JP2019128868A - Shape optimization analysis method for stiffening member of car body component and device therefor - Google Patents

Abstract

To provide a shape optimization analysis method and device for a stiffening member of a car body component that obtain an optimum shape and arrangement of the stiffening member stiffening the car body component.SOLUTION: A shape optimization analysis method for a stiffening member of a car body component according to the present invention comprises: a car body component model acquisition step S1 of acquiring a car body component model modeling the car body component having two components fastened via a space; an optimization block model creation step S3 of creating an optimization block model in the space in the car body component model; a material characteristic setting step S5 of setting a material characteristic of a stiffening member in the optimization block model; a coupling processing step S7 of coupling the optimization block model to the car body component model; and an optimization analysis step S9 of conducting optimization analysis of the optimization block model as an analysis object of the optimization, and obtaining an optimum shape and arrangement of the optimization block model.SELECTED DRAWING: Figure 12

Description

The present invention relates to a method and an apparatus for analyzing the shape optimization of a stiffening member of a vehicle body part for which the optimum shape and position of the stiffening member for stiffening a vehicle body part of a car are determined.
In the present invention, shape optimization is assumed to be a predetermined shape, for example, a T-shape in advance, and is not to obtain the optimum shape on the premise of the predetermined shape, but to analyze without assuming the predetermined shape. It means finding the optimal shape and arrangement that satisfy the conditions.

In recent years, especially in the automobile industry, weight reduction of the vehicle body due to environmental problems has been promoted, and analysis by computer aided engineering (hereinafter referred to as “CAE analysis”) has become an indispensable technology for designing the vehicle body.
By using optimization techniques such as mathematical optimization, plate thickness optimization, shape optimization, topology optimization, etc. in this CAE analysis, vehicle performance such as weight reduction and rigidity improvement can be improved. These optimization techniques are often used, for example, for structural optimization of castings such as engine blocks.

Among optimization techniques, topology optimization is particularly focused.
Topology optimization is to satisfy the condition by providing a design space of a certain size, incorporating a three-dimensional element in the design space, satisfying a given condition, and leaving a portion of the minimum necessary three-dimensional element. It is a method of finding the optimum shape. Therefore, topology optimization uses a method of directly constraining a three-dimensional element forming a design space and applying a direct load.

  As a technique relating to such topology optimization, Patent Document 1 discloses a method for topology optimization of components of a complex structure.

JP 2010-250818 A

Yumi, 1 other, "Optimum Design of Construction Machinery", Seikei University Engineering Research Report, Vol.41, No.1, 2004, p.1-5

  A structure such as a car body of an automobile is mainly configured using a thin plate, and in the case of optimizing the shape of one portion of a car body configured by such a thin plate by optimization technology, it has been disclosed in As described, a part of the target car body was taken out and the part was optimized independently. However, it is difficult to reflect the load and restraint state from the entire vehicle body to a part of the independent vehicle body, and hence there is a problem that it is difficult to apply the optimization technology to a part of the vehicle body . Moreover, even if it is going to obtain | require the optimization shape of a part of vehicle body, the target site | part of optimization may be lose | disappeared, There also existed the subject of how to carry out appropriately reflecting that in thin plate structure.

  The technique disclosed in Patent Document 1 relates to a mathematical calculation method and a physical system related to optimization analysis by topology optimization, and does not deal with the problem of optimization of the thin plate structure as described above. It does not give a solution.

  Furthermore, in a car body part that becomes a car body frame of an automobile, two parts formed of a metal plate are fastened via a space, and there is also a thing in which a stiffening member is disposed in the space. It has been desired to develop an optimized shape for determining the optimum shape and position of the stiffening member.

  The present invention has been made to solve the above-described problems, and is a vehicle body in which two parts formed of a metal plate are fastened through a space and a stiffening member is disposed in the space. It is an object of the present invention to provide a shape optimization analysis method and apparatus for a stiffening member of a vehicle body part for obtaining an optimum shape and arrangement of the stiffening member.

(1) The shape optimization analysis method of a stiffening member of a vehicle body part according to the present invention comprises: fastening two parts formed of a metal plate through a space and arranging the stiffening member in the space Determining the optimum shape and position of the stiffening member, the computer performing the following steps, and modeling the vehicle part using planar and / or solid elements A car body part model acquiring step of acquiring a car body part model, an optimization block model generating step of generating an optimization block model formed of three-dimensional elements by using the space in the car body part model as a design space, the optimization block model Material property setting step for setting the material property of the stiffening member, and a combined process for connecting the optimization block model to the vehicle body part model And the load / restraint condition and the optimization analysis condition, and the optimization analysis is performed on the optimization block model as an analysis target of the optimization, and the optimization analysis for finding the optimum shape and arrangement of the optimization block model And providing a step.

(2) In the above (1), the optimization analysis step is equivalent to the deformation of the vehicle body part when a predetermined load is input to the vehicle body model on which the vehicle body part model is installed. In the above, the load / restraint condition is determined.

(3) In the above-described (1) or (2), in the joining step, the node of the three-dimensional element on the outer surface of the optimized block model is selected from the body part model that is at the shortest distance from the node. The optimization block model and the vehicle body part model are coupled by connecting the planar element or the node of the solid element by using a rigid element.

(4) In any of the above (1) to (3), the optimization block model is a three-dimensional element having at least one pair of two faces which are not less than five and not more than eight and are parallel to each other. It is characterized by being made into a product.

(5) In the method according to any one of (1) to (4), in the optimization block model generation step, a plane parallel to a peripheral surface on which the design space in the body part model is set is It produces | generates so that it may become the maximum area, It is characterized by the above-mentioned.

(6) In the method according to any one of the above (1) to (5), the optimization block model generation step arranges nodes in a joint portion with a plane element and / or a solid element constituting the body part model Then, the hexahedral solid elements are generated so as to be stacked along a plane including the nodes arranged in the coupling portion.

(7) In any one of the above (1) to (6), the optimization block model generation step generates a plurality of block bodies composed of solid elements, and rigidifies the plurality of block bodies. It produces | generates by connecting using any of an element, a beam element, or a plane element, It is characterized by the above-mentioned.

(8) In the method according to any one of the above (1) to (7), the optimization analysis step is characterized by performing discretization with the optimization parameter in the optimization analysis.

(9) In the invention described in any one of (1) to (8), the optimization analysis step is characterized by performing optimization analysis by topology optimization.

