Method, device and program for designing automobile body, and method for manufacturing automobile body

Abstract

In order to design an automobile body in which a resin material is attached to or coated on the surface of a body member of a body-in-white structure (100) constituting the automobile body, and the vibration damping performance of a portion of the body-in-white structure (100) to which vibration noise is to be reduced is improved, the following steps are executed by a computer, comprises: an optimization analysis model generation step S1 for generating an optimization analysis model for performing optimization analysis on an optimal shape of a resin material attached to or applied to a vehicle body member in a body-in-white structure 100; and a resin material optimization analysis step (S3) for performing optimization analysis for obtaining the optimal shape of the resin material model in the generated optimization analysis model.

Description

Technical Field

[0001] The present invention relates to an automobile body design method, apparatus, and program for designing an automobile body that improves vibration-damping properties at a portion of a body-in-white structure of an automobile body that is a target for reducing vibration and noise, as well as a method for manufacturing an automobile body. Background Art

[0002] In recent years, there has been an increasing demand for the development of efficient design methods for automobile bodies with excellent vibration damping properties. One of the main reasons for this is the widespread adoption of battery-powered vehicles. This is because electric vehicles do not generate the vibration and noise caused by internal combustion engines, and therefore passengers are more sensitive to vibration and noise caused by other vibration sources. In addition, electric vehicles require large-capacity batteries, and their protective structures result in a body frame structure that is significantly different. As a result, the vibration transfer path differs from that of existing gasoline vehicles, and therefore previous rules of thumb regarding vibration damping structures for reducing vibration and noise are no longer universally applicable.

[0003] Therefore, as a means of obtaining a design guide for a high vibration damping structure without using empirical rules related to the design of the automobile body, an optimization analysis technology using a computer has been proposed. For example, Patent Document 1 discloses the following technology: In order to reduce the vibration noise caused by the vibration transmitted from the vibration source in the automobile to the panel part via the vibration transmission frame part, the vibration transmission frame part is divided into multiple areas, and the optimal plate thickness is determined for each divided area. In addition, Patent Document 2 discloses the following technology: For an automobile part having a metal plate-like member, a resin layer is coated or patched on the inner surface of the plate-like member, and a vibration suppression member made of a metal plate is adhered to the surface opposite to the resin layer, thereby improving the vibration damping performance of the automobile part.

[0004] Furthermore, as a technology for efficiently designing high-performance automobile bodies, optimization analysis using a computer to determine the optimal shape of automobile body parts is applied, for example, in Patent Document 3. This technology defines a design space, constraints, and loading conditions for the automobile body parts to be optimized, and eliminates unnecessary areas in the design space to satisfy objective conditions related to vehicle body performance, such as stiffness and weight, to thereby determine the optimized shape of the automobile body parts.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] Patent Document 1: Japanese Patent No. 6769536

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2022-132725

[0009] Patent Document 3: Japanese Patent No. 5585672 Summary of the Invention

[0010] [Problems to be Solved by the Invention]

[0011] As for the technology of patent document 1, since the plate thickness of each area in the vibration transmission skeleton component is changed, the vibration damping performance of the panel component that is the target of vibration noise reduction is improved, but other vehicle body performance (such as vehicle body rigidity) is sometimes reduced, making it difficult to take into account both vibration damping performance and other vehicle body performance.

[0012] Furthermore, the technology of Patent Document 2 does not specify the position and range of the resin layer and vibration suppression member provided on the plate-shaped member of the automotive component. Therefore, to fully enhance the vibration damping performance of the automotive component, the position and range of the resin layer and vibration suppression member must be determined through trial and error. Furthermore, the technology of Patent Document 2 is intended to enhance the vibration damping performance of a single automotive component when subjected to vibration. Therefore, when vibration is input to the entire automotive body, it is unclear whether the technology of Patent Document 2 can effectively enhance the vibration damping performance of the target area of ​​the automotive body to be reduced.

[0013] Furthermore, the method disclosed in Patent Document 3 can determine the optimal three-dimensional shape of a vehicle body component to achieve objective functions such as minimizing strain energy, minimizing generated stress, and maximizing impact absorption energy under multiple predetermined input loads. Therefore, to improve the vibration damping performance of the body-in-white structure of an automobile body, consideration has been given to applying the optimization analysis technology described in Patent Document 1 to optimize the frequency response related to vibration and acoustics to determine the optimal shape of the vehicle body component for improved vibration damping performance. However, attempts to do so have resulted in the optimal shape of the vehicle body component being a three-dimensionally scattered distribution, failing to achieve a shape useful for the actual body-in-white structure. Consequently, even if the optimal three-dimensional shape is determined using optimization analysis, it is impossible to determine a component shape that can be manufactured using press forming, etc., based on the determined optimal shape.

[0014] The present invention was created to address the aforementioned issues, and its object is to provide an automobile body design method, apparatus, and program for designing an automobile body that effectively improves the vibration damping performance of areas targeted for vibration noise reduction while maintaining vehicle body performance other than vibration damping. Another object of the present invention is to provide an automobile body manufacturing method for manufacturing an automobile body that effectively improves the vibration damping performance of areas targeted for vibration noise reduction while maintaining vehicle body performance other than vibration damping, such as vehicle body rigidity.

[0015] The automobile body design method according to the present invention is to design an automobile body in which a vibration-damping property of a vibration-noise reduction target portion of a body-in-white structure, which is a target for reducing vibration noise, is improved by attaching or coating a resin material to the surface of a body part constituting the body-in-white structure of the automobile body. The method comprises executing the following steps by a computer: an optimization analysis model generation step of generating an optimization analysis model for performing an optimization analysis on an optimal shape of the resin material attached or coated to all or part of the body parts in the body-in-white structure; and a resin material optimization analysis step of performing the optimization analysis using the generated optimization analysis model. The optimization analysis model generation step comprises: a design space setting step of setting a design space as a target for the optimization analysis along the surface of all or part of the body parts in the body-in-white structure; a resin material model generation step of generating, in the set design space, a resin material model using shell elements (shell elements) A resin material model is generated by modeling a solid element or solid element for optimization analysis; and a connecting processing step of connecting the generated resin material model to the body component in the body-in-white structure, wherein the resin material optimization analysis step includes: a material property setting step of setting at least an elastic modulus, a density, and an attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting step of setting a vibration input condition related to vibration applied to the optimization analysis model in the optimization analysis; an optimization analysis condition setting step of setting an objective function related to vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target portion in the optimization analysis model and a constraint condition related to the weight or volume of the resin material model as optimization analysis conditions; and an optimization analysis step of performing optimization analysis to determine an optimal shape of the resin material model in the optimization analysis model under the vibration input condition and the optimization analysis condition.

