A design method of automobile frontal crash honeycomb barrier for MPDB working condition

Abstract

The application relates to the field of automobile crash safety technology, in particular to a design method of a honeycomb barrier for MPDB working conditions. The method comprises the following steps: selecting a target vehicle model of a honeycomb aluminum barrier to be developed; according to the stiffness variation law of the front end structure of the target vehicle model in the crash process, the honeycomb aluminum barrier is divided into a front layer domain, a middle layer domain and a rear layer domain in the longitudinal direction; according to the differences and spatial position distribution characteristics of the stiffness of the front end components of the vehicle, the honeycomb aluminum barrier is divided into multiple layer domains in the vertical direction; a target configuration is selected by using finite element simulation; the appearance size of the honeycomb aluminum barrier and the size of each layer domain are determined according to the actual measurement data of the front end structures of multiple vehicles; the stiffness of each layer domain is distributed by combining the real vehicle and the force wall crash test data; and the honeycomb aluminum barrier is designed by cutting an angle. The application makes the honeycomb aluminum barrier closer to the front end structure of the real vehicle in terms of structural modeling and stiffness distribution.

Description

Technical Field

[0001] This application relates to the field of automotive collision safety technology, and more specifically, to a design method for a honeycomb barrier in frontal collisions of a vehicle under MPDB conditions. Background Technology

[0002] The 50% overlap moving progressive deformable barrier (MPDB) frontal crash test simulates real-world vehicle-to-vehicle collisions, evaluating a vehicle's occupant protection and aggressiveness. The MPDB barrier, a crucial testing component, simulates the other vehicle colliding with the test vehicle. A deformable honeycomb aluminum barrier is mounted at the front of the MPDB trolley, mimicking the front-end structure of a vehicle. The honeycomb barrier reflects the average characteristics of the other vehicle in the crash test, representing the average level of vehicle collision stiffness and serving as an important standard for collision strength.

[0003] The front-end structure of a vehicle is complex, generally including components such as the hood, radiator support, energy-absorbing box, bumper, front longitudinal beams, and subframe. Due to material and structural design considerations, the stiffness of these components varies significantly. In terms of component location, components like the hood and radiator support, located in the upper part of the front engine compartment, have much lower stiffness than components like the bumper and front longitudinal beams, located in the middle and lower parts. The widely used Euro NCAP MPDB honeycomb aluminum profile exhibits consistent stiffness in the Z-direction (vertical direction), meaning the stiffness is the same on any honeycomb aluminum cross-section perpendicular to the X-axis (longitudinal direction). However, this configuration is overly simplified and insufficiently represents the actual front-end structure of a vehicle.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] The purpose of this application is to provide a design method for a honeycomb barrier for frontal collisions of automobiles under MPDB conditions, so that the honeycomb aluminum barrier is closer to the front structure of a real vehicle in terms of structural shape and stiffness distribution.

[0006] To achieve the above objectives, this application adopts the following technical solution: This application provides a design method for a car frontal collision honeycomb barrier oriented towards MPDB conditions, including: Select the target vehicle model for the development of the honeycomb aluminum barrier; Based on the stiffness change pattern of the front structure of the target vehicle during the collision process, the honeycomb aluminum barrier is longitudinally divided into a front layer, a middle layer, and a rear layer. Based on the differences in stiffness and spatial distribution characteristics of the front-end components of the vehicle, the honeycomb aluminum barrier is divided into multiple upper and lower layers in the vertical direction. Based on the longitudinal and vertical division of the honeycomb aluminum barrier, multiple configurations are constructed, with different layer arrangements for different configurations; a suitable target configuration is selected using finite element simulation. Based on the actual measurement data of the front-end structure of multiple vehicles corresponding to the target model, the external dimensions of the honeycomb aluminum barrier and the dimensions of each layer are determined. Based on the data from the actual vehicle-to-force wall collision test, the stiffness of each longitudinal and vertical layer was allocated. The honeycomb aluminum barrier is designed with chamfered corners, which are used to fill the gap area between the edge of the front bumper and the front tire of the model vehicle.

