JP2015052924A - Fem analysis model generation system of press molding using fabric material or composite material and program, and fem analysis system including the same and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To predict occurrence of wrinkles with high accuracy in consideration of flexural rigidity while suppressing a calculation cost in a FEM analysis of a press-molding step.SOLUTION: A FEM analysis model generation system includes: a basic model generation unit for generating a basic model in which a blank plate is divided into a plurality of elements by a mesh on the basis of acquired shape data of the blank material; a multilayer model creation unit for creating a multilayer model by setting a membrane element at a thickness center position and setting a shell element which shares its node with the membrane element and which is regarded as being separated toward both sides from the central position by a predetermined distance; and a blank analysis model generation unit for generating the analysis model of the blank material by defining an inplane stress-strain characteristic for the membrane element and defining data used for expressing an out-of-plane flexural rigidity for the shell element, on the basis of material characteristic data.

Description

  TECHNICAL FIELD The present invention relates to a press molding FEM analysis model generation system and program using a woven material or a composite material impregnated with a resin, and an FEM analysis system and program including the same. Belongs to the technical field.

  Conventionally, as various members such as aircraft bodies and automobile bodies, a fabric material called dry fabric made of a reinforcing material such as carbon fiber or glass fiber, for example, for further weight reduction while maintaining strength, or A composite material (hereinafter referred to as “woven material etc.”) such as a prepreg sheet in which a fabric material such as carbon fiber is impregnated with a thermoplastic resin or a stampable sheet in which a thermosetting resin is impregnated is used as a blank material. A member that is press-molded in layers or laminated may be used.

  At this time, generally, in the press molding process, if molding is not performed under appropriate conditions according to the blank material, molding defects such as wrinkles and cracks occur in the molded product. In particular, when the blank material is a woven material or a woven material, the direction and degree of wrinkles generated vary depending on the internal structure (material characteristics and number of layers of reinforcing material, woven structure, fiber direction, etc.).

  Therefore, in recent years, in order to more efficiently manufacture high-quality members using woven materials or composite materials, it has been considered to create a press die shape model at the time of design and perform simulation analysis of the press molding process. .

  Non-Patent Document 1 describes a technique for performing press molding analysis by modeling a single-layer fabric material or the like with a membrane element as a single-layer model.

Y.Aimene, B.Hagege, F.Sidoroff, E.Vidal-Salle, P.Boisse, S.Dridi, “Hyperelastic Approach for Composite Reinforcement Forming Simulations”, International Journal of Material Forming, April 2008, Volume 1, Issue 1 Supplement, pp 811-814

  Here, the wrinkle generation mechanism in the press molding process can be explained as a buckling problem in which the compressive stress generated by the in-plane compressive deformation exceeds the buckling limit stress, and the in-plane compressive deformation branches to the out-of-plane bending deformation. . Since the bending stiffness and the buckling length greatly affect the buckling limit stress, an analysis in consideration of the bending stiffness is required to evaluate wrinkles, which are typical molding defects in the press molding process.

  In particular, when a fabric material or the like is press-molded as a blank material, slippage may occur between the reinforcing materials inside the material. The larger this slip, the smaller the bending rigidity, and the material properties and reinforcement of this reinforcing material. Since the direction and size of the slip generated according to the contact friction between the materials are different, the bending rigidity varies depending on the type of the woven material or the bending direction of the same woven material. Therefore, there is a great need to consider bending rigidity particularly in the analysis of press molding of a woven material or the like.

  However, in the conventional technique described in Non-Patent Document 1, an analysis model is created with a membrane element that does not take any out-of-plane bending stiffness into consideration in the first place. Since the influence is ignored, the analysis accuracy is insufficient.

  It is also conceivable to perform a so-called mesomodel analysis in which the woven structure of a fiber bundle made of a reinforcing material is modeled and analyzed in detail. In the case of this analysis, the analysis can be performed in consideration of the bending rigidity. However, since the scale of the analysis model becomes large, a very large calculation cost is required and it is difficult to apply to the actual design. Furthermore, when the blank material is a multi-layered woven material or the like, the scale of the analysis model increases depending on the number of layers, and therefore it is very difficult to apply to an actual design.

  Accordingly, an object of the present invention is to predict wrinkle generation with higher accuracy in consideration of bending rigidity while suppressing calculation cost in simulation analysis of a press forming process.

  In order to solve the above-described problems, the FEM analysis model creation system and program for press forming according to the present invention and the FEM analysis system and program including the same are configured as follows.

First, the invention according to claim 1 of the present application is
An FEM analysis model generation system for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit that acquires material property data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh;
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as being separated by a predetermined distance from the neutral plane;
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material A blank analysis model generation unit to perform,
It is characterized by having.

The invention according to claim 2 of the present application is
An FEM analysis model generation system for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit that acquires material property data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blanking material creation department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared with a shell element formed of the shell that is treated as being separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material A blank analysis model generation unit to perform,
It is characterized by having.

Further, the invention according to claim 3 of the present application is the invention according to any one of claims 1 and 2,
The blank analysis model generation unit calculates the predetermined distance and the elastic modulus as the bending rigidity based on the relationship between the predetermined distance and the elastic modulus of the shell element, and defines the shell element as the bending element. To do.

The invention according to claim 4 of the present application is the invention according to claim 3,
The blank material is the orthotropic material,
The blank analysis model generation unit sets the shear elastic modulus of the shell element to a predetermined value, and based on the relationship between the predetermined distance of the neutral surface of the shell element and the elastic modulus of the shell element, The predetermined distance is calculated from the elastic modulus, and the elastic modulus in the 0 ° and 90 ° directions of the shell element is calculated from the predetermined distance and defined in the shell element.

The invention according to claim 5 of the present application is
An FEM analysis system for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A mold analysis model generation unit for generating a mold analysis model;
Based on the blank material analysis model generated by the FEM analysis model generation system according to any one of claims 1 to 4, the generated mold analysis model, and set analysis conditions, An analysis unit for performing FEM analysis;
It is characterized by having.

The invention according to claim 6 of the present application is
An FEM analysis model generation program for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh,
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as having a neutral plane separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
It is made to function as.

The invention according to claim 7 of the present application is
An FEM analysis model generation program for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blank material production department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared with a shell element made of the shell that is treated as being separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
It is made to function as.

