Automobile crash test system and method based on CAE simulation

Abstract

The invention relates to the field of vehicle performance testing, in particular to an automobile crash test system and method based on CAE simulation. Comprising the following steps: constructing a three-dimensional geometric model based on an automobile design drawing and a simulation scene, initializing parameters required by collision simulation, calculating to obtain initial total kinetic energy, and calculating to obtain a composite energy gradient through a composite energy gradient adaptive modeling algorithm; based on the composite energy gradient, using a dynamic grid reconstruction algorithm to obtain a grid reconstruction factor; based on the grid reconstruction factor, the initial total kinetic energy and the composite energy gradient, the deformation distance of the automobile part in collision is obtained through a self-adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear rigidity correction, and whether the automobile meets the safety standard or not is evaluated according to the deformation distance. The technical problems that only the mass and the speed of the whole vehicle are considered and the difference between the independent mass and the initial speed of each component is neglected when the initial total collision kinetic energy is calculated by the existing method are solved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle performance testing, and in particular to a vehicle collision test system and method based on CAE simulation. Background Art

[0002] With the rapid development of the automobile industry, automobile safety has become a core issue that cannot be ignored in the design and manufacturing process. As an important means to evaluate vehicle safety performance, automobile collision tests have been widely used in the past few decades. Traditional physical collision tests rely on real vehicles and test equipment to test the performance of vehicle structures, occupant protection systems and other safety components by simulating actual collision scenarios. However, this method has disadvantages such as high cost, long cycle, and limited repeatability. Especially in the early stages of automobile design, frequent physical tests are often impractical. Therefore, simulation technology based on Computer-Aided Engineering (CAE) has gradually become an important supplement and alternative in the field of automobile collision testing. CAE simulation can analyze the performance of automobiles under various collision conditions efficiently and at low cost in a virtual environment through numerical simulation methods, providing strong support for design optimization and safety verification.

[0003] Efficient and economical evaluation of vehicle safety performance through virtual means makes up for the shortcomings of traditional physical tests and plays a key role in design optimization. With the continuous advancement of computing power and modeling technology, CAE simulation will play a more important role in future automobile development and make greater contributions to improving traffic safety and occupant protection.

[0004] However, the above-mentioned existing traditional vehicle collision simulation methods are often unable to accurately capture the complex energy distribution and material response characteristics, resulting in a large deviation between the simulation results and the actual collision behavior. The low-precision simulation has the risk of misjudging the deformation or failure of vehicle components. The lack of dynamic optimization in mesh division limits the feasibility of complex collision scenarios under conventional computing conditions. Traditional simulation technology does not adequately consider the nonlinear response of material stiffness and energy dissipation, making it difficult to reflect real physical phenomena such as material softening and enhanced energy dissipation in high-speed collisions, resulting in the problem that deformation predictions are inconsistent with experimental results. Summary of the invention

[0005] The present invention provides a car collision test system and method based on CAE simulation, so as to solve the technical problems that the existing methods often only consider the mass and speed of the whole vehicle when calculating the initial total kinetic energy of the collision, and ignore the independent mass and initial speed differences of each component; the traditional simulation lacks a means to quantify the energy distribution differences between components; the traditional grid division method is static and fixed, and the density cannot be adjusted according to the degree of energy concentration, resulting in the loss of local details or calculation redundancy; the existing technology often assumes that energy dissipation and material stiffness are constants, and fails to reflect the technical problems of enhanced dissipation caused by the increase in speed in the collision or reduced stiffness caused by stress concentration.

[0006] The present invention provides a CAE simulation-based automobile collision test system and method, which specifically includes the following technical solutions: A car collision test method based on CAE simulation includes the following steps: S1. Based on the automobile design drawings and simulation scenarios, a 3D geometric model is constructed and the parameters required for collision simulation are initialized; based on the parameters of the 3D geometric model and the parameters required for collision simulation, the initial total kinetic energy is calculated and the composite energy gradient is calculated by the composite energy gradient adaptive modeling algorithm; S2. Based on the composite energy gradient, the grid reconstruction factor is obtained using the dynamic grid reconstruction algorithm. Based on the grid reconstruction factor, the initial total kinetic energy and the composite energy gradient, the deformation distance of the automobile parts in the collision is obtained through the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, and the automobile is evaluated whether it meets the safety standards based on the deformation distance.

