This is a flow chart of a method for testing the stiffness of a vehicle door sheet metal panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] Exemplary embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings.

[0047] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present disclosure. These figures are not drawn to scale, and for the purpose of clarity, certain details are exaggerated and certain details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0048] In the context of this disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element or an intervening layer / element may exist therebetween. Additionally, if a layer / element is "on" another layer / element in one orientation, the layer / element may be "below" the other layer / element when the orientation is reversed. In the context of this disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0049] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with specific implementation methods. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0050] As the most frequently used component in automotive products, the performance of the door system has a significant impact on the entire vehicle. Therefore, testing the stiffness of door sheet metal parts is a key part of vehicle design. Related art testing methods for door sheet metal panels mainly include the dent resistance test (static load loading test) and the overall bending-torsion stiffness test (static load loading test). These methods analyze the static stiffness of the door sheet metal panels (i.e., the compression stiffness perceivable by the car user), but are unable to evaluate the stiffness of the door sheet metal panels at different frequencies. Consequently, it is impossible to determine whether the stiffness of the door sheet metal panels meets the standards at different frequencies. This, in turn, affects the door closing sound quality and the driving noise inside the vehicle, reducing the user experience.

[0051] In order to solve the above technical problems, an embodiment of the present invention provides a method for testing the stiffness of a vehicle door sheet metal panel. Figure 1 This is a flow chart of a method for testing the stiffness of a door sheet metal panel provided by an embodiment of the present invention. Figure 1 As shown, the test method includes:

[0052] Step S101: providing a test sample comprising a vehicle door sheet metal panel.

[0053] Optionally, the test sample is a door assembly or a complete vehicle.

[0054] Step S102: Select multiple panel stiffness test points on the door sheet metal panel of the test sample.

[0055] Step S103: performing a hammer test on multiple panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point.

[0056] Step S104: performing data processing on the origin vibration acceleration response results of each panel stiffness test point.

[0057] Step S105: Evaluate the stiffness of the door sheet metal panel based on the data processing result.

[0058] An embodiment of the present invention provides a method for testing the stiffness of a vehicle door sheet metal panel. This method selects multiple panel stiffness test points on a test sample's door sheet metal panel, then performs hammer impact tests on these test points within a set bandwidth frequency range. The origin vibration acceleration response of each panel stiffness test point is measured, and finally, the origin vibration acceleration response results of each panel stiffness test point are processed. Based on the data processing results, the stiffness of the vehicle door sheet metal panel can be evaluated. This testing method can evaluate the stiffness of a vehicle door sheet metal panel at different frequencies to determine whether the stiffness of the vehicle door sheet metal panel meets the standard at different frequencies. This can improve the quality of the vehicle door closing sound, reduce driving noise inside the vehicle, and enhance the user experience.

[0059] Figure 2 This is a flow chart of a method for testing the stiffness of a door sheet metal panel of a door assembly provided by an embodiment of the present invention, such as Figure 2 As shown, the test method includes:

[0060] Step S201: providing a vehicle door assembly including a vehicle door sheet metal panel.

[0061] In this embodiment, the test sample is a vehicle door assembly.

[0062] Step S202: Select a plurality of panel stiffness test points on the door sheet metal panel of the door assembly.

[0063] In one implementation of this embodiment, step S202 may include:

[0064] The first step is to select nine panel stiffness test points on the door sheet metal panel using the nine-square grid method;

[0065] Specifically, the first step may include:

[0066] Determine the center point of the door sheet metal panel as the center panel stiffness test point;

[0067] With the central panel stiffness test point as the center, eight panel stiffness test points are selected around the central panel stiffness test point, and the eight panel stiffness test points and the central panel stiffness test point are arranged in a 3×3 matrix.

[0068] The second step is to mark the nine panel stiffness test points.

[0069] Among them, a marker pen can be used to draw the position of each panel stiffness test point on the door sheet metal panel for marking.

[0070] Figure 3: is a schematic diagram of the position of a panel stiffness test point provided by an embodiment of the present invention, such as Figure 3 As shown in the figure, nine panel stiffness test points are marked on the door sheet metal panel, and the nine panel stiffness test points are arranged in a 3×3 matrix. The distance between each panel stiffness test point and the adjacent panel stiffness test points can be calibrated in real vehicles based on the design of the door skin.