The invention according to claim 8 of the present application is the invention according to any one of claims 6 and 7,
When the computer functions as the blank analysis model generation unit, the shell element is calculated by calculating the predetermined distance and the elastic modulus as the bending rigidity based on the relationship between the predetermined distance and the elastic modulus of the shell element. It is characterized by functioning as defined in

The invention according to claim 9 of the present application is the invention according to claim 8,
When functioning the computer as the blank material data acquisition unit, function to acquire an orthotropic material as the blank material,
When the computer functions as the blank analysis model generation unit, the shear elastic modulus of the shell element is set to a predetermined value, and the predetermined distance of the neutral surface of the shell element and the elastic modulus of the shell element Based on the relationship, calculating the predetermined distance from the shear elastic modulus, calculating the elastic modulus in the 0 ° and 90 ° directions of the shell element from the predetermined distance, and causing the shell element to function. Features.

The invention according to claim 10 of the present application is
An FEM analysis program for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh,
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as having a neutral plane separated by a predetermined distance,
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
A mold analysis model generation unit for generating a mold analysis model, and
An analysis unit that performs FEM analysis based on the generated blank material analysis model, the mold analysis model, and the set analysis conditions;
It is made to function as.

The invention according to claim 11 of the present application is
An FEM analysis program for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blank material production department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared and overlapped with a shell element formed of the shell that is treated as being separated by a predetermined distance;
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
A mold analysis model generation unit for generating a mold analysis model, and
An analysis unit that performs FEM analysis based on the generated blank material analysis model, the mold analysis model, and the set analysis conditions;
It is made to function as.

  With the above configuration, according to the invention according to each claim of the present application, the following effects can be obtained.

  In the case of a homogeneous continuum, such as sheet metal, for example, its flexural rigidity is automatically determined from the material properties of compression and tension, whereas in the case of textiles or composites, non-uniform discontinuities And slipping may occur inside. Since this slip affects the bending stiffness, the bending stiffness cannot be automatically determined from compression and tension material properties. However, as described above, it is necessary to consider bending rigidity in order to perform a more accurate analysis.

  According to the first aspect of the present invention, the membrane element is set at the thickness center position, and the membrane element and its node are shared, and the neutral planes are spaced apart from each other by a predetermined distance from the center position at the time of FEM analysis. A blank element analysis model is defined in which the shell element to be treated is defined, the in-plane stress-strain characteristics are defined in the membrane element, and the data used to represent the out-of-plane bending stiffness is defined in the shell element. Can be generated. Therefore, by combining modeling with membrane elements and shell elements, it is possible to set data to express out-of-plane bending stiffness completely independent of in-plane characteristics, so it is actually discontinuous. Textile materials and composite materials that are bodies can be expressed as a continuous analysis model. Therefore, by performing FEM analysis using this analysis model, a more accurate analysis result in consideration of bending rigidity can be obtained.

  In the case of multiple layers, slippage may occur between the layers, and the degree of slippage between the layers also affects the bending rigidity. According to the first aspect of the present invention, an analysis model that takes into account this bending stiffness affected by slippage between layers can be obtained by simply obtaining the actual bending stiffness of the blank material as a multilayer as blank material data. Can be created on the same scale. Therefore, when performing FEM analysis using this analysis model, the calculation cost is almost the same as in the case of a single layer. Therefore, the calculation cost can be greatly reduced especially when the number of stacked layers exceeds 100 layers. Therefore, according to the invention which concerns on Claim 1, generation | occurrence | production of a wrinkle can be estimated more accurately in consideration of bending rigidity, suppressing calculation cost in the simulation analysis of a press molding process.

  The invention according to claim 2 is that the order of meshing divided into a plurality of elements and the layering of stacking shells on both sides of the membrane are opposite to those of the invention according to claim 1 when the blank analysis model is generated. Is substantially different. However, according to the invention according to claim 2, since a blank analysis model similar to that of the invention according to claim 1 can be generated as a result, the same effect as that of the invention according to claim 1 can be obtained, and Since the order of meshing and layering can be arbitrarily set, the degree of freedom in actually designing the FEM analysis model generation system can be improved.

  According to the invention of claim 3, the blank analysis model generation unit uses the predetermined distance of the shell element neutral surface and the elastic modulus of the shell element as data for representing the out-of-plane bending rigidity based on the material property data. Is calculated and set in the shell element, so a blank analysis model that reflects the actual out-of-plane bending stiffness can be generated. By using this analysis model, the bending stiffness can be considered more accurately. Accurate analysis results can be obtained.

  According to the invention of claim 4, when an orthotropic material such as a plain weave widely used as a blank material is used, the same effect as that of the invention of claim 1 can be obtained.

  According to the inventions according to claims 5, 10, and 11, since no special configuration for analyzing the generated blank analysis model is required in the analysis unit, it is possible to perform FEM analysis using a general-purpose analysis solver. it can.

  According to the invention of claim 6, the same effect as that of the invention of the FEM analysis model generation system according to claim 1 can be obtained.

  According to the invention of claim 7, the same effect as that of the invention of the FEM analysis model generation system according to claim 2 can be obtained.

  According to the invention of claim 8, the same effect as that of the invention of the FEM analysis model generation system according to claim 3 can be obtained.

  According to the invention of claim 9, the same effect as that of the invention of the FEM analysis model generation system according to claim 4 can be obtained.

1 is a block diagram illustrating an overall configuration of a press-forming FEM analysis system according to an embodiment of the present invention. It is a block diagram which shows the structure of the processing apparatus of this system. It is a block diagram which shows the structure of the memory | storage device of this system. It is a figure which shows the blank material data regarding the material characteristic of a blank material. It is a figure which shows the blank material data regarding the shape etc. of a blank material. It is a figure which shows blank analysis model data. It is a figure which shows the FEM analysis data regarding an integration point. It is a figure which shows the FEM analysis data regarding the remainder. It is a figure which shows the example of the screen output-displayed on the output device of this system. It is explanatory drawing which illustrates a press molding process roughly. It is a perspective view of the blank material which is a textile material. It is an enlarged view of the blank material. Fig.12 (a) is an enlarged plan view explaining the textile structure of a textile material. Fig. 12 (b) is an enlarged side view when the fabric material is a single layer, and Fig. 12 (c) is an enlarged side view when the fabric material is a multilayer. It is a flowchart which shows the control method of the main routine of a blank analysis model production | generation system. It is a flowchart which shows the control method of the subroutine of blank analysis model generation in FIG. It is a flowchart which shows the control method of the subroutine of an out-of-plane bending rigidity calculation in FIG. It is a flowchart which shows the control method of the analysis part of a FEM analysis system. It is a figure explaining the analysis model of the blank material which is a textile material or a composite material. It is a figure which illustrates roughly the distortion which generate | occur | produces when the analysis model is bent. It is a figure explaining the calculation method of the stress which generate | occur | produced in the analysis model. It is a perspective view explaining press molding simulation. It is a perspective view which shows the analysis result of press molding simulation. FIG. 21A is a diagram illustrating a wrinkle generation state when a meso model analysis is performed. FIG. 21B is a diagram showing a wrinkle generation state when the analysis system of the present invention is used. FIG. 21C is a diagram showing a wrinkle generation state when the bending rigidity is not considered as a comparative example. It is a block diagram which shows the structure of the modification of the processing apparatus of the system.

