Systematic simulation performance analysis method for front-end frame modularization multiple working conditions

Abstract

The invention discloses a front-end frame modularized multi-working-condition systematic simulation performance analysis method, which belongs to the field of automobile part manufacturing, and comprises the following steps: establishing a front-end frame and peripheral part three-dimensional model according to data, performing mid-plane extraction and grid division by using hypermesh software, setting grid attributes and material parameters, and establishing a front-end frame and peripheral part three-dimensional model; comprising grid thickness, material elasticity modulus, material density and material Poisson's ratio, systematic performance verification of modularized multiple working conditions of each mounting point of the front end frame of the automobile is carried out, and dynamic stiffness performance verification of additional constraint modes and other mounting points is carried out. Comprising a front end frame constraint mode, radiator installation point dynamic stiffness, horn installation point dynamic stiffness and air filter installation point dynamic stiffness. The modular simulation analysis not only can quickly identify the use performance of the front-end frame, but also can provide the direction of structure optimization and light weight for the design stage.

Description

Technical Field

[0001] The present invention relates to the field of automobile parts manufacturing, and in particular to a front-end frame modular multi-working condition systematic simulation performance analysis method. Background Art

[0002] The front-end frame of a car is one of the important parts of its integrated design. It is the installation platform for the radiator, condenser, intercooler and other parts. It is also an important safety component that is directly related to the safety, stability and overall performance of the vehicle.

[0003] The front-end module is located at the front of the car. When the car is driving, it will encounter interference from various external forces, causing complex vibrations. At the same time, it will be subjected to multiple loads such as torsion, collision and tension. Therefore, the stiffness and strength performance of the front-end frame must meet the requirements.

[0004] There are many module installation points integrated on the front-end frame. For example, the performance of the headlight, horn, front bumper, and lock mechanism installation points also needs to be guaranteed. If the rigidity of each installation point is not enough, it will cause abnormal noise and affect the use effect. Therefore, the evaluation of the rigidity and strength performance of the front-end frame is of great significance.

[0005] However, with the rapid development of the new car market, the development cycle of automotive parts has been drastically shortened. As one of the important automotive parts products, the front-end framework has a wide variety of performance indicators and very strict target requirements. In most of the current simulation processes, each module needs to be simulated separately, and multiple iterations may be required to optimize the simulation parameters and results, which undoubtedly increases the total time of simulation analysis and invisibly increases the development cycle of automotive parts. Summary of the invention

[0006] The purpose of the present invention is to provide a systematic simulation performance analysis method for a modular multi-working condition of a front-end frame, which effectively solves the problem that the existing simulation performance analysis method for the multi-working condition of the automobile front-end frame is time-consuming and may extend the development cycle of automobile parts.

[0007] The technical solution of the present invention is as follows:

[0008] A front-end framework modular multi-condition systematic simulation performance analysis method includes the following steps:

[0009] Step 1: Establish a 3D model of the front-end frame and surrounding components based on the data. The 3D model of the surrounding components includes anti-collision beams, energy absorption boxes, middle support sheet metal, connecting sheet metal, and headlight crossbeam components;

[0010] Step 2: Use hypermesh software to extract mid-surfaces and divide meshes, and set the mesh size to 3mm;

[0011] Step 3: Set the mesh properties and material parameters, including mesh thickness, material elastic modulus, material density, and material Poisson’s ratio;

[0012] Step 4: Conduct modular multi-condition system performance verification of each installation point of the front-end frame, including: hood lock maximum load strength, X, Z-axis static stiffness, headlight installation point static stiffness, buffer block rigidity point static stiffness, radiator installation point static stiffness, front bumper installation point static stiffness;

[0013] Step 5: Additional verification of system constraint modes and dynamic stiffness performance of other module installation points is performed, including: front-end frame constraint modes, radiator installation point dynamic stiffness, speaker installation point dynamic stiffness, and air filter installation point dynamic stiffness.