[0007] Compared with the prior art, this application has the following beneficial effects: This application first analyzes the stiffness variation and spatial distribution characteristics of the front-end structure of the target vehicle during a collision to create a honeycomb aluminum barrier that is longitudinally and layered vertically. Then, a suitable configuration is selected through simulation. The dimensions of each layer are determined based on actual measurement data of the front-end structure. Stiffness distribution is then performed for each longitudinal and vertical layer based on experimental data, and chamfering is incorporated. The designed honeycomb barrier satisfies the stiffness variation characteristics of the vehicle's front end during an actual collision, conforms to the dimensions of the vehicle's front end, and can be stably compressed, making the honeycomb aluminum barrier more closely resemble the front-end structure of a real vehicle in terms of structural shape and stiffness distribution. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating a design method for a car frontal collision honeycomb barrier oriented towards MPDB conditions provided in an embodiment of this application. Figure 2 This is a schematic diagram of the upper and lower layer domains provided in the embodiments of this application; Figure 3 These are schematic diagrams of the tubular frame trolley model and the honeycomb aluminum barrier model provided in the embodiments of this application; Figure 4 This is a schematic diagram showing the offset alignment between the rigid tube frame impact head and the finite element model of the configuration provided in the embodiments of this application; Figure 5 These are schematic diagrams of the collision deformation modes of configurations 1 to 4 provided in the embodiments of this application; Figure 6This is a schematic diagram of the height dimensions of the vehicle front-end structure provided in the embodiments of this application; Figure 7 This is a schematic diagram of the length dimensions of the vehicle front-end structure provided in the embodiments of this application; Figure 8 This is a schematic diagram showing the dimensions of blocks 1-4 provided in the embodiments of this application; Figure 9 This is a schematic diagram of the distribution of the collision force wall and force measuring unit provided in the embodiments of this application; Figure 10 This is a schematic diagram of the collision force wall and force measuring unit number provided in the embodiments of this application; Figure 11 This is a schematic diagram of the chamfer angle design method provided in the embodiments of this application; Figure 12 This is a schematic diagram of the final honeycomb aluminum barrier model provided in the embodiments of this application. Detailed Implementation

[0010] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0011] Figure 1 This is a flowchart of a design method for a car frontal collision honeycomb barrier under MPDB conditions provided in this embodiment. This embodiment is applicable to the design scenario of a car frontal collision honeycomb barrier under MPDB conditions.

[0012] See Figure 1 The method provided in this embodiment includes: S110, Select the target vehicle model for the honeycomb aluminum barrier to be developed.

[0013] First, different vehicle types differ in the spatial distribution and dimensions of their front-end structures. The target vehicle for developing honeycomb aluminum is determined based on vehicle type (e.g., A0 to C class based on wheelbase, or sedans and SUVs based on space). This step serves as the benchmark for subsequent design. In selecting vehicle type, factors such as sales volume and ownership, as well as the vehicle's perceived vulnerability and aggression, should be considered. Setting a high sales volume and ownership level aims to highlight the vehicle's representativeness; setting a perceived vulnerability and aggression level ensures the effectiveness of the vehicle's aggression assessment.

[0014] Evaluating the aggressiveness of test vehicles is the core function of MPDB testing. If a highly aggressive vehicle model is used as the target vehicle model, the developed honeycomb aluminum barrier may be highly aggressive, and the aggressiveness of the test vehicle will not be effectively evaluated.

[0015] S120. Based on the stiffness change pattern of the front structure of the target vehicle during the collision process, the honeycomb aluminum barrier is longitudinally divided into a front layer, a middle layer, and a rear layer.

[0016] This step involves designing the X-axis (longitudinal) layer domain of the honeycomb aluminum barrier.

[0017] To better simulate the stiffness change of the front structure of a real vehicle during a collision, the honeycomb aluminum barrier is divided into three functionally distinct layers in the X direction (longitudinal direction), corresponding to the structural features of the front, middle, and rear of the vehicle's front engine compartment, respectively.

[0018] 1) The front layer is the energy absorption area, corresponding to the frontmost part of the vehicle (front skin, bumper, energy absorption box area). Its stiffness is less than the first set value and its stiffness is relatively small. It can adopt an equal stiffness design (see below) to simulate the initial energy absorption stage of the front of the vehicle and absorb collision energy through stable plastic crushing.

