Crash model analysis method

Abstract

The present invention relates to a method for analyzing a vehicle collision using a simplified model for vehicle collision model analysis based on finite element analysis using software to analyze a vehicle collision, the method including: a first region setting step in which a first region where deformation occurs due to a collision is defined in a first input unit, and modeling for the first region is input and stored in a storage unit; a second region setting step in which a second region where deformation is relatively small due to a collision is defined in a second input unit, and the second region is designated as a steel element, and simplified information on the steel element is input and stored in the storage unit; a correction step in which a boundary between the first region and the second region is designated as a first beam element in a correction unit, and one end of the first beam element is connected to the modeling and the other end is connected to the steel element and stored; and an analysis step in which a calculation unit automatically calculates the collision through a finite element analysis algorithm using the values ​​stored in the storage unit and the correction unit.

Description

[Technical Field]

[0001] The present invention relates to a method for analyzing a vehicle crash using a simplified model in a vehicle crash model analysis based on finite element analysis using software to analyze a vehicle crash. [Background technology]

[0002] To assess the reliability of parts and vehicles in vehicle collisions, crash tests are conducted using a frontal crash evaluation method.

[0003] The full rigid barrier (FRB) frontal crash test is a legal test in which a vehicle is crashed into a completely rigid wall at a speed of 48km / h or 56km / h.

[0004] The partial frontal collision test (Offset Deformable Barrier) involves crashing a portion (40%) of the front of the vehicle into a fixed wall at a speed of 64 km / h. While the full frontal collision test requires two front side members, this test requires only a portion.

[0005] The Small Overlap Front crash test involves crashing a small portion (25%) of the front of a vehicle into a fixed wall at 64km / h. This test involves almost all of the front side members coming off, and is usually handled by inserting a structure connected to the front side members, or by having them come off during the collision to transmit minimal impact to the occupants, thereby verifying the vehicle's reliability in a crash.

[0006] The above-mentioned crash tests are applied as the main evaluation criteria during vehicle development, and in the vehicle development stage, automobile companies conduct crash analysis based on the finite element method on all vehicles to determine whether they meet the relevant criteria in order to develop vehicles that meet these evaluation criteria.

[0007] Through such a crash analysis, the crash performance of the components constituting the vehicle, as well as the performance of the entire vehicle, is evaluated to determine the direction of improvement and the impact of the improvement.

[0008] Some companies are developing design techniques that use simplified analysis models rather than full-vehicle crash analysis models, but the results are inferior to full-vehicle crash analysis results and have limitations in their applicability to actual parts development. Furthermore, for electric vehicles, crash testing has become a crucial factor for battery safety. Therefore, parts manufacturers need a crash analysis method that allows for accurate crash testing and can be performed quickly. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2018-0009904 (Published on January 30, 2018) Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention is intended to solve the above problems and aims to provide a method for analyzing a crash model that can simulate a crash test using a simplified model rather than a full vehicle model. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention provides a method for analyzing a collision model formed as follows.

[0012] A collision model analysis method according to an embodiment of the present invention is a method for analyzing a vehicle collision model based on finite element analysis using software, and includes: a first region setting step in which a first region where deformation occurs due to a collision is defined in a first input unit, and modeling for the first region is input and stored in a storage unit; a second region setting step in which a second region where deformation is relatively small due to a collision is defined in a second input unit, and the second region is designated as a steel element, and simplification information for the steel element is input and stored in the storage unit; a correction step in which a boundary between the first region and the second region is designated as a first beam element in a correction unit, and one end of the first beam element is connected to the modeling and the other end is connected to the steel element and stored; and an analysis step in which a calculation unit automatically calculates a collision through a finite element analysis algorithm using values ​​stored in the storage unit and the correction unit.

[0013] The correction step may include a correction input step in which a first cross section, which is a cross section in the width direction of the vehicle, is input for a vehicle part designated as the first beam element and located on the boundary; a correction calculation step in which a first moment of inertia, which is the moment of inertia of the first cross section, is automatically calculated; and a correction storage step in which one end of the first beam element is connected to the first cross section of the modeling and the first moment of inertia is stored as information of the first beam element.

