METHOD AND DEVICE FOR PREDICTING FIBER ORIENTATION

Abstract

The present disclosure relates to a method and a device for predicting fiber orientation. The method includes: obtaining a mechanical property parameter value of a fiber composite material; obtaining a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value; and predicting fiber orientation in a forming process of the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, the preset fiber orientation model indicating a mapping relationship between the change value of the fiber property and the fiber orientation after the deformation of the fiber composite material.

Claims

1. A method for predicting fiber orientation, comprising: obtaining a mechanical property parameter value of a fiber composite material; obtaining a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value; and predicting fiber orientation in a forming process of the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, wherein the preset fiber orientation model indicates a mapping relationship between the change value of the fiber property and the fiber orientation after the deformation of the fiber composite material.

2. The method according to claim 1, wherein said obtaining a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value comprises: obtaining a length change value of a fiber in the fiber composite material along respective coordinate axes in a predetermined Cartesian coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the predetermined Cartesian coordinate system, after the deformation of the fiber composite material; and obtaining a length change value of a fiber in the fiber composite material along respective coordinate axes in a relative coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the relative coordinate system, after the deformation of the fiber composite material.

3. The method according to claim 2, wherein prior to said predicting fiber orientation in the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, the method further comprises: obtaining a Cartesian component of stress-strain tensor according to a change value of the fiber in a preset Cartesian coordinate system, wherein the change value of the fiber in the preset Cartesian coordinate system comprises: a length change value of the fiber along respective coordinate axes in the predetermined Cartesian coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the predetermined Cartesian coordinate system; obtaining a relative coordinate component of the stress-strain tensor according to a change value of the fiber in a relative coordinate system, wherein the change value of the fiber in the relative coordinate system comprises: a length change value of the fiber along respective coordinate axes in the relative coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system; and obtaining the preset fiber orientation model according to a relationship among a Cartesian component of the stress-strain tensor, a relative coordinate component of the stress-strain tensor, and fiber orientation.

4. The method according to claim 3, wherein the Cartesian component of the stress-strain tensor is expressed as: $\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the preset Cartesian coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the preset Cartesian coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the preset Cartesian coordinate system.

5. The method according to claim 4, wherein the relative coordinate component of the stress-strain tensor is expressed as: $\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the relative coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the relative coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system.

6. The method according to claim 5, wherein the relationship among the Cartesian component of the stress-strain tensor, the relative coordinate component of the stress-strain tensor and the fiber orientation comprises: the relative coordinate component of the stress-strain tensor is a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation.

7. The method according to claim 6, wherein said the relative coordinate component of the stress-strain tensor being a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation comprises: $\left\{\begin{array}{c}d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{11}\\ d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{22}\\ d.Math..Math.{\stackrel{\_}{}}_{12}\end{array}\right\}.Math.=\left[\begin{array}{ccc}{\cos }^2.Math..Math.& {\sin }^2.Math..Math.& \sin .Math..Math..Math..Math.\cos .Math..Math.\\ {\cos }^2\left(+\right)& {\sin }^2\left(+\right)& \sin \left(+\right).Math.\cos \left(+\right)\\ 2.Math..Math.\cos .Math..Math..Math..Math.\cos \left(+\right)& 2.Math..Math.\sin .Math..Math..Math..Math.\sin \left(+\right)& \sin \left(2.Math.+\right)\end{array}\right].Math.\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where the represents an angle change value of the angle between the fiber and the first coordinate axis in the preset Cartesian coordinate system; and the represents an angle value of the fiber orientation.

8. The method according to claim 1 wherein said obtaining a mechanical property parameter value of a fiber composite material comprises: obtaining the mechanical property parameter value of the fiber composite material by using preset simulation software.

9. A device for predicting fiber orientation, comprising: a processor; and a memory configured to store instructions executable by the processor, wherein the processor is configured to: obtain a mechanical property parameter value of a fiber composite material; obtain a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value; and predict fiber orientation in a forming process of the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, wherein the preset fiber orientation model indicates a mapping relationship between the change value of the fiber property and the fiber orientation after the deformation of the fiber composite material.