[0019] 2) The middle area is a transition zone, corresponding to the middle of the front of the car (the front section of the longitudinal beam and subframe). The stiffness gradually increases with the increase of the compressive displacement. A progressive stiffness design is adopted (see below) to simulate the gradual process of the longitudinal beam from initial bending to gradual crushing. 3) The rear layer is a rigid area, corresponding to the rear of the front of the vehicle (the area at the root of the longitudinal beam). Its stiffness is greater than the second set value, and its high stiffness represents the rigid structure of the rear of the vehicle's front compartment. It provides support in the later stages of a collision to prevent the barrier from being penetrated.

[0020] Assume the lengths of the three layer domains in the X direction , , The total length of the honeycomb aluminum barrier in the X direction is... Note that this step only sets up three layers, without specifying their dimensions.

[0021] S130. Based on the differences in stiffness and spatial distribution characteristics of the front-end components of the vehicle, the honeycomb aluminum barrier is divided into multiple upper and lower layers in the vertical direction.

[0022] This step, based on the X-direction layering, designs the Z-direction (vertical) layer domains of the honeycomb aluminum barrier. Table 1 is a layered stiffness table of vehicle front-end structural components provided in the embodiments of this application. Taking the upper edge of the longitudinal beam as the boundary, the upper part has weaker stiffness and the lower part has stronger stiffness. Therefore, based on the fact that the stiffness of the upper part of the vehicle's longitudinal beam is less than that of the lower part, the honeycomb aluminum barrier is vertically divided into upper and lower layer domains, with the upper edge of the longitudinal beam as the boundary. See [link / reference]. Figure 2 It can also be divided into multiple layers distributed vertically. The number of layers needs to be considered in conjunction with the stiffness fidelity and the stability and robustness of the honeycomb aluminum structure to avoid collision instability due to too many layers.

[0023] Table 1

[0024] S140. Based on the longitudinal and vertical division of the honeycomb aluminum barrier, construct various configurations with different layer arrangements for different configurations; use finite element simulation to select suitable target configurations.

[0025] Based on the longitudinal and vertical division of the honeycomb aluminum barrier into layers, these layers are arranged vertically and horizontally, or front-to-back. For example, multiple vertical layers can be arranged in the front layer, or multiple vertical layers can be arranged in the middle layer. Multiple vertical layers include two layers (upper and lower) and three layers (upper, middle, and lower).

[0026] To ensure the stability of honeycomb aluminum under different collision conditions and to select the configuration that best reflects the structural characteristics of the vehicle's front end, finite element simulation is used to select a suitable target configuration. Furthermore, physical experiments can be used to optimize and verify the configuration.

[0027] A model of the tubular trolley and finite element models of each configuration were created in the simulation environment. (See [link to documentation]). Figure 3 The front end of the tubular frame trolley model features a rigid tubular frame impact head to simulate the front-end structure of a vehicle. The stiffness of the upper thin tube of the rigid tubular frame impact head is less than that of the lower thick tube. The upper thin tube simulates the upward force transmission path of the vehicle, and the lower thick tube simulates the downward force transmission path. The finite element model of the honeycomb aluminum barrier configuration is fixedly mounted on a rigid backplate. To realistically reproduce the MPDB test conditions, an offset alignment is set between the rigid tubular frame impact head and the finite element model of the configuration, with an offset overlap rate of 80% of the configuration width. See [link to relevant documentation]. Figure 4 .

[0028] In the finite element model of the configuration, initial stiffness values ​​are set for each layer (which can be obtained experimentally or a rough stiffness range can be defined). Each layer is vertically aligned and longitudinally connected and fixed to thin partitions or backing plates between different layers. The mass (e.g., 1500 kg), impact velocity (e.g., 40 km / h), and sampling frequency (e.g., 20 kHz) of the tubular frame trolley model are set, and collision simulations are performed between the tubular frame trolley model and the finite element model of each configuration. The target configuration is selected based on whether the finite element model of the configuration exhibits a stable deformation mode.