  Hereinafter, an embodiment of an FEM analysis model generation system and program for press forming using a woven material or a composite material according to the present invention and an FEM analysis system and program including the same will be described. First, the FEM analysis system 1 as a total system including the FEM analysis model generation system 100 as a subsystem will be described.

(1) Outline of FEM Analysis System FIG. 1 shows a configuration of a computer 10 that is the center of a press-formed FEM analysis system 1 using a woven material or a composite material. The computer 10 includes a processing device 11 such as a CPU, a storage device 12 such as a memory or a hard disk, an input device 13 such as a keyboard, a mouse, or a CD-ROM drive, and an output device 14 such as a liquid crystal display or a printer. .

(1-1) Processing Device FIG. 2 shows the configuration of the processing device 11 of FIG. The processing device 11 is a combination of a series of work processes. Among them, a blank analysis model generation system 100 is included as a subsystem of the FEM analysis system 1.

The blank analysis model generation system 100, the blank data acquisition unit 110 for acquiring the blank data DT1, the basic model generating unit 120, multilayer model creation unit 130 to create a layered model _{M 2} to produce a basic model _{M 1,} blank It is mainly composed of the blank analysis model generating unit 140 for generating an analysis model M _3.

In addition, the processing apparatus 11 includes a mold shape data acquisition unit 200 that acquires the mold shape data DT5 of the press molding apparatus, and a mold analysis model generation that generates a mold analysis model m based on the mold shape data DT5. Part 220. Further, the processing unit 11 has an analysis unit 300 that performs press forming simulation using the blank analysis model M ₃ and mold analysis model m, analysis to display the press-forming simulation result to the output device 14 result display unit 400.

(1-2) Storage Device FIG. 3 shows the configuration of the storage device 12 of FIG. The storage device 12 mainly includes a program storage unit 12A and a data storage unit 12B. The program storage unit 12A stores a basic model generation program PR1, a multilayer model generation program PR2, a blank analysis model generation program PR3, a mold analysis model generation program PR4, an analysis program PR5 (so-called analysis solver), and a result display program PR6. Program storage units 12A _{1 to} 12A ₆ are included. The programs PR1 to PR6 are executed by the basic model generation unit 120, the multilayer model generation unit 130, the blank analysis model generation unit 140, the mold analysis model generation unit 220, the analysis unit 300, and the analysis result display unit 400 in the processing apparatus 11 described above. Each is executed.

The data storage portion 12B, blank data DT1, the basic model data DT2, layered model data DT3, the blank analysis model data DT4, the data storage unit 12B ₁ for storing a mold shape data DT5 preliminary mold analysis model data DT6 respectively ~12B ₆ has. Hereinafter, these data DT1 to DT6 will be described.

(1-2-1) Blank Material Data The blank material data DT1 is data relating to the material characteristics and shape of the blank material B. This blank material data DT1 is stored in a storage medium such as a CD-ROM, is input to the processing device 11 by the blank material data acquisition unit 110 via the input device 13 such as a CD-ROM drive, and is stored in the storage device 12. The

The data relating to the material characteristics of the blank material B includes a stress strain characteristic data table and a bending stiffness data table. When the blank B is an orthotropic material, specifically, as shown in FIG. 4, the stress strain characteristic data table includes stress strain characteristics of 0 °, 90 ° and shear. The bending stiffness data table includes bending stiffnesses EI ₀ , EI ₄₅ , and EI _{90 in the} directions of 0 °, 45 °, and 90 °.

The stress strain characteristics in the directions of 0 ° and 90 ° are obtained by an actual tensile test using a test piece made of the same material as that of the blank material B. In addition, the stress-strain characteristics of the shear can be obtained by a picture frame test or a Bias-Extension test in which a specimen with +/− 45 ° orientation is stretched. When the blank material B is a laminate of a plurality of woven materials or the like, the above-described test is performed using a multi-layer test piece that is in the same manner as the blank material. In general, the stress strain characteristics in the 0 ° direction, shear, and 90 ° direction have a substantially constant rate of change (slope) of stress with respect to the strain in the elastic range, and these rate of change is in the 0 ° direction. Technically mean tensile elastic modulus E ₀ , shear elastic modulus G and 90 ° tensile elastic modulus E ₉₀ .

The bending stiffness EI ₀ , EI ₄₅ , EI ₉₀ in the directions of 0 °, 45 ° and 90 ° is obtained by an actual bending test using a test piece formed of the same material as that of the blank material B. When the blank material B is a laminate of a plurality of woven materials or the like, the above-described test is performed using a multi-layer test piece that is in the same manner as the blank material. Generally, the magnitude of the moment with respect to the curvature is obtained by bending tests in the directions of 0 °, 45 °, and 90 °. However, the rate of change (slope) of the moment with respect to the curvature is substantially constant within the elastic range. These rates of change technically mean flexural stiffness EI ₀ , EI ₄₅ , EI ₉₀ in the 0 °, 45 ° and 90 ° directions, respectively.

  In addition, in order to obtain the above-mentioned data on the material characteristics, instead of actually performing the test using the test piece, a meso model analysis for analyzing a part of the blank B in which the structure is modeled in detail is performed. The analysis result may be used as data relating to the material characteristics described above.

  The data relating to the shape of the blank material B includes an outline data table and thickness data. The outline data table is data indicating the shape of the outline when the sheet-like blank B is viewed from the press direction, and is generated by the blank data acquisition unit 110 based on the CAD data of the blank B and the like. . Specifically, as shown in FIG. 5, the outline data table includes a line segment number L, a line segment type (fillet, arc, straight line), a first end point coordinate (XY coordinate), and a second end point coordinate (XY). Coordinate), center coordinate (XY coordinate), radius R, start angle α, and end angle β.

  Here, since the outline of the blank material B is considered as a closed curve composed of a plurality of line segments, the outline data is a line segment type indicating either a fillet, an arc, or a straight line for each line segment, and a line When the line segment is an arc or a fillet together with the first and second end point coordinates indicating the XY coordinates of both ends of the minute, the center coordinates and radius R, and the start angle α and the end angle β indicating the phase of both ends of the line segment It has as data.