10. The device according to claim 9, wherein the processor is further configured to: obtain a length change value of a fiber in the fiber composite material along respective coordinate axes in a predetermined Cartesian coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the predetermined Cartesian coordinate system, after the deformation of the fiber composite material; and obtain a length change value of a fiber in the fiber composite material along respective coordinate axes in a relative coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the relative coordinate system, after the deformation of the fiber composite material.

11. The device according to claim 10, wherein the processor is further configured to: obtain a Cartesian component of stress-strain tensor according to a change value of the fiber in a preset Cartesian coordinate system, wherein the change value of the fiber in the preset Cartesian coordinate system comprises: a length change value of the fiber along respective coordinate axes in the predetermined Cartesian coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the predetermined Cartesian coordinate system; obtain a relative coordinate component of the stress-strain tensor according to a change value of the fiber in a relative coordinate system, wherein the change value of the fiber in the relative coordinate system comprises: a length change value of the fiber along respective coordinate axes in the relative coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system; and obtain the preset fiber orientation model according to a relationship among a Cartesian component of the stress-strain tensor, a relative coordinate component of the stress-strain tensor, and fiber orientation.

12. The device according to claim 11, wherein the Cartesian component of the stress-strain tensor is expressed as: $\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the preset Cartesian coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the preset Cartesian coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the preset Cartesian coordinate system.

13. The device according to claim 12, wherein the relative coordinate component of the stress-strain tensor is expressed as: $\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the relative coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the relative coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the relative coordinate system.

14. The device according to claim 13, wherein the relationship among the Cartesian component of the stress-strain tensor, the relative coordinate component of the stress-strain tensor and the fiber orientation comprises: the relative coordinate component of the stress-strain tensor is a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation.

15. The device according to claim 14, wherein said the relative coordinate component of the stress-strain tensor being a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation comprises: $\left\{\begin{array}{c}d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{11}\\ d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{22}\\ d.Math..Math.{\stackrel{\_}{}}_{12}\end{array}\right\}.Math.=\left[\begin{array}{ccc}{\cos }^2.Math..Math.& {\sin }^2.Math..Math.& \sin .Math..Math..Math..Math.\cos .Math..Math.\\ {\cos }^2\left(+\right)& {\sin }^2\left(+\right)& \sin \left(+\right).Math.\cos \left(+\right)\\ 2.Math..Math.\cos .Math..Math..Math..Math.\cos \left(+\right)& 2.Math..Math.\sin .Math..Math..Math..Math.\sin \left(+\right)& \sin \left(2.Math.+\right)\end{array}\right].Math.\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$ where the represents an angle change value of the angle between the fiber and the first coordinate axis in the preset Cartesian coordinate system; the represents an angle value of the fiber orientation.

16. The device according to claim 9, wherein the processor is further configured to: obtain the mechanical property parameter value of the fiber composite material by using preset simulation software.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0021] FIG. 1 is a flowchart of a method for predicting fiber orientation according to an exemplary embodiment.

[0022] FIG. 2 is a diagram showing a positional relationship between fibers after spinning according to an exemplary embodiment.

[0023] FIG. 3 is a diagram showing a positional relationship between fibers after the fiber composite material is subject to a forming process according to an exemplary embodiment.

[0024] FIG. 4 is a schematic diagram of a change value of fiber property of the fiber composite material according to an exemplary embodiment.

[0025] FIG. 5 is a schematic diagram of an initial structure of fiber according to an exemplary embodiment.

[0026] FIG. 6 is a schematic diagram of a fiber orientation prediction according to an exemplary embodiment.

[0027] FIG. 7 is a schematic diagram of a limit structure of fiber orientation according to an exemplary embodiment.

[0028] FIG. 8 is a block diagram of a device for predicting fiber orientation according to an exemplary embodiment.

[0029] FIG. 9 is a block diagram of a second obtaining module in a device for predicting fiber orientation according to an exemplary embodiment.

