An automobile collision test system and method based on CAE simulation

Abstract

The present invention relates to the field of vehicle performance testing, and particularly to an automobile collision test system and method based on CAE simulation. It includes: constructing a three-dimensional geometric model based on the automobile design drawings and simulation scenarios, initializing the parameters required for collision simulation, calculating the initial total kinetic energy, and calculating the composite energy gradient through the composite energy gradient adaptive modeling algorithm; obtaining the grid reconstruction factor using the dynamic grid reconstruction algorithm based on the composite energy gradient; obtaining the deformation distance of automobile components during collision through the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction based on the grid reconstruction factor, the initial total kinetic energy, and the composite energy gradient, and evaluating whether the automobile meets the safety standard according to the deformation distance. It solves the technical problem that existing methods often only consider the vehicle mass and speed when calculating the initial total kinetic energy of collision, ignoring the independent mass and initial speed differences of each component.

Description

Technical Field

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

[0002] With the rapid development of the automotive industry, vehicle safety has become a core issue that cannot be ignored in the design and manufacturing processes. As an important means of evaluating 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 stage of vehicle design, it is often impractical to conduct physical tests frequently. Therefore, simulation technology based on Computer-Aided Engineering (CAE for short) has gradually become an important supplement and alternative in the field of automobile collision tests. Through numerical simulation methods, CAE simulation can efficiently and low-costly analyze the performance of automobiles under various collision conditions in a virtual environment, providing strong support for design optimization and safety verification.

[0003] Evaluating vehicle safety performance efficiently and economically through virtual means makes up for the deficiencies of traditional physical tests and plays a key role in design optimization. With the continuous progress of computing power and modeling technology, CAE simulation will play an even more important role in future vehicle development, making greater contributions to improving traffic safety and occupant protection levels.

[0004] However, the above-mentioned existing traditional vehicle collision simulation methods often cannot accurately capture complex energy distribution and material response characteristics, resulting in a large deviation between the simulation results and the actual collision behavior. Low-precision simulation poses a risk of misjudging the deformation or failure of vehicle components; there is a lack of dynamic optimization in mesh generation, restricting the feasibility of complex collision scenarios under conventional computing conditions; traditional simulation techniques do not adequately consider the non-linear response of material stiffness and energy dissipation, making it difficult to reflect real physical phenomena such as material softening and enhanced energy dissipation during high-speed collisions, leading to problems where the deformation prediction does not match the experimental results. Summary of the Invention

[0005] The present invention provides an automobile collision test system and method based on CAE simulation to solve the technical problems that in the existing methods, when calculating the initial total kinetic energy of a collision, only the vehicle mass and speed are often considered, ignoring 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 mesh generation method is static and fixed, unable to adjust the density according to the degree of energy concentration, resulting in loss of local details or computational redundancy; and the existing technologies often assume that the energy dissipation and material stiffness are constants, failing to reflect the enhanced dissipation caused by the increasing speed during the collision or the reduced stiffness caused by stress concentration.

[0006] An automobile collision test system and method based on CAE simulation of the present invention specifically include the following technical solutions:

[0007] An automobile collision test method based on CAE simulation includes the following steps:

[0008] S1. Based on the automobile design drawings and the simulation scenario, construct a three-dimensional geometric model and initialize the parameters required for the collision simulation; based on the parameters of the three-dimensional geometric model and the parameters required for the collision simulation, calculate the initial total kinetic energy, and calculate the composite energy gradient through the composite energy gradient adaptive modeling algorithm.

[0009] S2. Based on the composite energy gradient, use the dynamic mesh reconstruction algorithm to obtain the mesh reconstruction factor; based on the mesh reconstruction factor, the initial total kinetic energy, and the composite energy gradient, obtain the deformation distance of the automobile components during the collision through the adaptive deformation calculation algorithm for dynamic energy dissipation and nonlinear stiffness correction, and evaluate whether the automobile meets the safety standard according to the deformation distance.

