Design method of two-step method square woven prefabricated member

Abstract

The invention relates to a design method of a two-step method square woven prefabricated member, and belongs to the technical field of woven prefabricated member design, the design method of the two-step method square woven prefabricated member comprises the following steps: S100, obtaining a woven structure of the two-step method square woven prefabricated member to be designed, carrying out modeling simulation on the two-step method square woven prefabricated member to be designed; and S200, analyzing and judging the on-machine weavability and color effect of the to-be-designed two-step method square woven prefabricated part subjected to modeling simulation, and completing the design of the two-step method square woven prefabricated part. According to the method, the integration capacity of design and production manufacturing of the two-step method square woven prefabricated part can be improved, visualization and digitization of two-step method square woven prefabricated part product design are achieved, the process of repeated design and multiple proofing is omitted, the design and production cycle of the two-step method square woven prefabricated part product is shortened, and the production efficiency of the two-step method square woven prefabricated part product is improved. And the method has great commercial and market promotion values.

Description

Technical Field

[0001] The invention belongs to the technical field of modeling and simulation of braided preform models, and in particular relates to a design method for a two-step square braided preform. Background Art

[0002] The three-dimensional braided preform has a unique spatial interwoven structure and is a structural reinforcement skeleton for high-performance composite materials. It has the characteristics of continuous fibers, integral structure, superior performance, and strong designability. It is widely used in aerospace, automotive industry, national defense, military industry, and construction. The three-dimensional braiding technology is used to make the fiber-reinforced structure spatially distributed in a mesh shape, and the shape of the reinforcement can be customized. The material is seamless and there is no damage caused by secondary processing. It has the characteristics of high specific strength, high specific modulus, high damage tolerance, fracture toughness, impact resistance, non-delamination, crack resistance, and fatigue resistance.

[0003] Common three-dimensional braided preforms can be divided into two-step method, four-step method, multi-layer connection braiding method, multi-step method and rotation method according to the braiding process. Among them, the two-step method was proposed by Popper and McConnell in 1987. This braiding process has few moving parts, simple movement, and is relatively easy to automate. It can directly form more complex components. At the same time, the two-step braiding process is flexible, and the types and linear density ratios of the axial yarn and the braiding yarn are adjustable. The axial yarn content of its composite material can be as high as 80% or more, and the thickness direction can be enhanced without reducing the axial performance. It has superior mechanical properties and construction efficiency, promotes the improvement of production efficiency, reduces costs, optimizes component performance, and has certain application prospects in the aerospace field. In practical applications, the design and manufacturing of the modeling and simulation method of the two-step square braided preform need to fully consider the material properties and load distribution. The weaving of the two-step square braided preform can be formed in one time, which can be applied to high-performance ceramic-based composite materials and joints with high axial performance requirements.

[0004] With the leap of computer technology and digital manufacturing, especially the design and manufacturing of woven preforms based on mathematical models, the seamless connection from R&D design to production and manufacturing has been achieved by precisely controlling the shape, size and material properties of the preforms. For the three-dimensional model structure of the two-step square woven preform modeling and simulation method, the general method is to analyze its weaving trajectory, then abstract the law of point movement, and use the point drawing method to express its three-dimensional spatial topological structure. Common three-dimensional model modeling and simulation tools include: the first category is animation design software, such as 3DMax software, etc., the second category is mechanical design software, such as SolidWorks, Pro-E software, etc., and the third category is mathematical simulation tools, such as MATLAB software, etc. The square woven preform structure established by these three-dimensional model modeling and simulation methods can describe the spatial configuration of the yarn in the woven structure to a certain extent. However, for the modeling and simulation methods of the two-step square woven preforms, these three-dimensional modeling and simulation methods have not yet given a definite mathematical expression, and it is impossible to obtain the mathematical analysis of the modeling and simulation methods of the two-step square woven preforms, and it is impossible to effectively guide the modeling and simulation of the two-step square woven preforms, and it is impossible to effectively visualize and digitally guide the design of the two-step square woven preforms for the subsequent actual production and manufacturing of the two-step square woven preforms. Summary of the invention

[0005] The present invention proposes a design method for a two-step square braided preform, which aims to partially or completely solve the technical problems of the two-step square braided preform design currently existing in the prior art. The technical solution of the present invention is as follows:

[0006] A design method for a two-step square braided preform comprises the following steps:

[0007] Step S100: obtaining a braiding structure of a two-step square braided preform to be designed, and performing modeling simulation on the two-step square braided preform to be designed;

[0008] Step S200: analyzing and judging the weavability and color effect of the two-step square braided preform to be designed after the modeling and simulation is completed, and completing the design of the two-step square braided preform.