[0030] FIG. 10 is a block diagram of a device for predicting fiber orientation according to an exemplary embodiment.

[0031] FIG. 11 is a block diagram of a first obtaining module in a device for predicting fiber orientation according to an exemplary embodiment.

DETAILED DESCRIPTION

[0032] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the disclosure. Instead, they are merely examples of apparatuses and methods consistent with aspects related to the disclosure as recited in the appended claims.

[0033] In order to solve the above technical problem, the present disclosure provides a method for predicting fiber orientation, by which fiber orientation of a three-dimensionally woven long fiber composite material can be predicted.

[0034] FIG. 1 is a flowchart of a method for predicting fiber orientation according to an exemplary embodiment. As shown in FIG. 1, the method includes the following steps S101-S103:

[0035] In step S101, a mechanical property parameter value of a fiber composite material is obtained.

[0036] The mechanical property parameter value of the fiber composite material can be obtained by using preset simulation software.

[0037] For example, the mechanical property parameter value of the composite material can be obtained by using the finite element software Digimat.

[0038] Of course, before obtaining the mechanical property parameter value of the fiber composite material by using the preset simulation software, it is also possible to determine whether the mechanical property parameter value of the fiber composite material can be obtained through experiments. If experiment conditions are not met, the mechanical property parameter value of the fiber composite material is obtained by using preset simulation software.

[0039] In step S102, a change value of a fiber property of the fiber composite material after deformation of the fiber composite material is obtained, according to the mechanical property parameter value.

[0040] In step S103, fiber orientation in a forming process of the fiber composite material is predicted according to the change value of the fiber property and a preset fiber orientation model. The preset fiber orientation model indicates a mapping relationship between the change value of fiber property and the fiber orientation after the deformation of the fiber composite material.

[0041] The fiber orientation refers to directions of fibers in a woven structure, which are generally perpendicular to each other after completion of weaving (as shown in FIG. 2); and the directions of the fibers may be changed with the process (as shown in FIG. 3). Therefore, performance of the composite material is closely related to a distribution state of interior fiber orientation, and thus calculation, analysis and prediction of the fiber orientation are of great significance.

[0042] Referring to FIGS. 2 and 3, predicting the fiber orientation in a forming process of fiber composite material is to predict in FIG. 3. The present disclosure introduces a preset fiber orientation model for indicating a mapping relationship between a change value of a fiber property and fiber orientation after deformation of a fiber composite material, so that fiber orientation in a forming process of the fiber composite material can be predicted from the fiber change value as obtained.

[0043] It should be noted that the fiber composite material in the present disclosure includes a long fiber composite material; and the long fiber composite material includes a three-dimensionally woven long fiber composite material.

[0044] The technical solution provided in embodiment of the present disclosure may have the following beneficial effects: obtaining a mechanical property parameter value of a fiber composite material; obtaining a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value; and predicting fiber orientation in a forming process of the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, the preset fiber orientation model indicating a mapping relationship between the change value of the fiber property and the fiber orientation after the deformation of the fiber composite material. The present disclosure introduces a preset fiber orientation model for indicating a mapping relationship between the change value of the fiber property and the fiber orientation after deformation of the fiber composite material, so that fiber orientation in a forming process of the fiber composite material can be predicted from the fiber change value as obtained.

[0045] For example, the change value of the fiber property includes a change value of a fiber in a preset Cartesian coordinate system and a change value of a fiber in a relative coordinate system, the relative coordinate system being obtained according to a warp direction and a weft direction of the fiber composite material;

[0046] the change value of the fiber in the preset Cartesian coordinate system includes: a length change value of the fiber along respective coordinate axes in the preset Cartesian coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the preset Cartesian coordinate system; and

[0047] the change value of the fiber in the relative coordinate system includes: a length change value of the fiber along respective coordinate axes in the relative coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system.

