Winding shell aging performance analysis model construction method considering fiber interlacing effect

Abstract

The invention relates to a winding shell aging performance analysis model construction method considering a fiber interlacing effect, belongs to the field of composite material winding structures, and provides an analysis model mainly aiming at two main winding line types of cylindrical section fibers, namely equal-winding-angle geodesic winding and unequal-winding-angle non-geodesic winding. The method comprises the following steps: determining the diagonal length of a diamond on the surface of a wound cylinder; determining the center point of the rhombus by unfolding the side surface of the cylinder; on the basis of the center point position of the rhombus, calculating the fiber cross pattern form and size of galloon winding starting and ending; and determining the position of the rhombus. The method solves the problem that a complex fiber staggered pattern with a large winding linear tangency point number cannot be obtained through a simple crossed pattern adopted in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of composite material winding structures, and in particular relates to a method for constructing an aging performance analysis model of a winding shell taking into account the fiber interlacing effect. Background Art

[0002] With the continuous development of new technologies and equipment such as new energy vehicles, rocket engine systems, and satellites, stringent requirements have been put forward for pressure vessels carrying liquid fuels and high-pressure gases, such as high air tightness, light weight, and long life. Based on this practical demand, all countries have begun to develop lightweight composite pressure vessels with high structural efficiency, among which winding composite pressure vessels have gradually become the mainstream.

[0003] In the actual production process of wound pressure vessels, two layers of fiber bundles are mostly cross-wound. This winding molding method causes the fiber cross-wave effect in the structure and presents a mosaic pattern on the surface of the structure. However, the currently used laminate theory only considers the effect of the undulation angle on the elastic properties, and ignores the effect of the microstructure of the winding material (such as the resin-rich area caused by the fiber crossing) on ​​the elastic properties. At the same time, damage and cracks are prone to occur in the cross-wave area of ​​the fibers, which greatly affects the structural strength. Therefore, it is necessary to consider the cross-wave effect of the fibers and the mosaic pattern.

[0004] Therefore, the present invention proposes a fiber staggered pattern analysis model for a composite pressure vessel based on winding molding, especially for the problem of the influence of the cross-wave effect of the fibers in the winding cylindrical structure on its equivalent mechanical properties. Summary of the invention

[0005] Technical issues to be solved:

[0006] In order to avoid the shortcomings of the prior art, the present invention provides a method for constructing an aging performance analysis model for a winding shell that takes into account the fiber interlacing effect, and mainly provides an analysis model for two main winding line types of cylindrical fiber segments: geodesic winding with equal winding angles and non-geodesic winding with unequal winding angles. The present invention can be used to improve the design and manufacture of composite pressure vessels formed by winding, improve their structural strength and durability, meet the actual application requirements of high performance and high safety, and solve the problem that the simple cross pattern used in the prior art cannot obtain a complex fiber interlacing pattern with a large number of winding line tangent points.

[0007] The technical solution of the present invention is: a method for constructing an aging performance analysis model of a winding shell considering the fiber interlacing effect, and the specific steps are as follows:

[0008] Determine the length of the diagonal of the rhombus on the surface of the wrapped cylinder;

[0009] Determine the center point of the rhombus by unfolding the side of the cylinder;

[0010] Based on the center point position of the rhombus, the fiber crossing pattern form and size at the start and end of the tape winding are calculated;

[0011] Determine the location of the diamond.

[0012] A further technical solution of the present invention is: the winding shell is obtained by staggered winding of the yarn tape on the surface of the cylinder to be wound, and is evenly distributed in the circumferential direction of the surface of the cylinder to be wound; the winding direction of the yarn tape is at equal angles or non-equal angles with the center line of the cylinder to be wound, forming a mosaic diamond pattern of staggered fibers, wherein the diagonal length of a single diamond on the surface of the cylinder along the circumferential direction is l H , the length of the diagonal line along the axial direction on the cylindrical surface is l z .

[0013] A further technical solution of the present invention is that the diagonal length of the rhombus on the cylindrical surface along the circumferential direction is l H It is the quotient of the circumference s of the wound cylinder and the number of windings m.

[0014] A further technical solution of the present invention is that when the winding direction of the yarn tape is at an equal angle to the center line of the cylinder to be wound, the diagonal length of the rhombus on the surface of the cylinder along the axial direction is l z The calculation formula is as follows:

[0015]

[0016] Among them, l H is the diagonal length of the rhombus on the cylindrical surface along the circumferential direction, and α is the angle between the winding direction of the yarn and the center line of the cylinder to be wound.