[0071] Step S203: pre-treating the surface of the door sheet metal panel of the door assembly.

[0072] In this embodiment, the pretreatment is to clean the surface of the door sheet metal panel to remove dirt on the surface of the door sheet metal panel.

[0073] Step S204: Use elastic ropes to hoist the door assembly.

[0074] Elastic ropes are softer and have less impact on test results. Hoisting ensures that the door assembly is not in contact with its surroundings during static and impact tests.

[0075] Step S205: Perform hammer tests on multiple panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point.

[0076] Optionally, step S205 may include:

[0077] The first step is to set up an acceleration sensor at each panel stiffness test point;

[0078] For example, the acceleration sensor may be bonded and fixed next to each corresponding panel stiffness test point, so that the acceleration sensor is close to the corresponding panel stiffness test point to ensure detection accuracy.

[0079] It should be noted that the distance between the acceleration sensor and the corresponding panel stiffness test point does not exceed 2 cm.

[0080] The second step is to perform at least five hammer tests on each panel stiffness test point within the set bandwidth frequency range, and use the corresponding acceleration sensor to test the origin vibration acceleration response of each hammer test until at least five sets of origin vibration acceleration response results are obtained for each panel stiffness test point.

[0081] The bandwidth frequency range may be set to 0-1500 Hz. When actually testing, the bandwidth frequency range of 0-500 Hz may be preferably selected.

[0082] Optionally, the test method may further include:

[0083] A hammer test is performed on the plurality of panel stiffness test points under a set environment.

[0084] The noise level in the environment is set to no more than 50dB to prevent excessive noise from interfering with the final test results. Interval noise is not allowed.

[0085] Step S206: performing data processing on the origin vibration acceleration response results of each panel stiffness test point.

[0086] Optionally, step S206 may include:

[0087] The first step is to average at least five groups of origin vibration acceleration response results for each panel stiffness test point;

[0088] The second step is to obtain the relationship curve between stiffness and frequency of each panel stiffness test point based on the average value of the origin vibration acceleration response results of each panel stiffness test point.

[0089] For example, in one implementation of this embodiment, the process of obtaining the relationship curve between stiffness and frequency is as follows:

[0090] 1) According to the average value of the origin vibration acceleration response results of each panel stiffness test point, the first unit force acceleration response-frequency curve of each panel stiffness test point is obtained.

[0091] Figure 4 is a schematic diagram of a first unit force acceleration response-frequency curve provided by an embodiment of the present invention, such as Figure 4 As shown in the figure, the horizontal axis is frequency and the vertical axis is unit force acceleration response.

[0092] 2) Perform 1 / 3 octave processing on the first unit force acceleration response-frequency curve to obtain a second unit force acceleration response-frequency curve.

[0093] Figure 5 is a schematic diagram of a second unit force acceleration response-frequency curve provided by an embodiment of the present invention, such as Figure 5 As shown in the figure, the horizontal axis is frequency and the vertical axis is unit force acceleration response. Figure 5 The curve in Figure 4 The curve in is obtained by performing 1 / 3 octave processing.

[0094] 3) Integrate the second unit force acceleration response-frequency curve twice to obtain the third unit force displacement response-frequency curve of each panel stiffness test point.

[0095] Figure 6 : is a schematic diagram of a third unit force displacement response-frequency curve provided by an embodiment of the present invention, such as Figure 6 As shown, the horizontal axis is frequency and the vertical axis is unit force displacement response. Figure 6 The curve in Figure 5 The curve in is obtained by integrating it twice.

[0096] 4) Take the inverse of the third unit force-displacement response-frequency curve to obtain the fourth stiffness-frequency curve of each panel stiffness test point.

[0097] Figure 7 is a fourth stiffness-frequency curve schematic diagram provided by an embodiment of the present invention, such as Figure 7 As shown in the figure, the horizontal axis is frequency and the vertical axis is stiffness. Figure 7 The curve in Figure 6 The curve in is obtained by taking the inverse.

