A device and method for evaluating the stitchability of a three-dimensional fabric prepreg

Abstract

The application discloses a kind of three-dimensional fabric prepreg sewing process evaluation device and method, the device includes: fixed mechanism and needle puncture driving force test mechanism;Three-dimensional fabric prepreg is placed on the platform after being fixed by fixed mechanism, needle puncture driving force test mechanism is driven needle vertically three-dimensional fabric prepreg movement and passes through by air pressure, test pressure by high-precision pressure gauge, then calculate the driving force of needle, finally, the sewing process of three-dimensional fabric prepreg is characterized by driving force size.The application has simple operation process, high test precision, and can quantitatively evaluate the sewing process of three-dimensional fabric prepreg with thickness of 1-30mm.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fabric prepreg process performance evaluation, and particularly relates to a three-dimensional fabric prepreg stitching process performance evaluation device and method. BACKGROUND

[0002] Currently, 70% of advanced composite material products are formed by curing after prepreg laying. The prepreg refers to a kind of storage semi-finished product formed by impregnating fibers or fabrics with resin matrix under strict control, which is an important intermediate material for manufacturing composite material products. As early as the late 1940s, foreign countries began to use glass fiber reinforced prepreg. Until the late 1960s and early 1970s, with the advent of high-performance fibers such as carbon fibers and aramid fibers, the process stability and quality control of prepreg were reliably guaranteed, and the preparation technology of various prepregs has been greatly developed. After that, with the continuous improvement of the performance of reinforcing fibers and resin matrix, the research and development of prepreg have been promoted, and the process technology has become mature, and the application range has been continuously expanded.

[0003] The fibers in the prepreg have several forms such as chopped fibers, fiber felt, fiber cloth and three-dimensional fiber fabric. In terms of performance, the three-dimensional fabric has excellent overall mechanical properties of the composite material prepared by the prepreg due to the interaction between the fibers; in terms of production effect, compared with the laying, the three-dimensional fabric prepreg itself has large thickness, which can quickly prepare the composite material and realize efficiency improvement. The three-dimensional fabric prepreg becomes an important emerging prepreg.

[0004] At present, the main aspects of evaluating the performance of the prepreg include volatile content, resin content, gel time, viscosity, resin flowability, area density, fiber area density and the like, and these evaluations are mainly for short fibers and fiber cloth fabric prepregs. In the process of preparing a composite material by the three-dimensional fabric prepreg, the three-dimensional fabric prepregs often need to be overlapped and stitched together, and good stitching process performance is the basis for the wide application of the three-dimensional fabric prepreg. There is no evaluation standard and method for the stitching process performance of the three-dimensional fabric prepreg. SUMMARY

[0005] The technical problem of the present application is to overcome the shortcomings of the prior art, provide a three-dimensional fabric prepreg stitching process performance evaluation device and method, and realize quantitative evaluation of the stitching process performance of the three-dimensional fabric prepreg.

[0006] In order to solve the above technical problem, the present application discloses a three-dimensional fabric prepreg stitching process performance evaluation device, which comprises a fixing mechanism and a needle puncture pushing force testing mechanism.

[0007] The fixing mechanism comprises a first clamping plate, a second clamping plate, a third clamping plate and a fourth clamping plate; wherein the first clamping plate and the second clamping plate form a group, and the third clamping plate and the fourth clamping plate form another group; the two groups of clamping plates are connected by two screws.

[0008] The needle puncture pushing force testing mechanism comprises a piston, a cylinder body, a needle, pipeline A, pipeline B, pipeline C, pipeline D, valve A, pressure gauge A, valve B, pressure gauge B, valve C and valve D; wherein the piston is located in the cylinder body and can move up and down in the cylinder body; the needle is arranged at the bottom of the piston; pipeline A and pipeline C are respectively communicated with the upper part of the cylinder body; pipeline B and pipeline D are respectively communicated with the lower part of the cylinder body; valve A and pressure gauge A are arranged on pipeline A in sequence along the air inlet direction; valve B and pressure gauge B are arranged on pipeline B in sequence along the air inlet direction; valve C is arranged on pipeline C; and valve D is arranged on pipeline D.

[0009] In the above three-dimensional fabric prepreg sewing process evaluation device, the fixing mechanism is used to fix the three-dimensional fabric prepreg.

[0010] In the above three-dimensional fabric prepreg sewing process evaluation device, the needle puncture pushing force testing mechanism is used to test the sewing process of the fixed three-dimensional fabric prepreg.

