• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: A method for analyzing a vehicle panel stiffness by using a point mobility is provided to reduce a number of testing vehicles to manufacture and development period by performing a stiffness analysis in a booming area in advance. CONSTITUTION: A method for analyzing a vehicle panel stiffness by using a point mobility includes the steps of analyzing a low frequency idle vibration via a vehicle body finite element model(S1), modeling in detail a panel sensitive part in a high frequency vibration from the low frequency idle vibration analysis and an analysis data of a previous vehicle kind(S4), setting a stiffness target value for the panel sensitive part, and setting a vibration node, a vibration direction and a vibration frequency area for the analysis of high frequency vibration from the analysis data of the previous vehicle kind(S5,S6), computing frequency response characteristics of the panel sensitive part via a random response analysis by a point mobility with the set vibration node and the set vibration direction(S7,S8), and performing a testing evaluation by recognizing a stiffness level of the panel sensitive part according to the frequency response characteristics and manufacturing a testing vehicle if the recognized stiffness level is higher than the set target value(S11,S14).
    公开号:KR20000060929A
    申请号:KR1019990009622
    申请日:1999-03-22
    公开日:2000-10-16
    发明作者:김기창
    申请人:정몽규；현대자동차 주식회사；
    IPC主号:
    专利说明:

    Vehicle panel rigidity analysis using point mobility {METHOD FOR ANALYZING STRENGTH OF VEHICLE PANEL UTILIZING POINT MOBILITY}
    The present invention relates to a method for analyzing the rigidity of an automobile panel, and more particularly, to a method for analyzing the rigidity of an automotive panel using point mobility.
    In general, the vibration-related analysis technique of a vehicle improves the stiffness of the vehicle by analyzing the dynamic stiffness of a cell or a finished vehicle in the finite element model of the finite element model in the low frequency idle region.
    The stiffness in the low frequency region (0-50 Hz) is determined by the stiffness of the cross section or joining portion of the vehicle member member. In addition, vibration modeling in the low frequency region is well-suited to the test data through simple modeling of the automotive panel which is sensitive to the high frequency region.
    Booming noise generated in the high frequency range is noise generated during rapid acceleration for high speed driving and overtaking, and the torque fluctuation of the engine during vibration due to rapid acceleration and gear shift of the vehicle is caused by vibration of the engine. This causes membrane vibrations in the body panel area. In addition, in the bouncing rotation speed region, an abnormal sound, ie, noise, is generated due to fluctuations in sound pressure volume due to vehicle panel vibration, which gives an unpleasant feeling to the driver and passenger.
    In addition, the boosting vibration characteristic factors include an engine vibration force, an exhaust system (muffler), a speaker (acoustic), and the like, which may be limited to characteristics of a vibration generating source and a transmission path thereof.
    In order to analyze the stiffness of the vehicle panel in the high frequency region, in the past, a starter vehicle was made and then the stiffness of the vehicle body panel was improved according to the result obtained by the actual stiffness test through the test vehicle.
    However, in the conventional method, since the frequent design changes are made to improve the body panel stiffness, the development cost is not only increased, but also the start vehicle confirmation is caused by the addition of the production cost, which causes the cost of the automobile.
    The present invention is to solve such a problem, the object of the present invention is to design the actual vehicle by evaluating the stiffness of the vehicle panel in the initial or conceptual design stage to improve the booming noise caused by the vibration of the high frequency region in the prior development stage of the vehicle Is to ensure that the design needed to improve the stiffness can be reflected in the design.
    1 is a flowchart illustrating a method of analyzing the rigidity of the vehicle panel using point mobility according to the present invention,
    FIG. 2 is a perspective view illustrating a vehicle body finite element model in an automotive panel rigidity analysis method using point mobility according to the present invention;
    3 is a perspective view showing a detailed model of the cowl top of the panel sensitive portion in the method for analyzing vehicle panel rigidity using point mobility according to the present invention,
    4 is a graph illustrating a frequency response function cover for a cowl center portion in a method for analyzing vehicle panel stiffness using point mobility according to the present invention.