[0029] Figure 5This is a schematic diagram of the collision deformation modes of configurations 1-4 provided in the embodiments of this application. Simulation results show that configurations 1, 2, and 3 all exhibit honeycomb block bending during the collision process, mainly manifested as relative displacement or buckling between different Z-direction layer domains. This bending is an undesirable unstable deformation mode for the honeycomb aluminum barrier. The ideal deformation mode should be uniform crushing along the X-direction, allowing each layer domain to absorb energy collaboratively. Configuration 4 exhibits stable crushing behavior in the simulation, with no obvious Z-direction bending or instability. Each X-direction layer domain crushes sequentially, and the deformation mode is highly consistent with the expectation. Based on the above analysis, configuration 4 is determined to be the target configuration that meets the stability requirements. In summary, the criterion for determining a stable configuration is that it can maintain axially stable crushing deformation in the X-direction. It can be seen that the target configuration is: the honeycomb aluminum barrier is divided into a front layer domain, a middle layer domain, and a rear layer domain in the longitudinal direction, and the middle layer domain is divided into an upper layer domain and a lower layer domain in the vertical direction, that is, the upper layer domain and the lower layer domain constitute the middle layer domain.

[0030] S150. Based on the actual measurement data of the front-end structure of multiple vehicles corresponding to the target model, determine the appearance dimensions of the honeycomb aluminum barrier and the dimensions of each layer.

[0031] To improve the universality and representativeness of the honeycomb aluminum dimensions, the front-end structural dimensions of multiple vehicles within the target model range were measured. First, weights were determined based on the sales volume or ownership volume of the multiple vehicles corresponding to the target model. Higher sales volume or ownership volume indicates a larger market share and greater representativeness of the vehicle. Therefore, higher sales volume or ownership volume results in a higher weight. The weights were quantized to (0, 1), with the sum of the weights of the multiple vehicles being 1.

[0032] Obtain the actual measurement data of the front-end structure of each vehicle. The measurement items are shown in Table 2. Figure 6 and Figure 7 As shown, these dimensions directly guide the design of the height of the Z-axis layer domain and the length of the X-axis layer domain. Figure 7 In the image, the distance K between the front end of the bumper beam and the front end of the water tank bracket is partially magnified. Figure 7 The small image on the left.

[0033] Table 2

[0034] The actual measurement data are weighted and averaged according to their respective weights to obtain the comprehensive measurement data. Specifically, for multiple sets of data on the same measurement item (such as the height A of the upper edge of the bumper beam from the ground), the comprehensive measurement data is determined: ; Where N is the total number of vehicles measured. Let be the measured value of the height of the upper edge of the bumper crossbeam of the j-th vehicle from the ground. The weight corresponding to this car model, This is a weighted average of the height of the upper edge of the bumper beam from the ground. This method is also applicable to the averaging of the stiffness curves described below, to obtain stiffness curves with broad representativeness.

[0035] Finally, based on the comprehensive measurement data, the external dimensions of the honeycomb aluminum barrier and the dimensions of each layer were determined.

[0036] See Figure 8 (All values ​​are in mm). Based on the distance J between the front end of the bumper beam and the rear end of the energy-absorbing box, determine the length of the front layer, i.e. Figure 8 The length of middle block 1 is 300mm; the lengths of the middle and rear layers are determined based on the vehicle's longitudinal beam length N; that is, the sum of the lengths of the middle and rear layers is N. Specifically, the lengths of blocks 2, 3, and 4 can be determined based on simulation tests or real-vehicle crash tests. Figure 8 Blocks 2 and 3 are 500mm long, and block 4 is 50mm long. The ground clearance of the honeycomb aluminum barrier is determined based on the ground clearance F of the lower edge of the subframe. Figure 8 The ground clearance of the honeycomb aluminum barrier is 150mm. The height of the lower layer is determined based on the difference (GF) between the ground clearance of the upper edge of the front longitudinal beam and the ground clearance of the lower edge of the subframe. Figure 8 The height of the middle block 3 is 470mm. The height of the upper layer is determined based on the difference (IG) between the ground clearance of the front hood and the ground clearance of the upper edge of the front longitudinal beam. Figure 8 The height of the middle block 2 is 200mm.

[0037] As shown above, the size design of each layer has been completed.

[0038] S160. Based on the actual vehicle-to-wall collision test data, the stiffness of each longitudinal and vertical layer is allocated.

