WO2020208969A1 - 2d random oriented fiber model creation device, 2d random oriented fiber model creation method, and 2d random oriented fiber model creation program - Google Patents

Abstract

The present invention creates a 2D random oriented fiber model without increasing the number of beam elements. A 2D random oriented fiber model creation device is provided with: a random disposition quasi-isotropic fiber unit model creation unit for disposing, at random, a plurality of basic fiber models constituted of a plurality of nodes and a plurality of beam elements on a fiber area frame composed by arranging joint frames with no gap while satisfying quasi-isotropy; and a superposition unit for superposing, while maintaining a positional relationship between the respective joint frames and the nodes and beam elements within the respective joint frames, the nodes and the beam elements within the respective joint frames without being rotated, in such a manner that all remaining joint frames are overlapped with a center area frame as one of the joint frames, thereby creating a 2D random oriented fiber model area.

Description

2D random alignment fiber model creation device, 2D random alignment fiber model creation method, and 2D random alignment fiber model creation program

The present invention relates to a compression molding analysis system, a compression molding analysis method, and a compression molding analysis program.

Countermeasures against global warming are an urgent issue, and automobile manufacturers and others are required to significantly improve fuel efficiency by reducing the weight of automobiles in order to reduce CO ₂ emissions. Steel materials are used for conventional automobile parts and the like, but in recent years, fiber reinforced plastics have been studied as alternative materials.

Fiber reinforced resin is a composite material in which fibers such as glass fiber and carbon fiber are put in the resin to improve the strength. For example, polyamide nylon 6 is used as the resin for the fiber-reinforced resin used for automobile parts and the like, and glass fibers having a fiber length of 30 to 50 mm and a fiber diameter of 5 to 10 μm are put in this resin to make resin fibers. Some layers are formed, and about 40 layers of the resin fiber layers are laminated to make the plate thickness about 2 mm.

When such a fiber reinforced plastic is used for automobile parts or the like, it is molded by injection molding, press molding, etc., but since the fibers move and rotate due to the resin flow during molding, it depends on the velocity distribution of the fluid. Therefore, there are differences in the positions of individual fibers. Due to such differences in fiber positions, anisotropy such as elastic modulus and linear expansion coefficient may occur, which may cause unexpected decrease in strength and warpage deformation. Therefore, the movement of fibers is accurately performed in advance. Prediction is very important industrially.

For example, Patent Document 1 discloses a technique in which a fiber model is defined by continuous numerical analysis elements (beam elements) and the position, direction, and shape of the fibers are analyzed using the velocity distribution of the resin.

Japanese Unexamined Patent Publication No. 2014-226871

In the fiber reinforced resin as described above, a large amount of cut fibers may be randomly scattered in a plane (2D). In the present specification, such fiber orientation is referred to as 2D random orientation. The 2D random orientation means that the fibers contained in an arbitrarily selected region are isotropically distributed in a plane regardless of the location, and the fiber volume content (density) is the same regardless of the location. Is the case.

Patent Document 1 only states that it is desirable to automatically generate a fiber model at a random position and in a random direction when creating a model of a 2D randomly oriented fiber-reinforced resin, and there is no specific explanation. , The method of Patent Document 1 is not guaranteed to satisfy 2D random orientation.

If the number of fiber models can be modeled at the same level as the actual one (10 square mm x 500,000 to 8 million fibers per 1 mm of plate thickness), the same 2D random orientation as the actual one can be satisfied. However, such a method is not practical because the number of beam elements constituting the fiber model increases enormously and the calculation cost of the finite element method increases significantly.

The present invention has been made to solve the above problems, and in order to carry out the finite element method in a practical calculation time, the number of fiber models has been significantly reduced (1/400 or less). Even in this case, it is an object of the present invention to provide a 2D random alignment fiber model creation device capable of creating a fiber model satisfying 2D random alignment as much as possible, a 2D random alignment fiber model creation method, and a 2D random alignment fiber model creation program. ..

In order to solve the above-mentioned problems, one aspect of the 2D randomly oriented fiber modeling apparatus of the present invention is
Randomly arranged pseudo-isotropic fibers in which multiple basic fiber models consisting of multiple nodes and multiple beam elements are randomly arranged in a fiber region frame composed of congruent frames arranged in a plane without gaps while satisfying pseudo-isotropic. Random arrangement pseudo isotropic fiber unit model creation unit to create a unit model,
Without rotating the node and the beam element in each of the congruent frames, while maintaining the positional relationship between the congruent frame and the node and the beam element in each of the congruent frames. It is provided with a superimposing portion that creates a 2D randomly oriented fiber model region by superimposing the central region frame, which is one of the congruent frames, on the central region frame so that all the other congruent frames overlap.

In the present specification, in the "2D randomly oriented fiber", the fibers contained in an arbitrarily selected region are isotropically distributed in a plane regardless of the location, and the fiber volume content (density) is the same. It is a concept that includes being.

According to this aspect, the random arrangement pseudo-isotropic fiber unit model creation unit is a plurality of basic fiber models composed of a plurality of nodes and a plurality of beam elements in a fiber region frame composed of congruent frames arranged in a plane without gaps. Are randomly arranged while satisfying the pseudo-isotropic. The superimposing portion maintains the positional relationship between the node and the beam element in each of the congruent frames and the node and the beam element in each of the congruent frames. A 2D randomly oriented fiber model region is created by superimposing all the other congruent frames on the central region frame, which is one of the congruent frames, without rotation. Therefore, according to this aspect, even when the number of fiber models is significantly reduced from the actual number, a 2D randomly oriented fiber model filled with 2D random orientation is created.

In another aspect of the 2D randomly oriented fiber model creating apparatus of the present invention, the superimposing portion duplicates the randomly arranged pseudo isotropic fiber unit model to create a superimposing model, and the superimposing model is used as a unit. Overlapping may be performed.