[0016] In the design space setting step, the design space may be set in a gap between the vehicle body components.

[0017] In the design space setting step, a two-dimensional space along only one surface of the vehicle body component may be set as the design space, and in the resin material model generating step, the resin material model may be modeled using shell elements.

[0018] Alternatively, in the optimization analysis condition setting step, the objective function is set to minimize the frequency response value of any one of acceleration, inertance, or equivalent radiated power in a specified frequency band of the vibration noise reduction target portion, or to minimize a function with the frequency response value as a variable.

[0019] The automobile body design device according to the present invention is used to design an automobile body in which a resin material is attached or coated on the surfaces of body parts constituting a body-in-white structure of an automobile body, thereby improving the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure as a target for reducing vibration noise, wherein the automobile body design device comprises: an optimization analysis model generating unit that generates an optimization analysis model, wherein the optimization analysis model performs optimization analysis on an optimal shape of the resin material attached or coated on all or part of the body parts in the body-in-white structure; and a resin material optimization analysis unit that performs the optimization analysis using the generated optimization analysis model, wherein the optimization analysis model generating unit comprises: a design space setting unit that sets a design space as a target for the optimization analysis along the surfaces of all or part of the body parts in the body-in-white structure; and a resin material model generating unit that generates, in the set design space, a resin material model using shell elements or solid elements. a resin material model for performing an optimization analysis process based on element modeling; and a combining processing unit that combines the generated resin material model with the body component in the body-in-white structure, the resin material optimization analysis unit comprising: a material property setting unit that sets at least an elastic modulus, a density, and an attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting unit that sets a vibration input condition related to the vibration given to the optimization analysis model in the optimization analysis; an optimization analysis condition setting unit that sets an objective function related to the vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target part in the optimization analysis model and a constraint condition related to the weight or volume of the resin material model as optimization analysis conditions; and an optimization analysis unit that performs an optimization analysis to obtain an optimal shape of the resin material model in the optimization analysis model under the vibration input condition and the optimization analysis condition.

[0020] The present invention relates to an automobile body design program for designing an automobile body in which a resin material is attached or coated on the surfaces of body parts constituting a body-in-white structure of an automobile body, thereby improving the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure, which is a target for vibration noise reduction. The automobile body design program causes a computer to function as an optimization analysis model generation unit and a resin material optimization analysis unit. The optimization analysis model generation unit generates an optimization analysis model for performing optimization analysis on an optimal shape of the resin material attached or coated on all or part of the body parts in the body-in-white structure. The resin material optimization analysis unit performs the optimization analysis using the generated optimization analysis model. The optimization analysis model generation unit includes: a design space setting unit for setting a design space to be analyzed along the surfaces of all or part of the body parts in the body-in-white structure; and a resin material model generation unit for generating a resin material model based on the set design space. In space, a resin material model is generated by modeling with shell elements or solid elements for optimization analysis processing; and a combination processing unit is combined with the generated resin material model and the body component in the white body structure, and the resin material optimization analysis unit has: a material property setting unit, which sets at least elastic modulus, density and attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting unit, which sets vibration input conditions related to the vibration given to the optimization analysis model in the optimization analysis; an optimization analysis condition setting unit, which sets an objective function related to the vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target part in the optimization analysis model and a constraint condition related to the weight or volume of the resin material model as optimization analysis conditions; and an optimization analysis unit, which performs optimization analysis to obtain the optimal shape of the resin material model in the optimization analysis model under the vibration input conditions and the optimization analysis conditions.

[0021] The present invention relates to a method for manufacturing an automobile body for manufacturing an automobile body in which a resin material is attached or coated to body parts constituting a body-in-white structure of an automobile body, thereby improving the vibration damping performance of a vibration noise reduction target portion in the body-in-white structure, which is an object of reducing vibration noise. The method comprises using the automobile body design method of the present invention to determine an optimal shape of the resin material, and based on the determined optimal shape of the resin material, determining an optimal shape and position of the resin material for attaching or coating to the body parts. The resin material having the determined shape and position is then attached or coated to the body parts in the body-in-white structure.

[0022] Effects of the Invention

[0023] In the present invention, a resin material model is generated within a design space defined along the surfaces of all or a portion of the body components in the body-in-white structure of an automobile body, and an optimization analysis is performed to determine the optimal shape of the resin material model that improves the vibration damping performance of the target areas for vibration and noise reduction. This allows the optimal shape of the resin material to be applied or coated to the surfaces of the body components that constitute the body-in-white structure to be determined. As a result, an automobile body can be designed and manufactured that improves the vibration damping performance of the target areas for vibration and noise reduction while maintaining vehicle performance other than vibration damping, such as body rigidity. Furthermore, by defining a two-dimensional space along only one surface of the body component as the design space and performing an optimization analysis to determine the optimal shape of the resin material model, it is possible to obtain a shape that is easy to manufacture, such as a plate or sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a block diagram showing an automobile body design device according to the first embodiment of the present invention.

[0025] Figure 2 This is a diagram showing an example of the body-in-white structure of an automobile body used as an analysis target in the first embodiment, a portion to which vibration is input in the optimization analysis, and a portion to which vibration noise reduction is targeted.

[0026] Figure 3 This is a flowchart showing the flow of processing in the automobile body design method according to the first embodiment of the present invention.

[0027] Figure 4 This is a graph showing the frequency response of the equivalent radiated power of the base plate obtained as an example of vibration characteristics used for evaluating the vibration damping performance of the base plate in the first embodiment, using the base plate as the target site for vibration noise reduction.

[0028] Figure 5 In the figure, (a) is a diagram showing the design space set in the space between the vehicle body parts and the resin material model before optimization analysis in Example 1, and (b) is a diagram showing the optimization analysis model generated by combining the resin material model before optimization analysis with the white body structure in Example 1.

[0029] Figure 6 This is a diagram showing the optimal shape resin material model obtained through optimization analysis in Example 1.

[0030] Figure 7 This graph shows the frequency response of the equivalent radiated power of the floor panel in the body-in-white structure in Example 1, in which an optimally shaped resin material model is installed in the space between body components (dashed line: original body-in-white structure, solid line: body-in-white structure with the optimally shaped resin material model installed).

[0031] Figure 8 In the figure, (a) is a diagram showing the design space set only on a single surface of the vehicle body component and the resin material model before optimization analysis in Example 2, and (b) is a diagram showing the optimization analysis model generated by combining the resin material model before optimization analysis with the body-in-white structure in Example 2.