[0039] This step completes the stiffness distribution of each longitudinal and vertical layer.

[0040] First, based on the total length and compressibility of the aluminum honeycomb barrier, determine the total effective compression stroke of the aluminum honeycomb barrier. 0: ; Where ɛ is the compression ratio of the honeycomb aluminum. This represents the total length of the cellular barrier.

[0041] Based on the vertical division of the layers into front, middle, and rear sections, and according to the effective compression stroke corresponding to each layer, the total effective compression stroke is divided into a first interval, a second interval, and a third interval. The first interval... Corresponding to the front layer, the second interval Corresponding to the middle layer, the third interval For the corresponding rear layer, we have: ; ; in, The length of the front layer domain, The length of the middle layer. It is the effective compression stroke corresponding to the front layer domain. - It is the effective compression stroke corresponding to the middle layer domain. - It is the effective compression stroke corresponding to the rear layer domain.

[0042] The collision force of the target vehicle model is collected using a collision force wall. Based on the full force wall collision force-time curve, dynamic contact projection area, and vehicle B-pillar displacement-time curve, the overall vehicle stiffness-displacement curve is obtained. The overall vehicle stiffness-displacement curve is obtained based on the actual vehicle-force wall collision test data. A stiffness linear fitting is performed on the first interval, and a stiffness setpoint matching is performed on the third interval.

[0043] Specifically, analysis of extensive real-vehicle-force-wall collision test data revealed that the stiffness change of the front-end structure of real vehicles exhibits three distinct stages: an initial slow growth phase, a gradual strengthening phase in the middle, and a saturation phase at the rear. This characteristic closely matches the inverse shape of the Sigmoid function. This embodiment proposes using a piecewise function to accurately describe the stiffness-displacement relationship throughout the entire compression process.

[0044] Piecewise stiffness function The definition is as follows:

[0045] in: This is a longitudinal compressive displacement; The slope of the stiffness-displacement curve of the front layer is obtained by fitting a straight line to the stiffness of the front layer in the actual vehicle-force wall collision test. The horizontal axis is the vehicle displacement, corresponding to the effective compression stroke, and the vertical axis is the stiffness. The slope is obtained by fitting a straight line to the stiffness-displacement curve of the front layer.

[0046] , This represents the stiffness value at the end point of the front layer domain; The saturation stiffness value of the rear layer is typically designed to be 1.3 times the peak value of the overall vehicle stiffness curve to ensure that the rear layer has sufficient stiffness and prevent the honeycomb aluminum barrier from being penetrated. The stiffness growth rate factor in the middle layer controls the steepness of the curve; within the interval Internally, stiffness is determined by Continuously increasing.

[0047] The method for determining the unknown parameters in the piecewise function is as follows: The optimal values ​​of the above parameters can be determined by curve fitting the stiffness-displacement curve of the target vehicle model (the method for plotting the stiffness-displacement curve is described below, or refer to existing technologies). The fitting objective function is: ; in, The stiffness value is the one measured in the experiment. The calculated value is the piecewise stiffness function. Comparison between typical experimental data and the calculated function values ​​shows that if the two agree well, the effectiveness of this method is verified.

[0048] To facilitate the engineering manufacturing of the honeycomb aluminum barrier, the stiffness line obtained in the first interval is discretized to the corresponding layer domains to obtain the stiffness of the front layer domain. For the front layer domain: the average stiffness of this segment is taken as the design value of the uniform stiffness of the front layer domain. ; in, for The number of time data points For the front area i Stiffness of each data point This represents the design value for uniform stiffness in the front region.

[0049] For the rear layer: take 1.3 times the peak value of the whole vehicle stiffness curve as the stiffness constant value of the third interval to obtain the stiffness of the rear layer.

[0050] For the middle layer: the collision test between the real vehicle and the collision force wall is as follows: the collision force wall is used to collect the collision force of the target vehicle. The collision force of the target vehicle collected by the collision force wall is divided into zones, and the collision force-time curves of the upper region are obtained separately. And the impact force-time curve of the lower region : ; ; in, The force values ​​measured by each force measuring unit within the region at location (i,j). Figure 9 This is a schematic diagram of the collision force wall and force measuring unit distribution provided in an embodiment of this application. Note that the lower area only needs to cover the upper edge of the longitudinal beam. The upper area has 32 force measuring units arranged in a matrix, and the lower area also has 32 force measuring units arranged in a matrix. See [link to relevant documentation]. Figure 10 The number of the force measuring unit is shown.