[0007] Preferably, the S1 specifically includes: The kinetic energy of each component of the car is evaluated independently to obtain the kinetic energy value of a single component, and the kinetic energy values ​​of all components of the car are accumulated to obtain the initial total kinetic energy.

[0008] Preferably, the S1 specifically includes: After calculating the initial total kinetic energy, the composite energy gradient adaptive modeling algorithm is introduced to analyze the distribution of collision energy among different parts of the car and calculate the composite energy gradient.

[0009] Preferably, the S1 specifically includes: In the process of implementing the composite energy gradient adaptive modeling algorithm, the material characteristic parameters in the three-dimensional geometric model parameters of the automobile, including elastic modulus and yield strength, are introduced, and the spatial position of the automobile parts is analyzed. By combining the cosine function for adjustment, the composite energy gradient is obtained. The calculation formula is: , in, Indicates The composite energy gradient of each component; Indicates The kinetic energy term of each component; Indicates The quality of each component; Indicates The initial velocity of each component at the beginning of the collision; Indicates The elastic modulus of each component; Indicates The distance from the center of each component to the collision point; Indicates Yield strength of each component; Indicates The cosine of the angle between the velocity direction of each component and the collision normal.

[0010] Preferably, the S2 specifically includes: The dynamic mesh reconstruction algorithm compares the composite energy gradient of each component of the car with the preset reference energy gradient, and smoothes the force difference through square root operation. By combining the surface area and volume ratio of each component of the car, it reflects the influence of the geometric characteristics of the component on the mesh division, and finally generates a mesh reconstruction factor.

[0011] Preferably, the S2 specifically includes: The adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction is divided into three main parts: calculation of dynamic energy dissipation factor, calculation of corrected stiffness and calculation of final deformation distance.

[0012] Preferably, the S2 specifically includes: The dynamic energy dissipation factor is calculated by using a composite energy gradient and a grid reconstruction factor, while introducing the elastic modulus of the component and combining it with an exponential adjustment term; the modified stiffness is calculated by introducing the elastic modulus and combining it with an exponential function.

[0013] Preferably, the S2 specifically includes: Based on the dynamic energy dissipation factor and the modified stiffness, the calculation of the deformation distance combines the initial total kinetic energy, the surface area and the yield strength of the component, and the calculation formula is: , in, Indicates The deformation distance of each component; represents the initial total kinetic energy; Indicates Dynamic energy dissipation factor of each component; Indicates The surface area of ​​each component; Indicates The corrected stiffness of a component.

[0014] A car collision test system based on CAE simulation includes the following parts: Geometric modeling module, energy calculation module, grid reconstruction module, simulation solution module, performance evaluation module; Geometric modeling module: Based on the car design drawings and simulation scenarios, it builds the digital expression of the car, generates the three-dimensional geometric model of the car, initializes the parameters required for collision simulation, and outputs the parameters of the three-dimensional geometric model of the car and the parameters required for collision simulation to the energy calculation module; Energy calculation module: according to the parameters of the car in the geometric modeling module and the parameters required for collision simulation, the initial total kinetic energy is calculated, the composite energy gradient is calculated by the composite energy gradient adaptive modeling algorithm, the initial total kinetic energy is output to the simulation solution module, and the composite energy gradient is output to the network reconstruction module and the simulation solution module; Grid reconstruction module: Based on the composite energy gradient of the energy calculation module, the grid reconstruction factor of each component of the car is calculated using the dynamic grid reconstruction algorithm, and the grid reconstruction factor of each component of the car is output to the simulation solution module; Simulation solution module: runs dynamic explicit simulation, calculates the deformation distance of each component of the vehicle based on the mesh reconstruction factor of the mesh reconstruction module, the initial total kinetic energy and composite energy gradient of the energy calculation module, and the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, and outputs the deformation distance of each component of the vehicle to the performance evaluation module; Performance evaluation module: Analyzes the deformation distance of each component of the car output by the simulation solution module to evaluate whether the vehicle's collision performance meets safety standards.