[0010] Preferably, S1 specifically includes:

[0011] Independently evaluate the kinetic energy of each component of the automobile, obtain the kinetic energy value of a single component, and accumulate the kinetic energy values of all components of the automobile to obtain the initial total kinetic energy.

[0012] Preferably, S1 specifically includes:

[0013] After calculating the initial total kinetic energy, introduce the composite energy gradient adaptive modeling algorithm to analyze the distribution law of the collision energy among different components of the automobile and calculate the composite energy gradient.

[0014] Preferably, S1 specifically includes:

[0015] During the implementation of the composite energy gradient adaptive modeling algorithm, introduce the material property parameters in the parameters of the automobile three-dimensional geometric model, including the elastic modulus and yield strength, and analyze the spatial position of the automobile components. Through adjustment by combining the cosine function, obtain the composite energy gradient, and the calculation formula is:

[0016] ,

[0017] wherein, represents the composite energy gradient of the th component; represents the kinetic energy term of the th component; represents the mass of the th component; represents the initial velocity of the th component at the start of the collision; represents the elastic modulus of the th component; represents the distance from the center of the th component to the collision point; represents the yield strength of the th component; represents the cosine value of the angle between the velocity direction of the th component and the collision normal.

[0018] Preferably, the S2 specifically includes:

[0019] The dynamic mesh reconstruction algorithm compares the composite energy gradient of each component of the vehicle with a preset reference energy gradient, smooths the force difference through square root operation, reflects the influence of the geometric characteristics of the components on mesh generation by combining the surface area to volume ratio of each component of the vehicle, and finally generates a mesh reconstruction factor.

[0020] Preferably, the S2 specifically includes:

[0021] The adaptive deformation calculation algorithm for dynamic energy dissipation and non-linear stiffness correction is divided into three main parts: calculation of the dynamic energy dissipation factor, calculation of the corrected stiffness, and calculation of the final deformation distance.

[0022] Preferably, the S2 specifically includes:

[0023] The calculation of the dynamic energy dissipation factor is obtained by using the composite energy gradient and the mesh reconstruction factor, introducing the elastic modulus of the component, and combining an exponential adjustment term; the calculation of the corrected stiffness is obtained by introducing the elastic modulus and combining an exponential function.

[0024] Preferably, the S2 specifically includes:

[0025] Based on the dynamic energy dissipation factor and the corrected stiffness, the calculation of the deformation distance combines the initial total kinetic energy, the surface area of the component, and the yield strength, and the calculation formula is:

[0026] ,

[0027] Among them, represents the deformation distance of the th component; represents the initial total kinetic energy; represents the th component's dynamic energy dissipation factor; represents the th component's surface area; represents the th component's corrected stiffness.

[0028] An automobile collision test system based on CAE simulation, including the following parts:

[0029] Geometric modeling module, energy calculation module, mesh reconstruction module, simulation solution module, performance evaluation module;

[0030] Geometric modeling module: Based on the automobile design drawings and simulation scenarios, construct the digital representation of the automobile, generate the three-dimensional geometric model of the automobile, and initialize the parameters required for the collision simulation, and output the parameters of the automobile three-dimensional geometric model and the parameters required for the collision simulation to the energy calculation module;

[0031] Energy calculation module: According to the parameters of the automobile from the geometric modeling module and the parameters required for the collision simulation, calculate the initial total kinetic energy, calculate the composite energy gradient through the composite energy gradient adaptive modeling algorithm, output the initial total kinetic energy to the simulation solution module, and output the composite energy gradient to the network reconstruction module and the simulation solution module;

[0032] Mesh reconstruction module: Based on the composite energy gradient of the energy calculation module, use the dynamic mesh reconstruction algorithm to calculate the mesh reconstruction factor of each component of the automobile, and output the mesh reconstruction factor of each component of the automobile to the simulation solution module;

[0033] Simulation solution module: Run the dynamic explicit simulation, based on the mesh reconstruction factor of the mesh reconstruction module, the initial total kinetic energy and the composite energy gradient of the energy calculation module, through the adaptive deformation calculation algorithm of dynamic energy dissipation and non-linear stiffness correction, calculate the deformation distance of each component of the automobile, and output the deformation distance of each component of the automobile to the performance evaluation module;

[0034] Performance evaluation module: Analyze the deformation distance of each component of the automobile output by the simulation solution module, and evaluate whether the vehicle collision performance meets the safety standards.