[0051] Based on the collision force-time curve of the upper region and the dynamic contact projection area between the vehicle and the upper part of the force wall. And the displacement-time curve of the vehicle's B-pillar, to obtain the stiffness curve of the upper region. .

[0052] ; in, To determine the dynamic contact area between the upper front region of the test vehicle and the impact force wall, the displacement-time curve of the vehicle's B-pillar was obtained by performing a second integral on the acceleration of the vehicle's B-pillar. Similarly, based on the impact force-time curve of the lower region, the dynamic contact projection area between the vehicle and the lower part of the force wall, and the displacement-time curve of the vehicle's B-pillar, the stiffness curve of the lower region was obtained.

[0053] Based on the stiffness curves of the upper and lower regions and the corresponding effective compression stroke of the middle region, the stiffness curves of the second interval in the upper and lower regions are obtained. The two second-interval stiffness curves are then fitted with the inverse Sigmoid function to obtain the stiffness functions of the upper and lower regions, respectively. : ; Considering the manufacturing process and capabilities of variable stiffness aluminum honeycomb, the asymptotic stiffness is represented by a simple linear function for discrete data points. Through equivalent data processing, an asymptotic stiffness function conforming to the processing requirements of aluminum honeycomb is obtained, yielding the stiffness of the upper and lower layer domains respectively. ; ; in, K Let be the slope of the linear function. This is the design stiffness value at the end of the central region. The design of the honeycomb aluminum in this central layer must meet the following requirement: During compressive displacement from... arrive During the process, its accumulated absorbed energy is consistent with the stiffness inverse Sigmoid fitting function of the second interval.

[0054] The middle layer is divided into upper and lower layers, and the stiffness linear functions of the upper region and the lower region need to be defined separately.

[0055] The honeycomb aluminum barrier designed using the above method not only meets the stability requirements but also accurately reflects the geometric characteristics and stiffness distribution of the vehicle's front-end structure. A prototype was fabricated according to configuration 4, and a trolley crash test was conducted to ensure its robustness, the stability of the test results, and the repeatability. Comparison of the test results with simulation results further validates the effectiveness of this method.

[0056] S170. The honeycomb aluminum barrier is designed with chamfered corners. The chamfered corners are used in the gap area between the edge of the front bumper and the front tire of the model vehicle.

[0057] To realistically recreate the front profile of a vehicle, and with special consideration for the structural characteristics of vulnerable areas such as the headlights, this invention features a chamfered design on the front end of the honeycomb aluminum. The chamfered portion spatially simulates the gap between the edge of the front bumper and the front tire on a real vehicle. This area has relatively weak structural strength, particularly to avoid impacting the vulnerable headlight area and preventing violent rigid contact between the headlight area and the barrier in the initial stages of a collision.

[0058] Define the tangent region as a triangular prism, whose projection onto the XY plane (horizontal plane) is a right triangle. Let the two legs of the triangle be... and The angle of the cut Determined by the following formula: ; in, The X-axis (longitudinal) tangent length represents the horizontal distance in the X-axis from the edge of the bumper to the foremost point of the front tire. The Y-axis (lateral) chamfer width represents the lateral distance in the Y direction from the edge of the bumper to the sidewall of the front tire. This was obtained through extensive measurements of multiple vehicles. and Statistical average and Finally, the design dimensions of the chamfer are determined. The chamfer can be designed at a right angle facing the test vehicle (usually on the left side), or both sides can be chamfered to make the front profile of the honeycomb aluminum closer to the curved design of the real vehicle.

[0059] Figure 11 This is a schematic diagram of the chamfer angle design method provided in the embodiments of this application. Figure 11 The chamfer angle is 45 degrees. Based on the above design scheme, we obtain... Figure 12 The honeycomb aluminum barrier model shown is based on the MPDB (Multi-Party Explosion-Dash) scenario, which is a 50% offset vehicle-to-vehicle collision. Since the MPDB honeycomb aluminum barrier typically represents half of the vehicle's front-end structure, the final effect is as follows: Figure 12 As shown, the chamfer is only on the left side facing the test vehicle.

