A design method for a car B-pillar, a car B-pillar and a car

Abstract

This invention discloses a design method for a car B-pillar, comprising the following steps: determining the deformation mode of the B-pillar under side impact conditions based on the target vehicle model; dividing the B-pillar into several functional zones along the vertical direction according to the deformation mode; establishing a finite element model of the B-pillar thickness based on the thickness parameters of each functional zone; using the thickness parameters of each functional zone as design variables, sampling the thickness parameters of each zone using orthogonal experimental design, substituting the sample values ​​of the thickness parameters of each functional zone into the finite element model of the B-pillar thickness for simulation calculation, and obtaining the simulation calculation results; constructing a response surface function based on the simulation calculation results and the thickness parameters, and performing multi-objective optimization based on the response surface function to obtain the optimal solution set of the thickness parameters. The design method for the car B-pillar, the car B-pillar, and the car in this invention can reduce reliance on personal experience and manual input, more rationally improve the allocation and utilization rate of materials, and contribute to the lightweighting of the car B-pillar.

Description

Technical Field

[0001] This invention relates to the field of automotive design and manufacturing technology, and in particular to a design method for a car B-pillar, a car B-pillar, and a car. Background Technology

[0002] With the booming development of the automotive industry, the safety performance of vehicles has received increasing attention. A vehicle body that meets safety requirements needs to both reduce the impact on occupants by absorbing energy during a collision through deformation, and employ a high-strength body structure to ensure occupant survival space and prevent excessive deformation of the passenger compartment. In side-impact collisions, the structural strength of the B-pillar plays a crucial role, thus largely determining the overall strength of the vehicle body.

[0003] Currently, the main methods for strengthening B-pillars include welded reinforcements, thermoformed one-piece patch panels, laser-welded plates of varying thicknesses, and flexible rolling. Among these, the continuously variable thickness plates produced using flexible rolling technology can be continuously thickened without welds, providing more and more refined possibilities for B-pillar structural design. However, applying this technology faces the challenge of rationally designing the thickness of different parts of the B-pillar. Currently, the thickness distribution is often determined by experience, extensive manual adjustments, and simulation calculations, resulting in a large workload, long processing time, and an inability to achieve a higher degree of lightweight design, further increasing the threshold and cost of applying flexible rolling technology. Summary of the Invention

[0004] In order to overcome some shortcomings of the existing technology, the purpose of this invention is to provide a design method for automobile B-pillar, automobile B-pillar and automobile, which can reduce the dependence on personal experience and manual input, more rationally improve the allocation and utilization rate of materials, and is conducive to the lightweighting of automobile B-pillar.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A design method for a car B-pillar includes the following steps:

[0007] S1. Determine the deformation mode of the B-pillar in a side impact condition based on the target vehicle model;

[0008] S2. According to the deformation pattern, divide the B-pillar into several functional areas along the vertical direction;

[0009] S3. Establish a finite element model of the thickness of column B based on the thickness parameters of each functional area.

[0010] S4. Using the thickness parameters of each functional area as design variables, the thickness parameters of each partition are sampled using the orthogonal experimental design method. The sample values ​​of the thickness parameters of each functional area are substituted into the finite element model of the thickness of the B-pillar for simulation calculation to obtain the simulation calculation results.

[0011] S5. Construct a response surface function based on the simulation results and thickness parameters, and perform multi-objective optimization based on the response surface function to obtain the optimal solution set of thickness parameters.

[0012] Further, in step S2, the functional area includes a rigid area, an overlapping area, and a deformable area. The overlapping area is used to connect with the car door sill and / or A-pillar. The sampling range of each functional area satisfies the following conditions:

[0013] The thickness of the rigid zone is greater than the thickness of the deformable zone and the overlapping zone.

[0014] Furthermore, the rigid region also includes a reinforcing region and a retaining region, wherein the thickness of the reinforcing region is greater than the thickness of the retaining region.

[0015] Furthermore, the overlapping area includes a first overlapping area and a second overlapping area, the first overlapping area being used to connect with the car door sill, and the second overlapping area being used to connect with the car A-pillar; the retaining area includes a first retaining area and a second retaining area, and the reinforcing area is located between the first retaining area and the second retaining area; the B-pillar, from top to bottom, consists of a second overlapping area, a second retaining area, a reinforcing area, a first retaining area, a deformation area, and a first overlapping area.