[0011] In the above three-dimensional fabric prepreg sewing process evaluation device, the first clamping plate, the second clamping plate, the third clamping plate and the fourth clamping plate have the same structure size parameters; wherein the width of the clamping plate is 5-10 cm, the length is 5-20 cm, and the thickness is 1-3 cm.

[0012] In the above three-dimensional fabric prepreg sewing process evaluation device, one end of pipeline A is communicated with the cylinder body, and the other end is connected with air source A; one end of pipeline B is communicated with the cylinder body, and the other end is connected with air source B.

[0013] In the above three-dimensional fabric prepreg sewing process evaluation device, the accuracy of pressure gauge A and pressure gauge B is ≤10 Pa, and the range is ≥5 MPa.

[0014] In the above three-dimensional fabric prepreg sewing process evaluation device, the length of the needle is greater than 1-2 cm of the thickness of the fabric prepreg; and the diameter of the needle is 1-3 mm.

[0015] Correspondingly, the application also discloses a three-dimensional fabric prepreg sewing process evaluation method based on the above device, which comprises the following steps:

[0016] One side of the three-dimensional fabric prepreg is placed between the first clamping plate and the second clamping plate and clamped by tightening the screws; the other side of the three-dimensional fabric prepreg is placed between the third clamping plate and the fourth clamping plate and clamped by tightening the screws.

[0017] Put the three-dimensional fabric prepreg and the fixing mechanism integrally under the needle of the needle puncture pushing force test mechanism;

[0018] Close valve B and valve C, open valve D, then open valve A, record the pressure P1 of pressure gauge A when the needle starts to move, record the pressure P2 of pressure gauge A when the needle moves through the three-dimensional fabric prepreg;

[0019] Close valve A and valve D, open valve C, then open valve B, when the piston rises to the starting position, close valve B;

[0020] According to the recorded pressure P1 and pressure P1, the pushing force F of the needle through the three-dimensional fabric prepreg is calculated;

[0021] According to the calculated pushing force F, the three-dimensional fabric prepreg stitching process performance evaluation result is given; when F≤5N, the stitching process performance evaluation result is excellent; when 5N<F≤10N, the stitching process performance evaluation result is good; when 10N<F, the stitching process performance evaluation result is poor.

[0022] In the above method, F=S*(P2-P1); wherein S represents the area of the circular area on the upper surface of the piston.

[0023] In the above method, the opening control of valve A or valve B is used to ensure that the movement speed of the needle is 0.5-2.0mm / s.

[0024] The present application has the following advantages:

[0025] The present application discloses a three-dimensional fabric prepreg stitching process performance evaluation device and method, which is simple to operate, good in effect, and can quickly and quantitatively evaluate the stitching process performance of the three-dimensional fabric prepreg. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structure schematic diagram of a three-dimensional fabric prepreg stitching process performance evaluation device in the embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application clearer, the following will further describe the disclosed embodiments of the present application in combination with the drawings.

[0028] REFERENCE Figure 1 In the embodiment, the three-dimensional fabric prepreg stitching process performance evaluation device comprises a fixing mechanism and a needle puncture pushing force test mechanism. The fixing mechanism is used to fix the three-dimensional fabric prepreg, and the needle puncture pushing force test mechanism is used to test the stitching process performance of the fixed three-dimensional fabric prepreg.

[0029] The fixing mechanism mainly comprises: a first clamping plate 101, a second clamping plate 102, a third clamping plate 103 and a fourth clamping plate 104. Among them, the first clamping plate 101 and the second clamping plate 102 are a group, and the third clamping plate 103 and the fourth clamping plate 104 are a group, and each group of clamping plates is connected by two screws. The structure size parameters of the first clamping plate 101, the second clamping plate 102, the third clamping plate 103 and the fourth clamping plate 104 are consistent; wherein the width of the clamping plate is 5-10cm, the length is 5-20cm, and the thickness is 1-3cm.

[0030] The needle puncture pushing force test mechanism mainly comprises: a piston 201, a cylinder body 202, a needle 203, a pipeline A 204, a pipeline B 205, a pipeline C 206, a pipeline D 207, a valve A 208, a pressure gauge A 209, a valve B 210, a pressure gauge B 211, a valve C 212 and a valve D 213. Among them, the piston 201 is located in the cylinder body 202, and can move up and down in the cylinder body 202; the needle 203 is arranged at the bottom of the piston 201; the pipeline A 204 and the pipeline C 206 are respectively communicated with the upper part of the cylinder body 202; the pipeline B 205 and the pipeline D 207 are respectively communicated with the lower part of the cylinder body 202; the valve A 208 and the pressure gauge A 209 are arranged on the pipeline A 204 in sequence along the air inlet direction; the valve B 210 and the pressure gauge B 211 are arranged on the pipeline B 205 in sequence along the air inlet direction; the valve C 212 is arranged on the pipeline C 206; the valve D 213 is arranged on the pipeline D 207. One end of the pipeline A 204 is communicated with the cylinder body 202, and the other end is connected with the gas source A; one end of the pipeline B 205 is communicated with the cylinder body 202, and the other end is connected with the gas source B. The accuracy of the pressure gauge A 209 and the pressure gauge B 211 is ≤10Pa, and the range is ≥5MPa. The length of the needle 203 is greater than the thickness of the fabric prepreg by 1-2cm; the diameter of the needle 203 is 1-3mm.