[0098] It should be noted that the above Figures 4 to 7 The present invention only shows schematic diagrams of the various curves for illustrative purposes. In practice, when data processing is performed on the origin vibration acceleration response results of each panel stiffness test point, the resulting curves will also be different. Mature industrial software can be used to process the results of the hammer test: for example, vibration and noise testing systems such as LMS, HEAD, and BK. Specifically, the above-mentioned test system can be installed on a terminal such as a computer, and the results detected by the acceleration sensor during the knocking test can be input into the terminal. The above-mentioned test system performs the above-mentioned data processing on the origin vibration acceleration response results of each panel stiffness test point, and finally obtains a curve showing the relationship between stiffness and frequency for each panel stiffness test point.

[0099] Exemplarily, the electronic device may include a processor and a memory, wherein the processor and the memory may be connected via a bus or otherwise. The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other chips, or a combination of the above-mentioned various chips. The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs, non-transient computer executable programs and modules. The processor executes various functional applications and data processing of the processor by running the non-transient software programs, instructions and modules stored in the memory.

[0100] Step S207: Evaluate the stiffness of the door sheet metal panel based on the data processing result.

[0101] Optionally, step S207 may include:

[0102] Compare the stiffness and frequency relationship curve of each panel stiffness test point with the target curve to determine whether the stiffness of each panel stiffness test point reaches the target value;

[0103] If the stiffness of any panel stiffness test point does not reach the target value, the stiffness of the door sheet metal panel is evaluated as not meeting the standard.

[0104] In this embodiment, if the stiffness of the nine panel stiffness test points can all reach the target value, the stiffness of the door sheet metal panel is evaluated to be up to standard.

[0105] Specifically, in the early stage of vehicle model development, for panel stiffness test points whose stiffness does not reach the target value, a reinforcement plate can be set at the corresponding position of the panel stiffness test point to enhance the stiffness of the position so that the stiffness of the door sheet metal panel can meet the standard.

[0106] An embodiment of the present invention provides a method for testing the stiffness of a vehicle door sheet metal panel. This method selects multiple panel stiffness test points on a vehicle door assembly, then performs hammer tests on these panel stiffness test points within a set bandwidth frequency range. The origin vibration acceleration response of each panel stiffness test point is measured, and finally, the origin vibration acceleration response results of each panel stiffness test point are processed. Based on the data processing results, the stiffness of the vehicle door sheet metal panel can be evaluated. This testing method can evaluate the stiffness of a vehicle door sheet metal panel at different frequencies to determine whether the stiffness of the vehicle door sheet metal panel meets the standard at different frequencies. This can improve the quality of the vehicle door closing sound, reduce driving noise inside the vehicle, and enhance the user experience.

[0107] Figure 8 This is a flow chart of a method for testing the stiffness of a vehicle door sheet metal panel provided by an embodiment of the present invention, such as Figure 8 As shown, the test method includes:

[0108] Step S301: Provide a complete vehicle including a door sheet metal panel.

[0109] In this embodiment, the test sample is a whole vehicle.

[0110] Step S302: Select multiple panel stiffness test points on the door sheet metal panel of the entire vehicle.

[0111] In one implementation of this embodiment, step S202 may include:

[0112] The first step is to select nine panel stiffness test points on the door sheet metal panel using the nine-square grid method;

[0113] Specifically, the first step may include:

[0114] Determine the center point of the door sheet metal panel as the center panel stiffness test point;

[0115] With the center panel stiffness test point as the center, eight panel stiffness test points are selected around it. These eight panel stiffness test points and the center panel stiffness test point are arranged in a 3×3 matrix. The distance between each panel stiffness test point and the adjacent panel stiffness test point can be calibrated on the actual vehicle based on the design of the door skin.

[0116] The second step is to mark the nine panel stiffness test points.

[0117] Among them, a marker pen can be used to draw the position of each panel stiffness test point on the door sheet metal panel for marking.

[0118] In other implementations of this embodiment, panel stiffness test points may be selected based on the design of the door skin.

[0119] Step S303: pre-processing the surface of the door sheet metal panel of the entire vehicle.