[0009] Optionally, step S100 includes:

[0010] Step S101: obtaining a weaving structure of a two-step square braided preform to be designed, determining structural parameters, manufacturing process parameters, and arrangement of axial yarns and braiding yarns of the two-step square braided preform to be designed, and forming a weaving process of the two-step square braided preform to be designed;

[0011] Step S102: according to the weaving and weaving process of the two-step square braided preform to be designed, obtaining the motion law of the first, second, ..., Nth braiding yarns; according to the motion law of the first, second, ..., Nth braiding yarns, determining the motion trajectories of the first, second, ..., Nth braiding yarns in space, where N is a positive integer;

[0012] Step S103: Establish a rectangular coordinate system in the motion trajectory of the 1st, 2nd, ..., Nth braiding yarn in space, obtain the trajectory equations of the 1st, 2nd, ..., Nth braiding yarn in the X, Y, and Z directions, construct a two-step square braided preform model to be designed, and complete the simulation of the two-step square braided preform to be designed.

[0013] Optionally, step S200 includes:

[0014] Step S201: performing a weavability analysis and judgment on the two-step square braided preform to be designed after completing the modeling simulation to form a first judgment result;

[0015] Step S201: performing color effect analysis and judgment on the two-step square braided preform to be designed after completing modeling and simulation to form a second judgment result;

[0016] Step S203: When the first judgment result and the second judgment result are yes, it is reminded that the design of the two-step square braided preform is qualified; when the first judgment result is no or the second judgment result is no, it is reminded that the design of the two-step square braided preform is unqualified, and the two-step square braided preform is redesigned.

[0017] Optionally, it is characterized in that step S101 includes:

[0018] Step S1011: obtaining the braiding structure of the two-step square braided preform to be designed, and determining the structural parameters of the two-step square braided preform to be designed, the structural parameters including: braiding angle, outer dimensions of the preform, and knot length;

[0019] Step S1012: obtaining the weaving structure of the two-step square weaving preform to be designed, and determining the manufacturing process parameters of the two-step square weaving preform to be designed, wherein the manufacturing process parameters include: the number of axial yarn arrangements and the number of weaving yarn arrangements;

[0020] Step S1013: according to the structural parameters and manufacturing process parameters of the two-step square braided preform to be designed, the arrangement mode of the axial yarn and the braiding yarn is determined to form the braiding and weaving process of the two-step square braided preform to be designed; the axial yarn arrangement mode is at least: the axial yarns on adjacent rows are staggered and differ from each other by one axial yarn; the braiding yarn arrangement mode is at least: the braiding yarns are arranged at intervals outside the main yarn formed by the axial yarn;

[0021] Optionally, step S102 includes:

[0022] Step S1021: according to the weaving and weaving process of the two-step square braided preform to be designed, the motion law of the first braiding yarn is obtained, and according to the motion law of the first braiding yarn, the motion trajectory of the first braiding yarn in space is determined;

[0023] Step S1022: According to the movement trajectory of the first braiding yarn in space, the arrangement order and interweaving method of the second, ..., Nth braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, obtain the movement law of the second, ..., Nth braiding yarns; according to the movement law of the second, ..., Nth braiding yarns, determine the movement trajectory of the second, ..., Nth braiding yarns in space.

[0024] Optionally, the trajectory equations of the center lines of the 1st, 2nd, ..., Nth braided yarns in the X and Y directions are obtained by performing different phase transformations and adjustments based on the trajectory mother equation x=m×sin(π / (2m)×t) in the X direction and the trajectory mother equation y=n×sin(π / (2n)×t) in the Y direction, where m is the number of rows of the axial yarn, n is the number of columns of the axial yarn, m is an odd number, m+n=N, and N is a positive integer.