[0015] The beneficial effects of the technical solution of the present invention are: 1. By collecting the basic physical properties and material characteristic parameters of each component of the car and calculating the initial total kinetic energy based on the basic principles of physics, the initial energy state of the car collision is fully quantified, laying a reliable energy benchmark for subsequent simulation analysis, so that the energy reserve of the collision scene can be accurately grasped, thereby improving the consistency between the simulation results and the actual collision behavior, and providing more realistic data support for automobile safety assessment.

[0016] 2. Through the composite energy gradient adaptive modeling algorithm, the distribution law of collision energy among different parts of the vehicle is deeply analyzed, the composite energy gradient of each part is obtained, and the non-uniformity of energy distribution is identified, especially the concentrated energy borne by parts close to the collision point and with higher stiffness. This overcomes the assumption of uniform energy distribution in traditional methods. The refined energy distribution description provides a basis for modeling high-stress areas, thereby improving the simulation's ability to predict local stress concentration phenomena and making collision test results closer to reality.

[0017] 3. Based on the composite energy gradient, the grid reconstruction factor is calculated using the dynamic grid reconstruction algorithm, which optimizes the grid density distribution and achieves high-resolution simulation of high-energy concentrated areas, while avoiding redundant calculations in low-energy areas. This not only improves the simulation accuracy and makes the simulation of local stress distribution and deformation behavior more realistic, but also optimizes the allocation efficiency of computing resources, reduces computing costs and simulation time, making the simulation of complex collision scenarios feasible under conventional hardware conditions and significantly improving engineering practicality.

[0018] 4. Through the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, the deformation distance of automobile parts in the collision is accurately calculated, and whether the automobile meets the safety standards is evaluated based on the deformation distance. It overcomes the traditional simulation's neglect of energy dissipation and nonlinear response of material stiffness, obtains deformation results that are closer to actual physical behavior, enhances the simulation's ability to evaluate the state of components after a collision, and provides a reliable basis for the verification of safety performance. At the same time, it reduces dependence on expensive physical tests and reduces R&D costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of a car collision test system based on CAE simulation according to the present invention; Figure 2 The present invention is a flow chart of a car collision test method based on CAE simulation. DETAILED DESCRIPTION

[0020] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0022] The specific scheme of a car collision test system and method based on CAE simulation provided by the present invention is described in detail below with reference to the accompanying drawings.

[0023] See attached Figure 1 , which shows a structural diagram of a car collision test system based on CAE simulation provided by an embodiment of the present invention, the system includes the following parts: Geometric modeling module, energy calculation module, grid reconstruction module, simulation solution module, performance evaluation module; Geometric modeling module: Based on the car design drawings and simulation scenarios, it builds the digital expression of the car, generates the three-dimensional geometric model of the car, initializes the parameters required for collision simulation, and outputs the parameters of the three-dimensional geometric model of the car and the parameters required for collision simulation to the energy calculation module; Energy calculation module: Based on the parameters of the car in the geometric modeling module and the parameters required for collision simulation, the initial total kinetic energy is calculated through the basic principle of physics, that is, the kinetic energy formula, and the composite energy gradient is calculated through the composite energy gradient adaptive modeling algorithm. The initial total kinetic energy is output to the simulation solution module, and the composite energy gradient is output to the network reconstruction module and the simulation solution module; Grid reconstruction module: Based on the composite energy gradient of the energy calculation module, the grid reconstruction factor of each component of the car is calculated using the dynamic grid reconstruction algorithm, and the grid reconstruction factor of each component of the car is output to the simulation solution module; Simulation solution module: runs dynamic explicit simulation, calculates the deformation distance of each component of the vehicle based on the mesh reconstruction factor of the mesh reconstruction module, the initial total kinetic energy and composite energy gradient of the energy calculation module, and the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, and outputs the deformation distance of each component of the vehicle to the performance evaluation module; Performance evaluation module: Analyzes the deformation distance of each component of the car output by the simulation solution module, and evaluates whether the vehicle's collision performance meets safety standards, such as NCAP standards.