[0017] A further technical solution of the present invention is: the method for determining the center point of the rhombus is to unfold the side of the cylinder, and then extend the center lines of the two yarn winding trajectories of the unfolded cylindrical side winding cycle to intersect, and the resulting intersection is the center point C of the rhombus.

[0018] A further technical solution of the present invention is: the formula for calculating the fiber crossing pattern size at the start and end of the tape winding is as follows:

[0019]

[0020] Among them, l0 is the axial height of the diamond vertex at the starting end of the yarn winding, l n H is the axial height of the diamond vertex at the end of the yarn winding, c is the axial distance between the center point C of the rhombus and the bottom surface of the cylinder to be wound;

[0021] The fiber cross pattern sizes l0 and l1 at the beginning and end of the tape winding are calculated. n Determine the form of the fiber crossing pattern.

[0022] A further technical solution of the present invention is that when the winding direction of the yarn tape is at a non-equiangular angle with the center line of the cylinder to be wound, the shape of the winding end of the yarn tape is a triangle or a triangle + pentagon.

[0023] A further technical solution of the present invention is: the formula for calculating the size of the fiber crossing pattern at the end of the tape winding is as follows:

[0024] L=U(Ns)

[0025]

[0026] H s =g(θ s )

[0027] Where L is the distance between the interlaced winding tape a and the tape b, l s is the length of the bottom edge of the overlapping area of ​​​​the yarn a and the yarn b at the end, θ s is the central rotation angle corresponding to a point on the winding curve, H s is the height corresponding to a point on the winding curve; n is the number of rhombuses;

[0028] The fiber cross pattern size θ at the end of the tape winding is calculated s , H s Determine the form of the fiber crossing pattern.

[0029] An application of a winding shell aging performance analysis model considering the fiber interlacing effect, the specific steps are as follows:

[0030] Constructing a numerical model of the winding shell according to the dimensions calculated by the winding shell aging performance analysis model considering the fiber interlacing effect;

[0031] The numerical model is imported into the finite element simulation software, the winding cylinder is split, and the ply sequence is given according to the mosaic pattern to finally form a finite element analysis model;

[0032] The winding angle information is given to different regions respectively, and a mosaic model considering the actual fiber interlacing of the cylinder is established;

[0033] The progressive damage analysis method was established using the Hashin failure criterion and the direct stiffness reduction method. The load-displacement curves calculated by finite element method were in good agreement with the test results.

[0034] A further technical solution of the present invention is that the test piece in the test is wound with a single spiral winding layer, the winding angle is 45 degrees, the structure length is 148.7 mm, and the thickness is 0.54 mm.

[0035] Beneficial Effects

[0036] The beneficial effects of the present invention are as follows: the method of the present invention establishes an analysis model for the influence of winding line type on the fiber interlacing pattern of the winding structure, determines the fiber interlacing pattern (mosaic diamond size and position) on the surface of the shell structure under different winding line type parameters, and provides a feasible method for the analysis of the fiber interlacing pattern of multi-tangent point winding of the cylinder.

[0037] Based on the test piece information, the winding simulation of the cylinder is performed to predict the structural mosaic pattern, such as Fig.16 The Python parameterized script is used to split the cylinder and the ply order is given according to the mosaic pattern. The final finite element analysis model is as follows: Fig.17 The test was carried out in accordance with ASTM D2412. Fig.18 As shown, the test piece is placed between two rigid plates, the loading speed is 5 mm / min, and the finite element model is used to establish a discrete rigid body to simulate the rigid plate. The displacement load is applied through the reference point, and friction contact is adopted between the plate and the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the center turning angle of the winding curve of the barrel section;

[0039] Figure 2 It is a schematic diagram of the center turning angle of the two ends of the cylinder;

[0040] Figure 3 It is a diamond pattern formed by the yarn tape being wound around the surface of the cylinder;

[0041] Figure 4 The surface of the winding tape is a diamond pattern planned according to calculation;

[0042] Figure 5 Two staggered patterns of the yarn tape at the end of the cylinder; (a) ending with a triangle row, (b) ending with a pentagon + triangle;

[0043] Figure 6 Two prepregs overlapped in the form of (a) interlaced diamond units, (b) overlapped diamond units;

[0044] Figure 7 Schematic diagram of overlapping analysis of prepreg placement in a rectangular plane after unfolding the cylindrical surface;