[0032] Figure 9 This is a diagram showing the optimal shape resin material model obtained through optimization analysis in Example 2.

[0033] Figure 10 This is a graph showing the frequency response of the equivalent radiated power of the floor panel in a body-in-white structure in which an optimally shaped resin material model is installed on one side of the vehicle body component in Example 2 (dashed line: original body-in-white structure, solid line: body-in-white structure with the optimally shaped resin material model installed). DETAILED DESCRIPTION

[0034] Before describing the first and second embodiments of the present invention, the body-in-white structure of the automobile body, which is the subject of the present invention, will be described. In the drawings of this application, the X-axis, Y-axis, and Z-axis directions represent the front-to-back direction, the width direction, and the vertical direction of the vehicle body, respectively.

[0035] Body-in-white structure

[0036] As an example, Figure 2 As shown, the body-in-white structure 100 of an automobile body is composed of automotive parts such as body frame parts, reinforcement parts, and panel parts. Body frame parts are components that constitute the vehicle's body frame, and examples thereof include the front longitudinal members 101, side members 103, rear longitudinal members 105, A-pillar lowers 106, and tunnels 108. Reinforcement parts are components that are installed on each body frame part to reinforce it, and examples thereof include stiffeners (not shown). Panel parts are thin-plate structures such as outer panels and inner panels, and examples thereof include the floor panel 107.

[0037] In the body-in-white structure 100 , panel members such as the floor panel 107 can be exemplified as portions to be subjected to vibration noise reduction.

[0038] As described below, the present invention performs optimization analysis to determine the optimal shape of the resin material to be applied or applied to the vehicle body components constituting the vehicle body structure 100. Therefore, the vehicle body structure 100 includes vehicle body components modeled using shell elements and / or solid elements. Furthermore, element information, material properties, and the like of each vehicle body component modeled using shell elements and / or solid elements are stored in a vehicle body structure model file 21 (described below). Figure 1 )middle.

[0039] [Implementation Method 1]

[0040] <Automobile body design device>

[0041] The automobile body design device according to the first embodiment of the present invention is used to design an automobile body in which the vibration damping performance of the target portion of the vibration noise reduction in the body-in-white structure 100 is improved by attaching or coating a resin material to the body parts of the body-in-white structure 100 constituting the automobile body. Figure 1 As shown, the automobile body design device 1 is composed of a PC (personal computer) or the like and includes a display device 3, an input device 5, a storage device 7, a work data memory 9, and a processing unit 11. In the automobile body design device 1, the display device 3, the input device 5, the storage device 7, and the work data memory 9 are connected to the processing unit 11 and execute their respective functions in response to instructions from the processing unit 11. The following describes the various components of the automobile body design device 1.

[0042] The display device 3 is used to display analysis results and is comprised of, for example, a liquid crystal monitor. The input device 5 is used to display the vehicle body structure model file 21 and for operator input of conditions and is comprised of, for example, a keyboard and a mouse. The storage device 7 is used to store various files, such as the vehicle body structure model file 21, and is comprised of, for example, a hard disk. The working data memory 9 is used to temporarily store data used by the calculation processing unit 11 and to perform calculations and is comprised of, for example, RAM (Random Access Memory).

[0043] The calculation processing unit 11 is as follows Figure 1 The system shown includes an optimization analysis model generation unit 13 and a resin material optimization analysis unit 15, each comprised of a CPU (central processing unit) such as a PC. Each of these units functions as the CPU executes a specific program. The functions of each of these units within the processing unit 11 are described below.

[0044] Optimization Analysis Model Generation Unit

[0045] The optimization analysis model generating unit 13 is used to generate an optimization analysis model for performing optimization analysis on the optimal shape of the resin material attached or applied to all or part of the vehicle body parts in the vehicle body structure 100. Figure 1 As shown, the optimization analysis model generating unit 13 includes a design space setting unit 13 a , a resin material model generating unit 13 b , and a combination processing unit 13 c .

[0046] (Design space setting department)

[0047] The design space setting unit 13 a sets a design space to be subjected to optimization analysis along the surfaces of all or part of the vehicle body parts in the vehicle body structure 100 .

[0048] The vehicle body parts for which the design space is set are preferably vehicle body parts to which a resin material can be attached or coated without deteriorating the appearance of the vehicle body, or vehicle body parts for which a space is ensured for attaching or coating a resin material.

[0049] The design space setting unit 13a can set the design space within the space between vehicle body components, or it can set the design space within the two-dimensional space along the surface of the vehicle body components. This makes it easier to ensure space for applying or coating the resin material and prevents the appearance of the vehicle body from being damaged by the application of the resin material.

[0050] In this first embodiment, when setting a design range within the space between vehicle body components, the space within a thickness of 25 mm or less is used as a standard for the space within which the resin material can be applied. Examples of the space between vehicle body components for which the design range is set include the space formed between vehicle body frame components such as side sills, front side sills, tunnels, and front pillars, and the reinforcement members disposed within the vehicle body frame components as reinforcement members.

[0051] Examples of vehicle body component surfaces for which design space is defined include the inside or outside surfaces of vehicle body frame components such as side sills, A-pillar lowers, front longitudinal members, tunnels, front pillars, and center pillars. Examples also include the inside surfaces of panel components such as door panels, roof panels, and floor panels.

[0052] (Resin material model generation unit)

[0053] The resin material model generation unit 13b generates a resin material model within the design space set by the design space setting unit 13a, using shell elements or solid elements for modeling and performing optimized analysis processing. Furthermore, if the design space set by the design space setting unit 13a is a two-dimensional space along the surface of a vehicle body component, the resin material model generation unit 13b generates a resin material model using shell elements for modeling and performing optimized analysis processing. This is done to achieve the optimal shape of a plate-like or sheet-like resin material model that is easy to manufacture through optimized analysis processing.

[0054] (Combination Processing Unit)

[0055] The combining unit 13c combines the resin material model generated by the resin material model generating unit 13b with the vehicle body components in the vehicle body structure 100. By combining the resin material model with the vehicle body components by the combining unit 13c, an optimization analysis model can be generated.

[0056] The resin material model can be connected to the body components in the body-in-white structure 100 by, for example, connecting the nodes of the resin material model to the nodes of the body components using elements (rigid body elements, elastic body elements, or elastic-plastic body elements) (rigid joints or elastic joints). Alternatively, the resin material model and the body components can be connected by sharing the nodes of the resin material model with the nodes of the body components.