[0014] The first cross section may be a cross section of an A-pillar, a rocker, and a longitudinal floor.

[0015] The method may further include a battery frame setting step, which is located between the second area setting step and the calculation step, in which the correction unit sets a second beam element for a battery frame surrounding a battery area of ​​the vehicle, one end of the second beam element being connected to the modeling and the other end being connected to the steel body element and stored, and the battery frame setting step may include a battery frame input step in which a side frame forming a side of the battery frame and a second cross section which is a cross section in the width direction of a battery longitudinal frame disposed in a longitudinal direction of the vehicle below the battery area are input, a battery frame calculation step in which a second moment of inertia which is a moment of inertia of the second cross section are calculated, and a battery frame storage step in which the second cross section, the calculated value of the second moment of inertia, and one end of the second beam element are set to be connected to the second cross section and stored.

[0016] The battery frame setting step may further include a front frame setting step in which a battery front frame disposed in a width direction of the vehicle and located in the first region is input as a beam element and stored as a third beam element, the third beam element is set at a position of the front frame, and a third moment of inertia is calculated and stored at a cross section of any of the front frames in the vehicle length direction.

[0017] The simplified information may include a center of gravity and a mass of the second region.

[0018] The collision in the collision model analysis is a frontal collision, and the first region may include a part of the battery frame.

[0019] The first region may include a front bumper, a front subframe, and a front side member of the vehicle. [Effects of the Invention]

[0020] With the above-described configuration, the present invention can perform simulations for all vehicles and analyze collision models with high accuracy.

[0021] Moreover, the simulation can be analyzed in a short time.

[0022] This also makes it possible to more efficiently develop frontal collision analysis parts for protecting electric vehicle batteries, enabling parts manufacturers, in addition to automobile manufacturers, to independently conduct collision analysis. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a flowchart of a method for analyzing a crash model according to an embodiment of the present invention. [Figure 2] 1 is a configuration diagram of an apparatus for performing a method for analyzing a collision model according to an embodiment of the present invention; [Figure 3] 1 illustrates a first region and a second region according to one embodiment of the present invention. [Figure 4] 10 illustrates a state of data stored in a storage unit before an analysis stage of a collision model analysis method according to an embodiment of the present invention. [Figure 5] 1 shows the position and shape of a first cross section according to an embodiment of the present invention, and shows cross sections of (a) an A-pillar, (b) a rocker, and (c) a longitudinal floor. [Figure 6] 1 shows the cross sections and their shapes set in the battery frame setting step according to an embodiment of the present invention. (a) and (b) are the second cross sections, where (a) shows the cross section of the battery side frame, (b) shows the cross section of the battery lower longitudinal frame, and (c) is the third cross section, where (c) shows the cross section of the battery front frame. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the concept of the present invention is not limited to the examples shown, and a person skilled in the art who understands the concept of the present invention may easily propose other degenerate inventions or other embodiments within the concept of the present invention by adding, changing, or deleting other components within the same concept, which are also included within the concept of the present invention.

[0025] Furthermore, in describing the present invention, a "part" or "unit" may be realized in various ways, such as a processor, program instructions executed by a processor, a software module, microcode, a computer program product, a logic circuit, an application specific integrated circuit, firmware, etc.

[0026] The method contents disclosed in the embodiments of the present application can be directly implemented in a hardware processor, or can be implemented and performed by a combination of hardware and software modules in a processor. The software modules can be stored in conventional storage media such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage media are located in memory, and the processor reads the information stored in the memory and combines it with the hardware to complete the method contents described above. To avoid repetition, detailed descriptions will be omitted here.