[0024] See attached Figure 2 , which shows a flow chart of a car collision test method based on CAE simulation provided by an embodiment of the present invention, the method comprising the following steps: S1. Based on the automobile design drawings and simulation scenes, a three-dimensional geometric model is constructed, and the parameters required for the collision simulation are initialized; based on the parameters of the three-dimensional geometric model and the parameters required for the collision simulation, the initial total kinetic energy is calculated, and the composite energy gradient is calculated by the composite energy gradient adaptive modeling algorithm; Based on the automobile design drawings and simulation scenarios, a digital expression of the automobile is constructed, a three-dimensional geometric model of the automobile is generated, and parameters required for collision simulation are initialized; the parameters of the three-dimensional geometric model of the automobile include but are not limited to basic physical properties and material characteristic parameters of each component of the automobile, such as mass, elastic modulus and yield strength; the parameters required for collision simulation include but are not limited to the distance from the spatial position of each component of the automobile to the collision point, speed, angle between the speed direction and the collision normal, surface area and volume; The initial total kinetic energy is calculated through the basic principle of physics, that is, the kinetic energy formula. Specifically, the kinetic energy of each component of the car is evaluated independently, that is, the kinetic energy value of a single component is obtained by multiplying the mass by the square of the speed and taking half. The kinetic energy values ​​of all components are accumulated to obtain the initial total kinetic energy in joules. The initial total kinetic energy value represents the energy reserve of the car at the initial moment of collision and is the basis for subsequent analysis. The calculation formula is: , in, Represents the initial total kinetic energy in joules (J), which is the energy input in the crash simulation and is used to quantify the energy that the car has in its initial state due to motion; It means the kinetic energy of all car parts is accumulated; Indicates The mass of each component, in kilograms (kg), is specified by the parameters of the 3D geometric model of the vehicle; Indicates The initial velocity of each component at the start of the collision, in meters per second (m / s), specified by the parameters required for the collision simulation; After calculating the initial total kinetic energy, in order to quantify the composite energy gradient of each component of the car, the composite energy gradient adaptive modeling algorithm is used to deeply analyze the distribution law of collision energy among different components of the car and calculate the composite energy gradient; The composite energy gradient adaptive modeling algorithm introduces material characteristic parameters in the parameters of the three-dimensional geometric model of the automobile, including elastic modulus and yield strength. The elastic modulus is measured in Pascals, reflecting the stiffness characteristics of the material when subjected to force, while the yield strength is also measured in Pascals, indicating the maximum stress that the material can withstand. At the same time, the spatial position of the automobile parts is considered, that is, the distance from each automobile part to the collision point is measured in meters. The distance from each automobile part to the collision point directly affects the concentration of energy distribution. The closer the distance is, the greater the impact is. A directional factor is also introduced, that is, the angle between the speed direction of the part and the collision normal, measured in radians, which is adjusted by the cosine function to reflect the directional effect of energy transfer. For example, when the speed direction of the part is completely consistent with the collision normal, the cosine value is 1, and the energy transfer reaches the maximum. When the two are perpendicular, the cosine value is 0, and the energy transfer is zero. The calculation formula of the composite energy gradient is: , in, Indicates The composite energy gradient of each component, in joules per meter (J / m), is used to quantify the energy distribution characteristics of each component of the vehicle; Indicates The kinetic energy term of each component; Indicates The elastic modulus of each component, in Pascal (Pa), reflects the influence of material stiffness on energy response. The higher the material stiffness, the more concentrated the energy transfer. It comes from the material property