[0016] Furthermore, step S3 specifically includes: setting the thickness parameter range of each functional area according to the deformation mode.

[0017] Furthermore, in step S2, the junction of two adjacent functional areas includes a transition zone; in step S3, the thickness parameter of each functional area includes the thickness parameter of the transition zone.

[0018] Furthermore, the steps for constructing the thickness parameters of the transition region are as follows:

[0019] Each of the aforementioned transition zones is divided into several sub-units along the vertical direction with a fixed unit length;

[0020] Of all the sub-units, at least m consecutive sub-units are assigned a thickness value to each sub-unit sequentially with the same difference, based on the thickness of one of the functional areas adjacent to the transition zone, such that the thickness of the sub-unit gradually approaches the thickness of another adjacent functional area; wherein the difference is the ratio of the difference between the current thickness samples of the two functional areas adjacent to the transition zone and (m+1).

[0021] Furthermore, step S3 also includes:

[0022] The thickness coefficient is determined based on the deformation mode, and the thickness coefficient is the vertical length corresponding to each 1 mm thickness difference.

[0023] The length of the transition zone is calculated based on the thickness coefficient. The length of the transition zone is the product of the maximum thickness difference between the two adjacent functional zones and the thickness coefficient.

[0024] Furthermore, in the step of constructing the thickness parameter of the transition region, the calculation steps for m are as follows:

[0025] Calculate the thickness difference of the currently sampled thickness of the two adjacent functional areas of the transition section, and calculate the product of the thickness difference and the thickness coefficient;

[0026] The ratio of the product to the length of the sub-unit is calculated to obtain m.

[0027] Furthermore, sub-units beyond m units in the transition zone are assigned the thickness of the adjacent functional area.

[0028] Furthermore, the following is included after step S5:

[0029] S6. Integrate the finite element model of the B-pillar thickness into the whole vehicle side impact finite element model;

[0030] The optimal solution set of the thickness parameters is substituted into the finite element model of the whole vehicle side impact to obtain the calculation results;

[0031] Check if the calculation results meet the side impact requirements of the target vehicle model; if they do, stop the calculation and the optimal solution set is the final result; if they do not meet the requirements, return to S2.

[0032] Furthermore, the process includes the following after step S6:

[0033] S7. Adjust the division of functional areas and transition areas according to actual manufacturing factors, and adjust the sampling of thickness parameters to form actual thickness parameter sample values. The actual manufacturing factors include forming conditions and rolling direction.

[0034] Substitute the actual thickness parameter sample values ​​into the vehicle finite element model to verify whether they meet the side impact requirements of the target vehicle model. If they do, confirm that the actual thickness parameter sample values ​​are the final result. If they do not, return to the previous step and regenerate the actual thickness parameter sample values.

[0035] A type of automobile B-pillar, designed using the aforementioned automobile B-pillar design method.

[0036] An automobile, including the aforementioned B-pillar.

[0037] The design method for the automotive B-pillar in this invention determines the deformation mode under side-impact conditions based on different vehicle models, then divides functional zones according to the deformation mode, establishes a finite element model of the B-pillar thickness based on thickness parameters, and obtains the optimal solution set of thickness parameters by constructing response surface functions based on the thickness parameters of the functional zones and orthogonal experiments. This method is highly flexible and systematic, and a large amount of calculation can be performed using a computer, which can greatly improve design efficiency. In addition, the calculation process takes into account the matching between the transition zone and the functional zone, and the correlation between simulation test results and the test items, so the final result is highly reasonable, which can greatly reduce the dependence on the designer's experience, increase the material utilization rate, and achieve lightweighting of automotive B-pillar materials. Attached Figure Description

[0038] Figure 1 A flowchart illustrating a design method for a car B-pillar according to the present invention;

[0039] Figure 2 An embodiment of the automobile B-pillar design method of the present invention;

[0040] Figure 3 This is an example diagram illustrating the partitioning of a functional area and a transition area of ​​the B-pillar in a car according to a design method of the present invention. Detailed Implementation

[0041] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0042] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0043] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0044] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component, or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0045] Unless otherwise defined, 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 pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0046] The present invention provides a design method for a car B-pillar, comprising the following steps:

[0047] S1. Determine the deformation mode of the B-pillar in a side impact condition based on the target vehicle model;

[0048] Specifically, depending on the target vehicle model, the ground clearance of the B-pillar varies, and the deformation mode when subjected to a side impact also varies. Designers can set it according to the actual target vehicle model.