(10) The shape optimization analysis device for the stiffening member of a vehicle body part according to the present invention fastens two parts formed of a metal plate through a space and arranges the stiffening member in the space A vehicle body part model acquisition unit that obtains an optimal shape and arrangement of the stiffening member and obtains a body part model obtained by modeling the body part using a planar element and / or a solid element An optimization block model generation unit for generating an optimization block model composed of three-dimensional elements by using the space in the body part model as a design space, and a material for setting material characteristics of the stiffening member in the optimization block model A characteristic setting unit; a coupling processing unit coupling the optimization block model to the vehicle body part model; load / restraint conditions and optimization analysis conditions; Perform optimization analysis as the analysis target of the optimization, it is characterized in that and a optimization analysis unit for obtaining the placement and optimum shape of the optimization block model.

(11) In the one described in (10), the optimization analysis unit is configured to be equivalent to the deformation of the vehicle body part when a predetermined load is input to the vehicle body model on which the vehicle body part model is installed. In the above, the load / restraint condition is determined.

(12) In the above (10) or (11), the joint processing unit is configured to connect the node of the three-dimensional element on the outer surface of the optimized block model to the vehicle body part model at the shortest distance from the node. The optimization block model and the vehicle body part model are coupled by connecting the planar element or the node of the solid element by using a rigid element.

(13) In the above (10) to (12), the optimization block model is a three-dimensional element having at least one pair of two faces which are not less than five and not more than eight and are parallel to each other. It is characterized by being made into a product.

(14) In the configuration described in any one of (10) to (13), the optimization block model generation unit is configured such that a plane parallel to a peripheral surface on which the design space in the body part model is set is It produces | generates so that it may become the maximum area, It is characterized by the above-mentioned.

(15) In the configuration according to any one of (10) to (14), the optimization block model generation unit arranges a node at a connection portion with a plane element and / or a solid element constituting the vehicle body part model. Then, the hexahedral solid elements are generated so as to be stacked along a plane including the nodes arranged in the coupling portion.

(16) In the above (10) to (15), the optimization block model generation unit generates a plurality of block bodies composed of solid elements, and rigidifies the plurality of block bodies. It produces | generates by connecting using any of an element, a beam element, or a plane element, It is characterized by the above-mentioned.

(17) In the configuration described in any one of (10) to (16), the optimization analysis unit performs discretization with the optimization parameter in the optimization analysis.

(18) In any one of the above (10) to (17), the optimization analysis unit performs optimization analysis by topology optimization.

  In the present invention, in a vehicle body component in which two parts formed of a metal plate are fastened via a space and a stiffening member is disposed in the space, the optimum shape and arrangement of the stiffening member are obtained. A vehicle body part model acquisition step for acquiring a vehicle body part model obtained by modeling the vehicle body part using a planar element and / or a solid element, wherein the computer performs the following steps: An optimization block model generating step of generating an optimization block model consisting of three-dimensional elements by using the space in the part model as a design space, and a material property setting step of setting material characteristics of the stiffening member in the optimization block model Combining the optimization block model with the body part model, loading / restraint conditions and optimization analysis conditions And the optimization analysis step of performing optimization analysis on the optimization block model as an analysis object of optimization, and determining the optimum shape and position of the optimization block model When it acts, it is possible to obtain the optimum shape and position of the stiffening member, to improve the rigidity of the vehicle body component, or contribute to the weight reduction of the vehicle body component without reducing the rigidity. It becomes possible.

It is a block diagram of the shape optimization analysis apparatus of the stiffening member of the vehicle body part which concerns on embodiment of this invention. It is a top view of A pillar lower which is a car body part concerning an embodiment of the invention. It is a side view of A pillar lower which is a car body part concerning an embodiment of the invention. It is explanatory drawing of the A pillar lower model which modeled the vehicle body part which concerns on embodiment of this invention. It is a figure explaining the optimization analysis model which combines and generates an optimization block model and a body part in an embodiment of the present invention. FIG. 7 is a diagram for explaining an example of connecting a plurality of block bodies to generate an optimization block model in the embodiment of the present invention. In an embodiment of the present invention, it is a figure explaining a joint processing of an optimization block model and body parts. In embodiment of this invention, it is a figure explaining the load and restraint conditions (a) in the optimization analysis of a stiffening member, and the displacement measurement point (b) in rigidity evaluation. The vehicle body component which concerns on the other aspect of this Embodiment WHEREIN: It is a perspective view which shows an example of the analysis result of the optimization analysis of a stiffening member. In this embodiment, it is a figure showing modification of A pillar lower model in CAE analysis which targets stiffness by bending input from a suspension part by making a car body model into analysis object. In this embodiment, it is a figure showing modification in CAE analysis which gave load and restraint conditions by making an A pillar lower model into analysis object. It is a figure which shows the flowchart which shows the flow of the process in the shape optimization analysis method which concerns on this Embodiment. In an Example, it is a figure which shows the stiffening member model set based on the optimal shape of the optimization block model calculated | required by the optimization analysis which gave the volume constraint rate as a constraint condition ((a) Volume constraint rate 5%, (B) Volume constraint rate 10%). In an Example, it is a figure showing a stiffening member model set based on an optimal shape of an optimization block model obtained by optimization analysis which gave displacement as a constraint condition ((a) setting as optimal shape, ( b) Only the columnar portion of the optimum shape is set). It is a figure which shows the stiffening member model which carried out CAD modeling of the columnar part in the optimal shape of the optimization block model calculated | required by optimization analysis which gave displacement amount as constraint conditions in the Example in a dumbbell shape ((a) Plan view, (b) perspective view). In the embodiment, the columnar portion in the optimum shape of the optimization block model determined by shape optimization analysis given displacement amount as a constraint condition is further modeled as a dumbbell-shaped columnar portion and a flange residual portion as an adhesive agent. It is a figure which shows the stiffening member model which has an adhesive part made into. It is a figure which shows the A pillar lower model made into the comparative example in the Example ((a) there is no stiffening member model, (b) there is a stiffening member model which filled the stiffening member in space). In an Example, it is a graph which shows the rigidity improvement rate on the basis of the conventional vehicle body components, and the result of a weight change. In an Example, it is a graph which shows the result of the rigidity improvement rate per weight on the basis of the conventional vehicle body components.

  Prior to describing the shape optimization analysis method and apparatus for the stiffening member of a vehicle body part according to the embodiment of the present invention, the vehicle body part that is the object of the present embodiment will be described.

<Car body parts>
The vehicle body part according to the present invention is formed by fastening two parts formed of a metal plate via a space and arranging a stiffening member in the space, and in the embodiment of the present invention, As shown in FIGS. 2 and 3, an A-pillar lower 31 formed by fastening an outer panel 33 and an inner panel 35 via a space S and arranging a stiffening member (not shown) in the space S is targeted. Do.