[0031] In the embodiment, based on the above-mentioned device, the three-dimensional fabric prepreg stitching process evaluation method comprises:

[0032] S1, one side of the three-dimensional fabric prepreg 300 is placed between the first clamping plate 101 and the second clamping plate 102, and clamped by tightening the screw; the other side of the three-dimensional fabric prepreg 300 is placed between the third clamping plate 103 and the fourth clamping plate 104, and clamped by tightening the screw.

[0033] S2, the three-dimensional fabric prepreg 300 and the fixing mechanism are placed in front of the needle 203 of the needle puncture pushing force test mechanism.

[0034] S3, close valve B210 and valve C212, open valve D213; then, open valve A208, record the pressure P1 of pressure gauge A209 when needle 203 starts to move; record the pressure P2 of pressure gauge A209 when needle 203 moves through the 3D fabric prepreg 300.

[0035] S4, close valve A208 and valve D213, open valve C212; then, open valve B210, close valve B210 when piston 201 rises to the starting position.

[0036] S5, calculate the pushing force F of needle 203 when it moves through the 3D fabric prepreg 300 according to the recorded pressure P1 and pressure P1, wherein F=S*(P2-P1), S represents the area of the circular region on the upper surface of piston 201.

[0037] S6, give the evaluation result of the stitching process of 3D fabric prepreg 300 according to the calculated pushing force F, wherein when F≤5N, the evaluation result of the stitching process is excellent; when 5N<F≤10N, the evaluation result of the stitching process is good; when 10N<F, the evaluation result of the stitching process is poor.

[0038] It should be noted that when controlling valve A208 and valve B210, they should be opened slowly, and the opening degree of valve A208 or valve B210 should be controlled to ensure that the moving speed of needle 203 is 0.5-2.0mm / s, so as to realize the slow movement of needle 203.

[0039] Based on the above embodiment, two specific examples are described below.

[0040] Example 1

[0041] The 3D fabric prepreg stitching process evaluation device is made of 45# steel, and the size of the clamping plate is 10*5*2cm; the diameter of the piston is 10cm, and the area of the upper surface of the piston is 78.5cm 2 ; the diameter of the needle is 1mm, and the length is 3cm; the pressure gauge is a digital pressure gauge with an accuracy of 1pa and a range of 10mpa.

[0042] To test the stitching process of 3D fabric prepreg with a thickness of 10mm, the steps are as follows:

[0043] Place one side of the 3D fabric prepreg between the first clamping plate and the second clamping plate and clamp it by tightening the screws; place the other side of the 3D fabric prepreg between the third clamping plate and the fourth clamping plate and clamp it by tightening the screws.

[0044] Place the 3D fabric prepreg and the fixing mechanism as a whole directly below the needle of the needle puncture pushing force testing mechanism.

[0045] Close valve B and valve C, open valve D; then, slowly open valve A, when the needle starts to move at a speed of 1 mm / s, record the pressure of pressure gauge A at this time P1 = 10200 pa; when the needle contacts the 3D fabric prepreg, the needle stops moving, continues to slowly increase valve A, the needle continues to move at a speed of 1 mm / s and penetrates the 3D fabric prepreg 1 cm, record the pressure of pressure gauge A at this time P2 = 10800 pa.

[0046] Close valve A and valve D, open valve C; then, open valve B, when the piston rises to the starting position, close valve B.

[0047] The calculated thrust of the needle penetrating the 3D fabric prepreg is F = 600 * 78.5 * 10 -4 = 4.7N, and the evaluation result of the stitching process is excellent.

[0048] Example 2

[0049] The 3D fabric prepreg stitching process evaluation device is made of 45# steel, and the size of the clamping plate is 10*5*2cm; the diameter of the piston is 10cm, the upper surface area of the piston is 78.5cm 2 ; the diameter of the needle is 1mm, and the length is 3cm; the pressure gauge is a digital pressure gauge with an accuracy of 1pa and a range of 10mpa.