[0025] The beneficial effects achieved by the present invention are as follows:

[0026] (1) In the present application, according to the actual weaving process of the two-step square woven preform to be designed, the spatial motion law of the 1st, 2nd, ..., Nth weaving yarns during the weaving process is analyzed, and the spatial weaving motion trajectories of the 1st, 2nd, ..., Nth weaving yarns are obtained. The axial yarn is wrapped inside the 1st, 2nd, ..., Nth weaving yarns, so that the design of the two-step square woven preform to be designed is realized, and it can basically match the two-step square woven preform obtained by the final actual weaving.

[0027] (2) In the present application, a rectangular coordinate system is established in the motion trajectory of the 1st, 2nd, ..., Nth braiding yarn in space, and the trajectory equations of the 1st, 2nd, ..., Nth braiding yarn in the X, Y, and Z directions are obtained. According to mathematical knowledge such as the coordinate transformation principle, a model of a two-step square braided preform to be designed is constructed, and the simulation of the two-step square braided preform to be designed is completed, which lays a mathematical analysis foundation for the establishment of a deep geometric model, mechanical properties and simulation analysis, and has important reference significance for subsequent mechanical modeling, force analysis, failure mechanism analysis, etc.

[0028] (3) In the present invention application, after completing the modeling and simulation of the two-step square woven preform to be designed, the weavability and color effect of the two-step square woven preform to be designed can be effectively predicted, thereby reducing the sample production process and raw material waste, shortening the product design and production cycle, and realizing the rapid design, rapid simulation and digital display of the two-step square woven preform woven product, laying the foundation and strong technical support for the future innovative design and mechanical property testing of the two-step square woven preform.

[0029] (4) In the present invention application, the design of the two-step square woven preform is improved to improve the integration capability of the design and production of the two-step square woven preform, and the visualization and digitization of the product design of the two-step square woven preform is realized scientifically and accurately. By predicting the weavability and color effect on the machine, it replaces the traditional product that needs to complete the sample proofing and manufacturing before the weavability and color effect verification on the machine, thus saving the process of repeated design and proofing. The design of the two-step square woven preform can be directly applied to the actual production process of the two-step square woven preform product, which can not only reduce the production time, improve the production efficiency, reduce the production cost, shorten the design and production cycle of the two-step square woven preform product, but also improve the competitiveness of the enterprise, and has great commercial and market promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a schematic diagram of the principle of two-step square weaving in the prior art;

[0032] Figure 2 A schematic flow chart of a two-step square braided preform design method applied for by the present invention;

[0033] Figure 3 A schematic diagram of the working principle of the motion trajectory of the first braided yarn in space in the present invention;

[0034] Figure 4 Schematic diagram of the movement trajectories of the first, second, ..., and seventh braiding yarns in space of the present invention;

[0035] Figure 5 A schematic diagram of the trajectory equation of the first braided yarn in the X direction of the present invention;

[0036] Figure 6 A schematic diagram of the trajectory equation of the first braiding yarn in the Y direction of the present invention;

[0037] Figure 7 This is a schematic diagram of modeling and simulation of a two-step square braided preform applied for in the present invention.

[0038] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In order to make the purpose, technical solution and advantages of the present invention clearer, the implementation methods of the present invention will be further described in detail below in conjunction with the drawings.

[0041] like Figures 2 to 5 As shown, a design method of a two-step square braided preform comprises the following steps:

[0042] Step S100: obtaining a braiding structure of a two-step square braided preform to be designed, and performing modeling simulation on the two-step square braided preform to be designed;

[0043] Specifically, step S100 includes:

[0044] Step S101: obtaining a weaving structure of a two-step square braided preform to be designed, determining structural parameters, manufacturing process parameters, and arrangement of axial yarns and braiding yarns of the two-step square braided preform to be designed, and forming a weaving process of the two-step square braided preform to be designed;

[0045] Specifically, step S101 includes:

[0046] Step S1011: obtaining the braiding structure of the two-step square braided preform to be designed, and determining the structural parameters of the two-step square braided preform to be designed, the structural parameters including: braiding angle, outer dimensions of the preform, and knot length;