According to this aspect, the superimposing portion duplicates the randomly arranged pseudo isotropic fiber unit model to create a superimposing model, and performs the superimposing in units of the superimposing model. Therefore, the above-mentioned in the congruent frame. Overlapping can be performed without cutting out the nodes and the beam elements.

In another aspect of the 2D randomly oriented fiber modeling apparatus of the present invention, in the superposed portion, the superposed central region frame forms an example of m × n (m, n are natural numbers). The superposition model may be created and the superposition in units of the superposition model may be repeated so as to be arranged side by side.

According to this aspect, in one superposed central region frame, all the nodes and beam elements of the randomly arranged pseudo-isotropic fiber unit model contained in the fiber region frame are included, and the fibers The model is isotropically distributed in the plane. Therefore, a superposition model is created so that such a central region frame forms a row example of m × n (m, n is a natural number), and superposition is repeated in units of the superposition model. This makes it easy to create a 2D random alignment fiber model that satisfies the 2D random orientation.

In another aspect of the 2D randomly oriented fiber model creating apparatus of the present invention, the intersection of the beam element in the 2D randomly oriented fiber model region after the superposition and the frame of the 2D randomly oriented fiber model region is newly made. It includes a boundary node setting unit for setting as a node, and a cutting unit for cutting out the node and the beam element in the frame of the 2D randomly oriented fiber model region after setting the new node as a 2D randomly oriented fiber model. You may.

According to this aspect, the boundary node setting unit sets the intersection of the beam element in the 2D random alignment fiber model region after the superposition and the frame of the 2D random alignment fiber model region as a new node. .. In addition, the cutting section cuts out the node and the beam element in the frame of the 2D randomly oriented fiber model region after setting the new node as a 2D randomly oriented fiber model. Therefore, a 2D random alignment fiber model filled with 2D random orientation is easily created.

In another aspect of the 2D randomly oriented fiber model making apparatus of the present invention, the cutout portion forms the entire m × n row example and is lined up. It may be cut out as a model.

According to this aspect, the entire superposed central region frame includes all the nodes and beam elements of the randomly arranged pseudo-isotropic fiber unit model contained within the fiber region frame, and the fibers. The model is isotropically distributed in the plane. Therefore, by cutting out the entire central region frame, a 2D random alignment fiber model satisfying the 2D random orientation is created.

Another aspect of the 2D randomly oriented fiber modeling apparatus of the present invention is
The random arrangement pseudo isotropic fiber unit model creation unit
The basic fiber model creation unit that creates the basic fiber model,
A pseudo-isotropic fiber unit model creation unit that creates a pseudo-isotropic fiber unit model by arranging a plurality of basic fiber models at a predetermined angle around a predetermined point.
A central region frame setting unit that sets a rectangular central region frame at the center of the pseudo-isotropic fiber unit model,
The fiber region frame setting unit for setting the fiber region frame and
A random translational movement unit that randomly translates the basic fiber model within the range of the fiber region frame is provided.
The random arrangement pseudo isotropic fiber unit model may be created.

According to this aspect, the randomly arranged pseudo-isotropic fiber unit model creation unit includes a basic fiber model creation unit, a pseudo-isotropic fiber unit model creation unit, a central region frame setting unit, a fiber region frame setting unit, and random. It is equipped with a translational movement unit. The basic fiber model creation unit creates a basic fiber model consisting of a plurality of nodes and a plurality of beam elements. The pseudo-isotropic fiber unit model creation unit creates a pseudo-isotropic fiber unit model by arranging a plurality of basic fiber models shifted by a predetermined angle around a predetermined point. The central region frame setting unit sets a rectangular central region frame at the center of the pseudo-isotropic fiber unit model. The fiber region frame setting section includes the entire pseudo-isotropic fiber unit model by a central region frame and a congruent frame that duplicates the central region frame, is partitioned in a grid pattern, and has vertical and horizontal dimensions of the central region frame. Set a fiber region frame that is an integral multiple of the size. The random translational movement unit randomly translates the basic fiber model within a range within the fiber region frame. This state is referred to as a randomly arranged pseudo isotropic fiber unit model. In this state, the fiber model is isotropically distributed in the plane within the fiber region frame. The superimposition part maintains the positional relationship between the nodes and beam elements in each congruent frame in the randomly arranged pseudo-isotropic fiber unit model, and the nodes and beam elements in each congruent frame. At the same time, the nodes and beam elements included in the central region frame are superimposed. As a result, in the central region frame, all the nodes and beam elements of the randomly arranged pseudo isotropic fiber unit model included in the fiber region frame are included, and the fiber model is isotropically distributed in the plane. Therefore, according to this aspect, even when the number of fiber models is significantly reduced from the actual number, a 2D randomly oriented fiber model filled with 2D random orientation is created.

In order to solve the above-mentioned problems, one aspect of the method for creating a 2D randomly oriented fiber model of the present invention is
Randomly arranged pseudo-isotropic fiber unit model creation unit satisfies multiple basic fiber models consisting of multiple nodes and multiple beam elements in a fiber region frame composed of congruent frames arranged in a plane without gaps. While randomly arranging steps and
The overlapping portion allows the node and the beam element in each of the congruent frames to maintain the positional relationship between the congruent frame and the node and the beam element in the congruent frame. It comprises a step of creating a 2D randomly oriented fiber model region by superimposing all the other congruent frames on the central region frame, which is one of the congruent frames, without rotation.

According to one aspect of the 2D randomly oriented fiber model creating method of the present invention, the randomly arranged pseudo-isotropic fiber unit model creating unit has a plurality of nodes in a fiber region frame formed by arranging congruent frames in a plane without gaps. A plurality of basic fiber models consisting of a plurality of beam elements are randomly arranged while satisfying pseudo-isotropics. Therefore, according to this aspect, a 2D random alignment fiber model satisfying the 2D random orientation is created even when the number of fiber models is significantly reduced from the actual one.