  The outer panel 33, as shown in FIG. 2, is substantially T-shaped in plan view, and corresponds to a part (part P and part Q in FIG. 2) corresponding to the horizontal side of the substantially T-shape and the vertical side. It has a part (part R in FIG. 2) to be performed.

The portion P extends to the front (X-axis minus direction in the figure) of the vehicle at the upper part of the outer panel 33 and is connected to other vehicle body parts provided at the front of the vehicle.
The portion Q extends to the upper rear of the outer panel 33 in the upper rear of the vehicle (X-axis plus direction and Y-axis plus direction in the figure), and is connected to the A-pillar upper (not shown).
The portion R extends from the horizontal side of the substantially T-shape to the lower side of the vehicle (in the negative direction of the Y axis in the figure). Furthermore, the lower end portion of the portion R is curved in an L shape toward the rear (X-axis plus direction) of the vehicle and is connected to a locker (not shown).

  And the cross section which cross | intersects the site | part P, the site | part Q, and the site | part R is a cross-sectional hat shape which consists of the top-plate part 33a, the vertical wall part 33b, and the flange part 33c. The outer panel 33 having a hat-shaped cross section can be manufactured, for example, by press-forming a steel plate or an aluminum plate.

The inner panel 35 has a flange portion 35c joined to the flange portion 33c of the outer panel 33, as shown in FIG. Then, by joining the flange portion 35c of the inner panel 35 and the flange portion 35c of the outer panel 33, as shown in FIG. A space S is formed, and the outer panel 33 and the inner panel 35 are fastened via the space. Here, joining means that panels are brought into contact with each other by spot welding, arc welding, laser welding, an adhesive or the like to be fastened.
Moreover, what was manufactured by press-molding a steel plate or an aluminum plate can be used for the outer panel 33 and the inner panel 35, for example.

<Shape optimization analysis system for stiffening members of body parts>
Next, the configuration of the shape optimization analysis apparatus for a stiffening member of a vehicle body part according to the present embodiment (hereinafter simply referred to as “shape optimization analysis apparatus”) will be described below.

In the shape optimization analysis apparatus 1 according to the present embodiment, the outer panel 33 and the inner panel 35 as shown in FIGS. 2 and 3 are fastened via the space S, and a stiffening member is disposed in the space S. In the A-pillar lower 31 which is an automotive body part, the optimum shape and arrangement of the above-mentioned stiffening members are sought, and as shown in FIG. 1, it is composed of a PC (personal computer) etc. The device 5, the storage device 7, the work data memory 9, and the arithmetic processing unit 11 are included.
The display device 3, the input device 5, the storage device 7, and the work data memory 9 are connected to the arithmetic processing unit 11, and their respective functions are executed according to an instruction from the arithmetic processing unit 11.
Hereinafter, each configuration of the shape optimization analysis device 1 according to the present embodiment will be described.

«Display device»
The display device 3 is used to display analysis results and the like, and is configured of a liquid crystal monitor or the like.

«Input device»
The input device 5 is used for a display instruction of the vehicle body part model file 23 and an operator's condition input and the like, and is configured by a keyboard, a mouse and the like.

«Storage device»
The storage device 7 is used to store various files such as the body part model file 23 and the like, and is configured by a hard disk or the like.

«Work data memory»
The work data memory 9 is used for temporary storage and calculation of data used by the calculation processing unit 11, and is configured by a RAM (Random Access Memory) or the like.

<< operation processing part >>
As shown in FIG. 1, the arithmetic processing unit 11 has a vehicle body part model acquisition unit 13, an optimization block model generation unit 15, a material property setting unit 17, a coupling processing unit 19, and an optimization analysis unit 21. And a CPU (central processing unit) such as a PC. These units function when the CPU executes a predetermined program.
The functions of the above-described units in the arithmetic processing unit 11 will be described below.

(Car body parts model acquisition unit)
The body part model acquisition unit 13 acquires a body part model obtained by modeling a body part using a plane element and / or a solid element, and in the present embodiment, the A pillar lower 31 (see FIG. 2) is a plane. The A-pillar lower model 41 modeled using an element can be acquired from the body part model file 23 stored in the storage device 7 by reading the element information and the material characteristic information of the A-pillar lower model 41.

  The A-pillar lower model 41 according to the present embodiment is, as shown in FIG. 4, an outer panel model 43 obtained by modeling the outer panel 33 with planar elements, and an inner panel model 45 obtained by modeling the inner panel 35 with planar elements. As with the A pillar lower 31, a space S ′ (corresponding to the space S shown in FIG. 3) is formed between the outer panel model 43 and the inner panel model 45.

  Note that the vehicle body part model acquisition unit 13 may generate a new vehicle body part model by modeling the vehicle body by plane elements and / or solid elements based on the CAD data of the body parts.

(Optimized block model generation unit)
The optimization block model generation unit 15 generates an optimization block model consisting of three-dimensional elements with the space in the vehicle body component model acquired by the vehicle body component model acquisition unit 13 as a design space, and in the present embodiment, the outer panel model A space S '(FIG. 4) formed by the reference numeral 43 and the inner panel model 45 is set as a design space, and an optimization block model 47 (see FIG. 5) composed of solid elements is generated in the design space.

  The optimization block model 47 generated by the optimization block model generation unit 15 is a target of optimization analysis by the optimization analysis unit 21 described later, and is positioned at a portion unnecessary for stiffening in the process of the optimization analysis. 3D elements are eliminated, and the 3D elements located at the portions required for stiffening are left.

Preferably, the optimization block model 47 generated by the optimization block model generation unit 15 is modeled by a solid element having at least one pair of two faces which are not less than five faces and not more than eight faces and are parallel to each other. .
Further, it is preferable that the optimization block model generation unit 15 generate the optimization block model so that a surface parallel to a surface around the design space in the body part model has a maximum area.

  Furthermore, the optimization block model generation unit 15 arranges a node at a joint portion with a plane element and / or a solid element constituting the vehicle body part model, and a hexahedron solid so as to follow a plane including the node arranged at the joint portion. Elements may be stacked to generate an optimized block model.

Further, the optimization block model generation unit 15 generates a plurality of block bodies composed of solid elements in the design space, and connects the plurality of block bodies using a rigid body element, a beam element or a plane element. An optimized block model may be generated.
As an example of generating an optimization block model by a plurality of block bodies, as shown in FIG. 6, even if a block body A in which hexahedron solid elements are stacked and a block body B in which hexahedron solid elements are stacked are connected by a connecting portion. Good.