[0048] As shown in FIG. 2 and FIG. 3, FIG. 2 is a diagram showing a positional relationship between fibers after spinning according to an exemplary embodiment, in which fibers are typically perpendicular to each other, and FIG. 3 is a diagram showing a positional relationship between fibers after a fiber composite is subject to a forming process according to an exemplary embodiment. A coordinate system composed of coordinate axes e.sub.1 and e.sub.2 is a preset Cartesian coordinate system, and a coordinate system composed of coordinate axes g.sub.1 and g.sub.2 is a relative coordinate system.

[0049] In an embodiment, obtaining a change value of a fiber property of the fiber composite material after deformation of the fiber composite material includes the following substep:

[0050] obtaining a length change value of a fiber in the fiber composite material along respective coordinate axes in a preset Cartesian coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the preset Cartesian coordinate system, after the deformation of the fiber composite material.

[0051] The above substep may include the following substeps A1-A3:

[0052] A1: obtaining a first length value of the fiber along respective coordinate axes in the preset Cartesian coordinate system and a first angle value of an angle between the warp fiber and the weft fiber in the composite material in the preset Cartesian coordinate system, before deformation of the fiber,

[0053] A2: obtaining a second length value of the fiber along respective coordinate axes in the preset Cartesian coordinate system and a second angle value of an angle between the warp fiber and the weft fiber in the composite material in the preset Cartesian coordinate system, after the deformation of the fiber; and

[0054] A3: obtaining a length change value of the fiber along respective coordinate axes in the preset Cartesian coordinate system according to the second length value and the first length value, and obtaining a change value of the angle between the warp fiber and the weft fiber in the fiber composite material in the preset Cartesian coordinate system according to the second angle value and the first angle value.

[0055] After obtaining the first length value of the fiber along respective coordinate axes in the preset Cartesian coordinate system before deformation of the fiber and the second length value of the fiber along respective coordinate axes in the preset Cartesian coordinate system after the deformation of the fiber, the length change value of the fiber along respective coordinate axes in the preset Cartesian coordinate system can be obtained by subtracting the first length value from the second length value.

[0056] Similarly, after obtaining the first angle value of an angle between the warp fiber and the weft fiber in the composite material in the preset Cartesian coordinate system before deformation of the fiber and the second angle value of an angle between the warp fiber and the weft fiber in the composite material in the preset Cartesian coordinate system after the deformation of the fiber, the change value of the angle between the warp fiber and the weft fiber in the fiber composite material in the preset Cartesian coordinate system can be obtained by subtracting the first angle value from the second angle value.

[0057] The above steps can be implemented by simulation software, and the disclosure does not limit the type of the simulation software.

[0058] In an embodiment, obtaining a change value of a fiber property of the fiber composite material after the deformation of the fiber composite material includes the following substep:

[0059] obtaining a length change value of a fiber in the fiber composite material along respective coordinate axes in the relative coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the relative coordinate system, after the deformation of the fiber composite material.

[0060] The above substep may include the following steps B1-B3:

[0061] B1: obtaining a third length value of the fiber along respective coordinate axes in the relative coordinate system and a third angle value of an angle between the warp fiber and the weft fiber in the composite material in the relative coordinate system, before deformation of the fiber;

[0062] B2: obtaining a fourth length value of the fiber along respective coordinate axes in the relative coordinate system and a fourth angle value of an angle between the warp fiber and the weft fiber in the composite material in the relative coordinate system, after the deformation of the fiber, and

[0063] B3: obtaining a length change value of the fiber along respective coordinate axes in the relative coordinate system according to the fourth length value and the third length value, and obtaining a change value of the angle between the warp fiber and the weft fiber in the composite material in the relative coordinate system according to the fourth angle value and the third angle value.

[0064] After obtaining the third length value of the fiber along respective coordinate axes in the relative coordinate system before deformation of the fiber and the fourth length value of the fiber along respective coordinate axes in the relative coordinate system after the deformation of the fiber, the length change value of the fiber along respective coordinate axes in the relative coordinate system can be obtained by subtracting the third length value from the fourth length value.