    5 is a perspective view illustrating a stiffness improvement example of the cowl center portion in the vehicle panel rigidity analysis method using point mobility according to the present invention.
    In order to achieve the above object, the present invention comprises the steps of performing a low frequency idle vibration analysis through the vehicle body finite element model; Modeling a panel sensitive part sensitive to high frequency vibration from the low frequency idle vibration analysis and analysis data of a previous vehicle model; Setting a stiffness target value for the panel sensitive portion, and setting an excitation node, an excitation direction, and an excitation frequency region for high frequency vibration analysis from analysis data of a previous vehicle model; Calculating a frequency response characteristic through a random response analysis based on point mobility of the panel sensitive unit in a set excitation direction and an excitation node in the set excitation frequency domain; Determining the stiffness level of the panel sensitive portion according to the frequency response characteristic, and if the determined stiffness level is equal to or greater than the set stiffness target value, producing a starting vehicle and performing a test evaluation.
    The stiffness level of the panel sensitive portion is determined according to the frequency response characteristics, and when the determined stiffness level is smaller than the set stiffness target value, an improvement plan for increasing the stiffness is calculated and improved finite element modeling is performed. And repeating the calculation of the improvement plan such that the stiffness level is greater than or equal to the stiffness target value through a random response analysis based on the point mobility of the finite element model of the panel sensitive unit.
    Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
    FIG. 1 is a flowchart illustrating a method of analyzing the rigidity of a vehicle panel using point mobility according to the present invention. First, in order to analyze the body strength through the low frequency idle vibration analysis, the vehicle finite element modeling is performed as shown in FIG. S1) Next, the general mode analysis of the natural vibration analysis and the finite element static analysis is performed using the vehicle body finite element model (S2).
    At this time, the natural vibration analysis in the normal mode analysis (S2) calculates the natural frequency and vibration shape of the vehicle body, and in the finite element static analysis calculates the displacement and stress of the vehicle body according to the bending, torsional and bumping load conditions.
    Subsequently, the part where the panel film vibration is sensitive to the high frequency region which is the boosting region due to rapid acceleration while driving the vehicle is set by various test data of the previous vehicle model (S3). In this case, the panel sensitive portion may be a cowl top, a dash, a floor, a tunnel, a package tray, a roof, a spare tire room according to various test data. tire room).
    Further, detailed modeling is performed on the panel sensitive portion compared to the booming noise (S4) to form a finite element detailed model for each panel sensitive portion set as the finite element detailed model for the cowl top illustrated in FIG. 3.
    Then, after setting the stiffness target value of the panel sensitive part for improving the squeeze noise (S5), the excitation node, the excitation direction, and the frequency domain are set for analyzing the panel stiffness using the point mobility (S6). Point mobility is a method that determines the stiffness level or vibration sensitivity by determining the excitation node of the panel or member and analyzing the frequency response characteristics in the X, Y, and Z directions by tapping with an impulse hammer. In the present invention, it is to find an improvement part through an analysis, and analyzes the analysis and test data for the previous vehicle to set an excitation node, an excitation direction, and an excitation frequency region for point mobility.
    Subsequently, random response analysis is performed for each panel sensitive unit by the set excitation node excitation direction and excitation frequency domain (S7).
    Then, a random response analysis calculates the sensitivity (inertance; m / s 2 / N) for each excitation frequency range, that is, an acceleration level (m / s 2 ) function for the unit engine vibration force (N) (S8). Next, as shown in FIG. 4, a frequency response function curve (FRF) is generated (S9), and a stiffness curve is generated (S10).
    At this time, Figure 4 shows an example of the panel stiffness analysis using the point mobility, the Z-direction excitation in the cowl tower center portion, and shows an improvement example through the frequency characteristic analysis.