database; Indicates The distance from the center of each component to the collision point, in meters (m), reflects the effect of energy attenuation with distance. The closer the distance from the center of the component to the collision point, the greater the composite energy gradient; Indicates The yield strength of each component, in Pascal (Pa), reflects the material's ability to resist plastic deformation. The higher the yield strength, the more restricted the energy transfer. It comes from the material property database; Indicates The cosine value of the angle between the velocity direction of each component and the collision normal introduces the directionality of energy transfer. When the velocity direction is consistent with the collision normal, that is, , the energy transfer is strongest; when the velocity direction is perpendicular to the collision normal, that is, , the composite energy gradient is zero; The initial total kinetic energy provides a macroscopic perspective for the overall energy, while the composite energy gradient provides a refined description of the microscopic energy distribution of each component of the vehicle. By quantifying the initial total kinetic energy at the beginning of the collision, a global benchmark is provided for the energy state of the vehicle, which is convenient for evaluating the performance of the vehicle in different collision scenarios. By calculating the composite energy gradient, the non-uniformity of energy distribution can be identified, especially the concentrated energy borne by components close to the collision point and with higher stiffness, which provides a basis for the refined modeling of high stress areas in the simulation, overcomes the assumption of uniform energy distribution in traditional modeling, and improves the consistency between the simulation results and the actual collision behavior. S2. Based on the composite energy gradient, a dynamic grid reconstruction algorithm is used to obtain a grid reconstruction factor; based on the grid reconstruction factor, the initial total kinetic energy and the composite energy gradient, an adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction is used to obtain the deformation distance of the automobile parts in the collision, and whether the automobile meets the safety standards is evaluated based on the deformation distance; In computer simulation (CAE), the grid is calculated by dividing the car model into small blocks. When the grid is too coarse, the calculation accuracy is insufficient, and when the grid is too fine, the calculation amount is too large. The traditional method assumes that the energy is evenly distributed, ignoring the influence of local stress concentration, resulting in insufficient simulation accuracy. Based on the composite energy gradient, the dynamic grid reconstruction algorithm is used to calculate the grid reconstruction factor through dynamic analysis of energy distribution, thereby optimizing the grid density distribution. The dynamic mesh reconstruction algorithm compares the composite energy gradient of each component of the car with the preset reference energy gradient to measure the force difference of each component of the car, and smoothes the force difference through square root operation to linearly adjust the mesh density. By combining the surface area and volume ratio of each component of the car, it reflects the influence of the geometric characteristics of the component on the mesh division. Components with large surface area and small volume require higher mesh density to capture details. For example, thin plates are more easily deformed than thick plates. The mesh reconstruction factor finally generated is used to guide the dynamic adjustment of the mesh density. The calculation formula of the mesh reconstruction factor is: , in, Indicates The mesh reconstruction factor of each component; Represents the preset reference energy gradient, which is used to standardize the composite energy gradient to make the energy intensity comparable. The unit is joule / meter (J / m). It can be set according to the specific implementation scenario and is not limited here. Indicates The surface area of ​​each component in square meters (m²); Indicates The volume of each component in cubic meters (m³); By dynamically adjusting the grid density, higher resolution is ensured in high-energy concentration areas, thereby more realistically simulating the local stress distribution and deformation behavior of automotive components. At the same time, the allocation efficiency of computing resources is optimized, effectively reducing computing costs and avoiding redundant calculations. This not only shortens the simulation time, but also makes the simulation of complex collision scenarios feasible under conventional hardware conditions, with high engineering practicality.