[0060] This application has the following technical advantages: This application first analyzes the stiffness variation and spatial distribution characteristics of the target vehicle's front-end structure during a collision to create a honeycomb aluminum barrier, dividing it longitudinally and into upper and lower layers. Then, a suitable configuration is selected through simulation. The dimensions of each layer are determined based on actual measurement data of the front-end structure, and stiffness is allocated to each layer based on experimental data, with chamfering designed accordingly. The designed honeycomb barrier satisfies the stiffness variation characteristics of the vehicle's front end during an actual collision, conforms to the vehicle's front-end dimensions, and can be stably compressed, making the honeycomb aluminum barrier more closely resemble the front-end structure of a real vehicle in terms of structural shape and stiffness distribution.

[0061] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A design method for a honeycomb barrier in a frontal collision of a vehicle under MPDB conditions, characterized in that, include: Select the target vehicle model for the development of the honeycomb aluminum barrier; Based on the stiffness change pattern of the front structure of the target vehicle during the collision process, the honeycomb aluminum barrier is longitudinally divided into a front layer, a middle layer, and a rear layer. Based on the differences in stiffness and spatial distribution characteristics of the front-end components of the vehicle, the honeycomb aluminum barrier is divided into multiple upper and lower layers in the vertical direction. Based on the longitudinal and vertical division of the honeycomb aluminum barrier, multiple configurations are constructed, with different layer arrangements for different configurations; The finite element method is used to select suitable target configurations; Based on the actual measurement data of the front-end structure of multiple vehicles corresponding to the target model, the external dimensions of the honeycomb aluminum barrier and the dimensions of each layer are determined. Based on the data from the actual vehicle-to-force wall collision test, the stiffness of each longitudinal and vertical layer was allocated. The honeycomb aluminum barrier is designed with chamfered corners, which are used to fill the gap area between the edge of the front bumper and the front tire of the model vehicle. Based on data from real vehicle-to-wall collision tests, the stiffness of each longitudinal layer is allocated, including: The total effective compression stroke of the cellular aluminum barrier is determined based on the total length and compression ratio of the cellular aluminum barrier. Based on the vertical division of the layer domains into front, middle and back sections, and according to the effective compression stroke corresponding to each layer domain, the total effective compression stroke is divided into a first interval, a second interval and a third interval. The collision force of the target vehicle model is collected using a collision force wall. Based on the full force wall collision force-time curve, dynamic contact projection area, and vehicle B-pillar displacement-time curve, the vehicle stiffness-displacement curve is obtained. The vehicle stiffness-displacement curve is obtained based on the actual vehicle and force wall collision test data. The first interval is fitted with a stiffness straight line, and the third interval is matched with a stiffness setpoint. Discretize the stiffness line obtained in the first interval to the corresponding layer domain to obtain the stiffness of the front layer domain. The stiffness of the rear layer is obtained by taking 1.3 times the peak value of the whole vehicle stiffness curve as the stiffness constant value of the third interval. Based on data from actual vehicle-to-wall collision tests, the stiffness of each vertical layer is allocated, including: The collision force of the target vehicle model collected by the collision force wall is divided into zones to obtain the collision force-time curve of the upper region and the collision force-time curve of the lower region. The stiffness curve of the upper region is obtained based on the collision force-time curve of the upper region, the dynamic contact projection area between the vehicle and the upper part of the force wall, and the displacement-time curve of the vehicle's B-pillar. The stiffness curve of the lower region is obtained based on the collision force-time curve of the lower region, the dynamic contact projection area between the vehicle and the lower part of the force wall, and the displacement-time curve of the vehicle's B-pillar. Based on the stiffness curves of the upper region, the lower region, and the corresponding effective compression stroke of the middle region, the stiffness curves of the second interval of the upper region and the second interval of the lower region are obtained. The two second-interval stiffness curves were fitted with the inverse Sigmoid function, and the asymptotic stiffness function that meets the requirements of the honeycomb aluminum processing technology was obtained through equivalent data processing. The stiffness of the upper layer domain and the stiffness of the lower layer domain were obtained respectively.