[0049] S2. According to the deformation pattern, divide the B-pillar into several functional areas along the vertical direction;

[0050] Specifically, there are various ways to divide the functional areas based on different vehicle models and ground clearance. This embodiment provides a method for dividing the functional areas as follows: the functional areas include a rigid area, an overlapping area, and a deformable area. The overlapping area is used to connect with the vehicle door sill and / or A-pillar, and is generally overlapped and welded, thus having higher strength and allowing for a thinner thickness. The rigid area is the region that primarily maintains the structure from significant deformation during deformation, working in conjunction with the deformable area to protect vital areas such as the chest and head of the occupants. The deformable area is the region that primarily deforms after a side impact, and its deformation can absorb some of the collision energy. Therefore...

[0051] The rigid region is further divided into a reinforcement region and a retention region. This is because, due to factors such as shape, there are obviously weak sections in the rigid region that require additional material for reinforcement. The thickness of the reinforcement region is greater than the thickness of the retention region.

[0052] Since the upper and lower ends of the B-pillar need to overlap with other components, the overlapping area includes a first overlapping area and a second overlapping area. The first overlapping area is used to connect with the car door sill, and the second overlapping area is used to connect with the car A-pillar. The retaining area includes a first retaining area and a second retaining area. The reinforcing area is located between the first retaining area and the second retaining area. A typical B-pillar is thicker at the bottom and thinner at the top. The rigid area in the middle is itself the area that needs to be reinforced. The reinforcing area is located in the middle of the rigid area and is the most important area that needs to be reinforced. It needs to be the thickest area.

[0053] like Figure 1 As shown, the B-pillar provided in this embodiment is structurally divided into a second overlap area, a second retaining area, a reinforcing area, a first retaining area, a deformation area, and a first overlap area from top to bottom. This division method fully considers the stress conditions and structural characteristics of each location, and combined with the size distribution of the thicknesses of each location, it can achieve a good side impact resistance performance.

[0054] S3. Establish a finite element model of the thickness of column B based on the thickness parameters of each functional area.

[0055] Specifically, the thickness parameters of each functional area are set according to the deformation mode. In this embodiment, the sampling range of the thickness parameters preferably meets the following conditions: the thickness of the rigid area is greater than the thickness of the deformation area and the overlapping area, so that each functional area functions according to its set function during an actual side impact. If there is a significantly weak section in the rigid area, additional material is needed for reinforcement, and the thickness of the reinforcement area is greater than the thickness of the retaining area. The division of functional areas can be combined with factors such as vehicle model, ground clearance, and B-pillar cross-section to preliminarily predict the stress and deformation mode of the B-pillar when it is impacted. For example, unavoidable structural weak areas require increased thickness for reinforcement; areas overlapping with the sill and A-pillar have strong collision resistance and can be appropriately thinned. This helps to reasonably preset the thickness of each functional area, and the thickness is given in the form of a sampling range, reducing the adverse effects of errors that may occur when making preliminary predictions based on experience.

[0056] Furthermore, a transition zone is included at the junction of two adjacent functional areas; in step S3, the thickness parameter of each functional area includes the thickness parameter of the transition zone; the steps for constructing the thickness parameter of the transition zone are as follows:

[0057] Each of the aforementioned transition zones is divided into several sub-units along the vertical direction with a fixed unit length;

[0058] In all the aforementioned sub-units, at least m consecutive sub-units are assigned thickness values ​​progressively to each other using the thickness of one of the functional zones adjacent to the transition zone as a base value, with the same difference, so that the thickness of the sub-unit gradually approaches the thickness of another adjacent functional zone; wherein, the difference is the ratio of the difference between the current thickness samples of the two functional zones adjacent to the transition zone and (m+1). Each transition zone is divided into several sub-units, with at least m sub-units assigning values ​​to each sub-unit with the same difference, forming a stepped structure. The length of each sub-unit can be set as needed, and the computational and data volume can be easily adjusted. The difference of each sub-unit is also linked to the sampling of the current functional zone to better match the thickness of the adjacent functional zones. Based on this, a finite element model of the entire B-pillar is formed, facilitating rapid computational analysis using a computer.