In order to solve the above-mentioned problems, one aspect of the 2D randomly oriented fiber modeling program of the present invention is
A 2D random alignment fiber model creation program that causes a computer to create a 2D random alignment fiber model, and the 2D random alignment fiber model creation program causes the computer to create a 2D random alignment fiber model.
Randomly arranged pseudo-isotropic fiber unit model creation unit satisfies multiple basic fiber models consisting of multiple nodes and multiple beam elements in a fiber region frame composed of congruent frames arranged in a plane without gaps. While randomly arranging steps and
The overlapping portion allows the node and the beam element in each of the congruent frames to maintain the positional relationship between the congruent frame and the node and the beam element in the congruent frame. The step of creating a 2D randomly oriented fiber model region by superimposing all the other congruent frames on the central region frame, which is one of the congruent frames, without rotating is executed.

According to one aspect of the 2D random alignment fiber model creation program of the present invention, the random arrangement pseudo-isotropic fiber unit model creation unit has a plurality of nodes in a fiber region frame formed by arranging congruent frames in a plane without gaps. A plurality of basic fiber models consisting of a plurality of beam elements are randomly arranged while satisfying pseudo-isotropics. The superimposing portion maintains the positional relationship between the node and the beam element in each of the congruent frames and the node and the beam element in each of the congruent frames. A 2D randomly oriented fiber model region is created by superimposing all the other congruent frames on the central region frame, which is one of the congruent frames, without rotation. Therefore, according to this aspect, a 2D random alignment fiber model satisfying the 2D random orientation is created even when the number of fiber models is significantly reduced from the actual one.

According to the present invention, it is possible to create a fiber model that satisfies 2D random orientation as much as possible even when the number of fiber models is significantly reduced from the actual one.

It is a figure which shows the schematic structure of the 2D random alignment fiber model making apparatus which concerns on one Embodiment of this invention. It is a figure which shows the functional block which functions by the central processing unit executing the program which concerns on this embodiment. It is a flowchart which shows the flow of the 2D random alignment fiber model making process in this embodiment. (A) is a diagram showing a predetermined region in a fiber reinforced plastic in which fibers such as glass are mixed with a resin, and (B) is an enlarged view of the region A shown in (A). It is a figure which shows that the fiber is evenly distributed in the direction of 0 degree to 180 degree. It is a figure which shows that the fiber is mainly oriented 90 degrees. It is a figure for demonstrating the relationship between the region selected in the fiber reinforced plastic, the distribution of the angle of a fiber, and the fiber volume content. It is a figure which shows the comparison between the actual fiber reinforced plastic and the fiber model. It is a figure which shows an example of the basic fiber model. It is a figure which shows an example of the pseudo isotropic fiber unit model. It is a figure for demonstrating the central area frame. It is a figure for demonstrating the fiber area frame. It is a figure for demonstrating a random translation. It is a figure for demonstrating the cluster superposition method. It is a figure which shows the beam element 31 and the node 30 included in the central region frame 40 in the state which superposed by the cluster superimposing method. It is a figure for demonstrating the superimposition processing. It is a figure for demonstrating the superimposition processing. It is a figure for demonstrating the superimposition processing. It is a figure for demonstrating the superimposition processing. It is a figure which shows the 2D random alignment fiber model which was continuously generated by repeating the superposition process. (A) is a diagram showing the boundary of the 2D randomly oriented fiber model region and the beam element straddling it, and (B) is the intersection of the boundary of (A) and the beam element straddling it as a node of a new beam element. It is a figure which shows that it sets as. It is a figure which shows the region to cut out as a 2D random alignment fiber model. It is a figure which shows the 2D random alignment fiber model. It is a figure which shows the example which the region satisfying 2D random orientation moved in an arbitrary direction. It is a figure which shows the region which does not satisfy 2D random orientation. It is a figure which shows the image which photographed the actual fiber reinforced plastic. It is an enlarged view of the upper surface of a fiber reinforced resin. It is a figure for demonstrating the laminated state in the side view of a fiber reinforced resin.

Hereinafter, the 2D randomly oriented fiber producing apparatus according to the embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a 2D randomly oriented fiber producing apparatus 100 according to the present embodiment. As shown in FIG. 1, the 2D random alignment fiber producing device 100 of the present embodiment includes a central processing unit 1, a display device 2, a storage device 3, an input device 4, and an output device 5.

The central arithmetic unit 1 is a device such as a personal computer capable of executing a program, and includes a CPU, a memory, and the like. The display device 2 is a device such as a liquid crystal display capable of displaying characters and images. The storage device 3 is a device capable of storing programs and data such as an HDD (Hard Disk Drive), and an external database server or the like may be used. The program of the present invention is stored in the storage device 3. The input device 4 is a device such as a keyboard capable of inputting data or instructions by the user. The output device 5 is a device such as a printer capable of outputting characters and images. In the compression molding analysis system 100 of the present embodiment, the output device 5 may be omitted.

FIG. 2 is a diagram showing a functional block in which the central processing unit 1 functions by executing the program of the present invention. As shown in FIG. 2, the central processing unit 1 functions as a control unit 10. Further, the control unit 10 functions as a random arrangement pseudo isotropic fiber unit model creation unit 11, a superposition unit 17, a boundary node setting unit 18, and a cutting unit 19 according to the program of the present invention.