[0027] In the implementation process, each content of the above-mentioned method can be completed by a hardware logic integrated circuit in a processor or by instructions in the form of software. The content of the method disclosed in the embodiments of the present application can be directly implemented in a hardware processor, or can be implemented and performed by a combination of hardware and software modules in a processor. The software modules can be stored in conventional storage media such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage media is located in memory, and the processor reads the information stored in the memory and completes the content of the above-mentioned method in combination with the hardware.

[0028] That is, a person skilled in the art will understand that each exemplary unit and algorithm step described in the embodiments disclosed herein can be combined and realized by electronic hardware or a combination of computer software and electronic hardware. Whether such functions are implemented in a hardware manner or a software manner is determined by the specific application and design constraints of the technical solution. A person skilled in the art may implement the described functions using different methods for each specific application, but such implementation should not be considered as departing from the scope of this application.

[0029] In some embodiments provided in this application, it should be understood that the disclosed apparatus and method can be realized in other ways. For example, the above-described apparatus embodiments are merely examples, and the division of the above units is merely a type of logical functional division. In actual implementation, other division methods may exist. For example, multiple units or assemblies may be combined or integrated into another system, or some features may be omitted or not implemented. Furthermore, the coupling or direct coupling or communication connection between the shown or discussed mutually may be an indirect coupling or communication connection via some interface, device, or unit, which may be electrical, mechanical, or other form.

[0030] The units described above as separate components may be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed across multiple network units, some or all of which may be selected to achieve the purpose of the solution of this embodiment according to actual needs.

[0031] That is, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist independently, or two or more units may be integrated into one unit.

[0032] When the above functions are realized in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the essential or prior art contributions of the technical solutions of the present application or portions of the technical solutions can be realized in the form of a software product, and the computer software product is stored in a storage medium and contains some instructions to enable a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or some of the steps of the methods described in each embodiment of the present application. The above-mentioned storage medium includes various media capable of storing program code, such as USB memory, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk, or CD-ROM.

[0033] Computer-aided engineering (CAE) has been used to assist engineers in many tasks. For example, in structural or product design procedures, CAE analysis, particularly finite element analysis (FEA), has often been used to evaluate responses (e.g., stresses, displacements, etc.) under various loading conditions (e.g., static or dynamic).

[0034] The present invention relates to a vehicle crash analysis technology that is mainly applied to the design of core crash components in the front of a vehicle, based on changes in vehicle component design characteristics for protecting high-capacity batteries adopted for long-distance operation of existing internal combustion engine vehicles and eco-cars, especially electric vehicles.

[0035] The aim is to increase design efficiency by simplifying peripheral parts that effectively reflect the vehicle behavior characteristics and detailed modeling of core parts related to the frontal collision, instead of the costly and inefficient structure that is currently achieved through whole vehicle modeling, and to provide an analysis method that allows various approaches at the early stage of design without the need for whole vehicle information.

[0036] The present invention relates to a method for analyzing a vehicle crash model based on finite element analysis using software via an electronic device such as a computer, and the following content indicates that it is operated by a mechanical device.

[0037] Fig. 1 shows a simplified method according to an embodiment of the present invention, Fig. 2 shows a configuration formed by an embodiment of the present invention, Fig. 3 shows the first and second regions, Fig. 4 shows the state in which the second region is simplified according to an embodiment of the present invention, Fig. 5 shows the shape of the first cross section S1 specified in the correction step, and Fig. 6 shows the shapes of the second cross section S2 and the third cross section in the battery frame setting step.

[0038] The method for analyzing a collision model according to an embodiment of the present invention includes a first region setting step S10, a second region setting step S20, a correction step S30, and an analysis step S50.

[0039] Basic information is input to the input unit 1, and regions can be specified based on the overall shape of the vehicle depending on whether deformation due to a collision is significant. Then, detailed modeling can be used as is for regions with large regions, while regions where deformation is relatively small or negligible can be simplified and stored in the storage unit 3.

[0040] In the first region setting step S10, a first region D1, which is a region where deformation occurs due to a collision, is defined in the first input unit 11, and modeling for the first region D1 may be input and stored in the storage unit 3. Modeling showing all configurations in detail may be input as is for the first region D1. Externally input information may also be called up by the first input unit 11. The first region D1 may be stored as a steel element as the shape and information of the input modeling.