[0059] S4. Using the thickness parameters of each functional area as design variables, the thickness parameters of each partition are sampled using the orthogonal experimental design method. The sample values ​​of the thickness parameters of each functional area are substituted into the finite element model of the thickness of the B-pillar for simulation calculation to obtain the simulation calculation results.

[0060] S5. Construct a response surface function based on the simulation results and thickness parameters, and perform multi-objective optimization based on the response surface function to obtain the optimal solution set of thickness parameters.

[0061] Orthogonal experiments are a primary method of fractional factorial design, offering advantages such as high efficiency, speed, and economy. They connect simulation calculations with the design objectives, providing strong visibility. Among the objectives, the weight of the B-pillar serves as a measure of lightweighting, while side-impact safety performance is a mandatory requirement. These two test items are crucial; under the premise of meeting side-impact safety performance requirements, the lighter the B-pillar, the better. Side-impact safety performance can be represented by various data. This embodiment provides a method based on the size of the survival space at the B-pillar location after a side impact. The survival space is the distance between the centerline of the B-pillar inner panel and the centerline of the occupant's seat. A larger distance indicates less injury to the occupants and better safety performance.

[0062] Based on the above-mentioned inventive concept, by constructing a response surface function, the optimal solution for the combination of thickness parameters of each functional zone is derived. Subsequently, by utilizing the relationship between the transition zone and the functional zones, the optimal solution for each transition zone is calculated, resulting in the lightest thickness distribution scheme that satisfies safety performance. The response surface function can be constructed using methods such as neural networks, standard quadratic response surface methods, and Kriging response surfaces.

[0063] The S3 step further includes: determining a thickness coefficient based on the deformation mode, wherein the thickness coefficient is the vertical length corresponding to each 1 mm thickness difference;

[0064] The length of the transition zone is calculated based on the thickness coefficient. The length of the transition zone is the product of the maximum thickness difference between the two adjacent functional zones and the thickness coefficient.

[0065] Here, the length of the transition zone is established in relation to the thickness of the two adjacent functional zones, and the addition of a thickness coefficient facilitates flexible adjustment. Furthermore, since the thickness of each functional zone is sampled in real-time within the sampling range for each calculation, the length of the transition zone changes with the current sampling of the functional zone thickness. This is more reasonable than a fixed length, better matching the different thicknesses of the functional zones and reducing the likelihood of stress concentration in the transition zone. Dividing along the vertical direction facilitates sampling during subsequent mathematical model calculations and can adapt to various B-pillars with different shapes and extension directions.

[0066] Due to structural design requirements of the B-pillar, the thickness of each area is often not exactly the same. Therefore, the thickness difference is calculated by using the maximum difference in thickness between two adjacent functional areas to prevent the transition area from not connecting well when the boundary between two functional areas is exactly where the thickness difference is the greatest.

[0067] In the step of constructing the thickness parameter of the transition region, m is actually a sub-unit that needs to maintain a stepped progressive change. This embodiment provides a calculation step for m as follows:

[0068] Calculate the thickness difference of the currently sampled thickness parameters of two adjacent functional areas of the transition section, and calculate the product of the thickness difference and the thickness coefficient;

[0069] The ratio of the product to the length of the sub-unit is calculated to obtain m.

[0070] This calculation method is based on the current sampling of the thickness parameters of the functional areas in each calculation. Unlike the calculation of the transition area length, which uses the maximum thickness difference between the two functional areas, this method makes the transition section that needs a smooth transition more closely match the actual thickness.

[0071] Apart from the m sub-units with the stepped thickness mentioned above, the remaining sub-units can be considered as redundant sub-units that do not need to form a stepped structure. Therefore, the sub-units in the transition region that exceed the m units can be assigned the thickness of the adjacent functional area, which can reduce the amount of calculation and can also be consistent with the thickness of the adjacent functional area.