Randomly arranged pseudo-isotropic fiber unit model creation unit 11 pseudo-isotropic a plurality of basic fiber models composed of a plurality of nodes and a plurality of beam elements in a fiber region frame formed by arranging congruent frames in a plane without gaps. Arrange randomly while being satisfied. In the present embodiment, the randomly arranged pseudo-isotropic fiber unit model creation unit 11 includes a basic fiber model creation unit 12, a pseudo-isotropic fiber unit model creation unit 13, a central region frame setting unit 14, and a fiber region frame setting unit 15. And a random translational movement unit 16.

The basic fiber model creation unit 12 creates a basic fiber model composed of a plurality of nodes and a plurality of beam elements. Specific examples of the basic fiber model will be described later.

The pseudo-isotropic fiber unit model creation unit 13 creates a pseudo-isotropic fiber unit model by arranging a plurality of basic fiber models shifted by a predetermined angle around a predetermined point. A specific example of the pseudo isotropic fiber unit model will be described later.

The central area frame setting unit 14 sets a rectangular central area frame at the center of the pseudo isotropic fiber unit model. A specific example of the central region frame will be described later.

The fiber region frame setting unit 15 sets the fiber region frame including the entire pseudo-isotropic fiber unit model by the central region frame and the duplicate frame that duplicates the central region frame. The fiber region frame is partitioned in a grid pattern and has a size that is an integral multiple of the vertical and horizontal dimensions of the central region frame.

The random translational movement unit 16 randomly translates the basic fiber model within the range within the fiber region frame. This state is referred to as a randomly arranged pseudo isotropic fiber unit model. A specific example of randomly translating is described later.

The superimposing portion 17 maintains the positional relationship between the nodes and the beam elements in the respective duplication frames in the randomly arranged pseudo isotropic fiber unit model, and the nodes and the beam elements in the respective duplication frames. , Overlay on the nodes and beam elements contained in the central region frame.

In the present embodiment, the superimposing unit 17 duplicates a randomly arranged pseudo isotropic fiber unit model composed of a plurality of basic fiber models after being randomly translated by the random translational moving unit 16, and is a superimposing model. To create. Further, the superimposing unit 17 performs the above-mentioned superimposition in units of the superimposition model.

Further, in the present embodiment, the superimposing portion 17 is described above so that the above-mentioned superposed central region frames are arranged so as to form an example of m × n (m, n are natural numbers). A 2D randomly oriented fiber model region is created by repeating the superposition. Specific examples of superposition in this embodiment will be described later.

The boundary node setting unit 18 sets the intersection of the beam element in the 2D random alignment fiber model region after the superposition by the overlay unit 17 and the 2D random alignment fiber model region frame as a new node. A specific example of a new node set by the boundary node setting unit 18 will be described later.

The cutting unit 19 cuts out the nodes and beam elements in the 2D randomly oriented fiber model region as a 2D randomly oriented fiber model after the boundary node setting unit 18 sets a new node.

In the present embodiment, the central region frame on which the above-mentioned superposition is performed is created so as to form and line up m × n row examples, and the cutout portion 19 forms and arranges m × n row examples. The entire central region frame is cut out as a 2D randomly oriented fiber model. A specific example of cutting by the cutting portion 19 and a specific example of the 2D randomly oriented fiber model will be described later.

(About 2D random orientation)
Here, the 2D random orientation of the fibers will be described. The 2D random orientation of fibers refers to a state in which a large number of fibers are randomly scattered in a plane (2D). The actual product is made by randomly sprinkling a large amount of cut fibers. In order to satisfy the 2D random orientation in the 2D random alignment fiber model that models such a 2D random alignment fiber, the fibers contained in the arbitrarily selected region are isotropic in a plane regardless of the location. It is necessary that the fibers are distributed in and the fiber volume content (density) is the same.

FIG. 4A is a diagram showing a predetermined region in a fiber reinforced plastic in which fibers such as glass are mixed with a resin. FIG. 4 (B) is an enlarged view of the region A shown in FIG. 4 (A).

Here, paying attention to the region A of the fiber reinforced resin shown in FIG. 4 (A), the XY axis is considered for convenience in the enlarged view of the region A shown in FIG. 4 (B). Then, it is assumed that the angle of the fiber is measured with the angle indicating the positive direction of the X axis being 0 degrees, the angle indicating the positive direction of the Y axis being 90 degrees, and the angle indicating the negative direction of the X axis being 180 degrees.

5 and 6 are diagrams showing the distribution of fiber angles measured as described above. As shown in FIG. 5, when the fibers facing any angle from 0 degrees to 180 degrees are evenly distributed, and further, other regions such as region B and region C are also distributed in the same manner. Is isotropically distributed in the plane regardless of the location. On the other hand, as shown in FIG. 6, when the fibers are mainly oriented in the 90-degree direction, they are not isotropically distributed.

The fiber volume content (density) is expressed by the following formula.
(Number 1)
Fiber volume content (density) = fiber volume / composite volume

Here, the "fiber volume" is represented by the product of the "fiber length" and the "fiber cross-sectional area". Further, the "volume of the composite material" is represented by the sum of the "fiber volume" and the "resin volume".

FIG. 7 is a diagram for explaining the relationship between the region selected in the fiber reinforced plastic, the distribution of the fiber angles, and the fiber volume content. As shown in FIG. 7, when the selected region of the fiber reinforced plastic is as wide as 10 square mm × 1 mm in plate thickness, the fibers contained in the arbitrarily selected region are isotropic in a plane regardless of the location. 2D random orientation is satisfied because the fibers are distributed in a uniform manner and the fiber volume content (density) is the same. On the other hand, when an extremely small region of 0.1 parallel mm × 0.01 mm or less in thickness is selected, the number of fibers contained in the region is small, so that the fibers are scattered at random. May become apparent and may not satisfy the 2D random orientation.