[0014] Preferably, in step 4, the specific method for analyzing the large load strength of the hood lock is: applying a force of 5300N in the -Z direction at the hood lock installation point G, and calculating the overall stress distribution of the front end frame through software simulation. If the calculated maximum stress value exceeds the material yield limit, the front end frame may have cracks, breakage, etc., otherwise it will not appear;

[0015] The specific method for analyzing the X / Z static stiffness of the hood lock point G is as follows: apply forces of +200N in the X direction and -400N in the Z direction at the hood lock installation point G respectively, and calculate the X / Z deformation of point G through software to determine whether the engine hood is sinking when the engine hood is closed.

[0016] Preferably, in the above step 4, a force of 300N is applied to the headlight mounting point D1 / D2 in the -Z direction, and the deformation of the headlight point in the -Z direction is calculated by software to evaluate whether there is a jitter phenomenon in the headlight light.

[0017] Preferably, in the above step 4, a force of 400N is applied to the -Z direction of the rigid point H1 / H2 of the buffer block, and the deformation of the point H1 / H2 in the -Z direction is calculated by software to evaluate whether the engine cover is in a sinking state.

[0018] Preferably, in the above step 4, a force of 600N is applied to the -Z direction of the radiator mounting points S1 / S2 respectively, and the deformation of the radiator mounting points is calculated by software to determine whether there is shaking and abnormal noise at the mounting position of the radiator of the whole vehicle.

[0019] Preferably, in the above step 4, a force of 200N is applied to the front bumper mounting points Q1 / Q2 / Q3 / Q4 in the -Z direction respectively, and the deformation of the front bumper mounting points is calculated by software to determine whether there is shaking of the front bumper assembly in the whole vehicle state.

[0020] Preferably, in the above step five, an EIGRL modal card is created, the modal order is set to the first 10 orders, and the first-order constraint mode of the front-end frame is calculated by software to determine whether the front-end frame resonates with the entire vehicle, causing the front-end frame to fail.

[0021] Preferably, in the above step five, a dynamic load DARER of 1 is applied to the -Z direction of the radiator mounting point S1 / S2, and a dynamic stiffness curve within a frequency range of 20Hz-50Hz is calculated to determine whether cracks occur at the radiator mounting point under low frequency conditions.

[0022] Preferably, in the above step five, a dynamic load DARER of 1 is applied to the -Z direction of the speaker mounting point L1 / L2, and a dynamic stiffness curve within a frequency range of G frequency ±50 Hz is calculated by software to determine whether cracks occur at the speaker mounting point under medium and low frequency conditions.

[0023] Preferably, in the above step five, a dynamic load DARER of 1 is applied to the -Z direction of the air filter installation point K, and a dynamic stiffness curve in the frequency range of 20 Hz-50 Hz is calculated by software to determine whether cracks occur at the air filter installation point under low frequency conditions.

[0024] The advantages of the present invention are:

[0025] 1. The modular multi-working condition systematic simulation performance analysis method of the front-end frame designed by the present invention can simultaneously and quickly and accurately analyze and calculate the dynamic and static stiffness, structural strength and constraint mode of each installation point on the front-end frame, greatly reducing the analysis and verification time and thus shortening the development cycle of the front-end frame and the vehicle development cycle. It has extremely high practical value and promotion significance in the field of automobile front-end frame technology development.

[0026] 2. The present invention has obvious advantages in the systematic simulation analysis of modular multi-working conditions of the front-end frame of the automobile. The modular simulation analysis can not only quickly identify the performance of the front-end frame, but also provide directions for structural optimization and lightweighting in the design stage.

[0027] 3. The present invention not only constructs each individual module of the front-end framework, but also fully considers the system problems of the peripheral connection parts of the front-end framework, effectively avoiding the situation where the existing method has large calculation errors and improving the accuracy of data calculation.