[0045] Figure 8 A fiber cross pattern formed by winding a yarn tape at a variable angle on the surface of a cylinder through a winding cycle;

[0046] Fig. 9 The curve of the yarn winding angle change on the cylinder surface;

[0047] Fig.10is a cross pattern of fibers near the edge of the cylinder;

[0048] Fig.11 is a cross pattern of fibers near the edge of the cylinder;

[0049] Fig.12 This is a schematic diagram of the variable angle winding and crossing of the yarn tape;

[0050] Fig.13 This is a schematic diagram of the size of the variable angle winding fiber cross pattern;

[0051] Fig.14 Schematic diagram of fiber interlacing phenomenon in winding structure;

[0052] Fig.15 It is a mosaic model of interlaced fibers wound around a cylinder;

[0053] Fig.16 Predict structural mosaic patterns for Matlab winding simulations;

[0054] Fig.17 It is a finite element analysis model;

[0055] Fig.18 Schematic diagram of the experimental device and finite element boundary conditions used;

[0056] Fig.19 is the radial compression load-displacement curve of the cylinder;

[0057] Fig. 20 This is a simulation diagram of the fiber crossing pattern with equal winding angles;

[0058] Fig.21 This is a simulation diagram of the fiber crossing pattern with variable winding angle. DETAILED DESCRIPTION

[0059] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0060] Based on the problem that the simple cross pattern used in the prior art cannot obtain a complex fiber interlaced pattern with a large number of winding line tangent points, the present invention provides a method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect, and the specific steps are as follows:

[0061] Step 1: Determine the diagonal length of the rhombus on the surface of the wrapped cylinder;

[0062] Step 2: Determine the center point of the rhombus by unfolding the side of the cylinder;

[0063] Step 3: Based on the center point position of the rhombus, calculate the fiber cross pattern form and size at the start and end of the tape winding;

[0064] Step 4: Determine the location of the diamond.

[0065] The present invention can be used to improve the design and manufacture of composite pressure vessels formed by winding, enhance the structural strength and durability thereof, and meet the practical application requirements of high performance and high safety.

[0066] The above technical solution is further described below in conjunction with the accompanying drawings and specific embodiments:

[0067] This embodiment provides a method for constructing an aging performance analysis model for a winding shell taking into account the fiber interlacing effect, which is specifically described as follows:

[0068] 1) Introduction to winding line parameters

[0069] Reference Figure 1 and Figure 2 As shown in the figure, in the cylindrical structure, in the fiber winding, when the trolley goes back and forth from both ends of the cylinder in one cycle, the central rotation angle of the main shaft is ∑θ, and the central rotation angle can often correspond to the following relationship:

[0070]

[0071] Among them: θ1 is the center angle of the winding curve of the barrel; θ2 is the center angle of the winding transition at both ends of the cylinder; N is the number of full turns of the core mold; k / m is the remainder of the core mold rotation, which is required to be in the form of irreducible proper fractions, and k is the distance between two adjacent windings at the equator, with the yarn bandwidth as the unit standard. m can be expressed as

[0072]

[0073] Where: D is the equatorial diameter; B is the yarn width; α is the winding angle at the equator; m is the integer that divides the equatorial circumference equally with the yarn width at the equator, that is, the number of winding circles required to evenly cover the equator. The winding angle of the non-geodesic line changes within a certain range at the equator, so m can allow several integer values, and the number of its values ​​will affect the number of types of tangent points of the winding line type.

[0074] 2) Calculation of fiber interlacing pattern parameters on the surface of an equi-angle wound cylinder

[0075] Reference Figure 3 As shown in the figure, the diamond pattern is formed by the interlaced winding of the yarn ±α, which is evenly distributed around the cylinder. Therefore, the diagonal length of the diamond on the cylinder surface along the ring direction is l H It is the quotient of the circumference s of the cylinder and the number of windings m. Affected by the winding angle, the diagonal length l of the rhombus on the cylindrical surface along the axial direction z for:

[0076]

[0077] After the diamond size is determined, the diamond position needs to be determined. According to the actual yarn winding situation, the center of the diamond is located at the center line of the yarn.