FIG. 8 is a diagram showing a comparison between the actual fiber reinforced plastic and the fiber model. As shown in FIG. 8, in the fiber model used for simulation and the like, the number of fiber models needs to be extremely small (1/400 or less) as compared with the actual one in order to suppress the calculation cost. As a result, even in a wide area that satisfied the 2D random orientation in the real thing, the number of fibers contained in that area is small in the fiber model. Therefore, if the fiber model is randomly scattered by random numbers, the 2D random orientation cannot be satisfied. There is.

Therefore, in the present embodiment, a 2D random alignment fiber model capable of satisfying the 2D random orientation even with the above fiber model is created.

(2D random alignment fiber model creation process)
Next, the process of creating the 2D randomly oriented fiber model in the present embodiment will be described with reference to the attached drawings. FIG. 3 is a flowchart showing the flow of the process of creating the 2D randomly oriented fiber model in the present embodiment. FIG. 9 is a diagram showing an example of a basic fiber model.

First, the basic fiber model creating unit 12 creates a basic fiber model 32 including a plurality of nodes 30 and a plurality of beam elements 31 as shown in FIG. 9 (FIG. 3: S1). In the example shown in FIG. 9, the length of the beam element 31 is set to 1 mm as an example. Further, in the basic fiber model 32, as an example, eight beam elements 31 are connected. Therefore, the length of the basic fiber model 32 is 8 mm.

FIG. 10 is a diagram showing an example of a pseudo isotropic fiber unit model. As shown in FIG. 10, the pseudo isotropic fiber unit model creating unit 13 creates a pseudo isotropic fiber unit model 33 by arranging a plurality of basic fiber models 32 shifted by a predetermined angle around a predetermined point A. (Fig. 3: S2). In the example shown in FIG. 10, as an example, five basic fiber models 32 are arranged with a predetermined angle shifted by 36 degrees. Here, "pseudo-isotropic" means a state in which isotropic orientation is created by a smaller number of basic fiber models than the actual one.

FIG. 11 is a diagram for explaining a central region frame. As shown in FIG. 11, the central region frame setting unit 14 sets a rectangular central region frame 40 at the center A of the pseudo-isotropic fiber unit model 33 (FIG. 3: S3). The size of the central area frame 40 can be arbitrarily set. In the example shown in FIG. 11, a center region frame 40 of 2.3 mm × 2.3 mm was set as an example.

FIG. 12 is a diagram for explaining the fiber region frame 50. The fiber region frame setting unit 15 sets the fiber region frame 50 including the entire pseudo-isotropic fiber unit model 30 by the central region frame 40 and the duplicate frame 41 that duplicates the central region frame 40 (FIG. 3: S4). As shown in FIG. 12, the fiber region frame 50 is divided in a grid pattern by the central region frame 40 and the duplication frame 41, and is an integral multiple of the vertical and horizontal dimensions of the central region frame 40. In the example shown in FIG. 12, the fiber region frame 50 is a region in which the vertical and horizontal dimensions of the central region frame 40 are each tripled, and the area is nine times as large. In other words, the fiber region frame 50 is configured by arranging congruent frames in a plane without gaps.

FIG. 13 is a diagram for explaining random translation. The random translational movement unit 16 randomly translates each basic fiber model 32 forming the pseudo isotropic fiber unit model 33 as shown in FIG. 12 within the range within the fiber region frame 50, and randomly arranges the pseudo or the like. An anisotropic fiber unit model 34 is created (FIG. 3: S5).

The random translational movement unit 16 translates each basic fiber model 32 by a random distance in a random direction while maintaining the angle of each basic fiber model 32 with respect to the fiber region frame 50. That is, the random translational movement unit 16 does not rotate each basic fiber model 32. Therefore, even after the translational movement, each basic fiber model 32 maintains the "pseudo-isotropic" state within the fiber region frame 50. Further, the number of beam elements 31 in the fiber region frame 50 is the same as before the translational movement. This means that the fiber volume content does not change due to random translational movement.

FIG. 14 is a diagram for explaining the cluster superposition method in the present embodiment. FIG. 15 is a diagram showing beam elements 31 and nodes 30 included in the central region frame 40 in a state of being superposed by the cluster superposition method.

Here, as shown in FIG. 13, the duplication frames 41 around the central area frame 40 are numbered (1) to (8) for convenience. When the duplication frames 41 of (1) to (8) are considered separately as shown in FIG. 14, each of the duplication frames 41 of (1) to (8) constitutes a fragment of the basic fiber model 32. The beam element 31 and the node 30 are included. As described above, the pseudo-isotropic is satisfied even in the state of being randomly translated and moved as shown in FIG. Therefore, when the beam element 31 and the node 30 included in each of the duplicate frames 41 of (1) to (8) are superposed on the central region frame 40 as shown by the arrows in FIG. 14, after the superposition shown in FIG. The central region frame 40 of the above will include all the beam elements 31 of the randomly arranged pseudo isotropic fiber unit model 34. That is, the beam element 31 in the central region frame 40 after superimposition shown in FIG. 15 satisfies the pseudo isotropic. The method for achieving this is the cluster superposition method.

In the present embodiment, the nodes 30 and the beam elements 31 in the respective duplication frames 41 after being randomly translated are transferred to the nodes 30 and the beam elements 31 included in the central region frame 40 by the overlapping portion 17. Overlapping is performed (Fig. 3: S6). The superimposing portion 17 performs the superimposing while maintaining the positional relationship between each duplication frame 41 and the nodes and the beam element 31 in each duplication frame 41.

16 to 19 are diagrams for explaining the superposition process in the present embodiment. As shown in FIG. 16, the superimposing portion 17 duplicates the fiber region frame 50 and the randomly arranged pseudo isotropic fiber unit model 34 included in the fiber region frame 50 to create a superimposing model, and creates a superimposing model of the superimposing model. Overlay in units.