[0047] Step S1012: obtaining the weaving structure of the two-step square weaving preform to be designed, and determining the manufacturing process parameters of the two-step square weaving preform to be designed, wherein the manufacturing process parameters include: the number of axial yarn arrangements and the number of weaving yarn arrangements;

[0048] Step S1013: according to the structural parameters and manufacturing process parameters of the two-step square braided preform to be designed, the arrangement mode of the axial yarn and the braiding yarn is determined to form the braiding and weaving process of the two-step square braided preform to be designed; the axial yarn arrangement mode is at least: the axial yarns on adjacent rows are staggered and differ from each other by one axial yarn; the braiding yarn arrangement mode is at least: the braiding yarns are arranged at intervals outside the main yarn formed by the axial yarn;

[0049] In some embodiments, Figure 1 As shown, the hollow circle represents the axial yarn, and the solid circle represents the braiding yarn. The axial yarn remains stationary, and the braiding yarn moves in two steps: in the first step, the braiding yarn passes through the axial yarn array along the same diagonal direction to reach the empty space at the other edge; in the second step, the braiding yarn moves along the other diagonal direction. After one machine cycle, the arrangement of the yarn returns to the initial state, and the position without braiding yarn remains unchanged, thereby completing a preform with a pitch length. Through cyclic processing, a two-step square braided preform with the required structural parameters can be obtained, that is, a braiding and weaving process of a two-step square braided preform is formed, which can belong to the common technical knowledge of the existing two-step square braided preform.

[0050] Step S102: according to the weaving and weaving process of the two-step square braided preform to be designed, obtaining the motion law of the first, second, ..., Nth braiding yarns; according to the motion law of the first, second, ..., Nth braiding yarns, determining the motion trajectories of the first, second, ..., Nth braiding yarns in space, where N is a positive integer;

[0051] In some embodiments, the outside of the main yarn formed by the axial yarn is a rectangular structure. Along the length direction and direction of the rectangular structure, long rows and short rows are arranged at intervals with each other. The long rows are rows with a larger number of axial yarns, and the short rows are rows with a smaller number of axial yarns. The number of axial yarns in the long rows is one more than the number of axial yarns in the short rows. The number of rows of long rows is m, and the number of columns of long rows is n, where m is an odd number. At this time, the two-step square woven preform to be designed can usually be recorded as a two-step m×n square woven preform to be designed, and satisfies: m+n=N, where N is a positive integer.

[0052] Specifically, step S102 includes:

[0053] Step S1021: according to the weaving and weaving process of the two-step square braided preform to be designed, the motion law of the first braiding yarn is obtained, and according to the motion law of the first braiding yarn, the motion trajectory of the first braiding yarn in space is determined;

[0054] In the present application, the working principle of determining the motion trajectory of the first braiding yarn in space is: the position of the spline curve of the first braiding yarn can be determined with the help of graph paper. On the graph paper, when drawing the spline curve of the first braiding yarn, the center point of each small square that the braiding yarn has not passed through inside the complete braiding trajectory is the position of each axial yarn. Each step in the weaving process is recorded as t (initial position t=0), t is a positive integer, and the position of the point on the spline curve of the first braiding yarn is the center point of each small square through which the curve passes. Combined with the weaving and weaving process of the two-step square braiding preform, the complete motion trajectory of the first braiding yarn is drawn on the graph paper.

[0055] Step S1022: according to the movement trajectory of the first braiding yarn in space, the arrangement order and interweaving mode of the second, ..., Nth braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, obtain the movement law of the second, ..., Nth braiding yarns; according to the movement law of the second, ..., Nth braiding yarns, determine the movement trajectory of the second, ..., Nth braiding yarns in space;

[0056] In the present application, on the basis of the above-mentioned working principle of determining the motion trajectory of the first braiding yarn in space, because the braiding yarns outside the main yarn formed by the axial yarn are arranged at intervals, and combined with the arrangement order and interweaving method of the second, ..., Nth braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, accordingly, by analogy, the motion laws of the second, ..., Nth braiding yarns and the motion trajectories of the second, ..., Nth braiding yarns in space are obtained, and finally the spatial motion trajectories of the N braiding yarns can be obtained, which also realizes the consistency between the design of the two-step square braided preform to be designed and the two-step square braided preform actually obtained.