(1-2-2) Basic model data base model data DT2 is a mesh data of the basic model M ₁ of the plane is divided into a plurality of elements enclosed by the outline of the blank B. The basic model data DT2 is generated by the basic model generation unit 120 based on the outline data table and thickness data of the blank material data DT1 described above, and is stored in the storage device 12.

  The basic model data DT2 includes a nodal coordinate table and an element configuration data table. Specifically, the node coordinate table includes the XYZ coordinates of each node, and the element configuration data table includes the first node number, the second node number, the third node number, and the like when each element shape is a rectangle. The fourth node number is included.

(1-2-3) layer model data layer model data DT3, for each element of the basic model M _1, set the membrane elements in the thickness center position, it shares its nodes and membrane elements, centered at FEM analysis on either side of the position is data on layer model M ₂ which sets the shell elements to be treated as being a predetermined distance. The multilayer model data DT3 is created by the multilayer model creation unit 130 based on the basic model data DT2, and is stored in the storage device 12.

  The multilayer model data DT3 includes a component configuration data table, a node coordinate table, and an element configuration data table. Specifically, the component configuration data table includes the element type (film element or shell element) and thickness of each component, and the node coordinate table includes the XYZ coordinates of each node. Includes a part number, a first node number, a second node number, a third node number, and a fourth node number of each element.

(1-2-4) blank analysis model data blank analysis model data DT4 is data showing an analysis model _{M 3} of the blank B to be used in the analysis unit 300. The blank analysis model data DT4 is generated by the blank analysis model generation unit 140 based on the multilayer model data DT3 and stored in the storage device 12.

The blank analysis model data DT4 includes a component configuration data table, a node coordinate table, and an element configuration data table. Specifically, as shown in FIG. 6, the component configuration data table includes the element type (film element or shell element) and thickness of each component, and the node coordinate table includes the XYZ coordinates of each node. It is. The element configuration data table includes the part number, the first node number, the second node number, the third node number, and the fourth node number of each element, as well as the offset amount from the film element on the neutral surface of each shell element. d, the elastic modulus E _shell of each _shell element and the stress strain characteristics of each membrane element.

(1-2-5) Mold Shape Data The mold shape data DT5 is shape data such as CAD data of a press mold. The mold shape data DT5 is stored in a storage medium such as a CD-ROM, and is input to the processing device 11 by the mold shape data acquisition unit 200 via the input device 13 such as a CD-ROM drive. Remembered.

(1-2-6) Mold Analysis Model Data The mold analysis model data DT6 is data indicating an analysis model m of the press mold. The mold analysis model data DT6 is generated by the mold analysis model generation unit 220 based on the mold shape data DT5 and stored in the storage device 12.

(1-2-7) FEM analysis data FEM analysis data is data relating to each component or each integration point of the blank analysis model _{M 3} that is repeatedly calculated during analysis in the analysis unit 300. The FEM analysis data includes an integration point data table, an element configuration table, a material attribute data table, and a node coordinate table.

As shown in FIG. 7, the integral point data table, element number integration point and number P1, P2 · · · contained in each element of the blank analysis model M ₃ to be FEM analysis, each integration point included E1, E2,..., Position components (X, Y, Z) and stress components (σ _XX , σ _XY , σ _XZ , σ _YX , σ _YY , σ _YZ , σ _ZX ) of each integration point in the element coordinate system σ _ZY , σ _ZZ ) and strain components (ε _XX , ε _XY , ε _XZ , ε _YX , ε _YY , ε _YZ , ε _ZX , ε _ZY , ε _ZZ ).

  As shown in FIG. 8A, the element configuration table includes element numbers E1, E2..., Material numbers M1, M2..., In-plane integration points and out-of-plane integration points, The included first node number, second node number, third node number, and fourth node number are included.

  As shown in FIG. 8B, the material attribute data table includes material numbers M1, M2,...

  As shown in FIG. 8C, the node coordinate table includes node numbers N1, N2,..., And position components (X, Y, Z) of each node in the global coordinate system.

  The FEM analysis data is generated by the analysis unit 300 based on the blank analysis model data DT4, and the analysis result is output to the output device 14 by the analysis result output unit 400 based on the generated FEM analysis data.

(1-3) Input Device The input device 13 is used to input data related to the shape of the blank material B such as CAD data and mesh data and the press mold, to set various conditions such as analysis conditions, or to control the system 1. Used.

(1-4) Output device The output device 14 displays an input screen, an edit screen, an analysis result, and the like. For example, as shown in FIG. 9, a three-dimensional shape such as a woven material after press molding is displayed graphically.

(2) Press molding apparatus The press molding which performs a simulation analysis with the above-mentioned FEM analysis system 1 is demonstrated, referring FIG.

  As shown in FIG. 10, the press molding apparatus for performing the press molding includes a die D, a wrinkle presser F, and a punch P. The die D serving as the upper mold has a cavity C having a shape matching the shape of the molded product on the lower surface thereof. The wrinkle retainer F serving as a lower mold has an opening having a shape substantially along the contour of the cavity C of the die D at the center thereof, and a wrinkle having a shape matching the surface around the cavity C of the die D on its upper surface. Has a holding surface. Similarly, the punch P, which is the lower die, has an outer shape that is slightly smaller in shape corresponding to the shape of the opening of the wrinkle retainer F, and its upper surface has a convex shape that matches the shape of the cavity C of the die D.

  The punch P is disposed with a gap with respect to the inner wall surface of the opening of the wrinkle retainer F so that it can be moved up and down inside the opening of the wrinkle retainer F. In a state where the punch P is lowered most with respect to the wrinkle retainer F (see FIG. 10A), the uppermost end of the punch P is lower than the upper surface around the opening of the wrinkle retainer F. Further, in the state where the punch P is raised most with respect to the wrinkle retainer F (see FIG. 10B), the upper surface around the punch P is almost the same height as the upper surface around the opening of the wrinkle retainer F.

  In press forming using this press forming apparatus, first, as shown in FIG. 10A, the periphery of the flat blank B serving as the material of the product is used as the lower surface around the cavity C of the die D to suppress wrinkles. Wrinkle pressing is performed by sandwiching with the upper surface of F at a predetermined pressure.

  Next, as shown in FIG. 10B, the punch P is raised, the blank material B is pushed into the cavity C of the die D, and the blank material B is pressed between the die D and the punch P and pressed. In the press molding, the die D and the wrinkle presser F may be moved up and down with the punch P fixed.

  According to this press molding apparatus, a molded product B ′ as shown in FIG. 10B is obtained. This molded product B ′ is composed of a product part, a surplus part and a wrinkle holding part, and this product part and surplus part are in the cavity C between the punch P and the die D of the press molding apparatus described above. The wrinkle pressing portion is formed between the wrinkle pressing F and the die D. A desired product can be obtained by punching the molded product B 'along the product shape outline which is the outline of the product portion.