In the example shown in FIG. 16, the overlay model 50A is duplicated from the fiber region frame 50, and the position of the duplicate frame 41 on the upper left side with the reference numeral (1) is overlapped with the central region frame 40 of the fiber region frame 50. As described above, the superimposing model 50A is moved in the direction of arrow B by the superimposing portion 17.

Similarly, as shown in FIG. 17, the overlay model 50B is duplicated from the fiber region frame 50, and the position of the duplicate frame 41 in the upper center with the reference numeral (2) is set to the central region frame 40 of the fiber region frame 50. The superimposing model 50B is moved in the direction of arrow C by the superimposing portion 17 so as to superimpose on the above.

Similarly, as shown in FIG. 18, the overlay model 50C is duplicated from the fiber region frame 50, and the position of the upper right duplication frame 41 marked with the reference numeral (3) is set to the central region of the fiber region frame 50. The overlay model 50C is moved in the direction of arrow D by the overlay portion 17 so as to overlap the frame 40.

Similarly, the overlapping models 50D to 50H (not shown) are duplicated from the fiber region frame 50, and the positions of the duplicated frames 41 labeled with the reference numerals (4) to (8) are set at the center of the fiber region frame 50. The overlapping models 50D to 50H are moved by the overlapping portion 17 so as to be overlapped with the area frame 40.

FIG. 19 is a diagram showing a state in which the fiber region frame 50 has been superposed on the central region frame 40. As shown in FIG. 19, the central region frame 40 after the superposition as described above includes all the beam elements 31 of the randomly arranged pseudo isotropic fiber unit model 34. Therefore, the beam element 31 in the central region frame 40 is filled with pseudo isotropic. That is, the beam element 31 and the node 30 in the central region frame 40 at which the above superposition is completed can be used as a 2D randomly oriented fiber model.

In other words, the overlapping unit 17 maintains the positional relationship between the nodes 30 and the beam elements 31 in the respective congruent frames and the nodes 30 and the beam elements 31 in the respective congruent frames. The 2D randomly oriented fiber model region is created by superimposing all the other congruent frames on the central region frame 40, which is one of the congruent frames, without rotating.

Further, by repeating the above processing, a 2D randomly oriented fiber model can be continuously generated. The number of repetitions can be set arbitrarily. In the present embodiment, the superimposing unit 17 confirms the number of times the processing is repeated after the superimposing process (FIG. 6: S6) is completed (FIG. 6: S7). When the superimposing unit 17 determines that the processing is repeated (FIG. 6: S7; YES), the superimposing unit 17 repeats the superimposing process (FIG. 6: S6).

When this repetition is performed, the superimposing portion 17 is a superimposing model 50H (dotted line in FIG. 19) in which the position of the duplicate frame 41 with the reference numeral (1) in the above-mentioned fiber region frame 50 is the central region frame 40. (Indicated by the rectangle of) is newly used as the basic fiber region frame 50, and the above-mentioned superposition process is repeated.

Further, in the same manner, the superimposing portion 17 is a superimposing model 50G to 50A in which the position of the duplication frame 41 designated by the reference numerals (2) to (8) in the above-mentioned fiber region frame 50 is the central region frame 40. A new basic fiber region frame 50 is used, and the above-mentioned superposition process is repeated.

FIG. 20 is a diagram showing a 2D randomly oriented fiber model continuously generated by repeating the above-mentioned superposition processing. According to the present embodiment, as shown in FIG. 20, for example, nine central region frames 40 that have been overlapped can be continuously generated, and these can be used as a 2D randomly oriented fiber model.

As described above, in the present embodiment, the overlapping portions 17 are overlapped so that the overlapped central region frames 40 are arranged so as to form rows of m × n (m and n are natural numbers). The creation of the superposition model and the superimposition in units of the superposition model are repeated. As a result, a 2D randomly oriented fiber model of an arbitrary size is generated, and the region is designated as a 2D randomly oriented fiber model region 51. It should be noted that the outside of the region is not completely overlapped, so that the 2D randomly oriented fibers are not filled.

In the present embodiment, after repeating the above-mentioned superposition treatment to generate a 2D randomly oriented fiber model of a desired size, the boundary node setting unit 18 is described above as shown in FIG. 21 (A). When the boundary B1 of the 2D randomly oriented fiber model region 51 and the beam element 31 straddling the boundary B1 exist, the intersection of the beam element 31 straddling the boundary B1 and the boundary B1 is as shown in FIG. 21 (B). Is set as the node 30A of the new beam element 31 (FIG. 3: S8).

Then, the cutting section 19 cuts out the nodes 30, 30A and the beam element 31 in the 2D randomly oriented fiber model region 51 after setting the new node 31A as a 2D randomly oriented fiber model (FIG. 3: S9). FIG. 22 is a cut out 2D randomly oriented fiber model 60.

As described above, according to the present embodiment, it is possible to create a 2D random alignment fiber model that satisfies the 2D random orientation even when the number of fiber models is significantly reduced from the actual one.

(Region satisfying 2D random orientation)
Here, the conditions for satisfying the 2D random orientation in the created 2D random alignment fiber model will be described.

FIG. 23 is a diagram showing a 2D randomly oriented fiber model 60 created in the above-described embodiment. In the 2D randomly oriented fiber model 60, nine central region frames 40 are continuously generated after the superposition treatment described in the above-described embodiment is completed.

As shown in FIG. 23, the region in which the vertical or horizontal dimension of the central region frame 40 after the overlay processing is completed is enlarged by an integral multiple also satisfies the 2D random orientation. In FIG. 23, the region 40A is a region in which the vertical and horizontal dimensions of the central region frame 40 are doubled, and this region 40A also satisfies the 2D random orientation. Further, in FIG. 23, the region 40B is a region in which the lateral dimension of the central region frame 40 is doubled, and this region 40B also satisfies the 2D random orientation. As described above, in the present invention, the region in which the vertical or horizontal dimension of the central region frame 40 of the created 2D randomly oriented fiber model is enlarged by an integral multiple can also satisfy the 2D randomly oriented fiber model.