[0057] Resin Material Optimization Analysis Unit

[0058] The resin material optimization analysis unit 15 uses the optimization analysis model generated by the optimization analysis model generation unit 13 to perform optimization analysis on the optimal shape of the resin material to be attached or applied to the vehicle body part. Figure 1 As shown, the resin material optimization analysis unit 15 includes a material property setting unit 15a, a vibration input condition setting unit 15b, an optimization analysis condition setting unit 15c, and an optimization analysis unit 15d.

[0059] (Material property setting section)

[0060] The material property setting unit 15a sets at least elastic modulus, density, and attenuation rate as material properties of the resin material model. The elastic modulus, density, and attenuation rate set as material properties of the resin material model are preferably set as follows.

[0061] As for the elastic modulus (or storage modulus) of the resin material, the larger its value, the stronger its effect on the vibration characteristics, and the more it can improve the vibration damping performance of the target area for vibration noise reduction. In addition, the density of the resin material (density after curing) not only affects the vibration characteristics, but also greatly affects the weight reduction of the automotive body. The smaller its value, the higher the effect on the vibration characteristics and the weight reduction of the automotive body. Therefore, as for the elastic modulus and density of the resin material, it is sufficient to set a value for the resin material with a large ratio of the elastic modulus to the density (specific elastic modulus) (high rigidity in terms of density ratio), preferably set to 1000 (MPa / g·cm -3 ) or more, more preferably 1400 (MPa / g·cm -3 ) or more. In addition, the elastic modulus is 200MPa or more and 6GPa or less, and the density is 0.7g / cm 3 Above 1.8g / cm 3 The attenuation rate (or attenuation coefficient tanδ) of the resin material does not have a significant effect on the optimization analysis, but it is preferably set to a value equivalent to the actual attenuation rate of the resin material, preferably within the range of 0.1 to 0.15.

[0062] (Vibration input condition setting unit)

[0063] The vibration input condition setting unit 15 b is used to set vibration input conditions related to vibrations to be given to the optimization analysis model during optimization analysis.

[0064] The vibration input condition setting unit 15b sets the amplitude (magnitude of vibration), frequency, and the location in the body-in-white structure 100 where vibration is applied as vibration input conditions. The vibration input conditions can be appropriately set based on, for example, the vibration input to the body-in-white structure 100 while the vehicle is driving.

[0065] As a part that imparts vibration, Figure 2 As shown, a connection portion (marked with △ in the figure) between the front subframe 109 and the lower arm (not shown) can be exemplified.

[0066] (Optimization analysis condition setting section)

[0067] The optimization analysis condition setting unit 15 c sets, as optimization analysis conditions, an objective function related to vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target portion in the optimization analysis model and constraints related to the weight or volume of the resin material model.

[0068] The objective function is a condition set based on the vibration characteristics used to evaluate the vibration damping performance of the target vibration noise reduction area. For example, the vibration characteristics can be the vibration intensity of the target vibration noise reduction area. Examples of vibration intensity include frequency response values ​​such as acceleration, inertia, or equivalent radiated power (ERP) within a specified frequency band, or functions incorporating these as variables.

[0069] The vibration noise reduction target area can be appropriately set according to the operator's instructions. Figure 2 As shown, the floor panel 107 in the body-in-white structure 100 can be exemplified.

[0070] Inertia is a vibration characteristic expressed as the ratio of the force input to an object to the resulting acceleration, also known as the vibration transfer function.

[0071] Equivalent Radiated Power is an indicator that simply represents the level of sound emitted by a vibrating structure. It represents vibration characteristics based on the concept that the vertical component of the structure's vibration velocity imparts energy to the acoustic space.

[0072] Examples of functions using acceleration, inertia, or equivalent radiated power as variables include functions that give average and maximum values ​​of acceleration at multiple locations in a vehicle body member (panel member, etc.) serving as a target site for noise and vibration reduction.

[0073] The constraint condition is a constraint related to the weight or volume of the resin material model when performing optimization analysis of the resin material model using the optimization analysis model to improve the vibration damping performance of the vibration noise reduction target portion.

[0074] For example, a weight-related constraint can be set to keep the weight of the resin material model below a predetermined weight. Furthermore, a volume-related constraint can be set to keep the ratio of the volume of the resin material model relative to the volume of the design space set in the body-in-white structure 100 below a predetermined value. Constraints on the weight and volume of the resin material model can also be set based on the total weight and volume of the optimization analysis model.

[0075] (Optimization Analysis Department)

[0076] The optimization analysis unit 15d performs optimization analysis to determine the optimal shape of the resin material model in the optimization analysis model under the vibration input conditions set by the vibration input condition setting unit 15b and the optimization analysis conditions set by the optimization analysis condition setting unit 15c.

[0077] The optimization analysis performed by the optimization analysis unit 15d is preferably performed using topology optimization, for example. In topology optimization using density analysis, the hypothetical material densities of the elements (shell elements or solid elements) of the resin material model are used as design variables. An optimization analysis is performed to retain or delete elements, thereby determining the optimal shape of the resin material model. Furthermore, the optimal position of the resin material model can be determined based on the positions of the elements remaining in the optimization analysis.

[0078] <Automobile Body Design Methods>

[0079] The automobile body design method according to the first embodiment is used to design an automobile body in which the vibration damping performance of the vibration noise reduction target portion of the body-in-white structure 100 is improved by attaching or coating a resin material to the body parts constituting the automobile body. Figure 3 The steps shown in the figure are implemented, including the optimization analysis model generation step S1 and the resin material optimization analysis step S3. Figure 3 In the following description, each of the above steps is performed using the automobile body design device 1 ( Figure 1 ) to execute.

[0080] 《Steps for Generating an Optimization Analysis Model》

[0081] The optimization analysis model generation step S1 is a step of generating an optimization analysis model for determining the optimal shape of the resin material to be attached or applied to the vehicle body parts in the vehicle body structure 100. Figure 3 The process shown includes a design space setting step S1a, a resin material model generating step S1b, and a combining step S1c. In the first embodiment, the optimization analysis model generating step S1 is executed by the optimization analysis model generating unit 13 of the automobile body design device 1.

[0082] (Design space setting process)

[0083] The design space setting step S1a is a step of setting a design space to be analyzed for optimization along the surfaces of all or part of the vehicle body components in the vehicle body-in-white structure 100. In the first embodiment, the design space setting step S1a is executed by the design space setting unit 13a of the automobile body design device 1.