  Here, if the wrinkle pressing force between the wrinkle presser F and the die D is not appropriate, the molded product B 'may be cracked or wrinkled. In general, when the wrinkle holding force is large, cracks are likely to occur at portions where the fibers are locally stretched and the fiber breaks. On the other hand, when the wrinkle holding force is small, the blank B that has been squeezed into the cavity C of the die D tends to buckle and wrinkles are likely to occur.

(3) Textile material or composite material used as blank material The fabric material or composite material used as blank material B that is subjected to press molding by the above press molding apparatus will be described with reference to FIGS. 11 and 12.

  The fabric material handled here is a material in which organic or inorganic fibrous reinforcing materials (for example, carbon fibers, glass fibers, etc.) are woven into a sheet shape, and examples thereof include dry fabrics. In addition, the composite material handled here is a sheet by impregnating the above-mentioned woven material or non-woven fibrous reinforcing material as a base material with a thermoplastic or thermosetting resin as a base material. Examples of the material include a prepreg sheet impregnated with a thermosetting resin and a stampable sheet impregnated with a thermoplastic resin.

  FIG. 11 shows a woven material in which continuous carbon fibers are plain-woven as an example of the blank material B. As shown in FIG. 12 (a), the woven structure of the woven material is a warp (see white) and weft (see black) continuous fiber bundle in which a plurality of continuous carbon fibers are bundled. It is woven so that the warp and weft intersect one bundle at a time. Note that reinforcing materials having different material characteristics may be used for the warp and the weft. Further, the weaving method of the woven material is not limited to the plain weave, and may be, for example, a twill weave or a satin weave.

  This fabric material may be press-molded in a single layer state as shown in FIG. 12 (b), or a plurality of same or different types of fabric materials may be laminated as shown in FIG. 12 (c). In some cases, it is press-molded in the state of multiple layers. In addition, as an example of the composite material, there is one in which a reinforcing material serving as a base material in the composite material has the same structure as the above-described woven material, and the reinforcing material is impregnated with a desired resin.

  In a woven material or composite material having such a structure, since the fibrous reinforcing material extends in a specific direction, stress strain characteristics, bending rigidity, etc. differ depending on the direction, that is, the orientation of the material characteristics. It has a feature. For example, in the case of a plain woven fabric structure in which fibers extend in the 0 ° direction and 90 ° direction as shown in FIG. In the case of a composite material, the material characteristics such as stress-strain characteristics and bending rigidity differ depending on the material characteristics of the base material and the base material, the adhesion between the base material and the base material, and the like.

(4) Control Method Next, a series of control methods by the above-described processing apparatus 11 will be described below.

(4-1) by the blank analysis model generating method blank analysis model generation system 100, how to generate a blank analysis model M ₃ used during FEM analysis, will be described with reference to FIG.

  First, the blank material data acquisition unit 110 acquires blank material data DT1 related to the material characteristics and shape of the blank material B from the storage device 12 (S1).

Next, based on the outline data table of the blank material data DT1 acquired by the basic model generation unit 120, the two-dimensional mesh divided into a plurality of elements by meshing the surface surrounded by the outline of the blank B generating a basic model _{M 1} (S2). In general, in the field of structural analysis, meshing is a known technique, and thus detailed description thereof is omitted. In this embodiment, the shape of the mesh is a quadrangle, but it may be a triangle.

Next, the multilayer model creation part 130, the generated elements of the basic model M _1, as shown in FIG. 17, and sets the film element Ef in the thickness center position, the membrane elements Ef the node N share, on both sides of the center position during FEM analysis predetermined distance d (hereinafter, referred to as "offset d".) only creates a layer model M ₂ by setting the shell elements EsI, Es2 are treated as being spaced (S3).

Layer model M ₂ that are created, the thickness of the membrane elements Ef along with is set to the thickness t of the blank B, the upper and lower shell elements EsI, Es2 thickness is set to t / 2, respectively. In addition, when a blank material is a multilayer, the thickness t of this blank material B is the thickness between the outermost parts of a blank material also in the case of a multilayer.

Finally, the blank analysis model generating unit 140, based on the layer model M ₂ created, to generate a blank analysis model M ₃ in a manner described below (S4).

Here, the generation method of the blank analysis model M ₃ by the blank analysis model generating unit 140 will be described with reference to FIG. 14. FIG. 14 shows a subroutine of blank analysis model generation (S4) constituting the main routine shown in FIG.

  First, based on the material property data of the blank material data DT1, the in-plane stress strain property is defined in the film element Ef (S11).

Next, the offset amount d and the elastic moduli E _shell0, E _{shell45, and} E _shell90 of the neutral surfaces of the shell elements Es1 and Es2 are calculated as data representing the out-of-plane bending rigidity by the method described later (S12).

Finally, the data representing the calculated out-of-plane bending stiffness (specifically, the offset d and the elastic modulus E _shell0, E _shell45, E _shell90 of the neutral surface of the shell element) is defined for each shell element Es1, Es2. (S13), the process returns to the main routine described above.

  Here, a method for calculating data representing the out-of-plane bending stiffness will be described with reference to FIG. FIG. 15 shows a subroutine for calculating out-of-plane bending stiffness (S12) shown in FIG.

Generally, when the tensile elastic modulus E ₀ , E ₄₅ , E ₉₀ of the blank material B in the 0 °, 45 °, and 90 ° directions is compared, the tensile elastic modulus E _{45 in the} 45 ° direction is the smallest. Assuming that Poisson's ratio = 0, naturally the tensile elastic modulus E ₄₅ in the 45 ° direction is twice the shear elastic modulus G _shell . Based on these assumptions, the following will be described.

First, the elastic modulus E _shell45 in the 45 ° direction of the shell element is calculated by the following equation (1) based on the minimum tensile elastic modulus E _45, and the elastic modulus E _shell45 and the shear elastic modulus G _{shell in} the 45 ° direction of the shell element are calculated. The shear modulus G _shell of the shell element is calculated from the relational expression (2) (S21).

In formula (1), it was 1/50 of the elastic modulus E ₄₅ Tensile 45 ° direction of the elastic modulus E _Shell45 shell elements, not limited to the value of the 1/50. This value may be set so that the influence of the in-plane stress / strain characteristics of the shell element on the in-plane stress / strain characteristics of the membrane element is small and can be ignored.

Next, based on the bending rigidity EI ₄₅ of the blank material B in the 45 ° direction using the following equation (3) showing the relationship between the offset amount d of the neutral surface of the shell element and the elastic modulus E _shell 45 in the 45 ° direction. The offset amount d is calculated (S22).