[0072] The calculation of the transition zone length mentioned above involves a thickness coefficient, which reflects how long each thickness difference needs to be connected. In this embodiment, the thickness coefficient is preferably 50 to 150, that is, each 1 mm thickness difference corresponds to a length of 50 mm to 150 mm, so as to make the transition smoother. The thickness coefficient is preferably 100. This value balances the issues of smooth transition and manufacturing difficulty. It avoids the transition zone being too short, which would cause the transition to be too steep, and it can also avoid the transition zone being too long or even exceeding the length of the two adjacent zones themselves.

[0073] In orthogonal experiments, the choice of the number of levels for experimental factors greatly affects the computational difficulty and accuracy. In this embodiment, it is preferable to use the thickness of each zone of the B-pillar obtained in the above steps as the experimental factor, and to conduct experiments and simulations using the orthogonal experimental method to obtain experimental results. In the step where the experimental results include the weight of the B-pillar and the side-impact safety performance, the number of levels for the experimental factor is 3 to 5, with 4 being optimal. Through the inventors' practice, a number of levels below this range significantly reduces accuracy; a number of levels exceeding this range significantly increases the computational load, but the calculated results are close to those obtained within this range, failing to significantly improve the quality of the results.

[0074] As a further optimization, the construction of a response surface function based on the orthogonal experiments and simulation calculations, using one of the experimental results as the optimization objective, and obtaining the optimal solution set of the thickness parameter combination through the response surface function specifically includes:

[0075] Based on the orthogonal experiments and simulation calculations, a response surface function is constructed. With a preset minimum value for side-impact safety performance as a constraint and the minimum weight of the B-pillar as the optimization objective, the optimal solution for the combination of thickness parameters is obtained through the response surface function. Side-impact safety performance requirements have corresponding ranges in relevant regulations or manufacturer internal requirements. In this embodiment, to prioritize lightweighting, a preset minimum value is used as a constraint. That is, during the calculation process, the response surface function only needs to satisfy the preset minimum value for side-impact safety performance, and on this basis, the goal is to minimize the weight of the B-pillar to achieve the best lightweighting effect.

[0076] To further confirm whether the calculated B-pillar thickness data meets the requirements, this embodiment, after step S5, further includes:

[0077] S6. Integrate the finite element model of the B-pillar thickness into the whole vehicle side impact finite element model so as to perform calculations in combination with the whole vehicle and avoid the problem of insufficient consideration of factors caused by calculating the B-pillar alone.

[0078] Substituting the combination of thickness parameters and the optimal solution of the transition zone into the finite element model of the whole vehicle side impact, the calculation results are obtained;

[0079] Check if the calculation results meet the side impact requirements of the target vehicle model; if they do, stop the calculation, and the resulting optimal solution set is the final result; if not, return to S2 and resample the thickness of each functional area within the sampling range to form new thickness parameters. Since the factors of the test item have already been considered in the aforementioned calculation steps, cases where the optimal solution set does not meet the requirements are rare. However, by combining this optimal solution checking step, the sampling of the initially input thickness parameter combination can be adjusted to narrow the optimization sampling range, thereby improving the quality of the final optimal solution. In actual operation, the number of runs can be appropriately increased according to the actual situation.

[0080] After the above calculations are completed, excellent B-pillar thickness data can be obtained. However, considering that the actual shape of the B-pillar is not uniformly distributed in the vertical direction, this embodiment preferably includes the following after step S6:

[0081] S7. Adjust the division of functional areas and transition areas according to actual manufacturing factors, and adjust the sampling of thickness parameter combinations to form actual thickness parameter sample values. The actual manufacturing factors include forming conditions and rolling direction.

[0082] Substitute the actual thickness parameter sample values ​​into the vehicle finite element model to verify whether they meet the side impact requirements of the target vehicle model. If they do, confirm the actual thickness parameter combination as the final result. If they do not, return to the previous step and regenerate the actual thickness parameter sample values.

[0083] Step S7 takes into account actual manufacturing factors, making the results closer to actual production and manufacturing. The manufacturing cost is also closer to the expected effect in actual use, and both safety performance and lightweighting are guaranteed.

[0084] In addition, for ease of manufacturing and calculation, the thickness parameter in the above engineering optimization and verification steps is normalized in units of 0.05mm. For example, if the optimal solution for the thickness of a certain functional area is 1.334mm, it is normalized to 1.35mm.