[0057] Step S103: Establish a rectangular coordinate system in the motion trajectory of the 1st, 2nd, ..., Nth braiding yarn in space, obtain the trajectory equations of the 1st, 2nd, ..., Nth braiding yarn in the X, Y, and Z directions, construct a two-step square braided preform model to be designed, and complete the simulation of the two-step square braided preform to be designed.

[0058] Specifically, step S103 includes:

[0059] Step S1031: Establish a rectangular coordinate system in the movement trajectories of the 1st, 2nd, …, Nth braided yarns in space, and obtain the trajectory equations of the 1st, 2nd, …, Nth braided yarns in the X, Y, and Z directions;

[0060] In the present invention application, by observing the movement trajectory curves of the 1st, 2nd, …, Nth braided yarns in space, the movement trajectory curves of each braided yarn in space include three-direction component motions, namely, the X-direction motion, the Y-direction motion, and the Z-direction motion, which respectively mean that: corresponding to the coordinate changes in the X, Y, and Z directions, the trajectory equations of the centerlines of the 1st, 2nd, …, Nth braided yarns in the X and Y directions are obtained through different phase transformations and adjustments based on the X-direction trajectory parent equation x = m×sin(π / (2m)×t) and the Y-direction trajectory parent equation y = n×sin(π / (2n)×t).

[0061] Taking the 1st braided yarn as an example, the working principles of the trajectory equations of the 1st braided yarn in the X, Y, and Z directions are as follows:

[0062] For the trajectory equations of the 1st braided yarn in the X and Y directions, the initial position of the 1st braided yarn is separated from the rectangular coordinate origin o by a steps. a is the number of steps used for the braided yarn to reach the coordinate origin o from the initial position along its movement trajectory. Taking the trajectory of the 1st braided yarn as the standard, the initial positions of the points on each braided yarn appear ahead of the coordinate origin o during the braiding process, with a negative phase difference, and appear behind the coordinate origin o, with a positive phase difference. Correspondingly, the trajectory equation of the 1st braided yarn in the X direction and the trajectory equation in the Y direction are respectively:

[0063] x = m×sin(π / (2m)×(t - a)); y = n×sin(π / (2n)×(t - a));

[0064] For the trajectory equation of the 1st braided yarn in the Z direction, according to the braiding process of the two-step square braided preform to be designed, it can be known that when each braided yarn completes a braiding action from one edge of the two-step square braided preform to the other edge, the rising height D of the braided yarn is the same. Exemplarily, a1, a2, and a3 are all recorded as the different numbers of steps required for the 1st braided yarn to move from one edge of the fabric to the other edge. i is recorded as the number of times the braided yarn moves from one edge of the fabric to the other edge. i starts from 1. At different i-th times, a2 and a3 also change and are not the same.

[0065] At the 1st time, that is, when 0 <= t < a1 and i = 1, the increment Z1 in the Z direction corresponding to each step t is: Z1 = t*D / (a1 - 1)+(i - 1)D;

[0066] At the 2nd, 3rd,..., 14th times, that is, when a2 <= t < a3, i = 2, 3,..., 14, the increment Zi in the Z direction corresponding to each step t is:

[0067] Zi = (t - a2 + 1) * D / (a3 - a2) + (i - 1)D;

[0068] In the application of the present invention, based on the above working principle of determining the movement trajectory of the first braided yarn in space, observe the movement trajectory curves of the second, third,..., Nth braided yarns in space. For the trajectory equations of the second, third,..., Nth braided yarns in the X and Y directions respectively, determine the distances between the initial positions of the second, third,..., Nth braided yarns and the coordinate origin o, determine the corresponding phase differences of the second, third,..., Nth braided yarns, and obtain the trajectory equations of the second, third,..., Nth braided yarns in the X and Y directions; meanwhile, for the trajectory equations of the second, third,..., Nth braided yarns in the Z direction, they can be obtained by analog transformation according to the trajectory equation of the first braided yarn in the Z direction. In this way, the trajectory equations of the first, second, third,..., Nth braided yarns in the X, Y, and Z directions can be obtained;

[0069] Step S1032: Construct a two-step square braided preform model to be designed and complete the simulation of the two-step square braided preform to be designed.