Then, based on the flexural rigidity EI ₀ of 0 ° direction blank B, and elastic modulus E _Shell0 of 0 ° direction of the shell elements is calculated by the following equation (4) (S23).

Finally, based on the bending stiffness EI ₉₀ in the 90 ° direction of the blank material B, the 90 ° elastic modulus E _shell90 of the shell element is calculated by the following equation (5) (S24), and the process returns to the main routine described above.

Here, the relationship between the offset amount d of the neutral surface of the shell element and the elastic moduli E _shell0, E _{shell45, and} E _shell90 will be described in detail below with reference to FIGS. In the following description, the elastic modulus E _shell is used, but this can be considered by replacing it with elastic modulus E _shell0, E _{shell45, and} E _shell90 in all directions of 0 °, 45 °, and 90 °.

  First, the bending stiffness EI can be calculated from the moment M of the bending test and the curvature φ using the following relational expression (6). E represents the elastic modulus, and I represents the moment of inertia of the cross section.

Here, as shown in FIG. 18, when deformed bending blank analysis model M _3, the stress sigma _x are distributed above and below the shell element EsI, Es2. At this time, as shown in FIG. 19, the moment M at each of the shell elements Es1 and Es2 can be calculated by the following equation (7).

  Here, the following relational expressions (8) and (9) hold.

  From the above (8) and (9), the equation (7) becomes the following equation (10).

Therefore, a relational expression (11) between the offset amount d of the next neutral plane and the elastic modulus E _shell can be obtained from the expressions (7) and (10).

When the equation (11) is transformed into an equation for obtaining the elastic modulus E _shell , the following equation (12) is obtained.

_Thus , the relational expressions (11) and (12) between the offset amount d of the neutral surface of the shell elements Es1 and Es2 and the elastic moduli E _shell0, E _{shell45, and} E _shell90 were obtained.

It is assumed that E ₄₅ is the smallest, but the present invention is not limited to this. Based on the smallest elastic modulus among the tensile elastic modulus E ₀ , E ₄₅ , E ₉₀ , the shell elements Es 1, Es 2 in the same direction First, the elastic modulus E _shell is calculated, and the offset amount d of the neutral plane of the shell elements Es1, Es2 is calculated based on the calculated elastic modulus of the shell element, and the remaining directions are calculated based on the offset amount d. The elastic modulus E _shell of the shell elements Es1 and Es2 may be calculated.

(4-2) FEM analysis method Next, the blank analysis model _{M 3} generated by the FEM analysis model generation system 100, and the mold analysis model m generated in the mold analysis model generating unit 220, it is set The FEM analysis method executed by the analysis unit 300 based on the analysis conditions will be described with reference to FIG.

  First, the analysis at the time step number N = 1 is started (step S31).

Then, to acquire the FEM analysis data at time step number N of the blank analysis model M _3, from the internal memory of FEM analysis data already calculated is temporarily stored. Specifically, the stress tensor at time step number N of all the integration points that are in the entire elements constituting the blank analysis model M _3, to obtain the strain tensor (step S32).

Next, to extract one element from a plurality of elements constituting the blank analysis model M ₃ (step S33).

  Next, the displacement u of each node common to the shell element and the membrane element is calculated by solving the following equation of motion (13) based on the load and forced displacement amount of the punch P and the analysis conditions (S34). In the following equation (13), M represents a moment, K represents a stiffness matrix, and f represents a load. Since this equation of motion and its solution are well known in the art, a detailed description is omitted.

Next, based on the calculated displacement of the node, strains ε _membrance, ε _{upper-shell, and} ε _lower-shell of the integration points of the membrane element sharing this node and the shell elements above and below it are calculated. At this time, the strains ε _{upper-shell and} ε _lower-shell of the _upper and lower shell elements are calculated in consideration of the offset amount d of the neutral plane (S35). Here, the strain ε and the displacement u are in the relationship of the following equation (14).

Therefore, this model will be described in a simple manner assuming that the shell element has only one integration point in the thickness direction when the translational displacement of the node is a and the rotational displacement of the node is θ. The strains ε _membrance, ε _{upper-shell, and} ε _lower-shell can be calculated by the following equations (15) to (17), respectively.

Next, based on the calculated strain ε _membrance, ε _upper-shell, ε _lower-shell based on the in-plane stress-strain characteristics and elastic modulus defined for the shell element and membrane element, the stress σ of each element is calculated. Calculate (S36). Here, in general, the stress σ and the strain ε are in the relationship of the following equation (18).

Therefore, when this model is simply considered in one dimension, the stresses σ _membrance, σ _{upper-shell, and} σ _lower-shell of the membrane element and the upper and lower shell elements thereof are expressed by the following equations (19) to (21), respectively. Have the relationship.

That is, the stresses σ _membrance, σ _upper-shell, σ _lower-shell are expressed by the following equations (22) to (24) in which the above equations (15) to (17) are substituted into these equations (19) to (21). Can be calculated.

Next, based on the resultant stresses of the shell element and the membrane element σ _membrance, σ _{upper-shell, and} σ _lower-shell , the node load f shared by the shell element and the membrane element is calculated (S37). . Here, generally, the stress σ and the load f are in the relationship of the following equation (25).

Therefore, similarly, when this model is simply considered in one dimension, the load f and the stresses σ _membrance, σ _{upper-shell, and} σ _lower-shell have the relationship of the following equation (26).

  Substituting the above formulas (22) to (24) into this formula (26) and rearranging the formula, the following formula (27) is obtained.

_Since there is a relationship of _E 0 »E _shell0, formula (27) can be approximated by the following equation (28).

As is apparent from the equation (28), the translation load f can be determined only from the elastic modulus E ₀ of the membrane element and the translational displacement a of the node.

For example, when the integration point of each element is one point, the moment M and the stresses σ _membrance, σ _{upper-shell, and} σ _lower-shell are in the relationship of the following equation (29).

  The moment M is calculated by the following equation (30) obtained by substituting the above equations (23) to (24) into this equation (29).

As is apparent from this equation (30), the moment M is determined only from the elastic modulus E _shell0 of the shell element and the rotational displacement θ of the node. That is, the translational displacement a of the node does not affect the moment M.

Next, all the elements of the blank analysis model M ₃ determines whether the above calculation is completed, it is determined that no exit to the step S33 (step S38).

  If it is determined in step S38 that all elements of the analysis model have been completed, it is determined whether the FEM analysis in the FEM analysis unit 300 has been completed (step S39). This process is terminated (step S40).

  If it is determined in step S39 that the analysis has not been completed, the number of time steps N is changed to N + 1, and the process returns to step S32 (step S40).