[0084] In the design space setting step S1a, the design space can be set within the space between the vehicle body components, or the two-dimensional space along the surface of the vehicle body components. This makes it easier to ensure space for applying or coating the resin material and prevents the appearance of the vehicle body from being damaged by the application of the resin material.

[0085] (Resin material model generation process)

[0086] The resin material model generation step S1b is a step for generating a resin material model within the design space set in the design space setting step S1a, using shell elements or solid elements for modeling and performing optimized analysis. In the first embodiment, the resin material model generation step S1b is performed by the resin material model generation unit 13b of the automobile body design device 1.

[0087] If the design space set in the design space setting step S1a is a two-dimensional space along the surface of the vehicle body component, a resin material model is generated using shell element modeling and optimized analysis processing. This is done to obtain the optimal shape of the resin material model, which is easily manufacturable in the form of a plate or sheet, through the optimized analysis processing.

[0088] (Combined processing steps)

[0089] The combining process S1c combines the resin material model generated in the resin material model generating process S1b with the vehicle body components in the body-in-white structure 100. In the first embodiment, combining process S1c is performed by the combining process unit 13c of the automobile body design device 1. By combining the resin material model with the vehicle body components in combining process S1c, an optimized analysis model can be generated.

[0090] In the joining process step S1c, the resin material model is preferably joined to the body components in the body-in-white structure 100 by joining the nodes of the resin material model to the nodes of the body components using elements (rigid elements, elastic elements, or elasto-plastic elements) (rigid joining or elastic joining). Alternatively, the nodes of the resin material model may be joined to the nodes of the body components by sharing them.

[0091] Resin Material Optimization Analysis Steps

[0092] The resin material optimization analysis step S3 is a step of performing optimization analysis for finding the optimal shape of the resin material for improving the vibration damping performance of the vibration noise reduction target portion using the optimization analysis model generated in the optimization analysis model generation step S1. Figure 3 As shown, the resin material optimization analysis step S3 includes a material property setting step S3a, a vibration input condition setting step S3b, an optimization analysis condition setting step S3c, and an optimization analysis step S3d. In the first embodiment, the resin material optimization analysis step S3 is executed by the resin material optimization analysis unit 15 of the automobile body design device 1.

[0093] (Material property setting process)

[0094] The material property setting step S3a is a step of setting at least elastic modulus, density, and attenuation rate as material properties of the resin material model. In the first embodiment, the material property setting step S3a is executed by the material property setting unit 15a of the automobile body design device 1.

[0095] The material properties of the resin material model are as follows: elastic modulus of 200 MPa or more and 6 GPa or less, density of 0.7 g / cm 3 Above 1.8g / cm 3 It is preferable to set the attenuation rate within the range of 0.1 to 0.15.

[0096] (Vibration input condition setting process)

[0097] The vibration input condition setting step S3b is for setting vibration input conditions related to the vibration given to the optimization analysis model in the optimization analysis. In the first embodiment, the vibration input condition setting step S3b is executed by the vibration input condition setting unit 15b of the automobile body design device 1.

[0098] In the vibration input condition setting step S3b, the amplitude (magnitude of vibration), frequency (number of vibrations), and the location where vibration is applied are set as vibration input conditions. The vibration input conditions can be appropriately set by assuming, for example, the vibration input to the body-in-white structure 100 during vehicle driving.

[0099] The part imparting vibration is as mentioned above Figure 2 As shown, there can be exemplified a connection portion (marked with △ in the figure) between the front subframe 109 and the lower arm.

[0100] (Optimization analysis condition setting process)

[0101] The optimization analysis condition setting step S3c is a step for setting, as optimization analysis conditions, an objective function related to vibration characteristics used to evaluate the vibration damping performance of the target vibration noise reduction area in the optimization analysis model and constraints related to the weight or volume of the resin material model. In the first embodiment, the optimization analysis condition setting step S3c is executed by the optimization analysis condition setting unit 15c of the automobile body design device 1.

[0102] In the optimization analysis condition setting step S3c, the objective function can be set to minimize the vibration intensity of the target vibration noise reduction area in the optimization analysis model. Examples of the vibration intensity include frequency response values ​​of acceleration, inertia, or equivalent radiated power (ERP) within a specified frequency band, or functions using these as variables.

[0103] (Optimization Analysis Process)

[0104] Optimization analysis is performed to determine the optimal shape of the resin material model in the optimization analysis model under the optimization analysis step S3d, the vibration input conditions set in the vibration input condition setting step S3b, and the optimization analysis conditions set in the optimization analysis condition setting step S3c. In the first embodiment, optimization analysis step S3d is performed by the optimization analysis unit 15d of the automobile body design device 1.

[0105] The optimization analysis in the optimization analysis step is preferably performed by applying, for example, topology optimization. When topology optimization is applied, the optimal position of the resin material model can be obtained based on the positions of the elements remaining in the optimization analysis process.

[0106] <Automobile Body Design Program>

[0107] The above description of the first embodiment is about the automobile body design device and method. However, the first embodiment can be used as an automobile body design device 1 ( Figure 1 ) is composed of an automobile body design program in which each unit in the calculation processing unit 11 functions.

[0108] That is, the automobile body design program according to the first embodiment is used to design an automobile body in which the vibration damping performance of the target portion for reducing vibration noise in the body-in-white structure 100 is improved by attaching or coating resin materials to the body parts constituting the body-in-white structure of the automobile body. The automobile body design program according to the first embodiment enables a computer to Figure 1 The calculation processing unit 11 shown in FIG. 1 functions as an optimization analysis model generating unit 13 and a resin material optimization analysis unit 15 .

[0109] The automobile body design program according to the first embodiment makes the computer function as the optimization analysis model generation unit 13, and makes each unit of the optimization analysis model generation unit 13 function. Figure 1 As shown, it includes a design space setting unit 13a, a resin material model generating unit 13b and a combining processing unit 13c.

[0110] Furthermore, the automobile body design program according to the first embodiment makes the computer function as the resin material optimization analysis unit 15, and makes each unit of the resin material optimization analysis unit 15 function. The resin material optimization analysis unit 15 is as described above. Figure 1 The device shown includes a material property setting unit 15a, a vibration input condition setting unit 15b, an optimization analysis condition setting unit 15c, and an optimization analysis unit 15d.

[0111] As described above, the automobile body design device, method, and program according to the first embodiment determine the optimal shape of the resin material to be applied or coated to the surfaces of body components constituting the body-in-white structure of the automobile body. This allows for the design of an automobile body that improves vibration damping in target areas of the body-in-white structure while maintaining vehicle performance other than vibration damping, such as body rigidity.