[0035] The beneficial effects of the technical solution of the present invention are:

[0036] 1. By collecting the basic physical properties and material characteristic parameters of each component of the vehicle and calculating the initial total kinetic energy based on the basic principles of physics, a comprehensive quantification of the initial energy state of vehicle collisions is achieved, laying a reliable energy benchmark for subsequent simulation analysis, enabling the accurate mastery of the energy reserve in the collision scenario, thus improving the coincidence degree between the simulation results and the actual collision behavior, and providing more realistic data support for vehicle safety assessment.

[0037] 2. Through the composite energy gradient adaptive modeling algorithm, the distribution law of collision energy among different vehicle components is deeply analyzed, the composite energy gradient of each component is obtained, the non-uniformity of energy distribution is identified, especially the concentrated energy borne by the components close to the collision point and with higher stiffness, overcoming the assumption of uniform energy distribution in traditional methods. The refined energy distribution description provides a basis for the modeling of high-stress areas, thereby enhancing the simulation's prediction ability for local stress concentration phenomena and making the collision test results closer to the real situation.

[0038] 3. Based on the composite energy gradient, the grid reconstruction factor is calculated using the dynamic grid reconstruction algorithm, optimizing the grid density distribution, achieving high-resolution simulation of high-energy concentration areas, and avoiding redundant calculations in low-energy areas. This not only improves the simulation accuracy, making the simulation of local stress distribution and deformation behavior more realistic, but also optimizes the allocation efficiency of computing resources, reduces the computing cost and simulation time, making the simulation of complex collision scenarios feasible under conventional hardware conditions, and significantly enhancing the engineering practicability.

[0039] 4. Through the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, the deformation distance of vehicle components during collision is accurately calculated, and whether the vehicle meets the safety standards is evaluated based on the deformation distance. This overcomes the neglect of energy dissipation and nonlinear response of material stiffness in traditional simulations, obtains deformation results closer to actual physical behavior, enhances the simulation's evaluation ability for the state of components after collision, provides a reliable basis for the verification of safety performance, and at the same time reduces the dependence on expensive physical tests and lowers the R & D cost. Description of the Drawings

[0040] Figure 1 It is a structural diagram of a vehicle collision test system based on CAE simulation according to the present invention;

[0041] Figure 2 It is a flowchart of a vehicle collision test method based on CAE simulation according to the present invention. Detailed Embodiments

[0042] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0044] The following specifically describes in conjunction with the accompanying drawings the specific solutions of an automobile collision test system and method based on CAE simulation provided by the present invention.

[0045] Referring to the attached Figure 1 , which shows the structure diagram of an automobile collision test system based on CAE simulation provided by an embodiment of the present invention. The system includes the following parts:

[0046] A geometric modeling module, an energy calculation module, a mesh reconstruction module, a simulation solution module, and a performance evaluation module;

[0047] Geometric modeling module: Based on the automobile design drawings and the simulation scenario, construct a digital representation of the automobile, generate a three-dimensional geometric model of the automobile, and initialize the parameters required for the collision simulation, and output the parameters of the three-dimensional geometric model of the automobile and the parameters required for the collision simulation to the energy calculation module;