[0065] Similarly, after obtaining the third angle value of an angle between the warp fiber and the weft fiber in the composite material in the relative coordinate system before deformation of the fiber and the fourth angle value of an angle between the warp fiber and the weft fiber in the composite material in the relative coordinate system after the deformation of the fiber, the change value of the angle between the warp fiber and the weft fiber of the fiber composite material in the relative coordinate system can be obtained by subtracting the third angle value from the fourth angle value.

[0066] The above steps can be implemented by simulation software, and the disclosure does not limit the type of the simulation software.

[0067] In an embodiment, prior to said predicting fiber orientation in the fiber composite material according to the change value of the fiber property and a preset fiber orientation model, the method further includes the following substeps C1-C3:

[0068] C1: obtaining a Cartesian component of stress-strain tensor according to a change value of the fiber in a preset Cartesian coordinate system. The change value of the fiber in the preset Cartesian coordinate system includes: a length change value of the fiber along respective coordinate axes in the predetermined Cartesian coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the predetermined Cartesian coordinate system.

[0069] For example, the Cartesian component of the stress-strain tensor may be expressed as:

[00001]$\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0070] where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the preset Cartesian coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the preset Cartesian coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the preset Cartesian coordinate system.

[0071] Taking FIG. 2 and FIG. 3 as an example, d.sub.11 represents a length change value of the fiber along a coordinate axis e.sub.1 in a coordinate system composed of the coordinate axis e.sub.1 and a coordinate axis e.sub.2 d.sub.22 represents a length change value of the fiber along the coordinate axis e.sub.2 in the coordinate system composed of the coordinate axis et and the coordinate axis e.sub.2; and d.sub.12 represents a change value of the angle between the warp fiber and the weft fiber in the composite material in the coordinate system composed of the coordinate axis et and the coordinate axis e.sub.2.

[0072] C2: obtaining a relative coordinate component of the stress-strain tensor according to a change value of the fiber in a relative coordinate system. The change value of the fiber in the relative coordinate system including: a length change value of the fiber along respective coordinate axes in the relative coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system.

[0073] For example, the relative coordinate component of the stress-strain tensor can be expressed as:

[00002]$\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0074] where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the relative coordinate system; d.sub.12 represents a length change value of the fiber along a second coordinate axis in the relative coordinate system; and d.sub..sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system.

[0075] Taking FIG. 2 and FIG. 3 as an example, d.sub.11 represents a length change value of the fiber along a coordinate axis g.sub.1 in a coordinate system composed of the coordinate axis g.sub.1 and a coordinate axis g.sub.2; d.sub.22 represents a length change value of the fiber along the coordinate axis g.sub.2 in the coordinate system composed of the coordinate axis g.sub.1 and the coordinate axis g.sub.2; and d.sub.12 represents a change value of the angle between the warp fiber and the weft fiber in the composite material in the coordinate system composed of the coordinate axis g.sub.1 and the coordinate axis g.sub.2.

[0076] C3: obtaining the preset fiber orientation model according to a relationship among a Cartesian component of the stress-strain tensor, a relative coordinate component of the stress-strain tensor, and fiber orientation.

[0077] Since the three-dimensional woven long fiber composite material is a typical anisotropic material, non-uniformity and anisotropy of the material are the main difficulties. In this embodiment, in order to select a suitable preset fiber orientation model, a plane coordinate system (i.e., the relative coordinate system described above) that is consistent with the weft and warp of the woven fabric can be embedded in a shell element model. The relative coordinate components (i.e., an inverse stress component and a covariation strain component) of the stress-strain tensor in the constitutive relationship are introduced into the relative coordinate system described above. The preset fiber orientation model of the fiber composite material is derived by the transformation between the relative coordinate component of the stress-strain tensor and the Cartesian component of the stress-strain tensor.

[0078] Further, since stretching and shearing can be decoupled in the above constitutive relationship, the preset fiber orientation model can be obtained based on the above-described constitutive relationship.

[0079] In an embodiment, the relationship among the Cartesian component of the stress-strain tensor, the relative coordinate component of the stress-strain tensor and the fiber orientation includes:

[0080] the relative coordinate component of the stress-strain tensor is a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation.