[0078] Through the study of existing literature, the above parameters can be determined and the fiber crossing pattern can be drawn, but a problem is found in the drawing process, such as Figure 5 As shown in the figure, the yarn tape is affected by the winding line parameters, and the end position pattern is divided into two cases, triangle and pentagon + triangle combination. The existing research cannot determine the influence of the winding line type on these two forms. If the two cross pattern end forms are not considered, there will be Figure 6 The problem of interlacing the diamond-shaped units shown in (a) is that it is impossible to obtain a true cross pattern of a single winding layer.

[0079] For the above problems, refer to Figure 7 As shown in the figure, the side of the cylinder is unfolded, and the center lines of the two yarn winding trajectories of one winding cycle (when m=1) are extended (because it is an equal angle winding, after the side of the cylinder is unfolded, the winding curve becomes a straight line segment), and the two center lines intersect at a point, which is the center of the diamond C formed by the extension of the two yarns, and then according to the intersection height H c The length of the diagonal line with the axis of the rhombus is l z , the fiber cross pattern form and size l0, l0 at the beginning and end of the yarn tape can be calculated n .

[0080]

[0081] 3) Calculation of fiber interlacing pattern parameters on the surface of variable angle winding cylinder

[0082] Existing literature research shows that Figure 8 and Fig. 9 As shown in the figure, the variable angle winding of the cylinder can improve the mechanical properties of the fiber wound cylindrical structure. In order to facilitate the subsequent combination of winding parameter optimization analysis to improve the mechanical properties of the wound shell, a cross analysis study of the variable angle winding fiber pattern of the cylinder section was carried out.

[0083] Similar to the analysis of the fiber pattern of cylindrical structural yarn with equivariable angle winding, the diagonal length of the rhombus on the cylindrical surface along the circumferential direction is l H It is the quotient of the cylinder's circumference s and the number of windings m.

[0084] Affected by the change of winding angle, the diagonal length of the rhombus axis is l z like Fig.10 and Fig.11 As shown, it gradually increases inward along the edge of the cylinder. Without determining the rhombus position parameters, it is impossible to determine the axial diagonal length l of each rhombus. z .

[0085] The variable angle winding curve is different from the equal angle winding curve. After the side of the tube is unfolded, the variable angle winding is a curve, and the axial diagonal length is l z The position of the fiber cross pattern of the variable angle winding cannot be analyzed by the method of analyzing the position of the fiber cross pattern of the equi-angle winding. Through analysis, it is found that it is feasible to first determine the pattern size of the end of the cylinder winding, and then analyze the diamond position on the variable angle winding yarn. During the winding process of the winding cylinder structure, the yarn will be staggered to ensure that the yarn is evenly distributed on the surface of the cylinder.

[0086] Reference Fig.12 As shown, the yarn is wound back and forth many times, and the purple and red yarns are arranged closely in sequence (affected by the number of winding line tangent points, the yarns will be arranged in sequence or at intervals, but finally when the yarns are evenly spread over the cylinder, the yarns with the same winding direction will be arranged closely). The yarns in different directions are affected by the excessive center rotation angle (θ2) of the winding at both ends of the cylinder. When the winding angle is the same, a triangle appears at the end of the cylinder winding (for the convenience of analysis, the arc is simplified to a straight line, and the two isosceles sides of the actual red overlapping area are curves) or a triangle + pentagon combination ( Fig.12 The cross pattern of the red and yellow patterns). Based on this winding characteristic of the tightly arranged winding yarn, the form and size of the pattern at the end of the cylinder winding can be determined.

[0087] Fig.12 The middle yarn a and yarn b are two yarn tracks with different winding directions in a winding cycle. According to the winding characteristic that the winding yarns are closely arranged, assuming that the yarn a and the yarn b are separated by Ns yarns at the bottom (affected by the number of tangent points), then the distance L between the yarn a and the yarn b is calculated according to the winding theory linear planning. According to the above analysis, the diagonal length l of the diamond ring direction is obtained. H , then the length of the bottom side of the red overlapping area is l s for:

[0088] L=U(Ns)

[0089]

[0090] Fig.12 The red overlapping area (small triangle) at the bottom of the middle cylinder has a base length of l s After determination, since the fiber cross patterns are all symmetrical patterns, the diagonal length of the diamond ring is l H It is also known that Fig.13 Therefore, the center position S1 of the diamond pattern on a single yarn can be through l H , l s The center angle θ corresponding to a point on the winding curve is calculated by splicing and superposition, according to the winding line type analysis. s With height H s , there is a mathematical relationship

[0091]

[0092] H s =g(θ s )

[0093] Reverse deduction can obtain different central rotation angles θ on the curve s The height H corresponding to the position s , and then obtain the axial diagonal length l of the rhombus on the single yarn tape wound at a variable angle z ,Based on the above analysis, the fiber cross pattern on the cylinder surface can be drawn.