[0112] This first embodiment relates to a method for setting a design space in either the space between body parts or only on a single surface of a body part. However, the present invention is not limited to this method, and design spaces may be set in both the space between body parts and on a single surface of a body part, or on both surfaces of a body part.

[0113] In the first embodiment, the material properties of the resin material model are set for the optimization analysis model formed by combining the resin material model with the body-in-white structure 100 . However, the material properties may be set for the resin material model before combining with the body-in-white structure 100 .

[0114] In addition, if Figure 2 As shown, in the first embodiment, the optimization analysis is performed with a single location imparting vibration to the optimization analysis model. However, the present invention may also impart vibration to multiple locations, two or more. When imparting vibration to multiple locations, the locations may be imparted with the same amplitude and frequency, or with different amplitudes or frequencies. Furthermore, the vibrations may be imparted with their phases shifted.

[0115] Furthermore, the present invention is not limited to the above-mentioned topological optimization in the optimization analysis for determining the optimal shape of the resin material model, and may also be performed using other calculation methods. Furthermore, the optimization analysis may be performed using commercially available analysis software using the finite element method, for example.

[0116] [Implementation Method 2]

[0117] The automobile body design method according to the first embodiment is used to design an automobile body in which the vibration damping performance of the target vibration noise reduction portion is improved by attaching or coating a resin material to body parts constituting the body-in-white structure 100 of the automobile body.

[0118] However, the present invention can be constructed as a method for manufacturing an automobile body, which is used to adhere or apply resin material to body parts constituting the body-in-white structure of the automobile body to improve the vibration damping performance of the target area of ​​vibration noise reduction in the body-in-white structure.

[0119] In the automobile body manufacturing method according to the second embodiment, the automobile body design method according to the first embodiment is first used to determine the optimal shape of a resin material model to be attached or applied to all or some of the vehicle body components in the optimization analysis model. Next, based on the determined optimal shape of the resin material model, the optimal shape and position of the resin material to be attached or applied to the vehicle body components for which the optimal shape has been determined are determined. The resin material with the determined shape and position is then attached or applied to the vehicle body components in the body-in-white structure.

[0120] The following methods can be exemplified as methods for attaching or applying resin material to vehicle body components. As a specific example of the method for attaching the resin material, NC data (numerical control data) for NC machining is first generated based on the optimal shape of the resin material model from the optimization analysis model. An injection molding metal mold is then fabricated using an NC machine tool, and the resin material is manufactured by injection molding. The manufactured resin material is then attached to the vehicle body component in the body-in-white structure based on the position of the resin material model with the optimal shape from the optimization analysis model.

[0121] As a specific example of a resin material application method, the optimal shape and position of the resin material model from the optimization analysis model is converted into NC data. A robot that applies the resin material using the converted NC data is then operated, thereby applying the resin material to the body parts of the body-in-white structure. The applied resin material can be either liquid or foamed.

[0122] As described above, according to the automobile body manufacturing method according to the second embodiment, an automobile body can be manufactured in which the vibration damping performance of the vibration noise reduction target portion is improved while maintaining vehicle body performance other than vibration damping performance such as vehicle body rigidity.

[0123] Example

[0124] An analysis was conducted to verify the effect of improving the vibration damping performance of the target portion for reducing vibration noise in the body-in-white structure of an automobile body obtained by the automobile body design method, apparatus, and program according to the present invention.

[0125] In the analysis, Figure 2 The body-in-white structure 100 shown was used as the analysis target, with the floor panel 107 within the body-in-white structure 100 being the target site for vibration and noise reduction. Furthermore, an optimization analysis was conducted regarding the optimal shape of the resin material applied or coated to a portion of the vehicle body components within the body-in-white structure 100 to improve the vibration damping performance of the floor panel 107.

[0126] In the optimization analysis, the road noise when the car is running is assumed, and the joint position of the forward subframe 109 and the lower arm is set (at Figure 2 The vibration input conditions (indicated by the triangle mark in the figure) are as follows: an amplitude of 1N and a frequency of 1 Hz to 200 Hz. Furthermore, the frequency response of the equivalent radiated power of base plate 107 in the frequency band of 100 Hz to 200 Hz is used as the evaluation target for vibration damping performance.

[0127] Figure 4 2 shows the result of the frequency response of the equivalent radiated power of the base plate 107 obtained under the above-mentioned vibration input conditions.

[0128] Optimization analysis of the optimal shape of the resin material was performed for the method of attaching or applying the resin material in the space between the body parts (Examples 1 and 2) and the method of attaching or applying the resin material only on one side of the body part (Example 3).

[0129] <Example 1>

[0130] In Example 1, Figure 5As shown in (b), design spaces 111 are defined in the spaces between body components of the body-in-white structure 100. Design spaces 111a, 111b, 111c, and 111d are defined for the front side member 101, the side member 103 and the A-pillar lower portion 106, and the rear side member 105 and the tunnel 108, respectively.

[0131] Next, the set design space 111 is segmented using solid elements to generate a resin material model 113. In generating the resin material model 113, resin material models 113a, 113b, 113c, and 113d are generated for the design spaces 111a, 111b, 111c, and 111d set in the body-in-white structure 100, respectively. Figure 5 (a) is a diagram showing the design space 111 and the resin material model 113 extracted and displayed.

[0132] Next, the generated resin material model 113 is combined with the body-in-white structure 100, as shown in FIG. Figure 5 As shown in (b), the optimized analysis model 115 is generated. In generating the optimized analysis model 115, the surface of the resin material model 113 and the vehicle body parts in its vicinity (for example, the resin material model 113a and the front side member 101 in its vicinity) are connected by rigid body beam elements.

[0133] Next, the material properties of the resin material model 113 in the optimization analysis model 115 are set. In Example 1, the material properties of the resin material model 113 are set to be 6.0 GPa in elastic modulus and 1.4 g / cm in density. 3 (Specific elastic modulus is 4285MPa / g·cm -3 ), attenuation rate 0.15.

[0134] Next, the objective function and constraints were set as optimization analysis conditions. The objective function was set to minimize the maximum value of the equivalent radiated power of the floor panel 107 in the frequency band from 100 Hz to 200 Hz. Meanwhile, the constraints were set to keep the volume of the resin material model 113 at or below 10% of the volume of the design space set for the body-in-white structure 100.

[0135] Then, under the vibration input conditions and optimization analysis conditions set as described above, optimization analysis was performed to determine the optimal shape of the resin material model 113 in the optimization analysis model 115. Topology optimization using the density method was applied to the optimization analysis.