[0041] In the second region setting step S20, a second region D2, which is a region that is relatively less deformed due to a collision, is defined in the second input unit 12, the second region D2 is designated as a steel element, and simplification information for the steel element is input and stored in the storage unit 3.

[0042] As an example, the simplified information may include the center of gravity G and mass of the second region D2.

[0043] The second region D2 is a region that is relatively less deformed in a collision. The second region D2 may be input as a rigid element or may be automatically set by the second input unit 12. Then, simplification information may be transmitted. A center of gravity G and mass for the second region D2 may be defined, and the second region D2 may be stored in the storage unit 3 as a rigid element having a corresponding mass at the center of gravity G, rather than being modeled.

[0044] The first area D1 and the second area D2 are combined to form the entire vehicle model area, and the criteria for the first area D1 and the second area D2 may be automatically set based on basic data previously established through previous experience or experiments, or may be directly input by an experimenter.

[0045] As an example, when modeling of the entire vehicle is input, the calculation unit 4 may automatically calculate the mass moment of inertia to reflect the behavior characteristics of the entire vehicle, and the mass moment of inertia of the second region D2 may be automatically corrected taking into account the mass moment of inertia of the entire vehicle.

[0046] By dividing the region into the first region D1 and the second region D2 and simplifying the second region D2 to steel body elements, the analysis can be performed using a simplified analytical model.

[0047] When performing an analysis using the simplified model above, errors will occur compared to when performing an analysis using the actual modeling configured as a whole. In order to correct such errors, beam element B is set in a partial area, and the mass moment of inertia of cross section S where beam element B is set is taken into account.

[0048] In the correction step S30, a first beam element B1 is designated at the boundary between the first region D1 and the second region D2, and one end of the first beam element B1 can be connected to the modeling and the other end can be connected to the steel body element and stored.

[0049] The correction step S30 is a step of performing correction to take into account minute deformations due to elasticity and partial plasticity in the simplified collision analysis of the second region D2. That is, the minute deformations are taken into account by taking into account the actual center of gravity R relative to the overall modeling.

[0050] In the correction unit 2, in order to take into account the small deformation amount, a first beam element B1 may be automatically designated or set, and one end of the first beam element B1 may be connected to the modeling and the other end may be connected to the steel body element. The execution of the correction unit 2 as described above may be saved in the correction unit 2 simultaneously with the execution. Alternatively, the execution content of the correction step S30 may be saved in the saving unit 3.

[0051] According to an embodiment of the present invention, the correction step S30 may include a correction input step S31, a correction calculation step S32, and a correction storage step S33.

[0052] In the correction input step S31, a first cross section S1, which is a cross section in the width direction of the vehicle, may be input for the vehicle part that is designated as the first beam element B1 and is located on the boundary.

[0053] The correction calculation step S32 can automatically calculate the first moment of inertia, which is the moment of inertia of the first cross section S1.

[0054] In the correction storing step S33, one end of the first beam element B1 may be connected to the first cross section S1 of the modeling, and the first moment of inertia may be stored as information of the first beam element B1.

[0055] As an example, the first cross section S1 may be a cross section of an A-pillar, a rocker, and a longitudinal floor.

[0056] The first cross section S1 can be specified as a cross section of a part located at the boundary between the first region D1 and the second region D2, which is formed from the front part of the vehicle and connected to the rear part. Therefore, as described above, it can be a cross section cut in the width direction of the vehicle of the front pillar, rocker, and longitudinal floor. The cross section itself can be specified, or when the position is specified, the cross section can be automatically specified by the correction unit 2.

[0057] However, the components are not limited to the above, and may include all components located on the boundary between the first area D1 and the second area D2.

[0058] The application of beam elements allows the small deformations of the simplified region to be expressed using all degrees of freedom, which has the effect of increasing the accuracy of the representation of the entire vehicle crash behavior of the analysis model.