[0094] 4) Application of the analysis model of winding shell aging performance considering fiber interlacing effect

[0095] Reference Fig.14 As shown, the fiber tapes are interlaced during the structural forming process through the winding process to form a mosaic pattern (the pattern in the figure can also be achieved through existing public processes and is not a pattern protected by the present invention). This embodiment establishes a finite element model reflecting the characteristics of the winding structure to explore the influence of this effect on the structural damage and bearing capacity under internal pressure load.

[0096] In a characteristic area of ​​the mosaic pattern, the material has three distributions, such as Fig.14 As shown in the figure, the corresponding position of region A is the fiber interlacing area, the positive and negative winding layers are interlaced, and the structure is complex; the up and down order of the +α and -α layers in region B is alternating, and the material microscopic distribution is relatively simple; the material structure of region C is the same as that of the composite laminate, and region C occupies most of the area in the winding structure. The damage of the structure is generally determined by its weak link, so it is necessary to analyze the influence of the interlacing of the fibers in region A on the bearing capacity of the structure.

[0097] In engineering applications, the ratio of the width to the thickness of the yarn is generally greater than 30, and the results of the mosaic model are very different from the calculation results of the model elastic parameters that truly characterize the staggered mesoscopic pattern. This section aims to study the fiber staggering effect and its influence on the stress level of the spiral winding layer fiber direction under axial compression load, and describes the winding process. The finite element analysis model established based on the fiber staggering calculation method can accurately obtain the stress distribution in the fiber staggered area, providing effective simulation support for the aging performance analysis of the wound product.

[0098] The mosaic modeling method is used to simplify the staggered area, and this effect can be introduced into the actual structure for analysis. Based on the cylinder winding process, the actual movement trajectory and coverage of the yarn are considered, and the mosaic pattern is calculated and displayed by Matlab, as shown in the figure below. Fig.15As shown, the corresponding small diamond vertex position coordinates are output, and the cylindrical structure is split based on these coordinate data. The splitting operation of a simple cylindrical model also needs to be performed thousands of times, which brings a huge workload to the actual modeling process. Therefore, this paper establishes a Python parameterized script for automatic splitting, and assigns winding angle information of and to different areas, and establishes a mosaic model that takes into account the actual fiber interlacing of the cylinder.

[0099] Due to the limitation of the actual winding process, the sealing performance of the single-layer spiral winding cylinder is very poor, and the internal pressure load test cannot be carried out. At the same time, the yarns are very likely to be delaminated under loads such as axial pressure, and related tests are difficult to carry out. Most existing studies only conduct theoretical analysis of the unit cell model. In order to verify the effectiveness of the model in this paper, a finite element model is established for analysis and comparison with reference to the radial compression test in relevant literature. The test piece is wound with a single spiral winding layer, the winding angle is 45 degrees, the structure length is 148.7 mm, the thickness is 0.54 mm, and the material parameters are shown in Table 1.

[0100] Table 1 Material performance parameters

[0101]

[0102] Based on the test piece information, the winding simulation of the cylinder is performed to predict the structural mosaic pattern, such as Fig.16 The Python parameterized script is used to split the cylinder and the ply order is given according to the mosaic pattern. The final finite element analysis model is as follows: Fig.17 The test was carried out in accordance with ASTM D2412. Fig.18 As shown, the existing test device is used to place the test piece between two rigid plates. The loading speed is 5 mm / min. The finite element model is used to establish a discrete rigid body to simulate the rigid plate. The displacement load is applied through the reference point, and friction contact is adopted between the plate and the cylinder.

[0103] The progressive damage analysis method is established by using the Hashin failure criterion and the direct stiffness reduction method. Fig.19 As shown in the figure, the load displacement curve calculated by finite element method is in good agreement with the test. The average value of the ultimate load in the test is 881.6KN, and the ultimate load calculated by finite element method is 838.9KN, with a relative error of 4.84%, which fully verifies the effectiveness and accuracy of the modeling and damage analysis methods in this paper.

[0104] 5) Analysis examples

[0105] According to the above models, the simulation analysis is carried out using a computer, and the simulation results are shown as follows

[0106] Reference Fig. 20 As shown, the simulation of the fiber crossing pattern with equal winding angles:

[0107] Set the cylinder diameter to 400mm, the axis length to 800, and the default fiber width to 30mm.