[0070] In the application of the present invention, based on the trajectories of multiple axial yarns in the X, Y, and Z directions and the trajectory equations of the first, second, third,..., Nth braided yarns in the X, Y, and Z directions, a two-step square braided preform model to be designed can be constructed. As Figure 6 shown, after constructing the two-step square braided preform model to be designed, complete the simulation of the two-step square braided preform to be designed, that is, finally realize the modeling and simulation of the two-step square braided preform to be designed.

[0071] Exemplarily, taking m = 3, n = 4, and the structural parameters of the two-step square braided preform to be designed are: the braiding angle is 75 degrees, the external dimensions of the preform are 51 mm in length, 36 mm in width, 61 mm in height, the repeat length is 10 mm, the number of axial yarn arrangements is 18, and the number of braided yarn arrangements is 7, as an example:

[0072] In step S1021, according to the braiding process of the two-step square braided preform to be designed, obtain the movement law of the first braided yarn. According to the movement law of the first braided yarn, determine the movement trajectory of the first braided yarn in space, specifically including:

[0073] As Figure 2As shown, the working principle of determining the motion trajectory of the first braiding yarn in space is: the position of the spline curve of the first braiding yarn can be determined with the help of graph paper. When drawing the spline curve of the first braiding yarn on the graph paper, the center point of each small square that the braiding yarn has not passed through in the complete braiding trajectory is the position of each axial yarn. During the weaving process, each step is recorded as t (initial position t=0), and the position of the point on the spline curve of the first braiding yarn is the center point of each small square passed by the curve. Combined with the weaving and weaving process of the two-step square braiding preform, the complete motion trajectory of the first braiding yarn is drawn on the graph paper. At this time, the corresponding t value is 48. Figure 2 Each point in the figure is marked with a t value. The t values ​​above and below the same point represent the point being passed by in different weaving directions and with different weaving steps t, where t is a positive integer.

[0074] In step S1022, according to the movement trajectory of the first braiding yarn in space, the arrangement order and interweaving mode of the second, ..., and seventh braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, the movement law of the second, ..., and seventh braiding yarns is obtained; according to the movement law of the second, ..., and seventh braiding yarns, the movement trajectory of the second, ..., and seventh braiding yarns in space is determined;

[0075] In the present application, on the basis of the working principle of determining the motion trajectory of the first braiding yarn in space, the braiding yarns outside the main yarn formed by the axial yarn are arranged at intervals, and combined with the arrangement order and interlacing method of the second, ..., and seventh braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, accordingly, by analogy, the motion laws of the second, ..., and seventh braiding yarns can be obtained and the motion trajectories of the second, ..., and seventh braiding yarns in space can be drawn, and finally the spatial motion trajectories of the seven braiding yarns can be obtained (such as Figure 3 shown).

[0076] In step S1031, a rectangular coordinate system is established in the motion trajectory of the first, second, ..., seventh braiding yarn in space, and trajectory equations of the first, second, ..., seventh braiding yarn in the X, Y, and Z directions are obtained;

[0077] The trajectory equations of the center lines of the 1st, 2nd, ..., 7th braided yarns in the X and Y directions are obtained by performing different phase transformations and adjustments based on the trajectory mother equation x=4×sin(π / 8×t) in the X direction and the trajectory mother equation y=3×sin(π / 6×t) in the Y direction.

[0078] Taking the first braided yarn as an example, the working principle of the trajectory equation of the first braided yarn in the X, Y, and Z directions is as follows:

[0079] like Figure 5 , Figure 6 As shown in the figure, for the trajectory equations of the first braided yarn in the X and Y directions, the initial position of the first braided yarn is 3 steps away from the rectangular coordinate origin o. Taking the trajectory of the first braided yarn as the standard, the initial position of each braided yarn appears ahead of the coordinate origin o during the weaving process, and the phase difference is negative, and lags behind the coordinate origin o, and the phase difference is positive. Correspondingly, the trajectory equations of the first braided yarn in the X direction and the trajectory equations in the Y direction are:

[0080] x=4×sin(π / 8×(t-3)); y=3×sin(π / 6×(t-3)).