[0059] In the analysis step S50, the calculation unit 4 can automatically calculate the collision through a finite element analysis algorithm using the values ​​stored in the storage unit 3 and the correction unit 2.

[0060] As an example, the crash in the crash model analysis may be a frontal crash.

[0061] The method according to an embodiment of the present invention can simplify and analyze all collisions, but will be described below in connection with, but not limited to, a frontal collision.

[0062] In the case of a frontal collision, the first region D1 may include the front bumper, front subframe, and front side members of the vehicle. The roles of the components in a frontal collision, including the front bumper, front subframe, and front side members, which are components that absorb the most impact in a frontal collision, can all be confirmed.

[0063] As an example, a display unit 5 may be further provided so that the resultant values ​​calculated by the calculation unit 4 can be displayed on a device such as a display.

[0064] As an example, the first region D1 may include a part of the battery frame.

[0065] In this case too, the battery frame can be reinforced with beam elements to reflect the small deformation characteristics of the battery frame for battery protection.

[0066] If a portion of a battery frame is included, a battery frame setting step S40 can be further included to individually simplify and correct the battery frame.

[0067] As an example, the battery frame setting step S40 is located between the second area setting step S20 and the calculation step, and the correction unit 2 sets a second beam element B2 for the battery frame surrounding the battery area of ​​the vehicle, and one end of the second beam element B2 is connected to the modeling and the other end is connected to the steel body element and stored.

[0068] As an example, the battery frame setting step S40 may include a battery frame input step S41 in which a side frame forming a side of the battery frame and a second cross section S2, which is the widthwise cross section of the battery longitudinal frame disposed in the longitudinal direction of the vehicle below the battery area, are input; a battery frame calculation step S42 in which a second moment of inertia, which is the moment of inertia of the second cross section S2, is calculated; and a battery frame storage step S43 in which the second cross section S2, the calculated value of the second moment of inertia, and one end of the second beam element B2 are set and stored so that they are connected to the second cross section S2.

[0069] The second beam element B2, like the first beam element B1, may have one face connected to the detailed modeling region defined by the boundary between the first region D1 and the second region D2, and the other end connected to a steel element in the second region D2.

[0070] In addition, the battery frame setting step S40 may further include a front frame setting step in which a battery front frame arranged in the width direction of the vehicle and located in the first region D1 is input as a beam element and stored in a third beam element B3, the third beam element is set at the position of the front frame, and a third moment of inertia is calculated and stored at a cross section of any of the front frames in the vehicle length direction.

[0071] The front frame of the battery area does not have to be configured to be located at the boundary between the first area D1 and the second area D2, but can be further simplified by converting it into a beam element.

[0072] When the front frame is converted into the third beam element B3, it is not connected to the specific configuration of the second region D2, and the situation where it is originally fixed at the corresponding position can be applied as is.

[0073] According to the present invention, the first region D1, which is the design target region, can be modeled in detail to derive accurate collision deformation behavior and collision energy values ​​similar to those of a full-vehicle analysis model, and the second region D2, which is the simplified region, is simplified as much as possible, but is reinforced with beam elements B, which has the effect of enabling the deriving of collision behavior similar to that obtained when analyzed using full-vehicle modeling.

[0074] This also provides the effect of further improving the efficiency of the development of frontal collision analysis parts for protecting electric vehicle batteries.

[0075] Below are tables comparing the analysis of the full vehicle model with the analysis method of the collision model according to the present invention. Table 1 shows the results for each part for the full frontal collision test, Table 2 shows the results for the partial frontal collision test, and Table 3 shows the results for the small overlap collision test.

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3]

[0079] The table above shows the results of the overall modeling test for each test, focusing on the components that primarily absorb energy, according to an embodiment of the present invention. The results of the overall modeling are referred to as overall modeling, the results obtained according to an embodiment of the present invention are referred to as simplified modeling, and the comparison of the two values ​​is referred to as Simple / Full. As can be seen from the above, the energy absorption values ​​of the components that primarily absorb impact in all tests were within 10%, providing reliable results.