(Material property setting part)
The material characteristic setting unit 17 sets the material characteristic of the optimization block model generated by the optimization block model generation unit 15. In the present embodiment, the material characteristic setting unit 17 sets the material characteristic of the optimization block model 47 (FIG. 5). The Young's modulus, Poisson's ratio and specific gravity shown in Table 1 are set.

  Furthermore, in the case of setting material properties having in-plane anisotropy such as FRP (Fiber Reinforced Plastics), for example, the material property setting unit 17 changes in-plane differences of the material properties of the optimization block model. An in-plane anisotropy can be set to the material property of the optimization block model by giving the main axis angle giving the directionality and setting the value of the material property corresponding to the main axis angle.

(Joint processing unit)
The combination processing unit 19 combines the optimization block model generated by the optimization block model generation unit 15 with the vehicle body part model to generate an optimization analysis model, and as shown in FIG. 5 in the present embodiment. Then, the optimization block model 47 and the A pillar lower model 41 are combined to generate an optimization analysis model 51.

  A specific coupling process of the optimization block model 47 and the A-pillar lower model 41 by the coupling processing unit 19 will be described below by taking the coupling of the optimization block model 47 and the outer panel model 43 as an example.

  When the outer panel model 43 is modeled by the planar element 43a, as illustrated in FIG. 7, the coupling processing unit 19 sets the node 47b (node) of the solid element 47a on the outer surface of the optimization block model 47 The optimization block model 47 and the outer panel model 43 are coupled by connecting the node 43 b (node) of the plane element 43 a of the outer panel model 43 and the rigid element 49 at a shortest distance to 47 b. In addition, since a rigid body element does not deform | transform, it is preferable to make a rigid body element into the shortest distance.

  However, the coupling processing unit 19 is not limited to coupling processing using the rigid block 49 and the optimization block model 47 and the outer panel model 43 as described above, and may be beam elements, beam elements, rod elements, planar elements, etc. Alternatively, the node 47b of the optimized block model 47 and the node 43b of the outer panel model 43 may be coupled using an element to which a load is transmitted.

  Alternatively, the coupling processing unit 19 couples the node 47 b of the optimization block model 47 and the node 43 b of the outer panel model 43 without coupling the optimization block model 47 and the outer panel model 43 via an element such as a rigid element 49. You may combine so that it may share.

  Furthermore, in the case where the outer panel model 43 is modeled by a solid element, the coupling processing unit 19 loads the node of the solid element and the node 47b of the solid element 47a of the optimization block model 47 It may be coupled via an element to be transmitted or coupled by node sharing.

  The combination processing unit 19 performs the same process as the combination of the optimization block model 47 and the outer panel model 43 with respect to the combination of the optimization block model 47 and the inner panel model 45.

(Optimization analysis unit)
The optimization analysis unit 21 generates load / restraint conditions and optimization analysis as analysis conditions for the optimization analysis model 51 generated by the coupling processing unit 19 performing the coupling process between the optimization block model 47 and the A pillar lower model 41. Conditions are given, and optimization analysis is performed on the optimization block model 47 as an analysis target of optimization, and the optimum shape and arrangement for the optimization block model 47 are determined.

  In the present embodiment, the load and constraint conditions shown in FIG. 8 are given as the load and constraint conditions given to the optimization analysis model 51. The load / restraint condition shown in FIG. 8 assumes that the rigidity due to bending input from the suspension of the car body is targeted, and the lower part of the optimization analysis model 51 is restrained by the jig 53 for optimization. A load of 2000 N is inputted downward in the height direction (Y-axis minus direction) into a load input section provided at the upper part of the analysis model 51.

In addition, as the optimization analysis condition given to the optimization analysis model 51, the objective condition set according to the purpose of the optimization analysis and the constraint condition imposed on performing the optimization analysis are given.
The target conditions include, for example, the minimization of the total of strain energy in the optimization analysis model 51, the minimization of the displacement, the maximization of the rigidity, and the like.
On the other hand, the constraint conditions include the volume constraint rate, displacement amount, and the like of the optimization block model 47 to be subjected to optimization analysis. A plurality of constraints can be set.

  For example, topology optimization can be applied to the optimization analysis performed by the optimization analysis unit 21. When there is much intermediate density when using the density method in topology optimization, it is preferable to give a penalty coefficient as an optimization parameter and discretize it, as expressed by the following equation.

  The penalty coefficient often used for discretization is 2 or more, and the value of the penalty coefficient can be set as appropriate.

FIG. 9 shows an example of the optimum shape 55 of the optimization block model 47 obtained by applying topology optimization to the optimization analysis unit 21 in the present embodiment.
The optimum shape 55 sets the material properties in Table 1 in the optimization block model 47 and gives the load / restraint conditions shown in FIG. 8 and restricts the stiffness maximum at the volume minimum as the objective condition in the optimization analysis conditions. This is a result obtained by giving the condition that the displacement amount is 0.5 mm or less at the displacement measurement point (FIG. 8 (b)). 9 (a) shows the arrangement of the optimum shape 55 on the outer panel model 43 with the inner panel model 45 hidden to display the optimum shape 55, and FIG. 9 (b) shows A part of the optimum shape 55 remaining in the space S ′ formed between the outer panel model 43 and the inner panel model 45 is shown.

  As shown in FIG. 9, the optimum shape 55 of the optimization block model 47 is obtained by remaining and eliminating solid elements so as to satisfy the above analysis conditions (load / restraint conditions, target conditions, constraint conditions).

  As described above, the load / restraint condition shown in FIG. 8 exemplifies the load / restraint condition to be input to the optimization analysis model 51 when assuming that the rigidity due to bending input from the suspension portion of the vehicle body is targeted. Is. Specifically, the deformation of the A-pillar lower model 41 in the CAE analysis targeting the rigidity due to the bending input from the suspension portion with the vehicle body model 59 shown in FIG. 10 as the analysis target, and the A-pillar lower model 41 shown in FIG. The load / restraint condition to be input to the A-pillar lower model 41 is acquired so that the deformation in the CAE analysis in which only the analysis target is analyzed is equivalent, and the load to input the acquired load / restriction condition to the optimization analysis model 51・ It may be a restraint condition.

  As described above, FIGS. 8 and 9 show the case where the A pillar lower 31 (FIG. 2) is an analysis target. However, in the case where other body parts are the analysis target, the optimization analysis unit 21 The position and direction to which a load is input to the vehicle body component, and further, the vehicle body component is restrained so as to be equivalent to the deformation of the vehicle body component when a predetermined load is input to the vehicle body on which the vehicle body component is installed. It is preferable to determine the load / restraint that gives the part.