[0136] Figure 63 shows the optimum shape of the resin material model 113 (optimum shape resin material model 117 ) obtained by the optimization analysis.

[0137] Furthermore, the optimal shape resin material model 117 is combined with the body-in-white structure 100 , and the same vibration input conditions as those used in the optimization analysis are applied to calculate the frequency response of the equivalent radiated power of the floor panel 107 . Figure 7 , which is a graph showing the frequency response of the equivalent radiated power of the floor in the body-in-white structure 100 incorporating the optimal shape resin material model. Figure 7 , for comparison, the frequency response (dashed line) of the equivalent radiated power of the floor panel 107 obtained for the body-in-white structure 100 before incorporation of the optimal shape resin material model 117 is also shown.

[0138] like Figure 7 As shown, in the body-in-white structure 100 incorporating the optimally shaped resin material model 117, the maximum equivalent radiated power (ERP) of the floor panel 107 in the frequency band from 100 Hz to 200 Hz was reduced by 3.0 dB. This result demonstrates that the vibration damping performance of the floor panel 107, the target area for vibration noise reduction, has been improved.

[0139] <Example 2>

[0140] In Example 2, the material properties (elastic modulus, density) of the resin material model 113 in the optimization analysis model 115 of Example 1 were changed, and the specific elastic modulus was set to 800 to 4300 MPa / g·cm in accordance with Example 1. -3 In addition, compared with the embodiment 1, Figure 7 Similarly, for the body-in-white structure 100 incorporating the optimal-shape resin material model 117, the amount of reduction in the maximum value of the equivalent radiated power ERP of the floor panel 107 in the frequency band from 100 Hz to 200 Hz (ERP reduction) was determined. The ERP reduction was calculated based on the maximum value of the equivalent radiated power of the floor panel 107 obtained for the original body-in-white structure 100 without the optimal-shape resin material model 117.

[0141] Table 1 shows the material properties (elastic modulus, density, and attenuation rate) of the resin material model 113, along with the resin's specific elastic modulus, the maximum value of the equivalent radiated power (ERP), and the amount of ERP reduction. Table 1 also shows the maximum value of the equivalent radiated power (ERP) found for the original body-in-white structure 100.

[0142] [Table 1]

[0143]

[0144] As the specific elastic modulus increases, the ERP reduction increases. When the specific elastic modulus is 1000 MPa / g·cm -3 (Example 2-b) or more, the ERP reduction amount becomes 1 dB or more. In addition, when the specific elastic modulus is 1400 MPa / g·cm -3 (Example 2-d) or more, the ERP reduction amount becomes 2 dB or more, and the specific elastic modulus increases until the specific elastic modulus reaches 4286 MPa / g·cm -3 Up to (Example 1), the ERP reduction amount gradually increased.

[0145] From this result, it is known that the larger the specific elastic modulus of the resin material model 113, the higher the vibration damping performance of the base plate 107 as the target portion for vibration noise reduction, and the preferred value is 1000 (MPa / g·cm -3 ) or more, more preferably 1400 (MPa / g·cm -3 )The above is better.

[0146] <Example 3>

[0147] In Example 3, Figure 8 As shown in FIG. 1( b ), a two-dimensional space along the surface of the vehicle body member (including the floor panel 107 ) constituting the lower portion of the vehicle body structure 100 is set as a design space 121 .

[0148] Next, for the set design space 121, as Figure 8 As shown in (b) of FIG. 1 , the resin material model 123 is generated using the shell element. When the resin material model 123 is generated using the shell element, the thickness of the shell element is set to 2 mm. Figure 8 (a) is a diagram showing the design space 121 and the resin material model 123 extracted.

[0149] Next, the generated resin material model 123 is combined with the body-in-white structure 100, as shown in FIG. Figure 8 As shown in (b) of FIG. 1 , the optimization analysis model 125 is generated. In generating the optimization analysis model 125, the surface of the resin material model 123 and the adjacent vehicle body parts are connected by rigid beam elements.

[0150] Next, the material properties of the resin material model 123 in the optimization analysis model 125 are set. In Example 2, the material properties of the resin material model 123 are set to be 6.0 GPa in elastic modulus and 1.4 g / cm in density. 3 (Specific elastic modulus is 4286MPa / g·cm -3 ), attenuation rate 0.15.

[0151] Next, the objective function and constraints were set as optimization analysis conditions. The objective function was set to minimize the maximum value of the equivalent radiated power of base plate 107 in optimization analysis model 125 within the frequency band from 100 Hz to 200 Hz. Meanwhile, the constraints were set to ensure that the volume of resin material model 123 was less than 10% of the volume of the design space. Furthermore, under the vibration input conditions and optimization analysis conditions set as described above, optimization analysis was performed to determine the optimal shape of resin material model 123 in optimization analysis model 125. Topological optimization using the density method was applied to the optimization analysis.

[0152] Figure 9 3 shows the optimum shape of the resin material model 123 (optimum shape resin material model 127 ) obtained by the optimization analysis.

[0153] also, Figure 10 3 shows the frequency response of the equivalent radiated power of the floor panel 107 calculated by applying the same vibration input conditions as those used in the optimization analysis to the body-in-white structure 100 incorporating the optimal shape resin material model 127 .

[0154] like Figure 10 As shown, in the body-in-white structure 100 incorporating the optimally shaped resin material model 127, the maximum equivalent radiated power (ERP) of the floor panel 107 in the frequency band from 100 Hz to 200 Hz was reduced by 2.0 dB. This result demonstrates that even when the optimally shaped resin material model 127 is determined by setting a design space only on a single surface of the body component, the vibration damping performance of the floor panel 107, the target area for vibration noise reduction, is improved.

[0155] Industrial applicability

[0156] According to the present invention, it is possible to provide an automobile body design method, apparatus, and program for designing an automobile body that effectively improves the vibration damping performance of areas targeted for vibration noise reduction while maintaining vehicle body performance other than vibration damping. Furthermore, according to the present invention, it is possible to provide an automobile body manufacturing method for manufacturing an automobile body that improves the vibration damping performance of areas targeted for vibration noise reduction while maintaining vehicle body performance other than vibration damping, such as vehicle body rigidity.