[0120] In this embodiment, the pretreatment is to clean the surface of the door sheet metal panel to remove dirt on the surface of the door sheet metal panel.

[0121] Step S304: performing a hammer test on multiple panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point.

[0122] Optionally, step S304 may include:

[0123] The first step is to set up an acceleration sensor at each panel stiffness test point;

[0124] For example, the acceleration sensor may be bonded and fixed next to each corresponding panel stiffness test point, so that the acceleration sensor is close to the corresponding panel stiffness test point to ensure detection accuracy.

[0125] It should be noted that the distance between the acceleration sensor and the corresponding panel stiffness test point does not exceed 2 cm.

[0126] The second step is to perform at least five hammer tests on each panel stiffness test point within the set bandwidth frequency range, and use the corresponding acceleration sensor to test the origin vibration acceleration response of each hammer test until at least five sets of origin vibration acceleration response results are obtained for each panel stiffness test point.

[0127] The bandwidth frequency range may be set to 0-1500 Hz. When actually testing, the bandwidth frequency range of 0-500 Hz may be preferably selected.

[0128] Optionally, the test method may further include:

[0129] A hammer test is performed on the plurality of panel stiffness test points under a set environment.

[0130] The noise level in the environment is set to no more than 50dB to prevent excessive noise from interfering with the final test results. Interval noise is not allowed.

[0131] Step S305: performing data processing on the origin vibration acceleration response results of each panel stiffness test point.

[0132] Optionally, step S305 may include:

[0133] The first step is to average at least five groups of origin vibration acceleration response results for each panel stiffness test point;

[0134] The second step is to obtain the relationship curve between stiffness and frequency of each panel stiffness test point based on the average value of the origin vibration acceleration response results of each panel stiffness test point.

[0135] In this embodiment, mature industrial software can be used to process the hammer test results: for example, vibration and noise testing systems such as LMS, HEAD, and BK. Specifically, the above-mentioned testing system can be installed on an electronic device, and the results detected by the acceleration sensor during the hammer test can be input into a terminal. The above-mentioned testing system then performs the above-mentioned data processing on the origin vibration acceleration response results of each panel stiffness test point, ultimately obtaining a stiffness-frequency relationship curve for each panel stiffness test point.

[0136] Exemplarily, the electronic device may include a processor and a memory, wherein the processor and the memory may be connected via a bus or otherwise. The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components and other chips, or a combination of the above-mentioned various chips. The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs, non-transient computer executable programs and modules. The processor executes various functional applications and data processing of the processor by running the non-transient software programs, instructions and modules stored in the memory.

[0137] Step S305 is the same as step S206. For details, please refer to the relevant description of step S206, which will not be repeated here in this embodiment.

[0138] Step S306: Evaluate the stiffness of the door sheet metal panel based on the data processing result.

[0139] Optionally, step S306 may include:

[0140] Compare the stiffness and frequency relationship curve of each panel stiffness test point with the target curve to determine whether the stiffness of each panel stiffness test point reaches the target value;

[0141] If the stiffness of any panel stiffness test point does not reach the target value, the stiffness of the door sheet metal panel is evaluated as not meeting the standard.

[0142] In this embodiment, if the stiffness of the nine panel stiffness test points can all reach the target value, the stiffness of the door sheet metal panel is evaluated to be up to standard.

[0143] Specifically, in the early stage of vehicle model development, for panel stiffness test points whose stiffness does not reach the target value, a reinforcement plate can be set at the corresponding position of the panel stiffness test point to enhance the stiffness of the position so that the stiffness of the door sheet metal panel can meet the standard.

[0144] An embodiment of the present invention provides a method for testing the stiffness of a vehicle door sheet metal panel. This method selects multiple panel stiffness test points on a vehicle door sheet metal panel, then performs hammer tests on these test points within a set bandwidth frequency range. The origin vibration acceleration response of each panel stiffness test point is measured, and finally, the origin vibration acceleration response results of each panel stiffness test point are processed. Based on the data processing results, the stiffness of the vehicle door sheet metal panel can be evaluated. This testing method can evaluate the stiffness of a vehicle door sheet metal panel at different frequencies to determine whether the stiffness of the vehicle door sheet metal panel meets the standard at different frequencies. This can improve the quality of the vehicle door closing sound, reduce vehicle driving noise, and enhance the user experience.