[0048] Energy calculation module: According to the parameters of the automobile from the geometric modeling module and the parameters required for the collision simulation, calculate the initial total kinetic energy through the basic principles of physics, that is, the kinetic energy formula, calculate the composite energy gradient through the composite energy gradient adaptive modeling algorithm, output the initial total kinetic energy to the simulation solution module, and output the composite energy gradient to the network reconstruction module and the simulation solution module;

[0049] Mesh reconstruction module: Based on the composite energy gradient from the energy calculation module, calculate the mesh reconstruction factor of each component of the automobile using the dynamic mesh reconstruction algorithm, and output the mesh reconstruction factor of each component of the automobile to the simulation solution module;

[0050] Simulation solution module: Run dynamic explicit simulation, and based on the mesh reconstruction factor from the mesh reconstruction module, the initial total kinetic energy and the composite energy gradient from the energy calculation module, calculate the deformation distance of each component of the automobile through the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction, and output the deformation distance of each component of the automobile to the performance evaluation module;

[0051] Performance Evaluation Module: Analyze the deformation distances of each component of the vehicle output by the simulation solution module, and evaluate whether the vehicle collision performance meets safety standards such as the NCAP standard.

[0052] Refer to the appendix Figure 2 , which shows a flowchart of a vehicle collision test method based on CAE simulation provided by an embodiment of the present invention. The method includes the following steps:

[0053] S1. Based on the vehicle design drawings and simulation scenarios, construct a three-dimensional geometric model and initialize the parameters required for the collision simulation; based on the parameters of the three-dimensional geometric model and the parameters required for the collision simulation, calculate the initial total kinetic energy, and calculate the composite energy gradient through the composite energy gradient adaptive modeling algorithm;

[0054] Based on the vehicle design drawings and simulation scenarios, construct a digital representation of the vehicle, generate a three-dimensional geometric model of the vehicle, and initialize the parameters required for the collision simulation; the parameters of the vehicle three-dimensional geometric model include but are not limited to the basic physical properties and material characteristic parameters of each component of the vehicle, such as mass, elastic modulus, and yield strength; the parameters required for the collision simulation include but are not limited to the distance from the spatial position of each component of the vehicle to the collision point, speed, angle between the speed direction and the collision normal, surface area, and volume;

[0055] Calculate the initial total kinetic energy through the basic principles of physics, that is, the kinetic energy formula. Specifically, independently evaluate the kinetic energy of each component of the vehicle, that is, obtain the kinetic energy value of a single component by multiplying the mass by the square of the speed and then taking half, and accumulate the kinetic energy values of all components to obtain the initial total kinetic energy. In joules, the initial total kinetic energy value represents the energy reserve at the initial moment of vehicle collision and is the basis for subsequent analysis. The calculation formula is:

[0056] ,

[0057] where represents the initial total kinetic energy, with the unit of joule (J), which is the energy input in the collision simulation and is used to quantify the energy possessed by the vehicle due to motion in the initial state; represents the accumulation of the kinetic energies of all vehicle components; represents the th component's mass, with the unit of kilogram (kg), specified by the parameters of the vehicle three-dimensional geometric model; represents the th component's initial velocity at the start of the collision, with the unit of meter per second (m / s), specified by the parameters required for the collision simulation;

[0058] 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;

[0059] 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.

[0060] The calculation formula of the composite energy gradient is:

[0061] ,

[0062] 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 the strongest; when the velocity direction is perpendicular to the collision normal, i.e., , the composite energy gradient is zero;

[0063] The initial total kinetic energy provides a macroscopic perspective on 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 initial stage of the collision, it provides a global benchmark for the energy state of the vehicle, facilitating the assessment of the vehicle's performance under different collision scenarios. By calculating the composite energy gradient, the non-uniformity of the energy distribution can be identified, especially the concentrated energy borne by components close to the collision point and with higher stiffness, providing a basis for the refined modeling of high-stress regions in the simulation, overcoming the assumption of uniform energy distribution in traditional modeling and improving the agreement between the simulation results and the actual collision behavior;