  Furthermore, the optimization analysis unit 21 may perform topology optimization processing, or may be optimization processing using another calculation method. Furthermore, as the optimization analysis unit 21, for example, analysis software using a commercially available finite element can be used.

<A method for shape optimization analysis of stiffening members of body parts>
Next, the method for analyzing the shape optimization of the stiffening member of the vehicle body part according to the present embodiment (hereinafter simply referred to as “the method for analyzing the shape optimization”) will be described below.

In the shape optimization analysis method according to the present embodiment, the outer panel 33 and the inner panel 35 as shown in FIGS. 2 and 3 are fastened via the space S, and a stiffening member (not shown) is provided in the space S. In the A-pillar lower 31 disposed, the arrangement of the optimal shape of the stiffening member is determined, and as shown in FIG. 12, a car body part model acquisition step S1 and an optimization block model generation step S3. A material characteristic setting step S5, a coupling processing step S7, and an optimization analysis step S9 are provided. Each step will be described below.
In the shape optimization analysis method according to the present embodiment, the above-described steps are performed using the shape optimization analysis device 1 (see FIG. 1) configured by a computer.

«Car body parts model acquisition step»
The car body part model acquisition step S1 is a step of acquiring a car body part model obtained by modeling a car body part using a plane element and / or a solid element, and in the present embodiment, a car body part of the shape optimization analysis apparatus 1 The model acquisition unit 13 acquires an A-pillar lower model 41 obtained by modeling the A-pillar lower 31 using a plane element.

<< Optimization block model generation step >>
The optimization block model generation step S3 is a step of setting a space in the vehicle body part model as a design space and generating an optimization block model consisting of three-dimensional elements in the design space. In the present embodiment, the optimization block model generation is The section 15 uses the space S 'between the outer panel model 43 and the inner panel model 45 of the A-pillar lower model 41 as a design space, and generates an optimization block model 47 composed of three-dimensional elements.

<< material property setting step >>
The material property setting step S5 is a step of setting the material property of the optimization block model generated in the optimization block model generation step S3. In the present embodiment, the material property setting unit 17 selects the optimization block model 47. The Young's modulus, Poisson's ratio and specific gravity shown in Table 1 are set as the material properties of
Also, when the material property of the stiffening member has in-plane anisotropy, the main axis angle giving the in-plane anisotropy is given, and the value of the material property corresponding to the main axis angle is set in the optimization block model You may

<< combination processing step >>
The coupling processing step S7 is a step of coupling the optimization block model generated in the optimization block model generation step S3 to the vehicle body part model, and in the present embodiment, the coupling processing unit 19 performs optimization processing The model 47 is coupled to the A-pillar lower model 41 to generate an optimization analysis model 51.

«Optimization analysis step»
The optimization analysis step S9 performs load / restraint conditions and optimization analysis conditions, performs optimization analysis with the optimization block model as an analysis target of optimization, and finds the optimal shape and arrangement of the optimization block model In the present embodiment, the optimization analysis unit 21 gives the optimization analysis model 51 the load / restraint condition and the optimization analysis condition as analysis conditions, and the optimization block model 47 is an analysis object of optimization. The optimization analysis is performed to determine the optimum shape 55 as illustrated in FIG.

  As analysis conditions given to the optimization analysis model 51, a load / restraint condition (see FIG. 8) giving a position at which a load is applied to the optimization analysis model 51 and a constraint position (see FIG. 8) and purpose set according to the purpose of optimization analysis. There are conditions and constraints.

  Here, the load / restraint condition given to the optimization analysis model 51 in the optimization analysis step S9 is A when a predetermined load is input to the car body model 59 (FIG. 10) in which the A pillar lower model 41 is disposed. It is preferable to determine so as to be equivalent to the deformation of the pillar lower model 41.

  Further, topology optimization can be applied to the optimization analysis in the optimization analysis step S9. Furthermore, when applying the density method in topology optimization, it is preferable to set the penalty coefficient given as an optimization parameter to 2 or more to perform discretization.

  However, for the optimization analysis in the optimization analysis step S9, optimization analysis processing can be applied by other calculation methods. Examples of the optimization analysis processing include commercially available finite elements. Analysis software using can also be used.

  As described above, according to the shape optimization analysis method and apparatus for a stiffening member of a vehicle body part according to the present embodiment, it is possible to accurately obtain the optimum shape and arrangement of the stiffening member for stiffening the vehicle body part. Furthermore, the weight reduction of the vehicle body part can be achieved by using the stiffening member having the optimum shape and arrangement. The weight reduction of the vehicle body parts using the stiffening member having the optimum shape and arrangement will be specifically described in the embodiments described later.

  Although the above description has been directed to optimizing the shape of the stiffening member for stiffening the A-pillar lower as a car body part, the car body parts targeted for shape optimization in the present invention are limited to this. Instead, it may be a vehicle body part in which two parts made of a metal plate are fastened through a space and a stiffening member is disposed in the space.

Further, as an application example of the present invention, a resin, FRP (fiber reinforced resin, GFRP, CFRP, etc.), or a composite material of these is disposed on a car body part made of steel plate, aluminum plate, magnesium plate, titanium plate, etc. There is no particular limitation on the material of the stiffening member.
Furthermore, in order to dispose the stiffening member on the vehicle body part, the stiffening member may be fastened to the vehicle body part by any method such as bonding or mechanical fastening.

  Optimal Shape and Arrangement of the Stiffening Member Determined by the Shape Optimization Analysis Device and Method of Stiffening Member of a Car Body Component According to the Present Invention, and the Car Body Component Provided with the Stiffening Member of the Optimal Shape and Arrangement An experiment for verifying the effect of improving the rigidity and reducing the weight was performed, and this will be described below.

  In the experiment, first, an A pillar lower model 41 obtained by modeling the A pillar lower 31 that is a vehicle body part using a planar element was obtained. As shown in FIG. 4, the A-pillar lower model 41 is one in which an outer panel model 43 and an inner panel model 45 are fastened via a space S ′. Here, the material of the outer panel model 43 and the inner panel model 45 is a steel plate, the plate thickness of the outer panel model 43 is 0.8 mm or 1.0 mm, and the plate thickness of the inner panel model 45 is 1.4 mm.