[0081] For example, the relative coordinate component of the stress-strain tensor being a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation can be expressed as:

[00003]$\left\{\begin{array}{c}d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{11}\\ d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{22}\\ d.Math..Math.{\stackrel{\_}{}}_{12}\end{array}\right\}.Math.=\left[\begin{array}{ccc}{\cos }^2.Math..Math.& {\sin }^2.Math..Math.& \sin .Math..Math..Math..Math.\cos .Math..Math.\\ {\cos }^2\left(+\right)& {\sin }^2\left(+\right)& \sin \left(+\right).Math.\cos \left(+\right)\\ 2.Math..Math.\cos .Math..Math..Math..Math.\cos \left(+\right)& 2.Math..Math.\sin .Math..Math..Math..Math.\sin \left(+\right)& \sin \left(2.Math.+\right)\end{array}\right].Math.\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0082] where the represents an angle change value of the angle between the fiber and the first coordinate axis in the preset Cartesian coordinate system; and the represents an angle value of the fiber orientation.

[0083] Taking FIG. 2 and FIG. 3 as an example, the represents an angle change value of the angel between the fiber and the coordinate axis e.sub.1 in the coordinate system composed of the coordinate axis et and the coordinate axis e.sub.2; and the represents an angle value of the fiber orientation.

[0084] In practical application, the finite element software Abaqus can be used to predict fiber orientation in a forming process of fiber composite material.

[0085] Specifically, using Abaqus' VUMAT user-defined subroutine function, a user can input the above fiber orientation model via VUMAT.

[0086] Since the Abaqus software is able to calculate the change value of the fiber property of the fiber composite material (as shown in FIG. 4), the Abaqus software can predict fiber orientation in the forming process of the fiber composite material by calculating the change value of the fiber property of the fiber composite material and by using the input fiber orientation model.

[0087] In this case, the distribution result of the fiber orientation is output as shown in FIGS. 5-7. FIG. 5 is a schematic diagram of an initial structure of fiber according to an exemplary embodiment, and FIG. 6 is a schematic diagram of a fiber orientation prediction according to an exemplary embodiment. Further, FIG. 7 is a schematic diagram of a limit structure of fiber orientation according to an exemplary embodiment. That is, the angle value in the fiber orientation has a minimum value .sub.min when the fiber composite material deforms, where w is the width of the fiber and s is the distance between the fibers.

[0088] The following is a device embodiment of the present disclosure, which may be used to implement the method embodiments of the present disclosure.

[0089] FIG. 8 is a block diagram of a device for predicting fiber orientation according to an exemplary embodiment. As shown in FIG. 8, the device for predicting fiber orientation includes:

[0090] a first obtaining module 11, configured to a mechanical property parameter value of a fiber composite material;

[0091] a second obtaining module 12, configured to obtain a change value of a fiber property of the fiber composite material after deformation of the fiber composite material, according to the mechanical property parameter value obtained by the first obtaining module 11; and

[0092] a predicting module 13, configured to predict fiber orientation in a forming process of the fiber composite material according to the change value of the fiber property obtained by the second obtaining module 12 and a preset fiber orientation model, the preset fiber orientation model indicating a mapping relationship between the change value of the fiber property and the fiber orientation after the deformation of the fiber composite material.

[0093] In an embodiment, as shown in FIG. 9, the second obtaining module 12 includes a first obtaining sub-module 121 and a second obtaining sub-module 122,

[0094] the first obtaining sub-module 121 is configured to obtain a length change value of a fiber in the fiber composite material along respective coordinate axes in a predetermined Cartesian coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the predetermined Cartesian coordinate system, after the deformation of the fiber composite material; and

[0095] the second obtaining sub-module 122 is configured to obtain a length change value of a fiber in the fiber composite material along respective coordinate axes in a relative coordinate system and a change value of an angle between a warp fiber and a weft fiber in the fiber composite material in the relative coordinate system after the deformation of the fiber composite material.