[0064] S2. Based on the composite energy gradient, use the dynamic grid reconstruction algorithm to obtain the grid reconstruction factor; based on the grid reconstruction factor, the initial total kinetic energy, and the composite energy gradient, use the adaptive deformation calculation algorithm of dynamic energy dissipation and non-linear stiffness correction to obtain the deformation distance of the vehicle components during the collision, and evaluate whether the vehicle meets the safety standard according to the deformation distance;

[0065] In computer-aided engineering (CAE) simulations, the grid divides the vehicle model into small blocks for calculation. When the grid is too coarse, the calculation accuracy is insufficient, and when the grid is too fine, the computational cost is too high. Traditional methods assume uniform energy distribution and ignore the influence of local stress concentration, resulting in insufficient simulation accuracy; based on the composite energy gradient, use the dynamic grid reconstruction algorithm to calculate the grid reconstruction factor through the dynamic analysis of the energy distribution, thereby optimizing the grid density distribution;

[0066] The dynamic grid reconstruction algorithm compares the composite energy gradient of each component of the vehicle with a preset reference energy gradient to measure the force difference of each component of the vehicle, and smooths the force difference through square root operation for linear adjustment of the grid density. By combining the surface area-to-volume ratio of each component of the vehicle, it reflects the influence of the geometric characteristics of the component on the grid division. Components with a larger surface area and a smaller volume require a higher grid density to capture details. For example, thin plates are more easily deformed than thick plates. The finally generated grid reconstruction factor is used to guide the dynamic adjustment of the grid density. The calculation formula of the grid reconstruction factor is:

[0067] ,

[0068] where, represents the grid reconstruction factor of the th component; Represents a preset reference energy gradient, which is used to standardize the composite energy gradient so that the energy intensity is comparable. The unit is joules per meter (J / m), and it can be specifically set according to the specific implementation scenario and is not limited here; Represents the surface area of the Represents the volume of the

[0069] By dynamically adjusting the grid density, it ensures that higher resolution is obtained in high-energy concentration areas, thus more realistically simulating the local stress distribution and deformation behavior of automotive components. At the same time, it optimizes the allocation efficiency of computing resources, effectively reduces the computing cost, avoids redundant calculations, not only shortens the simulation time, but also makes the simulation of complex collision scenarios feasible under conventional hardware conditions, with high engineering practicability.

[0070] In order to overcome the neglect of energy dissipation and non-linear 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, through an adaptive deformation calculation algorithm of dynamic energy dissipation and non-linear stiffness correction, accurately calculate the deformation distance of automotive components in a collision, and evaluate whether the vehicle meets the safety standard according to the deformation distance;

[0071] The adaptive deformation calculation algorithm of dynamic energy dissipation and non-linear stiffness correction is divided into three main parts: calculation of the dynamic energy dissipation factor, calculation of the corrected stiffness, and calculation of the final deformation distance;

[0072] The calculation of the dynamic energy dissipation factor is used to quantify the proportion of energy reduction due to dissipation during vehicle collision. Using the obtained composite energy gradient and grid reconstruction factor, and introducing the elastic modulus of the component as part of the denominator to form a basic ratio, and then multiplying by an exponential adjustment term, based on the ratio of the initial velocity of the component to a preset reference velocity, calculate a value between 0 and 1 through an exponential function to simulate the non-linear effect of velocity on energy dissipation: when the initial velocity is much greater than the preset reference velocity, the dissipation effect tends to saturate, and when the initial velocity is less than the preset reference velocity, the dissipation effect is weak;

[0073] The corrected stiffness is used to characterize the dynamic change of the stiffness of automotive components in a collision. The design is based on a physical intuition: in high-energy gradient areas, the material may show a decrease in stiffness due to stress concentration, while in low-energy gradient areas, the stiffness is close to the original value, and an exponential function is introduced to ensure the smoothness and non-linear characteristics of the stiffness change, avoiding the assumption of constant stiffness in traditional methods, and adjusting the stiffness of each component to a value more in line with the actual collision response;