[0025] In order to overcome the neglect of energy dissipation and nonlinear response of material stiffness in traditional simulation methods and improve the authenticity and accuracy of simulation, based on the grid reconstruction factor, initial total kinetic energy and composite energy gradient, an adaptive deformation calculation algorithm with dynamic energy dissipation and nonlinear stiffness correction is used to accurately calculate the deformation distance of automobile parts in a collision, and evaluate whether the automobile meets the safety standards based on the deformation distance; The adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction is divided into three main parts: calculation of dynamic energy dissipation factor, calculation of corrected stiffness and calculation of final deformation distance; The calculation of the dynamic energy dissipation factor is used to quantify the proportion of energy reduction due to dissipation during a car collision. The obtained composite energy gradient and grid reconstruction factor are used, and the elastic modulus of the component is introduced as part of the denominator to form a basic ratio, which is then multiplied by an exponential adjustment term. Based on the ratio of the initial speed of the component to a preset reference speed, a value between 0 and 1 is calculated through an exponential function to simulate the nonlinear effect of speed on energy dissipation: when the initial speed is much greater than the preset reference speed, the dissipation effect tends to saturation, and when the initial speed is less than the preset reference speed, the dissipation effect is weak; The modified stiffness is used to characterize the dynamic change of stiffness of automobile parts in collision. The design is based on a physical intuition: in the high energy gradient area, the material may show a phenomenon of reduced stiffness due to stress concentration, while in the low energy gradient area, the stiffness is close to the original value. The exponential function is introduced to ensure the smoothness and nonlinear characteristics of the stiffness change, avoiding the assumption of constant stiffness in traditional methods, so that the stiffness of each component is adjusted to a value that is more in line with the actual collision response; The deformation distance represents the deformation amount of the automobile component in the collision. Starting from the initial total kinetic energy, considering the influence of the dynamic energy dissipation factor, the initial total kinetic energy is multiplied by a term minus the dynamic energy dissipation factor to obtain the remaining effective energy, which is then distributed to the geometric and material properties of the component. Specifically, the product of the surface area, yield strength and modified stiffness of the component is used as the denominator for division operation. The surface area reflects the size of the area of ​​the component that bears the energy, the yield strength measures the ability of the material to resist deformation, and the modified stiffness further adjusts the efficiency of converting energy into deformation; , in, Indicates The deformation distance of each component, in meters (m), is used as the simulation result to evaluate the collision performance of the car; Indicates The dynamic energy dissipation factor of each component reflects the proportion of energy dissipated due to inelastic effects such as friction and heat consumption in a collision. The calculation formula is: , in, Indicates the value used to measure the The energy concentration of each component and the material's ability to resist deformation; represents an exponential adjustment term, which is used to describe the contribution of velocity to energy dissipation. Using an exponential decay function, when the initial velocity increases, the dissipation ratio approaches 1, reflecting that energy dissipation is more significant in high-speed collisions; Indicates the preset reference speed in meters per second (m / s), which is used for normalization operations and provides a comparison benchmark; Indicates The corrected stiffness of each component is in Pascal (Pa) and is calculated as: , in, represents the correction factor, which reflects the nonlinear effect that the corrected stiffness decreases with increasing energy. When it is larger, the corrected stiffness is significantly reduced, which is used to simulate material softening; By introducing the dynamic energy dissipation factor and the corrected stiffness, the traditional method overcomes the neglect of energy dissipation and nonlinear response of stiffness, making the calculation of component deformation distance closer to the physical behavior in actual collision, which is crucial for evaluating automobile safety performance (such as NCAP standards) and can effectively reduce dependence on expensive physical tests and reduce R&D costs.