  Next, with the space S 'formed between the outer panel model 43 and the inner panel model 45 as a design space, an optimization block model 47 consisting of three-dimensional elements was generated, and its material characteristics were set. In this example, assuming that resin stiffening members are arranged, Young's modulus, Poisson's ratio, and specific gravity shown in Table 1 above are set as material properties of the optimized block model 47.

  The generated optimization block model 47 was disposed in the space S ′ of the A-pillar lower model 41 and combined with the outer panel model 43 and the inner panel model 45 to generate an optimization analysis model 51. As shown in FIG. 7, the coupling process between the optimization block model 47 and the A-pillar lower model 41 is the node 47 b of the solid element 47 a on the outer surface of the optimization block model 47 as shown in FIG. ) And the node 43b (node) of the plane element 43a of the outer panel model 43 at the shortest distance by the rigid body element 49, and the coupling process between the optimization block model 47 and the inner panel model 45 is similarly performed. It was.

  As for the load / constraint conditions given to the optimization analysis model 51, the lower part of the optimization analysis model 51 is restrained by the jig 53 as shown in FIG. A load of 2000 N was input downward in the height direction (in the negative direction of the Y-axis) to the load input portion provided at the top.

  In this embodiment, the optimization analysis condition is the condition (condition A) in which the objective condition is the displacement amount minimum and the rigidity maximum, and the constraint condition is a predetermined volume restriction rate (condition A), and the object condition is the volume minimum and the rigidity maximum. There are two conditions (condition B) in which a predetermined displacement amount is given to the constraint condition. Here, the volume constraint rate of the constraint condition in the condition A was 5% or 10%, and the displacement amount of the constraint condition in the condition B was 0.5 mm or less.

  Then, optimization analysis is performed by topology optimization for the optimization analysis model 51 given the above load and constraint conditions and optimization analysis conditions, and the optimum shape of the optimization block model 47 is placed in the A pillar lower model 41. As a stiffening member model. Then, the rigidity and weight reduction when the stiffening member model was disposed on the A-pillar lower model 41 were evaluated.

  In this embodiment, the stiffening member model set based on the optimum shape obtained by the above optimization analysis is arranged in the A pillar lower model 41 as invention examples (invention examples 1 to 6, invention examples 11 to 11). It was set as Example 16). Here, Inventive Examples 1 to 6 have a plate thickness of 0.8 mm for the outer panel model 43, Inventive Examples 11 to 16 correspond to the Inventive Examples 1 to 6 respectively, and the outer panel model 43 is The plate thickness is 1.0 mm.

  FIG. 13 shows a stiffening member model according to Invention Example 1 and Invention Example 2, and FIG. 14 and FIG. 15 show stiffening member models in Invention Example 3 to Example 6, respectively. Inventive Example 11 to Inventive Example 16 are the same as Inventive Example 1 to Inventive Example 6 except for the thickness of the outer panel model 43, so that the stiffening member model in Inventive Example 11 to Inventive Example 16 is used. These are the shape and arrangement | positioning substantially the same as the stiffening member model in the invention example 1-invention example 6 shown in FIGS.

  Invention Example 1 and Invention Example 2 are based on the optimum shape of the optimization block model obtained as the optimum analysis condition as the above-mentioned condition A (the objective condition is minimum displacement and maximum stiffness, and the constraint is a predetermined volume restriction rate). The shape and arrangement of the stiffening member model are set.

  The stiffening member model 61 (FIG. 13 (a)) according to the invention example 1 has a constraint condition of a volume constraint rate of 5%, and the stiffening member model 63 (FIG. 13 (b)) according to the invention example 2 is a constraint condition. Based on the optimal shape of optimization analysis with a volume restriction rate of 10%. The stiffening member models 61, 63 are formed of columnar portions 61a, 63a disposed in the space S 'between the outer panel model 43 and the inner panel model 45, and flange remaining portions 61b, 63b remaining in the flange portion 43c. Respectively.

  Invention Example 3 to Invention Example 6 are optimum shapes of optimization block models remaining by optimization analysis under the above-described condition B (the objective condition is the volume minimum and maximum rigidity and the constraint condition is a predetermined displacement amount) described above. The shape and arrangement of the stiffening member model are set based on 55 (FIG. 9).

As shown in FIG. 14A, the stiffening member model 71 according to Inventive Example 3 has the same shape and arrangement as the columnar portion 55a and the flange remaining portion 55b of the optimum shape 55 (FIG. 9) of the optimization block model 47. And the flange remaining portion 71b.
The stiffening member model 73 according to the invention example 4 has only the columnar part 71 a by eliminating the flange remaining part 71 b in the stiffening member model 71 according to the invention example 3.

As shown in FIG. 15, the stiffening member model 81 according to the fifth example of the invention is a pillar obtained by CAD modeling of dumbbell shapes (see FIG. 15B) in which both ends of the columnar portion 55a of the optimum shape 55 are expanded. A portion 81a is disposed.
The stiffening member model 83 according to Inventive Example 6, as shown in FIG. 16, is the outer panel model at the position of the flange remaining part 55b of the optimum shape 55 in addition to the columnar part 81a of the stiffening member model 81 according to Inventive Example 3. It has the adhesion part 83b modeled as what bonds 43 and the inner panel model 45 with an adhesive agent.

Further, in this example, as a comparison object, an A pillar lower model 41 (FIG. 17A) in which the outer panel model 43 and the inner panel model 45 are made of steel plates without using the stiffening member model is used as the comparative example 1 and Comparative Example 11 is a comparative example in which a stiffening member model 91 in which a space S ′ between the outer panel model 43 and the inner panel model 45 is filled with a resin having the material characteristics shown in Table 1 is arranged (FIG. 17B). The weight reduction and the rigidity were evaluated in the same manner as in the above-mentioned invention example, as 2 and comparative example 12.
Here, Comparative Example 1 and Comparative Example 2 have a thickness of 0.8 mm for the outer panel model 43 and the inner panel model 45, and Comparative Examples 11 and 12 have a thickness of 1.0 mm for the outer panel model 43 and the inner panel model 45. It is what.

  In the present example, the rigidity of the A-pillar lower model in each of the invention example, the conventional example, and the comparative example was evaluated as follows.

  First, CAE analysis is performed by giving load and restraint conditions shown in FIG. 8 for each of the invention example, the conventional example, and the comparative example, and the displacement measurement points provided at the front end of the A pillar lower model 41 (FIG. The amount of displacement of b)) in the vertical direction downward (Y-axis minus direction in FIG. 8) was obtained. Here, the load / restraint condition shown in FIG. 8 is, as in the case of the load / restraint condition in the shape optimization analysis described above, completely restricted the locker connection portion (see FIG. 2B) to which the locker is connected. A load of 2000 N was input to the load input portion provided at the front end of the lower model 41. A value obtained by dividing the displacement amount at the displacement measurement point by the input load was calculated as the stiffness value.