[0157] Description of Reference Signs

[0158] 1 Automobile body design device

[0159] 3 Display device

[0160] 5 Input devices

[0161] 7 Storage Devices

[0162] 9 Working data storage

[0163] 11. Processing unit

[0164] 13 Optimization analysis model generation unit

[0165] 13a Design space setting section

[0166] 13b Resin material model generation unit

[0167] 13c Combined processing unit

[0168] 15 Resin material optimization analysis unit

[0169] 15a Material property setting section

[0170] 15b Vibration input condition setting unit

[0171] 15c Optimization analysis condition setting section

[0172] 15d Optimization Analysis Department

[0173] 21 Body-in-white structure model file

[0174] 100 Body-in-white structure

[0175] 101 front longitudinal beam

[0176] 103 side beam

[0177] 105 rear longitudinal beam

[0178] 106 Lower part of A-pillar

[0179] 107 base plate

[0180] 108 channels

[0181] 109 front subframe

[0182] 111 Design Space

[0183] 111a, 111b, 111c Design Space

[0184] 113 Resin Material Model

[0185] 113a, 113b, 113c Resin material models

[0186] 115 Optimization Analysis Model

[0187] 117 Best Shape Resin Material Model

[0188] 121 Design Space

[0189] 123 Resin Material Model

[0190] 125 Optimization Analysis Model

[0191] 127 Best Shape Resin Material Model

Claims

1. A method for designing an automobile body, wherein a resin material is attached or coated on the surfaces of body parts constituting a body-in-white structure of the automobile body to thereby enhance the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure, the vibration noise being reduced, the method comprising executing the following steps on a computer, wherein: include: an optimization analysis model generating step of generating an optimization analysis model for performing optimization analysis on an optimal shape of a resin material attached or applied to all or part of the vehicle body parts in the body-in-white structure; as well as The resin material optimization analysis step uses the generated optimization analysis model to perform the optimization analysis. The optimization analysis model generation step includes: a design space setting step of setting a design space as a target of the optimization analysis along surfaces of all or part of the vehicle body components in the vehicle body-in-white structure; a resin material model generating step of generating a resin material model for performing an analysis process for optimization by using shell elements or solid elements for modeling in the set design space; and In a combining process, the generated resin material model is combined with the body part in the body-in-white structure. The resin material optimization analysis step includes: a material property setting step of setting at least elastic modulus, density, and attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting step of setting a vibration input condition related to the vibration given to the optimization analysis model in the optimization analysis; an optimization analysis condition setting step of setting, as optimization analysis conditions, an objective function related to vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target portion in the optimization analysis model and constraints related to the weight or volume of the resin material model; and The optimization analysis step performs optimization analysis to determine an optimal shape of the resin material model in the optimization analysis model under the vibration input condition and the optimization analysis condition.

2. The automobile body design method according to claim 1, wherein: In the design space setting step, the design space is set in a gap between the vehicle body components.

3. The automobile body design method according to claim 1, wherein: In the design space setting step, a two-dimensional space along only one surface of the vehicle body component is set as the design space, and in the resin material model generating step, the resin material model is modeled using shell elements.

4. The automobile body design method according to any one of claims 1 to 3, wherein: In the optimization analysis condition setting step, the objective function is set to minimize the frequency response value of any one of acceleration, inertia, or equivalent radiated power in a predetermined frequency band of the vibration noise reduction target portion, or to minimize a function with the frequency response value as a variable.

5. An automobile body design device for designing an automobile body in which a resin material is attached or coated on the surface of a body part constituting a body-in-white structure of an automobile body to improve the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure, the vibration noise being reduced. The automobile body design device comprises: an optimization analysis model generating unit configured to generate an optimization analysis model for performing optimization analysis on an optimal shape of a resin material to be attached or applied to all or part of the vehicle body parts in the vehicle body-in-white structure; as well as A resin material optimization analysis unit performs the optimization analysis using the generated optimization analysis model, The optimization analysis model generating unit has: a design space setting unit that sets a design space to be the subject of the optimization analysis along the surfaces of all or part of the vehicle body components in the vehicle body-in-white structure; a resin material model generating unit that generates a resin material model for performing an analysis process for optimization by modeling with shell elements or solid elements in the set design space; and a combining processing unit that combines the generated resin material model with the vehicle body component in the vehicle body structure. The resin material optimization analysis unit has: a material property setting unit that sets at least elastic modulus, density, and attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting unit that sets a vibration input condition related to the vibration given to the optimization analysis model in the optimization analysis; an optimization analysis condition setting unit that sets, as optimization analysis conditions, an objective function related to vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target portion in the optimization analysis model and a constraint condition related to the weight or volume of the resin material model; as well as An optimization analysis unit performs optimization analysis to obtain an optimal shape of the resin material model in the optimization analysis model under the vibration input condition and the optimization analysis condition.

6. An automobile body design program for designing an automobile body in which a resin material is attached or coated on the surface of a body part constituting a body-in-white structure of an automobile body, thereby improving the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure, the vibration noise being reduced. The automobile body design program enables the computer to function as an optimization analysis model generation unit and a resin material optimization analysis unit. The optimization analysis model generating unit generates an optimization analysis model for performing optimization analysis on an optimal shape of a resin material attached or applied to all or part of the vehicle body parts in the vehicle body structure. The resin material optimization analysis unit uses the generated optimization analysis model to perform the optimization analysis. The optimization analysis model generating unit has: a design space setting unit that sets a design space to be the subject of the optimization analysis along the surfaces of all or part of the vehicle body components in the vehicle body-in-white structure; a resin material model generating unit that generates a resin material model for performing an analysis process for optimization by modeling with shell elements or solid elements in the set design space; and a combining processing unit that combines the generated resin material model with the vehicle body component in the vehicle body structure. The resin material optimization analysis unit has: a material property setting unit that sets at least elastic modulus, density, and attenuation rate as material properties of the resin material model in the optimization analysis model; a vibration input condition setting unit that sets a vibration input condition related to the vibration given to the optimization analysis model in the optimization analysis; an optimization analysis condition setting unit that sets, as optimization analysis conditions, an objective function related to vibration characteristics used for evaluating the vibration damping performance of the vibration noise reduction target portion in the optimization analysis model and a constraint condition related to the weight or volume of the resin material model; as well as An optimization analysis unit performs optimization analysis to obtain an optimal shape of the resin material model in the optimization analysis model under the vibration input condition and the optimization analysis condition.

7. A method for manufacturing an automobile body, wherein a resin material is attached or applied to body parts constituting a body-in-white structure of the automobile body to improve the vibration damping performance of a vibration noise reduction target portion of the body-in-white structure, the vibration noise being reduced. The automobile body design method according to claim 1 or 2 is used to determine the optimal shape of the resin material. Based on the obtained optimal shape of the resin material, the optimal shape and position of the resin material to be attached or applied to the vehicle body part are determined. The resin material having the determined shape and position is attached or applied to the vehicle body component in the body-in-white structure.

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