[0028] 4. The present invention not only takes into account its large load strength and static stiffness of some installation points, but more importantly, takes into account the system mode and the dynamic stiffness of the installation points. In the whole vehicle analysis, there is low-frequency vibration, which may cause the occurrence of system resonance or insufficient dynamic stiffness of the installation point, resulting in damage to the installation point, etc. (such as insufficient dynamic stiffness of the radiator, which may cause the radiator rubber pad to be damaged and fall off), thereby improving the accuracy of the data of the systematic simulation performance analysis method of the modular multi-working conditions of the front-end frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process of the present invention;

[0030] Figure 2 It is a schematic diagram of the static stiffness detection positions of the front-end frame except the radiator mounting point of the present invention;

[0031] Figure 3 It is a schematic diagram of the dynamic stiffness detection position of the speaker position in the front end frame of the present invention;

[0032] Figure 4 It is a schematic diagram of the radiator installation point, air filter installation point and detection position in the front end frame of the present invention. DETAILED DESCRIPTION

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] like Figures 1 to 4 As shown, the present invention provides a front-end framework modular multi-condition systematic simulation performance analysis method, which includes the following steps:

[0037] Step 1: Establish a 3D model of the front-end frame and surrounding components based on the data. The 3D model of the surrounding components includes anti-collision beams, energy absorption boxes, middle support sheet metal, connecting sheet metal, and headlight crossbeam components;

[0038] Step 2: Use hypermesh software to extract mid-surfaces and divide meshes, and set the mesh size to 3mm;

[0039] Step 3: Set the mesh properties and material parameters, including mesh thickness, material elastic modulus, material density, and material Poisson’s ratio;

[0040] Step 4: Conduct modular multi-condition system performance verification of each installation point of the front-end frame, including: hood lock maximum load strength, X, Z-axis static stiffness, headlight installation point static stiffness, buffer block rigidity point static stiffness, radiator installation point static stiffness, front bumper installation point static stiffness;

[0041] Step 5: Additional verification of system constraint modes and dynamic stiffness performance of other module installation points is performed, including: front-end frame constraint modes, radiator installation point dynamic stiffness, speaker installation point dynamic stiffness, and air filter installation point dynamic stiffness.

[0042] It should be noted that according to the motion control equation From the equation of simple harmonic motion, we can see that Knowable F=(-ω 2 m+jωc+k)x , and then transform to get the dynamic stiffness expression k d =F / x=-ω 2 m+jωc+k. From the above dynamic stiffness expression, we can see that dynamic stiffness is related to frequency, mass and damping. When the frequency is 0, the dynamic stiffness is the static stiffness.

[0043] According to the expression, the motion process can be divided into three stages: low frequency band, resonance frequency band and high frequency band: first, the dynamic stiffness in the low frequency band is close to the static stiffness, that is, the static stiffness dominates in this frequency band; second, the amplitude of the dynamic stiffness in the resonance frequency band decreases significantly, and this frequency band is mainly controlled by damping. A damping scheme can be used to suppress the occurrence of system resonance; third, the dynamic stiffness in the high frequency band is significantly affected by the mass of the system, which produces a large inertial resistance and enhances the ability to resist deformation. Based on the above theoretical derivation, the following actual engineering calculations are performed.

[0044] Setting of material parameters of the front-end frame module. The materials commonly used for the front-end frame are long glass fiber reinforced polypropylene plastic products and glass fiber reinforced nylon 6. The brands are PP+LGF30, PP+LGF35, PP+LGF40, PA6+GF30, etc., where the numbers represent the glass fiber content of 30%, 35%, 40%, etc. The material properties are different for different glass fiber contents. The parameters of long glass fiber reinforced polypropylene plastic products and glass fiber reinforced nylon 6 are usually provided by material manufacturers, and the performance analysis of the front-end frame mainly involves parameters such as material mesh thickness, material elastic modulus, material density, and material Poisson's ratio.

[0045] Preferably, in step 4, the specific method for analyzing the large load strength of the hood lock is: applying a force of 5300N in the -Z direction at the hood lock installation point G, and calculating the overall stress distribution of the front end frame through software simulation;

[0046] It should be noted that if the calculated maximum stress value exceeds the yield limit of the material, cracks, breakage, etc. may occur in the front frame, otherwise this will not occur.