And the rigidity improvement ratio (%) based on the rigidity value of the conventional example and the rigidity improvement ratio per unit weight normalized by the weight of the stiffening member model (%) ) Was calculated.
Furthermore, the weight change on the basis of the weight of the conventional A pillar lower model 41 was calculated for the invention example and the comparative example.

  The result of the rigidity improvement rate is shown in FIG. 18, and the result of the rigidity improvement rate per weight obtained by standardizing the rigidity improvement rate by the weight of the stiffening member model is shown in FIG. Further, FIG. 18 also shows the numerical value of the weight change under each condition.

  According to FIG. 18, all of the invention examples 1 to 6 and 11 and the invention examples 13 to 16 have a positive rigidity improvement rate and a negative weight change, the outer panel The A-pillar lower model 41 in which the material of the model 43 and the inner panel model 45 is a steel plate and in which the stiffening member model 81 having a dumbbell-like columnar portion 81a is provided has improved rigidity compared to the conventional example made of aluminum plate. It has been shown that both weight reduction and weight reduction can be achieved. Moreover, although the weight change was slightly plus (plus) in the invention example 12, it turns out that rigidity improves remarkably.

  On the other hand, in Comparative Example 1, although the weight change was negative and the weight was reduced, the rigidity improvement rate was also a negative value, and the rigidity was lower than that of the conventional example. Furthermore, in Comparative Example 2, although the rigidity improvement rate is significantly increased, the weight change of the stiffening member model 71 is a positive value, which results in a significant increase in weight over the conventional example, and the rigidity improvement rate per weight Only a slight increase.

Next, invention examples 1 to 6 will be compared and studied.
First, comparing Inventive Example 1 and Inventive Example 2 with different constraint conditions and Inventive Example 3 to Inventive Example 6, within the constraint condition in this example, Inventive Example 1 and Invention in which the volume constraint rate is given as the constraint condition Although the rigidity improvement rate was larger in Example 2 (FIG. 18), the rigidity improvement rate and change weight per weight were smaller (FIG. 19) because the weight of the stiffening member model was increased.

  Also, comparing Invention Example 1 and Invention Example 2 with different volume restriction rates, although the volume of the optimization block model remaining is larger in the invention example 2 with a larger volume restriction rate, the rigidity improvement rate is larger. Because of the increase in the weight of the stiffening member model 63, both the rigidity improvement rate per weight and the change weight were smaller than those of Invention Example 1.

Next, invention examples 3 to 6 in which displacement amounts are given as constraint conditions are compared.
First, when Invention Example 3 and Invention Example 4 were compared, the weight change was -1.9 g in both cases, resulting in equivalent weight reduction. On the other hand, in terms of rigidity, the invention example 3 having the flange remaining portion 55b in the flange portion where the outer panel model 43 and the inner panel model 45 are joined is compared with the invention example 4 having only the columnar portion 55a in the optimum shape 55. The rigidity improvement rate was increased from 7.7% to 29.1%, and the rigidity improvement rate per weight was also increased from 8442.2% / kg to 2770.2% / kg. This result shows that the rigidity can be improved even if only the columnar stiffening member is disposed in the space between the outer panel and the inner panel.

  Moreover, when the invention example 4 and the invention example 5 are compared, while the weight change in the invention example 4 which is a shape as the columnar part 55a of the optimal shape 55 is -1.9 kg, the dumbbell shaped columnar part 81a The weight change in the arranged invention example 5 was −1.8 kg, and although the difference was slightly generated, the weight was reduced to approximately the same level. On the other hand, with respect to rigidity, in the invention example 5 in which the dumbbell-shaped columnar part 81a is arranged, the rigidity improvement rate is increased from 7.7% to 19.2% as compared with the invention example 5 in which the columnar part 55a of the optimum shape is arranged. The rigidity improvement rate per weight was reduced from 844.2% / kg to 494.72% / kg. This result indicates that the rigidity can be improved by spreading both ends of the columnar portion disposed in the space between the outer panel and the inner panel in a dumbbell shape.

  Furthermore, when Inventive Example 5 and Inventive Example 6 are compared, both are arranged in the shape of a dumbbell in which CAD-modeled columnar portions 81a are arranged, and the weight change is both -1.8 g, which is equivalent to weight reduction. On the other hand, regarding rigidity, in the invention example 6 in which the adhesion part 83b is further disposed in the flange portion of the outer panel model 43 and the inner panel model 45, the rigidity improvement rate is 19.2 as compared with the invention example 5 in which only the columnar part 81a is disposed. As a result, the rigidity improvement rate per weight increased from 494.7% / kg to 965.4% / kg. This result shows that the rigidity can be further improved without causing an increase in weight by further joining the outer panel and the inner panel with an adhesive at the position of the flange remaining portion in the optimum shape.

  In the invention examples 11 to 16 in which the plate thickness of the outer panel model 43 is 1.0 mm, as compared with the above-described invention examples 1 to 6, as a whole, although the weight change is reduced, the rigidity improvement rate is improved. Furthermore, the influence on the rigidity improvement rate and the rigidity improvement rate per weight due to the difference in the constraint condition and the shape of the stiffening member model became the same tendency as in Inventive Examples 1 to 6.

  As described above, according to the shape optimization analysis method and apparatus according to the present invention, in the A pillar lower, which is a vehicle body component that is fastened via a space and in which a stiffening member in the space is disposed, the optimal shape of the stiffening member It has been shown that both the improvement in the rigidity and the weight reduction of the A-pillar lower can be achieved by determining the arrangement. Furthermore, the weight of the A pillar lower is increased by bonding the outer panel and the inner panel with an adhesive at the position of the optimization block model remaining in the flange portion joining the outer panel model and the inner panel model in shape optimization analysis. It has been shown that the rigidity improvement rate can be further increased without increasing the rigidity.