Further, according to the present invention, even if the region satisfying the 2D random orientation moves in an arbitrary direction, the region satisfies the 2D random orientation. FIG. 24 is a diagram showing an example in which a region satisfying 2D random orientation moves in an arbitrary direction.

The region 40C shown in FIG. 24 is a region in which the region 40 shown in FIG. 23 is moved in an oblique direction. In the region 40C, the regions separated by the central region frame 40 are designated by the reference numerals (1) to (4). The area (1) is the same as the area 40E. The area (2) is the same as the area 40F. The area (3) is the same as the area 40D. Therefore, the region 40C composed of the regions (1) to (4) is composed of the region (4), the region 40E, the region 40F, and the region 40D, which is the same as the region 40. Therefore, the region 40C satisfies the 2D random orientation.

The region 40G shown in FIG. 24 is a region in which the region 40B shown in FIG. 23 is arbitrarily moved in the lateral direction, and the region 40G also satisfies the 2D random orientation.

However, the region where the vertical or horizontal dimension of the region satisfying the 2D random orientation is not enlarged by an integral multiple does not satisfy the 2D random orientation. FIG. 25 is a diagram showing a region that does not satisfy the 2D random orientation. The regions 40H, 40J, and 40K shown in FIG. 25 do not satisfy the 2D random orientation because the vertical or horizontal dimensions of the central region frame 40 are not enlarged by an integral multiple. The area 40J has an area three times (integer multiple) the central region frame 40, but does not satisfy the 2D random orientation because the vertical or horizontal dimension is not an integral multiple.

(Application example)
Next, an application example of this embodiment will be described. FIG. 26 is a diagram showing an image of an actual fiber reinforced plastic. FIG. 27 is an enlarged view of the upper surface of the fiber reinforced resin. FIG. 28 is a diagram for explaining a laminated state of the fiber reinforced resin in a side view.

Fiber reinforced plastic (FRP (Fiber Reinforced Plastics)) is a composite material in which fibers are mixed with resin, and glass fibers (Glass) or carbon fibers (Carbon) are often used as the fibers. Glass fiber is lighter than steel, but has the characteristics of being less rigid and stronger than steel. Carbon fiber is a material that can replace steel because it is lighter than steel and has rigidity and strength equal to or higher than that of steel. However, carbon fiber is more expensive than glass fiber and steel.

Resins include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include epoxy resins and phenolic resins. Thermosetting resins are generally soft at room temperature, and when heated to high temperatures, they cure and harden by a chemical reaction, but the chemical reaction takes time. The thermosetting resin remains solid even when cooled to room temperature after curing, and has irreversibility. This property makes it generally difficult to recycle.

Examples of thermoplastic resins include polypropylene, polyamide and the like. Thermoplastic resins are generally hard at room temperature, soften when heated to a temperature higher than the melting temperature of the resin, and hard when returned to room temperature, and thus have reversibility. Due to this property, it is generally easy to recycle. Unlike thermosetting resins, thermoplastic resins do not require a chemical reaction to cure the resin, and thus have the advantage of high productivity.

The fibers used for the fiber reinforced resin include continuous fibers and discontinuous fibers. The continuous fiber is a fiber having a fiber length of 50 mm or more and is very long. The discontinuous fiber is called a discontinuous long fiber when the fiber length is 2 mm to 50 mm, and is called a discontinuous short fiber when the fiber length is 2 mm or less. The longer the fiber, the better the strength characteristics. When the fiber length is 10 mm or more, high strength is exhibited, and when the fiber length is 40 mm or more, high toughness is exhibited.

In this embodiment, as an example, a flow simulation is performed when a discontinuous long fiber reinforced resin manufactured by Bond-Laminates GmbH, whose product name is Tepex (registered trademark) flowcore, is compression-molded.

The discontinuous length fiber reinforced resin 20 shown in FIG. 26 has fibers of glass and a fiber length of 30 to 50 mm. As shown in FIG. 27, the fiber orientation of the fibers 21 is random in 2D. Thermoplastic polyamide nylon 6 is used as the resin.

The plate thickness d of the discontinuous length fiber reinforced resin 20 shown in FIG. 26 is 2 mm, and about 40 fiber layers 22 are laminated. The fiber volume content is 0.47 (47%). The fiber volume fraction is the ratio of the volume of fibers contained in the fiber reinforced resin.

The discontinuous long fiber reinforced resin 20 as described above can be molded into a complicated shape by compression molding. Compression molding is a method of pressing a material using a mold composed of a male mold and a female mold. The feature of compression molding is that the fibers contained in the discontinuous long fiber reinforced resin 20 can be molded into a desired shape while maintaining the long fibers without breaking, so that high strength characteristics can be obtained even after molding. Further, in the case of the thermoplastic discontinuous length fiber reinforced resin 20, the discontinuous length fiber reinforced resin heated to a high temperature is molded while being cooled by a low temperature mold and cured in about several minutes, so that from the start of molding. The advantage is that the time to complete the parts is short.

As shown in FIG. 8, the number of fibers in the actual discontinuous length fiber reinforced resin 20 is 500,000 to 8 million per 10 square mm × plate thickness 1 mm, whereas the number of fibers in the fiber model is 10. The number is reduced to 1,250 to 20,000 per mm2 x 1 mm thickness.

However, by using the 2D random alignment fiber model in the present embodiment as the fiber model of such a discontinuous long fiber reinforced resin 20, even when the number of fiber models is significantly reduced from the actual one, the 2D random orientation is satisfied. A 2D randomly oriented fiber model can be used for simulation. As a result, high-precision simulation can be performed. As such a simulation, the simulation of Japanese Patent No. 6420881 can be given as an example.