[0026] In summary, a car collision test system and method based on CAE simulation has been completed.

[0027] The order of the embodiments of the invention is for description only and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0028] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A car collision test method based on CAE simulation, characterized in that: The following steps are involved: S1. Build a 3D geometric model based on the car design drawings and simulation scenarios, and initialize the parameters required for collision simulation; Based on the parameters of the three-dimensional geometric model and the parameters required for collision simulation, the initial total kinetic energy is calculated, and the composite energy gradient is calculated by the composite energy gradient adaptive modeling algorithm; S2. Based on the composite energy gradient, the grid reconstruction factor is obtained using the dynamic grid reconstruction algorithm; Based on the grid reconstruction factor, initial total kinetic energy and composite energy gradient, the deformation distance of automobile parts in collision is obtained through an adaptive deformation calculation algorithm with dynamic energy dissipation and nonlinear stiffness correction, and whether the automobile meets the safety standards is evaluated based on the deformation distance.

2. The CAE simulation-based automobile collision test method according to claim 1, characterized in that: The S1 specifically includes: The kinetic energy of each component of the car is evaluated independently to obtain the kinetic energy value of a single component, and the kinetic energy values ​​of all components of the car are accumulated to obtain the initial total kinetic energy.

3. The CAE simulation-based automobile collision test method according to claim 2, characterized in that: The S1 specifically includes: After calculating the initial total kinetic energy, the composite energy gradient adaptive modeling algorithm is introduced to analyze the distribution of collision energy among different parts of the car and calculate the composite energy gradient.

4. The CAE simulation-based automobile collision test method according to claim 3, characterized in that: The S1 specifically includes: In the process of implementing the composite energy gradient adaptive modeling algorithm, the material characteristic parameters in the three-dimensional geometric model parameters of the automobile, including elastic modulus and yield strength, are introduced, and the spatial position of the automobile parts is analyzed. By combining the cosine function for adjustment, the composite energy gradient is obtained. The calculation formula is: ， in, Indicates The composite energy gradient of each component; Indicates The kinetic energy term of each component; Indicates The quality of each component; Indicates The initial velocity of each component at the beginning of the collision; Indicates The elastic modulus of each component; Indicates The distance from the center of each component to the collision point; Indicates Yield strength of each component; Indicates The cosine of the angle between the velocity direction of each component and the collision normal.

5. The automobile collision test method based on CAE simulation according to claim 1, characterized in that: The S2 specifically includes: The dynamic mesh reconstruction algorithm compares the composite energy gradient of each component of the car with the preset reference energy gradient, and smoothes the force difference through square root operation. By combining the surface area and volume ratio of each component of the car, it reflects the influence of the geometric characteristics of the component on the mesh division, and finally generates a mesh reconstruction factor.

6. The automobile collision test method based on CAE simulation according to claim 1, characterized in that: The S2 specifically includes: The adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction is divided into three main parts: calculation of dynamic energy dissipation factor, calculation of corrected stiffness and calculation of final deformation distance.

7. The CAE simulation-based automobile collision test method according to claim 6, characterized in that: The S2 specifically includes: The dynamic energy dissipation factor is calculated by using a composite energy gradient and a grid reconstruction factor, while introducing the elastic modulus of the component and combining it with an exponential adjustment term; the modified stiffness is calculated by introducing the elastic modulus and combining it with an exponential function.

8. The CAE simulation-based automobile collision test method according to claim 7, characterized in that: The S2 specifically includes: Based on the dynamic energy dissipation factor and the modified stiffness, the calculation of the deformation distance combines the initial total kinetic energy, the surface area and the yield strength of the component, and the calculation formula is: ， in, Indicates The deformation distance of each component; represents the initial total kinetic energy; Indicates Dynamic energy dissipation factor of each component; Indicates The surface area of ​​each component; Indicates The corrected stiffness of a component.

9. A CAE simulation-based automobile collision test system, used in the CAE simulation-based automobile collision test method according to claim 1, characterized in that: Includes the following parts: Geometric modeling module, energy calculation module, grid reconstruction module, simulation solution module, performance evaluation module; Geometric modeling module: Based on the car design drawings and simulation scenarios, it builds the digital expression of the car, generates the three-dimensional geometric model of the car, initializes the parameters required for collision simulation, and outputs the parameters of the three-dimensional geometric model of the car and the parameters required for collision simulation to the energy calculation module; Energy calculation module: according to the parameters of the car in the geometric modeling module and the parameters required for collision simulation, the initial total kinetic energy is calculated, the composite energy gradient is calculated by the composite energy gradient adaptive modeling algorithm, the initial total kinetic energy is output to the simulation solution module, and the composite energy gradient is output to the network reconstruction module and the simulation solution module; Grid reconstruction module: Based on the composite energy gradient of the energy calculation module, the grid reconstruction factor of each component of the car is calculated using the dynamic grid reconstruction algorithm, and the grid reconstruction factor of each component of the car is output to the simulation solution module; Simulation solution module: runs dynamic explicit simulation, calculates the deformation distance of each component of the vehicle based on the mesh reconstruction factor of the mesh reconstruction module, the initial total kinetic energy and composite energy gradient of the energy calculation module, and the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, and outputs the deformation distance of each component of the vehicle to the performance evaluation module; Performance evaluation module: Analyzes the deformation distance of each component of the car output by the simulation solution module to evaluate whether the vehicle's collision performance meets safety standards.

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