[0096] In an embodiment, as shown in FIG. 10, the device further includes: a third obtaining module 14, a fourth obtaining module 15, and a fifth obtaining module 16,

[0097] the third obtaining module 14 is configured to obtain a Cartesian component of stress-strain tensor according to a change value of the fiber in a preset Cartesian coordinate system, the change value of the fiber in the preset Cartesian coordinate system including: a length change value of the fiber along respective coordinate axes in the predetermined Cartesian coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the predetermined Cartesian coordinate system;

[0098] the fourth obtaining module 15 is configured to obtain a relative coordinate component of the stress-strain tensor according to a change value of the fiber in a relative coordinate system, the change value of the fiber in the relative coordinate system including: a length change value of the fiber along respective coordinate axes in the relative coordinate system, and a change value of an angle between a warp fiber and a weft fiber in the composite material in the relative coordinate system; and

[0099] the fifth obtaining module 16 is configured to obtain the preset fiber orientation model according to a relationship among a Cartesian component of the stress-strain tensor obtained by the third obtaining module 14, a relative coordinate component of the stress-strain tensor obtained by the fourth obtaining module 15, and fiber orientation.

[0100] In an embodiment, the Cartesian component of the stress-strain tensor is expressed as:

[00004]$\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0101] where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the preset Cartesian coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the preset Cartesian coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the composite material in the preset Cartesian coordinate system.

[0102] In an embodiment, the relative coordinate component of the stress-strain tensor is expressed as:

[00005]$\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0103] where d.sub.11 represents a length change value of the fiber along a first coordinate axis in the relative coordinate system; d.sub.22 represents a length change value of the fiber along a second coordinate axis in the relative coordinate system; and d.sub.12 represents a change value of an angle between a warp fiber and a weft fiber in the relative coordinate system.

[0104] In an embodiment, the relationship among the Cartesian component of the stress-strain tensor, the relative coordinate component of the stress-strain tensor and the fiber orientation includes:

[0105] the relative coordinate component of the stress-strain tensor is a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation.

[0106] In an embodiment, said the relative coordinate component of the stress-strain tensor being a product of the Cartesian component of the stress-strain tensor, and a preset trigonometric function value corresponding to an angular value of the fiber orientation includes:

[00006]$\left\{\begin{array}{c}d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{11}\\ d.Math..Math.{\stackrel{\_}{\mathrm{.Math.}}}_{22}\\ d.Math..Math.{\stackrel{\_}{}}_{12}\end{array}\right\}.Math.=\left[\begin{array}{ccc}{\cos }^2.Math..Math.& {\sin }^2.Math..Math.& \sin .Math..Math..Math..Math.\cos .Math..Math.\\ {\cos }^2\left(+\right)& {\sin }^2\left(+\right)& \sin \left(+\right).Math.\cos \left(+\right)\\ 2.Math..Math.\cos .Math..Math..Math..Math.\cos \left(+\right)& 2.Math..Math.\sin .Math..Math..Math..Math.\sin \left(+\right)& \sin \left(2.Math.+\right)\end{array}\right].Math.\left\{\begin{array}{c}d.Math..Math.{\mathrm{.Math.}}_{11}\\ d.Math..Math.{\mathrm{.Math.}}_{22}\\ d.Math..Math.{}_{12}\end{array}\right\}$

[0107] where the represents an angle change value of the angle between the fiber and the first coordinate axis in the preset Cartesian coordinate system; the represents an angle value of the fiber orientation.

[0108] In an embodiment, as shown in FIG. 11, the first obtaining module 11 includes a third obtaining sub-module 111;

[0109] the third obtaining sub-module 111 is configured to obtain the mechanical property parameter value of the fiber composite material by using preset simulation software.

[0110] For the device in the above embodiment, the specific manners in which various modules operate have been described in detail in the embodiment relating to the above method, and therefore will not be repeated herein.

[0111] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed here. This application is intended to cover any variations, uses, or adaptations of the disclosure following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

[0112] It will be appreciated that the present disclosure is not limited to the exact construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. It is intended that the scope of the disclosure only be limited by the appended claims.