[0047] The specific method for analyzing the X / Z-direction static stiffness of the bonnet lock point G is as follows: apply a force of 200N in the +X direction and 400N in the -Z direction at the bonnet lock installation point G;

[0048] It should be noted that the deformation of the G point in the X / Z direction is calculated by software to determine whether the engine hood is sinking when the engine hood is closed.

[0049] Preferably, in the above step 4, a force of 300N is applied to the headlight mounting point D1 / D2 in the -Z direction;

[0050] It should be noted that the Z-axis deformation of the headlight is calculated by software to evaluate whether there is any jitter in the light of the headlight.

[0051] Preferably, in the above step 4, a force of 400N is applied to the -Z direction of the rigid point H1 / H2 of the buffer block;

[0052] It should be noted that the deformation in the Z direction at the H1 / H2 point is calculated by software to evaluate whether the engine cover is sinking.

[0053] Preferably, in the above step 4, a force of 600N is applied to the -Z direction of the heat sink mounting points S1 / S2 respectively;

[0054] It should be noted that the deformation of the radiator installation point is calculated by software to determine whether there is shaking and abnormal noise at the installation position of the radiator of the whole vehicle.

[0055] Preferably, in the above step 4, a force of 200N is applied to the front bumper mounting points Q1 / Q2 / Q3 / Q4 in the -Z direction respectively;

[0056] It should be noted that the deformation of the front bumper installation point is calculated by software to determine whether there is shaking in the front bumper assembly of the entire vehicle.

[0057] Preferably, in the above step 5, an EIGRL modal card is created, and the modal order is set to the first 10 orders;

[0058] It should be noted that the first-order constraint mode of the front-end frame is calculated by software to determine whether the front-end frame resonates with the entire vehicle, causing the front-end frame to fail.

[0059] Preferably, in the above step 5, a dynamic load of 1 is applied to the -Z direction of the heat sink mounting points S1 / S2 respectively;

[0060] The dynamic stiffness curve within the frequency range of 20Hz-50Hz is calculated to determine whether cracks occur at the radiator mounting point under low frequency conditions.

[0061] Preferably, in the above step 5, a dynamic load DARER of 1 is applied to the -Z direction of the speaker mounting points L1 / L2 respectively;

[0062] It should be noted that the dynamic stiffness curve within the frequency range of G frequency ±50Hz is calculated by software to determine whether cracks occur at the speaker installation point under medium and low frequency conditions.

[0063] Preferably, in the above step 5, a dynamic load DARER of 1 is applied to the -Z direction of the air filter installation point K;

[0064] It should be noted that the dynamic stiffness curve in the frequency range of 20Hz-50Hz is calculated by software to determine whether cracks occur at the air filter installation point under low-frequency conditions.

[0065] Detailed usage and effects of the above embodiments:

[0066] A 3D model of the front-end frame and surrounding components is established based on the 3D data of the front-end frame. The front-end frame is then meshed using the hypermesh software. The front-end frame parameters are then set (including mesh thickness, material elastic modulus, material density, material Poisson's ratio, etc.). Finally, a performance evaluation is performed based on the front-end frame usage specifications (including hood lock maximum load strength, X and Z static stiffness, headlight mounting point static stiffness, buffer block rigidity point static stiffness, radiator mounting point static stiffness, front bumper mounting point static stiffness. System constraint modes and dynamic stiffness performance verification of other module mounting points are also added, including: front-end frame constraint modes, radiator mounting point dynamic stiffness, horn mounting point dynamic stiffness, air filter mounting point dynamic stiffness).

[0067] The following table shows the analysis methods of the front-end frame strength, first-order mode, static stiffness and dynamic stiffness:

[0068]

[0069] Finally, the analysis results are compared with the target values. Only when the static stiffness, dynamic stiffness and semi-locked large load strength performance of each installation point of the front-end frame are met, the performance of the front-end frame meets the standard. Otherwise, it does not meet the standard and various parameters need to be optimized again.