[0080] Furthermore, according to an embodiment of the present invention, in the case of a full frontal collision test for analyzing a collision by overall modeling, the required time is significantly reduced at a level of about 35% from 21h36m (100.0%) to 7h22m (34.1%), in the case of a partial frontal collision test, from 20h49m (100.0%) to 7h29m (35.9%), and in the case of a small overlap collision test, from 21h14m (100.0%) to 7h17m (34.3%).

[0081] As described above, the present invention has been described mainly with reference to the embodiments. However, the present invention is not limited to the above-described embodiments, and can also be modified and implemented by an ordinary technician without changing the technical idea of the present invention claimed in the claims.

Explanation of Reference Numerals

[0082] S10 First Region Setting Step S20 Second Region Setting Step S30 Correction Step S40 Battery Frame Setting Step S50 Analysis Step 1 Input Unit 2 Correction Unit 3 Storage Unit 4 Calculation Unit 5 Display Unit

Claims

1. A method for analyzing a vehicle crash model based on finite element analysis using software, a first region setting step in which a first region where deformation occurs due to a collision is defined in a first input unit, and modeling for the first region is input and stored in a storage unit; a second region setting step in which a second region, which is a region that is relatively less deformed due to a collision, is defined in a second input unit, the second region is designated as a rigid element, and simplification information for the rigid element is input and stored in the storage unit; a correction step in which a first beam element is designated in a correction unit at the boundary between the first region and the second region, and one end of the first beam element is connected to the modeling element and the other end is connected to the steel element and stored; and an analysis step of automatically calculating the collision through a finite element analysis algorithm using the values ​​stored in the storage unit and the correction unit in a calculation unit.

2. In the correction step, 2. The method for analyzing a collision model according to claim 1, further comprising: a correction input step of inputting a first cross section, which is a cross section in the width direction of the vehicle, for a vehicle part designated as the first beam element and located at the boundary; a correction calculation step of automatically calculating a first moment of inertia, which is a moment of inertia of the first cross section; and a correction storage step of connecting one end of the first beam element to the first cross section of the modeling and storing the first moment of inertia as information of the first beam element.

3. The first cross section is 3. The method for analyzing a collision model according to claim 2, wherein the cross sections are of an A-pillar, a rocker, and a longitudinal floor.

4. Located between the second region setting step and the calculation step, 4. The method of claim 3, further comprising a battery frame setting step in which a battery frame surrounding a battery area of ​​the vehicle is set as a second beam element in the correction unit, one end of the second beam element being connected to the modeling and the other end being connected to the steel body element and stored.

5. The battery frame setting step includes: a battery frame input step in which a side frame forming a side surface of the battery frame and a second cross section, which is a cross section in the width direction of a battery longitudinal frame disposed in a longitudinal direction of the vehicle below the battery area, are input; a battery frame calculation step of calculating a second moment of inertia, which is the moment of inertia of the second cross section; 5. The method for analyzing a collision model according to claim 4, further comprising a storing step of storing the second cross section, the calculated value of the second moment of inertia, and a battery frame configured so that one end of the second beam element is connected to the second cross section.

6. The battery frame setting step includes: A battery front frame disposed in the width direction of the vehicle and disposed in the first region is input as a beam element and stored as a third beam element; 6. The method for analyzing a collision model according to claim 5, further comprising a front frame setting step in which the third beam element is set at the position of the front frame, and a third moment of inertia is calculated and stored at any cross section of the front frame in the vehicle length direction.

7. The simplified information is The method for analyzing a crash model according to claim 1 , further comprising the step of: determining a center of gravity and a mass of the second region;

8. The collision in the collision model analysis is a frontal collision, The method for analyzing a crash model according to claim 1 , wherein the first region includes a part of a battery frame.

9. The first region is The method for analyzing a crash model according to claim 8 , wherein the crash model includes a front bumper, a front subframe, and a front side member of the vehicle.

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