[0085] Based on the above method, in order to facilitate finite element analysis and obtain the response surface function in a computer, and to more intuitively demonstrate the design concept of the present invention, this embodiment provides a method for determining the thickness parameters of each functional area using a coordinate system, as follows:

[0086] Establish an xy coordinate system vertically, with the bottom of column B as the origin of the y-axis. Assume the boundary line between functional areas is parallel to the x-axis, and the y-coordinate is y = y'. n Then, from bottom to top, they are y1, y2, y3, ... y nIn two adjacent functional areas, the lower boundary of the upper functional area coincides with the lower boundary of the transition area. Assume the upper boundary of the transition area is parallel to the x-axis, and its y-coordinate is y. n_(n+1) Then, from bottom to top, they are y 1_2 ,y 2_3 ,y 3_4 ,……y n_(n+1) Let the thickness of each functional area be t. n The thickness coefficient is k, and the length of the reserved transition section is L, where L = y n_(n+1) -y n =k|t n+1 -t n | max This value represents the y-axis length of the transition zone.

[0087] With attachment Figure 1 Taking the B-pillar shown as an example, when the maximum thickness difference between the deformation zone and the first retaining zone is 0.4 mm, and the thickness coefficient is 100, the y-direction length L of the transition zone between the deformation zone and the first retaining zone is y 2_3 -y2=100*0.4=40mm.

[0088] Regarding the method of assigning values ​​to each sub-unit, referring to the scheme description in the above implementation, let the length of the sub-unit be a, then m = (k / a)|t n+1 -t n |

[0089] Let the thickness of the sub-unit be t. [n_(n+1)]m The total number of sub-units d = L / a

[0090] The thickness of sub-units beyond m units in the transition zone is assigned as follows, so that all of them are equal to the thickness of the adjacent functional zones.

[0091] t [n_(n+1)](m+1) =t n

[0092] t [n_(n+1)](m+2) =t n

[0093] t [n_(n+1)](m+3) =t n . .

[0096] t [n_(n+1)](m+d) =t n+1

[0097] The thickness of up to m sub-elements within the transition region is assigned as follows, increasing with the same thickness difference:

[0098] t [n_(n+1)]1 =[(|tn+1 -t n |) / (m+1)]+t n

[0099] t [n_(n+1)]2 =[(2|t n+1 -t n |) / (m+1)]+t n

[0100] t [n_(n+1)]3 =[(3|t n+1 -t n |) / (m+1)]+t n . .

[0103] t [n_(n+1)]m =[(m|t n+1 -t n |) / (m+1)]+t n .

[0104] After dividing the functional areas and transition sections according to the above method, the B-pillar of the car in this embodiment is roughly divided as follows: Figure 2 As shown.

[0105] This embodiment provides a preferred thickness for each functional area of ​​a B-pillar, wherein the thickness of the first overlapping area, the second overlapping area, and the deformation area is 1.2 mm to 1.6 mm, the thickness of the first retaining area and the second retaining area is 1.6 mm to 2.0 mm, and the thickness of the reinforcing area is 2.0 mm to 2.4 mm.

[0106] This embodiment also provides a car B-pillar, which is designed using the above-described car B-pillar design method.

[0107] An automobile includes a B-pillar. In this embodiment, the material distribution of the B-pillar is more scientific and reasonable, simultaneously meeting the requirements of automobile safety performance and lightweighting, and has strong application prospects. Except for the B-pillar, the rest of the structure of the automobile in this embodiment adopts general solutions in the art, and will not be described in detail here.

[0108] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A design method of a B-pillar of an automobile, characterized by, The method comprises the following steps: S1, determining the deformation mode of the B-pillar in a side impact condition according to a target vehicle model; S2, dividing the B-pillar into a plurality of functional zones along a vertical direction according to the deformation mode, and the junction of two adjacent functional zones comprises a transition zone; S3, establishing a finite element model of the thickness of the B-pillar according to the thickness parameters of each functional zone, the thickness parameters of each functional zone including the thickness parameters of the transition zone, and the thickness parameters of the transition zone are constructed as follows: Each of the transition zones is divided into a plurality of sub-units along the vertical direction at a fixed unit length; In all the sub-units, at least m continuous sub-units are assigned thickness values in sequence based on the thickness of one of the functional zones adjacent to the transition zone as a base value, with the same difference value, so that the thickness of the sub-units gradually approaches the thickness of the other adjacent functional zone; wherein the difference value is the ratio of the difference between the current thickness values of the two functional zones adjacent to the transition zone and (m+1); S4, taking the thickness parameters of each functional zone as design variables, sampling the thickness parameters of each sub-zone by an orthogonal experimental design method, substituting the sample values of the thickness parameters of each functional zone into the finite element model of the thickness of the B-pillar for simulation calculation, and obtaining simulation calculation results; S5, constructing a response surface function based on the simulation calculation results and the thickness parameters, and performing multi-objective optimization based on the response surface function to obtain an optimal solution set of the thickness parameters.