[0070] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A front-end framework modular multi-condition systematic simulation performance analysis method, characterized in that: The steps include: Step 1: Establish a 3D model of the front-end frame and surrounding components based on the data. The 3D model of the surrounding components includes anti-collision beams, energy absorption boxes, middle support sheet metal, connecting sheet metal, and headlight crossbeam components; Step 2: Use hypermesh software to extract mid-surfaces and divide meshes, and set the mesh size to 3mm; Step 3: Set the mesh properties and material parameters, including mesh thickness, material elastic modulus, material density, and material Poisson’s ratio; Step 4: Conduct modular multi-condition system performance verification of each installation point of the front-end frame, including: hood lock maximum load strength, X, Z-axis static stiffness, headlight installation point static stiffness, buffer block rigidity point static stiffness, radiator installation point static stiffness, front bumper installation point static stiffness; Step 5: Additional verification of system constraint modes and dynamic stiffness performance of other module installation points is performed, including: front-end frame constraint modes, radiator installation point dynamic stiffness, speaker installation point dynamic stiffness, and air filter installation point dynamic stiffness.

2. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In step 4, the specific method for analyzing the large load strength of the hood lock is as follows: a force of 5300N in the -Z direction is applied at the hood lock installation point G, and the stress distribution of the entire front-end frame is calculated by software simulation. If the calculated maximum stress value exceeds the yield limit of the material, the front-end frame may have cracks, breakage, etc., otherwise it will not appear; The specific method for analyzing the X / Z static stiffness of the hood lock point G is as follows: apply forces of +200N in the X direction and -400N in the Z direction at the hood lock installation point G respectively, and calculate the X / Z deformation of point G through software to determine whether the engine hood is sinking when the engine hood is closed.

3. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 4, a force of 300N is applied to the headlight mounting point D1 / D2 in the -Z direction, and the deformation of the headlight point in the -Z direction is calculated by software to evaluate whether there is jitter in the headlight light.

4. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 4, a force of 400N is applied to the -Z direction of the rigid point H1 / H2 of the buffer block, and the deformation of the H1 / H2 point in the -Z direction is calculated by software to evaluate whether the engine cover is in a sinking state.

5. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 4, a force of 600N is applied to the -Z direction of the radiator mounting points S1 / S2 respectively, and the deformation of the radiator mounting points is calculated by software to determine whether there is shaking and abnormal noise at the radiator mounting position of the entire vehicle.

6. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 4, a force of 200N is applied to the front bumper mounting points Q1 / Q2 / Q3 / Q4 in the -Z direction respectively, and the deformation of the front bumper mounting points is calculated by software to determine whether there is shaking of the front bumper assembly in the state of the whole vehicle.

7. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In step five above, an EIGRL modal card is created, and the modal order is set to the first 10 orders. The first-order constraint mode of the front-end frame is calculated by software to determine whether the front-end frame resonates with the entire vehicle, causing the front-end frame to fail.

8. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 5, a dynamic load DARER of 1 is applied to the -Z direction of the radiator mounting point S1 / S2, and a dynamic stiffness curve within a frequency range of 20Hz-50Hz is calculated to determine whether cracks occur at the radiator mounting point under low frequency conditions.

9. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1 is characterized in that: In the above step 5, a dynamic load DARER of 1 is applied to the -Z direction of the speaker mounting point L1 / L2, and the dynamic stiffness curve within the frequency range of G frequency ±50Hz is calculated by software to determine whether the speaker mounting point is cracked under medium and low frequency conditions.

10. The front-end framework modular multi-condition systematic simulation performance analysis method according to claim 1, characterized in that: In the above step 5, a dynamic load DARER of 1 is applied to the -Z direction of the air filter installation point K. The dynamic stiffness curve in the frequency range of 20 Hz-50 Hz is calculated by software to determine whether cracks occur at the air filter installation point under low frequency conditions.

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