[0081] As for the trajectory equation of the first braiding yarn in the Z direction, it can be known from the braiding and weaving process of the two-step square braided preform to be designed that when each braiding yarn completes a braiding action from one edge to the other edge of the two-step square braided preform to be designed, the braiding yarn rises to the same height D. Taking D=1 as an example, a1(a1=7), a2, and a3 are all recorded as the different steps required for the first braiding yarn to move from one edge of the fabric to another edge, and Zi=(t-a2+1)*D / (a3-a2)+(i-1)D is used to calculate:

[0082] At the first time, that is, when a1=7, when 0<=t<7, i=1, that is, t=0, 1, 2, 3, 4, 5, 6, the increment Z1 in the Z direction corresponding to each step t is:

[0083] Z1=t / 6;

[0084] At the second time, that is, when a2=7, a3=8, that is, when 7<=t<8, i=2, that is, t=7, the increment Z2 in the Z direction corresponding to each step t is:

[0085] Z2=(t-6)+1;

[0086] At the third time, that is, when a2=8, a3=13, that is, when 8<=t<13, i=3, that is, t=8, 9, 10, 11, 12, the increment Z3 in the Z direction corresponding to each step t is:

[0087] At Z3 = (t-7) / 5 + 2;

[0088] At the fourth time, that is, when a2=13, a3=16, that is, when 13<=t<16, i=4, that is, t=13, 14, 15, the increment Z4 in the Z direction corresponding to each step t is:

[0089] Z4=(t-12) / 3+3;

[0090] ..., and so on. Accordingly, the trajectory equations of the first braided yarn in the X, Y, and Z directions are shown in formula (1):

[0091]

[0092] The initial position of the second braided yarn is 33 steps away from the coordinate origin o. Correspondingly, the trajectory equations of the first braided yarn in the X direction and the Y direction are: x = 4 × sin (π / 8 × (t + 33)); y = 3 × sin (π / 6 × (t + 33)); Similarly, the trajectory equations of the second braided yarn in the X, Y, and Z directions are shown in formula (2):

[0093]

[0094] Step S200: analyzing and judging the weavability and color effect of the two-step square braided preform to be designed after the modeling and simulation is completed, and completing the design of the two-step square braided preform;

[0095] Specifically, step S200 includes:

[0096] Step S201: performing a weavability analysis and judgment on the two-step square braided preform to be designed after completing the modeling simulation to form a first judgment result;

[0097] Step S201: performing color effect analysis and judgment on the two-step square braided preform to be designed after completing modeling and simulation to form a second judgment result;

[0098] Step S203: When the first judgment result and the second judgment result are yes, it is reminded that the design of the two-step square braided preform is qualified; when the first judgment result is no or the second judgment result is no, it is reminded that the design of the two-step square braided preform is unqualified, and the two-step square braided preform is redesigned.

[0099] In the present invention application, after completing the modeling and simulation of the two-step square woven preform to be designed, the weavability and color effect of the woven fabric of the two-step square woven preform to be designed can be effectively predicted, thereby reducing the sample production process and raw material waste, shortening the product design and production cycle, and realizing the rapid design, rapid simulation and digital display of the two-step square woven preform woven fabric products, providing strong technical support for the future innovative design of the two-step square woven preform.

[0100] In the present invention application, first, the weaving structure of the two-step square braided preform to be designed is obtained; then, the weavability and color effect analysis and judgment of the two-step square braided preform to be designed after the modeling simulation is completed are performed to complete the design of the two-step square braided preform. In this way, through the above-mentioned design method of the two-step square braided preform, the integration of the design and production of the two-step square braided preform can be improved, and the visualization and digitization of the product design of the two-step square braided preform can be scientifically and accurately realized. In addition, by predicting the weavability and color effect on the machine, the traditional product needs to complete the sample proofing and manufacturing to verify the weavability and color effect on the machine, saving the process of repeated design and proofing. The design of the two-step square braided preform can be directly applied to the actual production process of the two-step square braided preform product, which can not only reduce the production time, improve the production efficiency, reduce the production cost, shorten the design and production cycle of the two-step square braided preform product, improve the competitiveness of the enterprise, and have great commercial and market promotion value.