2. The method according to claim 1, characterized in that, The stiffness variation law includes: The front layer is an energy absorption zone with stiffness less than the first set value, simulating the initial energy absorption stage of the vehicle's front end, absorbing collision energy through stable plastic crushing. The central region is a transition zone where the stiffness gradually increases with the increase of compressive displacement, simulating the gradual process of the longitudinal beam from initial bending to gradual crushing. The rear layer is a rigid zone with a stiffness greater than the second set value. It represents the rigid structure of the rear of the vehicle's front compartment, providing support in the later stages of a collision to prevent the barrier from being penetrated.

3. The method according to claim 2, characterized in that, Based on the differences in stiffness and spatial distribution characteristics of the vehicle's front-end components, the honeycomb aluminum barrier is vertically divided into multiple upper and lower layers, including: Based on the fact that the stiffness of the upper part of the longitudinal beam of the vehicle is less than that of the lower part, the honeycomb aluminum barrier is divided into an upper layer and a lower layer in the vertical direction, with the upper edge of the longitudinal beam as the boundary.

4. The method according to claim 3, characterized in that, Based on the longitudinal and vertical division of the honeycomb aluminum barrier into layered regions, various configurations can be constructed, including: The honeycomb aluminum barrier is divided into layers along its longitudinal and vertical axes, and each layer is arranged vertically and horizontally.

5. The method according to claim 3, characterized in that, Finite element simulation is used to screen suitable target configurations, including: A tubular frame trolley model and finite element models for each configuration are established in a simulation environment. The front end of the tubular frame trolley model has a rigid tubular frame impact head to simulate the front-end structure of the vehicle. The stiffness of the upper thin tube of the rigid tubular frame impact head is less than the stiffness of the lower thick tube. The upper thin tube simulates the upward force transmission path of the vehicle, and the lower thick tube simulates the downward force transmission path. The finite element model of the honeycomb aluminum barrier configuration is fixedly installed on a rigid backplate. An offset alignment is set between the rigid tubular frame impact head and the finite element model of the configuration, with an offset overlap rate of 80% of the configuration width. In the finite element model of the configuration, initial stiffness values ​​are set for each layer, each layer is attached vertically, and each layer is connected and fixed in the longitudinal direction to thin partitions or back plates between different layers. Set the mass, impact velocity, and sampling frequency of the tube frame trolley model, and perform collision simulations between the tube frame trolley model and the finite element model of each configuration. The target configuration is selected based on whether a stable collision deformation mode appears in the finite element model of the configuration.

6. The method according to claim 5, characterized in that, The target configuration is as follows: the honeycomb aluminum barrier is divided into a front layer, a middle layer and a rear layer in the longitudinal direction, and the middle layer is divided into an upper layer and a lower layer in the vertical direction.

7. The method according to claim 6, characterized in that, Based on actual measurement data of the front-end structures of multiple vehicles corresponding to the target model, the external dimensions and dimensions of each layer of the honeycomb aluminum barrier are determined, including: The weighting is determined based on the sales volume or ownership of multiple vehicles corresponding to the target model; The actual measurement data of the front-end structure of each vehicle is obtained, and the actual measurement data is weighted and averaged according to the weights to obtain the comprehensive measurement data; Based on the comprehensive measurement data, the external dimensions of the honeycomb aluminum barrier and the dimensions of each layer are determined.

8. The method according to claim 7, characterized in that, Based on the comprehensive measurement data, the external dimensions of the honeycomb aluminum barrier and the dimensions of each layer are determined, including: The length of the front layer is determined based on the distance from the front end of the bumper beam to the rear end of the energy-absorbing box. Determine the lengths of the middle and rear layers based on the length of the vehicle's longitudinal beams; Determine the ground clearance of the honeycomb aluminum barrier based on the ground clearance of the lower edge of the subframe; The height of the lower layer is determined based on the difference between the ground clearance of the upper edge of the front longitudinal beam and the ground clearance of the lower edge of the subframe. The height of the upper layer is determined by the difference between the ground clearance of the front end of the hood and the ground clearance of the upper edge of the front longitudinal beam.

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