[0145] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0146] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0147] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A method for testing the stiffness of a vehicle door sheet metal panel, characterized in that: The test method includes: Providing a test sample including a door sheet metal panel; Selecting a plurality of panel stiffness test points on the door sheet metal panel of the test sample; Performing a hammer test on the plurality of panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point; Performing data processing on the origin vibration acceleration response results of each panel stiffness test point; evaluating the stiffness of the door sheet metal panel according to the data processing result; The hammer test is performed on the plurality of panel stiffness test points within a set bandwidth frequency range to test the origin vibration acceleration response of each panel stiffness test point, including: An acceleration sensor is provided at each panel stiffness test point; Within the set bandwidth frequency range, performing hammer tests on each panel stiffness test point at least five times, and using the corresponding acceleration sensor to test the origin vibration acceleration response of each hammer test, until at least five sets of origin vibration acceleration response results are obtained for each panel stiffness test point; The data processing of the origin vibration acceleration response result of each panel stiffness test point includes: Taking an average value of at least five groups of origin vibration acceleration response results of each panel stiffness test point; Obtaining a relationship curve between stiffness and frequency for each panel stiffness test point according to an average value of the origin vibration acceleration response results of each panel stiffness test point; The process of obtaining a relationship curve between stiffness and frequency of each panel stiffness test point based on the average value of the origin vibration acceleration response result of each panel stiffness test point includes: Obtaining a first unit force acceleration response-frequency curve of each panel stiffness test point according to an average value of the origin vibration acceleration response results of each panel stiffness test point; Performing 1 / 3 octave processing on the first unit force acceleration response-frequency curve to obtain a second unit force acceleration response-frequency curve for each panel stiffness test point; Integrating the second unit force acceleration response-frequency curve twice to obtain a third unit force displacement response-frequency curve for each panel stiffness test point; The inverse of the third unit force displacement response-frequency curve is taken to obtain a fourth stiffness-frequency curve of each panel stiffness test point.

2. The testing method according to claim 1, wherein: The method comprises selecting a plurality of panel stiffness test points on the door sheet metal panel of the test sample, including: Nine panel stiffness test points are selected on the door sheet metal panel using a nine-square grid method; The nine panel stiffness test points are marked.

3. The testing method according to claim 2, wherein: The nine panel stiffness test points are selected on the door sheet metal panel using the nine-square grid method, including: Determining the center point of the door sheet metal panel as the center panel stiffness test point; With the central panel stiffness test point as the center, eight panel stiffness test points are selected around the central panel stiffness test point, and the eight panel stiffness test points and the central panel stiffness test point are arranged in a 3×3 matrix.

4. The testing method according to claim 1, wherein: The test method further comprises: A hammer test is performed on the plurality of panel stiffness test points under a set environment, wherein the set environment is an environment where the noise level does not exceed 50 dB.

5. The testing method according to claim 1, wherein: The step of evaluating the stiffness of the door sheet metal panel according to the data processing result includes: Comparing the stiffness and frequency relationship curve of each panel stiffness test point with the target curve to determine whether the stiffness of each panel stiffness test point reaches the target value; If the stiffness of any of the panel stiffness test points does not reach the target value, it is evaluated that the stiffness of the door sheet metal panel does not meet the standard.

6. The testing method according to claim 1, wherein: Before performing a hammer test on a plurality of panel stiffness test points within a set bandwidth frequency range, the test method further comprises: The surface of the vehicle door sheet metal panel of the test sample is pretreated to remove dirt on the surface of the vehicle door sheet metal panel.

7. The testing method according to claim 1, wherein: The test sample is a door assembly or a complete vehicle.

8. The testing method according to claim 7, characterized in that: When the test sample is a vehicle door assembly, before performing the hammer test on multiple panel stiffness test points within a set bandwidth frequency range, the test method further includes: The vehicle door assembly is hoisted using elastic ropes.

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