In the above-described embodiment, as an example of application, an example in which a 2D randomly oriented fiber model is used in an analysis simulation when performing compression molding has been described, but the 2D randomly oriented fiber model of the present invention is limited to such an embodiment. It does not mean that. The 2D randomly oriented fiber model of the present invention can also be applied to an analysis simulation when performing press molding.

The 2D random alignment fiber model creation program according to the above aspect can be provided in a form stored in a computer-readable recording medium and installed in the computer. The recording medium is, for example, a non-transitory recording medium, and an optical recording medium such as a CD-ROM is a good example, but any known type such as a semiconductor recording medium or a magnetic recording medium can be used. It may include a recording medium. It is also possible to provide the above-mentioned program in the form of distribution via a communication network and install it on a computer.

The 2D random alignment fiber model creation device, the 2D random alignment fiber model creation method, and the 2D random alignment fiber model creation program according to the embodiment of the present invention have been described above, but the present invention is not limited thereto. , Various changes can be made without departing from the gist of the present invention.

10 Control unit 11 Random arrangement pseudo isotropic fiber unit model creation unit 12 Basic fiber model creation unit 13 Pseudo isotropic fiber unit model creation unit 14 Central area frame setting unit 15 Fiber area frame setting unit 16 Random translation movement unit 17 Overlapping unit 18 Boundary node setting part 19 Cutout part 30 Node 30A Node 31 Beam element 32 Basic fiber model 33 Pseudo-isotropic fiber unit model 34 Random arrangement Pseudo isotropic fiber unit model 40 Central area frame 41 Duplicate frame 50 Fiber area frame 50A-50H Overlapping Alignment model 51 2D random alignment fiber model area 60 2D random alignment fiber model 100 2D random alignment fiber model creation device

Claims (8)

1. Randomly arranged pseudo-isotropic fibers in which multiple basic fiber models consisting of multiple nodes and multiple beam elements are randomly arranged in a fiber region frame composed of congruent frames arranged in a plane without gaps while satisfying pseudo-isotropic. Random arrangement pseudo isotropic fiber unit model creation unit to create a unit model,
   Without rotating the node and the beam element in each of the congruent frames, while maintaining the positional relationship between the congruent frame and the node and the beam element in each of the congruent frames. A superimposing portion that creates a 2D randomly oriented fiber model region by superimposing the central region frame, which is one of the congruent frames, so that all the other congruent frames overlap.
   A 2D randomly oriented fiber model making device.
2. The superimposition portion duplicates the random arrangement pseudo isotropic fiber unit model to create a superposition model, and performs the superposition in units of the superposition model.
   The 2D randomly oriented fiber model creating apparatus according to claim 1.
3. The superimposition portion is formed by creating the superimposition model and superimposing the superimposition model so that the superposed central region frames are arranged so as to form an example of m × n (m and n are natural numbers). Repeating the superposition in units of the mating model,
   The 2D randomly oriented fiber model creating apparatus according to claim 2.
4. A boundary node setting unit that sets the intersection of the beam element in the 2D random alignment fiber model region after the superposition and the frame of the 2D random alignment fiber model region as a new node.
   It is provided with a cutout portion for cutting out the node and the beam element in the frame of the 2D randomly oriented fiber model region after setting the new node as a 2D randomly oriented fiber model.
   The 2D randomly oriented fiber model creating apparatus according to any one of claims 1 to 3.
5. The cutout portion cuts out the entire central region frame in which the overlap is performed so as to form an example of m × n as a 2D randomly oriented fiber model.
   The 2D randomly oriented fiber model creating apparatus according to claim 4.
6. The random arrangement pseudo isotropic fiber unit model creation unit
   The basic fiber model creation unit that creates the basic fiber model,
   A pseudo-isotropic fiber unit model creation unit that creates a pseudo-isotropic fiber unit model by arranging a plurality of basic fiber models at a predetermined angle around a predetermined point.
   A central region frame setting unit that sets a rectangular central region frame at the center of the pseudo-isotropic fiber unit model,
   The fiber region frame setting unit for setting the fiber region frame and
   A random translational movement unit that randomly translates the basic fiber model within a range within the fiber region frame is provided.
   The 2D randomly oriented fiber model creating apparatus according to any one of claims 1 to 5, wherein the randomly arranged pseudo isotropic fiber unit model is created.
7. Randomly arranged pseudo-isotropic fiber unit model creation unit satisfies multiple basic fiber models consisting of multiple nodes and multiple beam elements in a fiber region frame composed of congruent frames arranged in a plane without gaps. While randomly arranging steps and
   The overlapping portion allows the node and the beam element in each of the congruent frames to maintain the positional relationship between the congruent frame and the node and the beam element in the congruent frame. It comprises a step of creating a 2D randomly oriented fiber model region by superimposing all the other congruent frames on a central region frame, which is one of the congruent frames, without rotation.
   A method for creating a 2D randomly oriented fiber model.
8. A 2D random alignment fiber model creation program that causes a computer to create a 2D random alignment fiber model, and the 2D random alignment fiber model creation program causes the computer to create a 2D random alignment fiber model.
   Randomly arranged pseudo-isotropic fiber unit model creation unit satisfies multiple basic fiber models consisting of multiple nodes and multiple beam elements in a fiber region frame composed of congruent frames arranged in a plane without gaps. While randomly arranging steps and
   The overlapping portion allows the node and the beam element in each of the congruent frames to maintain the positional relationship between the congruent frame and the node and the beam element in the congruent frame. The step of creating a 2D randomly oriented fiber model region by superimposing all the other congruent frames on the central region frame, which is one of the congruent frames, without rotating is executed.
   A 2D randomly oriented fiber model creation program characterized by this.

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