    In FIG. 4, the cover from the lower left to the upper right is a rigid cover, and the unit is Kgf / mm. That is, how many Kgf force is required for 1mm panel vibration, in other words, when the same load is applied, the lower the cover level is, the lower the vibration amount is, which means that the rigidity is large, and the value of the rigid curve is the cover by log scale. It is expressed by multiples of 50, 100, 200, 400 by the formula.
    In FIG. 4, the horizontal axis is a natural frequency, and 0 to 100 Hz in the frequency domain (0 to 600 Hz) is associated with the skeleton stiffness of the vehicle, and 100 to 600 Hz region is managed in association with the panel local stiffness as the medium and high speed booming region. , Vertical axis means sensitivity. In addition, the high peak value of the cover means that the vibration level is high in the corresponding frequency range.
    As described above, after generating the frequency response function cover to which the rigid cover is added to each panel sensitive unit, it is determined whether the detected rigidity level of the panel sensitive unit is greater than or equal to the set rigidity target value (S11).
    At this time, if the stiffness level of the panel sensitive portion (the cowl top) is smaller than the set stiffness target value as shown in the cover B of FIG. 4, the reinforcement panel 11, the foamed asphalt pad 12, and the like inside the cowl top as shown in FIG. 5. After calculating the improvement plan for increasing the stiffness (S12), performing finite element modeling on the improved panel sensitive portion (S13), and repeating the process of random response analysis through the improved finite element model of the panel sensitive portion. (S7, S8, S9, S10, S11) When the stiffness level of the panel sensitive part is higher than the set stiffness target value, a starting vehicle is produced and the test evaluation is performed.
    As described above, the present invention performs the stiffness analysis for the stiffness level and the sensitive portion of the cowl, the dash, the floor, the roof, the package tray, the spare tire room, and the like in the booming region (200 Hz to 400 Hz) due to rapid acceleration while driving the vehicle. In the development stage, it is possible to reduce the number of test car productions and shorten the development period by reflecting the improvement plan, and not only reduce the cost of automobile production, but also secure early merchandise.
    权利要求:
    Claims (3)
    [1" claim-type="Currently amended] Performing low frequency idle vibration analysis through a body finite element model;
    Modeling a panel sensitive part sensitive to high frequency vibration from the low frequency idle vibration analysis and analysis data of a previous vehicle model;
    Setting a stiffness target value for the panel sensitive portion, and setting an excitation node, an excitation direction, and an excitation frequency region for high frequency vibration analysis from analysis data of a previous vehicle model;
    Calculating a frequency response characteristic through a random response analysis based on point mobility of the panel sensitive unit in a set excitation direction and an excitation node in the set excitation frequency domain;
    Determining the stiffness level of the panel sensitive portion according to the frequency response characteristic, and if the determined stiffness level is equal to or more than the set stiffness target value, producing a starting vehicle and performing test evaluation. Automotive Panel Stiffness Analysis Method
    [2" claim-type="Currently amended] The finite element modeling method of claim 1, wherein the stiffness level of the panel sensitive unit is determined according to the frequency response characteristics. The method further includes repeating the calculation of the improvement plan such that the stiffness level is equal to or greater than the stiffness target value by analyzing the finite element model of the improved panel sensitive part based on the point mobility. Automotive Panel Stiffness Analysis Method.
    [3" claim-type="Currently amended] According to claim 1 or 2, In determining the rigidity level of the panel sensitive portion in accordance with the frequency response characteristics, by adding a rigid cover to the frequency response characteristics, the rigidity of the panel sensitive portion relative to the rigid cover Automotive panel stiffness analysis method using point mobility characterized in that the level is identified.
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    同族专利:
    公开号 | 公开日
    KR100288236B1|2001-04-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-03-22|Application filed by 정몽규, 현대자동차 주식회사
    1999-03-22|Priority to KR1019990009622A
    2000-10-16|Publication of KR20000060929A
    2001-04-16|Application granted
    2001-04-16|Publication of KR100288236B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019990009622A|KR100288236B1|1999-03-22|1999-03-22|Method for analyzing strength of vehicle panel utilizing point mobility|
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