[0074] The deformation distance represents the amount of deformation of an automotive component during a collision. Starting from the initial total kinetic energy and considering the influence of the dynamic energy dissipation factor, the initial total kinetic energy is multiplied by a term that subtracts the dynamic energy dissipation factor to obtain the remaining effective energy. The remaining effective energy is then distributed to the geometric and material properties of the component, specifically through division by the product of the surface area, yield strength, and modified stiffness of the component. The surface area reflects the size of the area where the component bears energy, the yield strength measures the ability of the material to resist deformation, and the modified stiffness further adjusts the efficiency of energy conversion into deformation;

[0075] ,

[0076] where, represents the deformation distance of the th component, in meters (m), and is used as a simulation result to evaluate the automotive collision performance; represents the dynamic energy dissipation factor of the th component, which reflects the proportion of energy dissipated due to non - elastic effects such as friction and heat consumption during the collision. The calculation formula is:

[0077] ,

[0078] where, represents a measure of the energy concentration degree and the material's ability to resist deformation of the th component; represents an exponential adjustment term used to describe the contribution of velocity to energy dissipation. Using an exponential decay function, when the initial velocity increases, the dissipation proportion approaches 1, reflecting that energy dissipation is more significant in high - speed collisions; represents a preset reference velocity, in meters per second (m / s), which is used for normalization operations and provides a comparison benchmark;

[0079] represents the modified stiffness of the th component, in pascals (Pa). The calculation formula is:

[0080] ,

[0081] where, represents a correction factor that reflects the non - linear effect that the modified stiffness decreases as energy increases. When is large, the modified stiffness decreases significantly, which is used to simulate material softening;

[0082] By introducing a dynamic energy dissipation factor and a modified stiffness, the neglect of energy dissipation and stiffness nonlinear response in traditional methods is overcome, making the calculation of the component deformation distance closer to the physical behavior in actual collisions, which is crucial for evaluating vehicle safety performance (such as NCAP standards), can effectively reduce the dependence on expensive physical tests, and lower the R & D costs.

[0083] In summary, a vehicle collision test system and method based on CAE simulation have been completed.

[0084] The order of the invention embodiments is only for description and does not represent the superiority or inferiority 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.

[0085] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments.

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention and should all 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 3D geometric model and the parameters required for collision simulation, the kinetic energy of each component of the car is independently evaluated 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; The composite energy gradient adaptive modeling algorithm is used to introduce the material characteristic parameters in the three-dimensional geometric model parameters of the automobile, including elastic modulus and yield strength, and analyze the spatial position of the automobile parts. 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 value of the angle between the velocity direction of each component and the collision normal; S2. Based on the composite energy gradient, a dynamic mesh reconstruction algorithm is introduced to compare the composite energy gradient of each component of the car with the preset reference energy gradient. The force difference is smoothed by square root operation, and the mesh reconstruction factor is finally generated by combining the surface area and volume ratio of each component of the car. The calculation formula is: ， in, Indicates The mesh reconstruction factor of each component; represents a preset reference energy gradient; Indicates The surface area of ​​each component; Indicates The volume of each component; 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 by the adaptive deformation calculation algorithm of dynamic energy dissipation and nonlinear stiffness correction. 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 each component; The calculation formula of the dynamic energy dissipation factor is: ， in, Indicates the value used to measure the The energy concentration of each component and the material's ability to resist deformation; represents the index adjustment item; Indicates the preset reference speed; The calculation formula of the modified stiffness is: ， in, represents the correction factor; And based on the deformation distance, it is evaluated whether the car meets the safety standards.

2. The automobile collision test method based on CAE simulation according to claim 1, 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.

3. 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.

4. The CAE simulation-based automobile collision test method according to claim 3, 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.

5. 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 sections: 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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