2. The design method of a B pillar of an automobile according to claim 1, wherein In the S2 step, the functional zones include a rigid zone, an overlapping zone and a deformation zone, the overlapping zone is used to connect with the vehicle door sill and / or the A-pillar, and the value range of the thickness parameters of each functional zone satisfies the following conditions: The thickness of the rigid zone is greater than the thickness of the deformation zone and the thickness of the overlapping zone.

3. The design method of a B pillar of an automobile according to claim 2, wherein The rigid zone further comprises a reinforcing zone and a retaining zone, and the thickness of the reinforcing zone is greater than the thickness of the retaining zone.

4. The design method of a B pillar of an automobile according to claim 3, wherein The overlapping zone comprises a first overlapping zone and a second overlapping zone, the first overlapping zone is used to connect with the vehicle door sill, and the second overlapping zone is used to connect with the vehicle A-pillar; the retaining zone comprises a first retaining zone and a second retaining zone, and the reinforcing zone is located between the first retaining zone and the second retaining zone; the B-pillar sequentially comprises the second overlapping zone, the second retaining zone, the reinforcing zone, the first retaining zone, the deformation zone and the first overlapping zone from top to bottom.

5. The design method of a B pillar of an automobile according to any one of claims 1 to 4, characterized in that, The S3 step specifically comprises: setting the thickness parameter interval of each functional zone according to the deformation mode.

6. The design method of a B pillar of an automobile according to claim 1, wherein The S3 step further comprises: determining a thickness coefficient according to the deformation mode, the thickness coefficient being a vertical length corresponding to a thickness difference of 1 mm; calculating the length of the transition zone according to the thickness coefficient, the length of the transition zone being the product of the maximum thickness difference of the two functional zones adjacent to the transition zone and the thickness coefficient.

7. The design method of a B pillar of an automobile according to claim 1, wherein In the step of constructing the thickness parameters of the transition zone, the calculation steps of m are as follows: calculating the thickness difference of the current values of the thickness of the two functional zones adjacent to the transition zone, and calculating the product of the thickness difference and the thickness coefficient; calculating the ratio of the product and the length of the sub-unit, i.e. m.

8. The design method of a B pillar of an automobile according to claim 7, wherein assigning the thickness of the sub-units exceeding m in the transition zone to the thickness of the functional zone adjacent thereto.

9. The design method of a B pillar of an automobile according to claim 1, wherein After the S5 step, it further comprises: S6, combining the finite element model of the B-pillar thickness into the whole vehicle side impact finite element model; Substituting the optimal solution set of the thickness parameter into the whole vehicle side impact finite element model to obtain a calculation result; Checking whether the calculation result meets the side impact requirement of the target vehicle model; if yes, stopping the calculation, and the optimal solution set obtained is the final result; if not, returning to S2.

10. The design method of a B pillar of an automobile according to claim 9, wherein After the S6 step, it further comprises: S7, adjusting the division of the functional area and the transition area according to actual manufacturing factors, and adjusting the sampling of the thickness parameter to form actual thickness parameter sample values, wherein the actual manufacturing factors include forming conditions and rolling directions; Substituting the actual thickness parameter sample values into the whole vehicle finite element model to check whether the side impact requirement of the target vehicle model is met; if yes, confirming that the actual thickness parameter sample values are the final result; if not, returning to the previous step to re-form the actual thickness parameter sample values.

11. An automotive B-pillar, characterized in that The automobile B-pillar is designed by the design method of any one of claims 1 to 10.

12. An automobile characterized by comprising: The automobile B-pillar comprises the automobile B-pillar of claim 11.

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