Thus, the blank analysis model _{M 3} can be performed FEM analysis.

(5) Modification Next, in the above embodiment will be described below modification, which is a partial modification of the procedure up to create a layered model M _2.

(5-1) Processing Device FIG. 22 shows the configuration of the processing device 11 of FIG. As shown in FIG. 22, the processing unit 11 of this modification, in place of the basic model generating unit 120 which generates a basic model M _1, it differs only in that the multilayered blank generating section 135 is provided.

(5-2) a blank analysis model M ₃ relates blank analysis model generating method blank B how to generate the blank analysis model generation system 100 will be described.

  The blank material data acquisition unit 110 acquires material characteristic data and shape data of the blank material B.

Based on the shape data of the blank material B acquired by the blank material data acquisition unit 110 by the multi-layered blank material creation unit 125, a film is set at the thickness center position, and the shells are overlapped on both sides of the film to form layers. A multilayered blank material model M ₁ ′ is created.

The multi-layer model creating unit 130 divides the multi-layer blank material model M ₁ ′ created by the multi-layer blank material creating unit 125 into a plurality of elements, and each element is composed of the above-described film disposed at the center position thereof. In addition to setting the membrane element, the membrane element and its node are shared, and the shell element composed of the above-described shell is set to be treated as being separated by a predetermined distance d on both sides from the center position at the time of FEM analysis. to create a model _{M 2.}

  The blank analysis model generation unit 140 defines in-plane stress-strain characteristics in the film element based on the material characteristic data, and defines data used to express out-of-plane bending stiffness in the shell element to define the blank material B. Generate an analysis model.

By the above, the meshing of dividing the model into a plurality of elements, even if the order of layering overlaying the shell on either side of the membrane is reversed, the blank analysis model M ₃ double layer produced is carried out ahead of Since it has the same structure as the form, it can be similarly analyzed by the analysis unit 300.

(6) Verification of blank analysis model generation system and FEM analysis system In order to verify the analysis by the blank analysis model generation system 100 described above, analysis was performed in the following procedure.

First, as shown in FIG. 20A, die analysis models m _D and m _P for a die D and a punch P constituting a press die were prepared.

Next, as shown in FIG. 20B, the models m _P , m _D , and M ₃ of the press mold and the blank material B were aligned.

  Next, as shown in FIG. 20C, the conditions of the mold (load, displacement condition) and the contact conditions of the press mold and the blank material B were set as analysis conditions. Specifically, the stroke of the punch P was set to a predetermined value (see arrows), and conditions were set so that the four corners (see circles) of the blank material B were constrained to the die D.

  Based on this, FEM analysis of press molding simulation was performed using the FEM analysis system 1.

  FIG. 21 shows the shape of the molded product, which is the analysis result when the FEM analysis of the press molding simulation of FIG. 20 is performed on the blank analysis model generated by a different method. FIG. 21A shows the analysis result when meso model analysis is performed. The analysis result of this mesomodel analysis was interpreted as the actual wrinkle occurrence. FIG. 21B shows an analysis result when the analysis system of the present invention is used. FIG. 21C shows an analysis result of a conventional technique in which a blank analysis model is created using only membrane elements as a comparative example. Since this conventional technique generates a blank analysis model of only a membrane element, out-of-plane bending rigidity is not considered in the analysis result.

  As is clear from FIG. 21, the wrinkle occurrence state of the present invention (FIG. 21 (b)) is a real wrinkle occurrence state (FIG. 21 (a)) than that of the prior art (FIG. 21 (c)). ) And very close. This is because the buckling limit stress is larger than in the prior art because the present invention considers bending rigidity, the in-plane compression deformation is branched into the out-of-plane bending deformation, and buckling is less likely to occur and wrinkles are reduced. it is conceivable that.

(7) Features of Blank Analysis Model Generation System and FEM Analysis System According to the blank analysis model generation system 100 of the present invention, a film element is set at the center of thickness, and the film element and its node are shared. A shell element that is treated as having a neutral plane spaced apart by a predetermined offset amount d on both sides of the center position is set, and in-plane stress-strain characteristics are defined in the membrane element, and the analysis model M ₃ of the blank of the data defined in the shell elements are used to represent the bending stiffness can be produced.

In other words, by combining modeling with membrane elements and shell elements, it is possible to set data to express out-of-plane bending stiffness completely independently of in-plane characteristics, so in practice discontinuous the woven material and composite material which is a body can be expressed as an analysis model M ₃ of the continuum. Therefore, by performing the FEM analysis using the analysis model M _3, high analysis results accuracy than considering bending stiffness is obtained.

In addition, when the blank material B is a multi-layer, slip may occur between the layers, and the slip condition between the layers also affects the bending rigidity. However, the actual bending rigidity of the blank material B as the multi-layer is determined as blank material data. only to acquire as DT1, can slip between the layers of the analytical model M ₃ in consideration of this bending stiffness influence, created on the same scale as in the single layer. Therefore, when performing FEM analysis using the analysis model M _3, the calculation cost is almost unchanged in the case of a single layer. Therefore, especially in the case of multiple layers, the calculation cost can be greatly reduced as compared with meso model analysis. Therefore, in the simulation analysis of the press forming process, the generation of wrinkles can be predicted with higher accuracy in consideration of the bending rigidity while suppressing the calculation cost.

Further, when generating the blank analysis model, and meshed divided into a plurality of elements, also the order of layering overlaying the shell on either side of the membrane is a reverse, it can produce similar blank analysis model M ₃ as a result . Therefore, since the order of meshing and layering can be arbitrarily set, the degree of freedom in actually designing the FEM analysis model generation system 100 can be improved.

Moreover, the blank analysis model generation unit 140 uses the offset amount d of the shell element neutral surface and the elastic modulus of the shell element as data for representing the out-of-plane bending rigidity based on the material property data of the blank material data DT1. since calculates and sets the shell elements, can generate a blank analysis model M ₃ which reflects the actual plane of bending rigidity, the use of the analysis model M _3, considering bending rigidity more precisely Further, an analysis result with higher accuracy can be obtained.

  In addition, the same effect can be obtained when an orthotropic material such as a plain weave widely used as the blank material B is used.