DESCRIPTION OF SYMBOLS 1 shape optimization analysis device 3 display device 5 input device 7 storage device 9 working data memory 11 arithmetic processing unit 13 body part model acquisition unit 15 optimization block model generation unit 17 material property setting unit 19 coupling processing unit 21 optimization analysis Part 23 Body part model file 31 A pillar lower 33 Outer panel 33a Top plate 33b Vertical wall 33c Flange 35 Inner panel 35a Inner surface 35c Flange 41 A pillar lower model 43 Outer panel model 43a Flat element 43b Node 43c Flange 45 Inner panel model 47 Optimized Block Model 47a Solid Element 47b Node 49 Rigid Body Element 51 Optimized Analysis Model 53 Jig 55 Optimal Shape 55a Columnar Part 55b Flange Remaining Part 59 Car Body Model 61 Stiffening Member Model 61a Columnar 61b Flange Remaining Part 63 Stiffening Member Model 63a Columnar Part 63b Flange Remaining Part 71 Stiffening Member Model 71a Columnar Part 71b Flange Remaining Part 73 Stiffening Member Model 81 Stiffening Member Model 81a Columnar Part 83 Stiffening Member Model 83b Bonding Part 91 Stiffening member model

Claims (18)

In a vehicle body component in which two parts formed of metal plates are fastened via a space and a stiffening member is disposed in the space, a support for the vehicle body part for which an optimal shape and arrangement of the stiffening member are determined It is a shape optimization analysis method of a rigid member, and a computer performs the following steps:
A car body part model acquiring step of acquiring a car body part model obtained by modeling the car body part using a plane element and / or a solid element;
An optimization block model generation step of generating an optimization block model consisting of three-dimensional elements by setting the space in the body part model as a design space;
A material property setting step of setting material properties of the stiffening member to the optimization block model;
Combining processing step of coupling the optimization block model to the body part model;
An optimization analysis step of performing optimization analysis on the optimization block model as an analysis object of optimization given load / restraint conditions and optimization analysis conditions, and determining an optimal shape and arrangement of the optimization block model; The shape optimization analysis method of the stiffening member of the vehicle body part characterized by having.   The optimization analysis step is characterized in that the load and restraint conditions are determined so as to be equivalent to the deformation of the vehicle body part when a predetermined load is input to the vehicle body model on which the vehicle body part model is installed. The shape optimization analysis method of a stiffening member of a vehicle body part according to claim 1.   The coupling processing step couples the nodes of the solid elements on the outer surface of the optimization block model with the nodes of the plane elements of the vehicle body part model or the solid elements at the shortest distance from the nodes using rigid elements. The method according to claim 1 or 2, wherein the optimization block model and the body part model are combined.   4. The model according to any one of claims 1 to 3, wherein the optimization block model is modeled by a three-dimensional element having at least one pair of two faces which are not less than five faces and not more than eight faces and are parallel to each other. The shape optimization analysis method of the stiffening member of the vehicle body part described in 1.   5. The optimization block model generating step according to any one of claims 1 to 4, wherein a surface parallel to a peripheral surface in which the design space in the body part model is set is the largest area. The shape optimization analysis method of a stiffening member of a vehicle body component according to any one of the preceding claims.   In the optimization block model generation step, a node is arranged at a joint portion with a plane element and / or a solid element constituting the body part model, and a hexahedron solid element is arranged along a plane including the node arranged at the joint portion. The shape optimization analysis method for a stiffening member of a vehicle body part according to any one of claims 1 to 5, wherein the shape optimization analysis method is generated so as to be stacked.   The optimization block model generation step generates a plurality of block bodies composed of solid elements, and generates the plurality of block bodies by using any of rigid elements, beam elements or plane elements. The shape optimization analysis method of a stiffening member of a vehicle body part according to any one of claims 1 to 6, characterized in that   The shape optimization analysis method of a stiffening member for a vehicle body part according to any one of claims 1 to 7, wherein the optimization analysis step performs discretization with optimization parameters in the optimization analysis.   The shape optimization analysis method of a stiffening member for a vehicle body part according to any one of claims 1 to 8, wherein the optimization analysis step performs optimization analysis by topology optimization. In a vehicle body component in which two parts formed of metal plates are fastened via a space and a stiffening member is disposed in the space, a support for the vehicle body part for which an optimal shape and arrangement of the stiffening member are determined It is a shape optimization analysis device of a rigid member, and
A body part model acquisition unit for acquiring a body part model obtained by modeling the body part using a plane element and / or a solid element;
An optimization block model generation unit that generates an optimization block model composed of three-dimensional elements by using the space in the body part model as a design space;
A material property setting unit for setting the material property of the stiffening member to the optimization block model;
A coupling processing unit coupling the optimization block model to the vehicle body part model;
An optimization analysis unit which performs optimization analysis with the optimization block condition as the analysis object of optimization given load / restraint conditions and optimization analysis conditions, and determines an optimal shape and arrangement of the optimization block model; A shape optimization analysis device for a stiffening member of a vehicle body part characterized by comprising.   The optimization analysis unit determines the load / restraint condition so as to be equivalent to the deformation of the vehicle body part when a predetermined load is input to the vehicle body model on which the vehicle body part model is installed. The shape optimization analysis apparatus for a stiffening member of a vehicle body part according to claim 10.   The coupling processing unit couples a node of a solid element on an outer surface of the optimization block model with a node of a plane element of the vehicle body part model or a solid element at a shortest distance from the node using a rigid body element. The shape optimization analysis apparatus for a stiffening member of a vehicle body part according to claim 10 or 11, wherein the optimization block model and the vehicle body part model are combined.   The model according to any one of claims 10 to 12, wherein the optimization block model is modeled by a three-dimensional element having at least one pair of two faces which are not less than five faces and not more than eight faces and are parallel to each other. The shape optimization analysis apparatus of the stiffening member of the vehicle body part described in 1.   14. The optimization block model generation unit according to any one of claims 10 to 13, wherein a surface parallel to a peripheral surface on which the design space in the body part model is set has a maximum area. The shape optimization analysis device for a stiffening member of a vehicle body component according to any one of the preceding claims.   The optimization block model generation unit arranges a node at a joint portion with a plane element and / or a solid element constituting the vehicle body part model, and places a hexahedron solid element along a plane including the node arranged at the joint portion. The shape optimization analysis device for a stiffening member of a vehicle body component according to any one of claims 10 to 14, wherein the shape optimization generation device is configured to be stacked.   The optimization block model generation unit generates a plurality of block bodies composed of solid elements, and generates the plurality of block bodies by connecting the plurality of block bodies using any one of a rigid element, a beam element, and a plane element. The shape optimization analysis apparatus for a stiffening member of a vehicle body part according to any one of claims 10 to 15.   The shape optimization analysis device for a stiffening member of a vehicle body component according to any one of claims 10 to 16, wherein the optimization analysis unit performs discretization with the optimization parameter in the optimization analysis.   The shape optimization analysis device for a stiffening member of a vehicle body component according to any one of claims 10 to 17, wherein the optimization analysis unit performs optimization analysis by topology optimization.