[0108] Reference Fig.21 As shown, the simulation of the fiber crossing pattern with variable winding angle:

[0109] The cylinder diameter is 400mm, the shaft length is 600, and the default yarn width is 25mm

[0110] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect, characterized in that The specific steps are as follows: Determine the length of the diagonal of the rhombus on the surface of the wrapped cylinder; Determine the center point of the rhombus by unfolding the side of the cylinder; Based on the center point position of the rhombus, the fiber crossing pattern form and size at the start and end of the tape winding are calculated; Determine the location of the diamond.

2. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 1, characterized in that: The winding shell is obtained by interlacing the yarn tape on the surface of the cylinder to be wound, and is evenly distributed in the circumferential direction of the cylindrical surface to be wound; the winding direction of the yarn tape is at equal angles or non-equal angles with the center line of the cylinder to be wound, forming a mosaic diamond pattern of interlaced fibers, wherein the diagonal length of a single diamond on the cylindrical surface along the circumferential direction is l H , the length of the diagonal line along the axial direction on the cylindrical surface is l z .

3. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 2, characterized in that: The diagonal length of the rhombus on the cylindrical surface along the circumferential direction is l H It is the quotient of the circumference s of the wound cylinder and the number of windings m.

4. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 3, characterized in that: When the winding direction of the yarn is at an equal angle to the center line of the cylinder to be wound, the diagonal length of the rhombus on the surface of the cylinder along the axial direction is l z The calculation formula is as follows: Among them, l H is the diagonal length of the rhombus on the cylindrical surface along the circumferential direction, and α is the angle between the winding direction of the yarn and the center line of the cylinder to be wound.

5. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 4, characterized in that: The method for determining the center point of the rhombus is to unfold the side of the cylinder, and then extend the center lines of the two yarn winding trajectories of the unfolded cylindrical side winding cycle to intersect each other, and the obtained intersection is the center point C of the rhombus.

6. A method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 5, characterized in that: The formula for calculating the fiber cross pattern size at the start and end of the tape winding is as follows: Among them, l0 is the axial height of the diamond vertex at the starting end of the yarn winding, l n H is the axial height of the diamond vertex at the end of the yarn winding, c is the axial distance between the center point C of the rhombus and the bottom surface of the cylinder to be wound; The fiber cross pattern sizes l0 and l1 at the beginning and end of the tape winding are calculated. n Determine the form of the fiber crossing pattern.

7. The method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 3 is characterized in that: When the winding direction of the yarn tape is at a non-equiangular angle with the center line of the cylinder to be wound, the shape of the winding end of the yarn tape is a triangle or a triangle + a pentagon.

8. The method for constructing an aging performance analysis model for a winding shell considering the fiber interlacing effect according to claim 4 is characterized in that: The formula for calculating the fiber cross pattern size at the end of the tape winding is as follows: L=U(Ns) H s =g(θ s ) Where L is the distance between the interlaced winding tape a and the tape b, l s is the length of the bottom edge of the overlapping area of ​​​​the yarn a and the yarn b at the end, θ s is the central rotation angle corresponding to a point on the winding curve, H s is the height corresponding to a point on the winding curve; n is the number of rhombuses; The fiber cross pattern size θ at the end of the tape winding is calculated s , H s Determine the form of the fiber crossing pattern.

9. An application of a winding shell aging performance analysis model considering the fiber interlacing effect, characterized in that The specific steps are as follows: According to the dimensions calculated by the winding shell aging performance analysis model considering the fiber interlacing effect according to any one of claims 1 to 8, a numerical model of the winding shell is constructed; The numerical model is imported into the finite element simulation software, the winding cylinder is split, and the ply sequence is given according to the mosaic pattern to finally form a finite element analysis model; The winding angle information is given to different regions respectively, and a mosaic model considering the actual fiber interlacing of the cylinder is established; The progressive damage analysis method was established using the Hashin failure criterion and the direct stiffness reduction method. The load-displacement curves calculated by finite element method were in good agreement with the test results.

10. The application of the winding shell aging performance analysis model considering the fiber interlacing effect according to claim 9 is characterized in that: The test piece in the test was wound with a single spiral winding layer, with a winding angle of 45 degrees, a structural length of 148.7 mm, and a thickness of 0.54 mm.

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