In general, a general-purpose analysis solver generates mesh data by dividing the outer surface or inner surface into a plurality of elements based on drawing data indicating the shape of the outer surface or inner surface of the plate, and calculates strain. For example, it has a function of correcting the mesh data generated on the neutral plane set at the center of the plate thickness to be offset by half of the plate thickness. In order to use this function, general-purpose analysis solvers are usually configured so that an offset amount for offsetting the generated mesh data to the neutral plane can be arbitrarily input so that the neutral plane can be set at an arbitrary position. . By applying the above-described function, the present invention inputs the offset amount d from the membrane element of the neutral surface of each shell element of the blank analysis model data DT4 to the general-purpose analysis solver as data relating to the offset amount. Further, all of the remaining data included in the blank analysis model data DT4 is normally used in a general-purpose analysis solver. Therefore, according to the FEM analysis system 1 of the present invention, the analysis unit 300, since the blank analysis model M ₃ generated is not required any special arrangement for analyzing, performing FEM analysis using a general-purpose analysis solver be able to.

  It should be noted that the present invention is not limited to the illustrated embodiment, and it goes without saying that various improvements and design changes can be made without departing from the gist of the present invention.

  For example, in this embodiment, the press molding apparatus is configured with the die D as the upper mold and the punch P and the wrinkle presser F as the lower mold, but with the die D as the lower mold and the punch P and the wrinkle presser F as the upper mold. May be.

  Further, in the present embodiment, as the composite material, a material in which a fiber reinforcing material as a base material is impregnated with a resin as a base material has been described, but the composite material that is an object of the present invention is not limited thereto. For example, a particulate reinforcing material or a tape-shaped reinforcing material may be used as the base material. Further, ceramics, metals, polymers, or the like may be used as the base material. Furthermore, the blank material B which is an object of the present invention is not limited to a woven material and a composite material, and in a broad sense is a material in which two or more components are combined, and these components are atomically melted together. Instead, any material having an interface that separates each other may be used.

  As described above, according to the present invention, it is possible to perform press molding simulation of single-layer and multi-layer laminated composite materials such as dry fabric, prepreg impregnated with thermosetting resin, stampable sheet impregnated with thermoplastic resin, and the like. Therefore, there is a possibility that it can be suitably used in the manufacturing industry of structural parts such as vehicles and aircraft.

1 FEM Analysis System 10 Computer 100 Blank Analysis Model Generation System 110 Blank Material Data Acquisition Unit 120 Basic Model Generation Unit 125 Multilayered Blank Material Generation Unit 130 Multilayer Model Generation Unit 140 Blank Analysis Model Generation Unit 220 Mold Analysis Model Generation Unit 300 Analysis Part

Claims (11)

An FEM analysis model generation system for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit that acquires material property data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh;
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as being separated by a predetermined distance from the neutral plane;
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material A blank analysis model generation unit to perform,
An FEM analysis model generation system characterized by comprising: An FEM analysis model generation system for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit that acquires material property data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blanking material creation department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared with a shell element formed of the shell that is treated as being separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material A blank analysis model generation unit to perform,
An FEM analysis model generation system characterized by comprising: The blank analysis model generation unit calculates the predetermined distance and the elastic modulus as the bending rigidity based on the relationship between the predetermined distance and the elastic modulus of the shell element, and defines the shell element as the bending element. The FEM analysis model generation system according to any one of claims 1 and 2. The blank material is an orthotropic material,
The blank analysis model generation unit sets the shear elastic modulus of the shell element to a predetermined value, and based on the relationship between the predetermined distance of the neutral surface of the shell element and the elastic modulus of the shell element, 4. The FEM analysis according to claim 3, wherein the predetermined distance is calculated from an elastic modulus, and the elastic modulus in the 0 ° and 90 ° directions of the shell element is calculated from the predetermined distance and defined in the shell element. Model generation system. An FEM analysis system for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A mold analysis model generation unit for generating a mold analysis model;
Based on the blank material analysis model generated by the FEM analysis model generation system according to any one of claims 1 to 4, the generated mold analysis model, and set analysis conditions, An analysis unit for performing FEM analysis;
An FEM analysis system comprising: An FEM analysis model generation program for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh,
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as having a neutral plane separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
An FEM analysis model generation program characterized by functioning as An FEM analysis model generation program for generating an analysis model for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blank material production department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared with a shell element made of the shell that is treated as being separated by a predetermined distance; and
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
An FEM analysis model generation program characterized by functioning as When the computer functions as the blank analysis model generation unit, the shell element is calculated by calculating the predetermined distance and the elastic modulus as the bending rigidity based on the relationship between the predetermined distance and the elastic modulus of the shell element. The FEM analysis model generation program according to any one of claims 6 and 7, wherein the FEM analysis model generation program according to any one of claims 6 and 7 is functioned. When functioning the computer as the blank material data acquisition unit, function to acquire an orthotropic material as the blank material,
When the computer functions as the blank analysis model generation unit, the shear elastic modulus of the shell element is set to a predetermined value, and the predetermined distance of the neutral surface of the shell element and the elastic modulus of the shell element Based on the relationship, calculating the predetermined distance from the shear elastic modulus, calculating the elastic modulus in the 0 ° and 90 ° directions of the shell element from the predetermined distance, and causing the shell element to function. 9. The FEM analysis model generation program according to claim 8, wherein An FEM analysis program for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired by the blank material data acquisition unit, a basic model generation unit that generates a basic model in which the blank material is divided into a plurality of elements with a mesh,
For each element of the basic model generated by the basic model generation unit, a film element is set at the thickness center position, and the film element and its node are shared. A multi-layer model creation unit that creates a multi-layer model by setting shell elements that are treated as having a neutral plane separated by a predetermined distance,
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
A mold analysis model generation unit for generating a mold analysis model, and
An analysis unit that performs FEM analysis based on the generated blank material analysis model, the mold analysis model, and the set analysis conditions;
FEM analysis program characterized in that it functions as An FEM analysis program for simulating press molding using a woven material or a composite material as a blank material by FEM analysis,
A blank material data acquisition unit for acquiring material characteristic data and shape data of the blank material,
Based on the shape data of the blank material acquired in the blank material data acquisition unit, a film is set at the thickness center position, and a multilayer material is formed by stacking the shells on both sides of the film to overlap each other. Blank material production department,
The multilayered blank material created by the multilayered blank material creation unit is divided into a plurality of elements, and a film element made of a film disposed at the center position and neutrals on both sides of the center position at the time of FEM analysis. A multi-layer model creating unit that creates a multi-layer model in which nodes are shared and overlapped with a shell element formed of the shell that is treated as being separated by a predetermined distance;
Based on the material property data, in-plane stress-strain characteristics are defined in the membrane element, and data used to represent out-of-plane bending stiffness is defined in the shell element to generate an analytical model of the blank material Blank analysis model generation unit,
A mold analysis model generation unit for generating a mold analysis model, and
An analysis unit that performs FEM analysis based on the generated blank material analysis model, the mold analysis model, and the set analysis conditions;
FEM analysis program characterized in that it functions as