[0101] The present invention and its implementation methods are described above, but such description is not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A design method for a two-step square braided preform, comprising the following steps: Step S100: obtaining a braiding structure of a two-step square braided preform to be designed, and performing modeling simulation on the two-step square braided preform to be designed; Step S200: analyzing and judging the weavability and color effect of the two-step square braided preform to be designed after the modeling and simulation is completed, and completing the design of the two-step square braided preform.

2. A two-step square braided preform design method according to claim 1, characterized in that: Step S100 includes: Step S101: obtaining a weaving structure of a two-step square braided preform to be designed, determining structural parameters, manufacturing process parameters, and arrangement of axial yarns and braiding yarns of the two-step square braided preform to be designed, and forming a weaving process of the two-step square braided preform to be designed; Step S102: according to the weaving and weaving process of the two-step square braided preform to be designed, obtaining the motion law of the first, second, ..., Nth braiding yarns; according to the motion law of the first, second, ..., Nth braiding yarns, determining the motion trajectories of the first, second, ..., Nth braiding yarns in space, where N is a positive integer; Step S103: Establish a rectangular coordinate system in the motion trajectory of the 1st, 2nd, ..., Nth braiding yarn in space, obtain the trajectory equations of the 1st, 2nd, ..., Nth braiding yarn in the X, Y, and Z directions, construct a two-step square braided preform model to be designed, and complete the simulation of the two-step square braided preform to be designed.

3. The design method of a two-step square braided preform according to claim 2, characterized in that: Step S200 includes: Step S201: performing a weavability analysis and judgment on the two-step square braided preform to be designed after completing the modeling simulation to form a first judgment result; Step S201: performing color effect analysis and judgment on the two-step square braided preform to be designed after completing modeling and simulation to form a second judgment result; Step S203: When the first judgment result and the second judgment result are yes, it is reminded that the design of the two-step square braided preform is qualified; when the first judgment result is no or the second judgment result is no, it is reminded that the design of the two-step square braided preform is unqualified, and the two-step square braided preform is redesigned.

4. The design method of a two-step square braided preform according to claim 2, characterized in that: Step S101 includes: Step S1011: obtaining the braiding structure of the two-step square braided preform to be designed, and determining the structural parameters of the two-step square braided preform to be designed, the structural parameters including: braiding angle, outer dimensions of the preform, and knot length; Step S1012: obtaining the weaving structure of the two-step square weaving preform to be designed, and determining the manufacturing process parameters of the two-step square weaving preform to be designed, wherein the manufacturing process parameters include: the number of axial yarn arrangements and the number of weaving yarn arrangements; Step S1013: According to the structural parameters and manufacturing process parameters of the two-step square woven preform to be designed, the arrangement of the axial yarn and the braiding yarn is determined to form the weaving and weaving process of the two-step square woven preform to be designed; the axial yarn arrangement is at least: the axial yarns on adjacent rows are staggered and differ by one axial yarn from each other; the braiding yarn arrangement is at least: the braiding yarns are arranged at intervals outside the main yarn formed by the axial yarn.

5. A two-step square braided preform design method according to claim 4, characterized in that: Step S102 includes: Step S1021: according to the weaving and weaving process of the two-step square braided preform to be designed, the motion law of the first braiding yarn is obtained, and according to the motion law of the first braiding yarn, the motion trajectory of the first braiding yarn in space is determined; Step S1022: According to the movement trajectory of the first braiding yarn in space, the arrangement order and interweaving method of the second, ..., Nth braiding yarns in the weaving and weaving process of the two-step square braided preform to be designed, obtain the movement law of the second, ..., Nth braiding yarns; according to the movement law of the second, ..., Nth braiding yarns, determine the movement trajectory of the second, ..., Nth braiding yarns in space.

6. A two-step square braided preform design method according to claim 5, characterized in that: The trajectory equations of the center lines of the 1st, 2nd, ..., Nth braiding yarns in the X and Y directions are obtained by performing different phase transformations and adjustments based on the trajectory mother equation x=m×sin(π / (2m)×t) in the X direction and the trajectory mother equation y=n×sin(π / (2n)×t) in the Y direction, where m is the number of rows of the axial yarn, n is the number of columns of the axial yarn, m is an odd number, m+n=N, and N is a positive integer.

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