[0050] To test the stitching process of a 3D fabric prepreg with a thickness of 15mm, follow the steps below:

[0051] Place one side of the 3D fabric prepreg between the first and second clamping plates and clamp it by tightening the screws; place the other side of the 3D fabric prepreg between the third and fourth clamping plates and clamp it by tightening the screws.

[0052] Place the 3D fabric prepreg and the fixing mechanism directly below the needle of the needle penetration and pushing force testing mechanism.

[0053] Close valve B and valve C, open valve D; then, slowly open valve A, when the needle starts to move at a speed of 0.5mm / s, record the pressure of pressure gauge A at this time P1 = 10100 pa; when the needle contacts the 3D fabric prepreg, the needle stops moving, continues to slowly increase valve A, the needle continues to move at a speed of 0.5mm / s and penetrates the 3D fabric prepreg 1.5cm, record the pressure of pressure gauge A at this time P2 = 11200 pa.

[0054] Close valve A and valve D, open valve C; then, open valve B, when the piston rises to the starting position, close valve B.

[0055] The calculated push force F = 1100*78.5*10 when the needle penetrates the stereoscopic fabric prepreg is 8.6N, and the stitching process evaluation result is good. -4

[0056] Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solutions of the present application shall fall within the protection scope of the technical solutions of the present application.

[0057] The contents not described in detail in the specification of the present application belong to the known technology of the person skilled in the art.​

Claims

1. A device for evaluating the sewing processability of three-dimensional prepreg fabrics, characterized in that, include: Fixation mechanism and needle puncture force testing mechanism; The fixing mechanism includes: a first clamping plate (101), a second clamping plate (102), a third clamping plate (103), and a fourth clamping plate (104); wherein the first clamping plate (101) and the second clamping plate (102) are a group, the third clamping plate (103) and the fourth clamping plate (104) are a group, and each group of clamping plates is connected by two screws. The needle puncture force testing mechanism includes: a piston (201), a cylinder body (202), a needle (203), tubing A (204), tubing B (205), tubing C (206), tubing D (207), valve A (208), pressure gauge A (209), valve B (210), pressure gauge B (211), valve C (212), and valve D (213); wherein, the piston (201) is located inside the cylinder body (202) and can move up and down within the cylinder body (202); the needle (203) is mounted on the piston (201). Bottom; Pipes A (204) and C (206) are connected to the upper part of the cylinder body (202) respectively; Pipes B (205) and D (207) are connected to the lower part of the cylinder body (202) respectively; Pipe A (204) is equipped with valve A (208) and pressure gauge A (209) in sequence along the air intake direction; Pipe B (205) is equipped with valve B (210) and pressure gauge B (211) in sequence along the air intake direction; Pipe C (206) is equipped with valve C (212); Pipe D (207) is equipped with valve D (213).

2. The device for evaluating the sewing processability of three-dimensional prepreg fabrics according to claim 1, characterized in that, A fixing mechanism is used to fix the three-dimensional fabric prepreg.

3. The three-dimensional fabric prepreg sewing process evaluation device according to claim 2, characterized in that, The needle puncture force testing mechanism is used to perform sewing process testing on fixed three-dimensional fabric prepreg.

4. The device for evaluating the sewing processability of three-dimensional prepreg fabrics according to claim 1, characterized in that, The structural dimensions of the first clamping plate (101), the second clamping plate (102), the third clamping plate (103), and the fourth clamping plate (104) are the same; the width of the clamping plate is 5-10cm, the length is 5-20cm, and the thickness is 1-3cm.

5. The device for evaluating the sewing processability of three-dimensional prepreg fabrics according to claim 1, characterized in that, One end of pipe A (204) is connected to the cylinder body (202), and the other end is connected to the air source A; one end of pipe B (205) is connected to the cylinder body (202), and the other end is connected to the air source B.

6. The device for evaluating the sewing processability of three-dimensional prepreg fabrics according to claim 1, characterized in that, The accuracy of pressure gauge A (209) and pressure gauge B (211) are both ≤10Pa and the range is both ≥5MPa.

7. The device for evaluating the sewing processability of three-dimensional prepreg fabrics according to claim 1, characterized in that, The length of the needle (203) is greater than or equal to the thickness of the prepreg fabric, which is 1 to 2 cm. The diameter of the needle (203) is 1 to 3 mm.

8. A method for evaluating the sewing processability of three-dimensional fabric prepregs based on the device described in claim 1, characterized in that, include: One side of the three-dimensional fabric prepreg (300) is placed between the first clamping plate (101) and the second clamping plate (102) and clamped by tightening screws; the other side of the three-dimensional fabric prepreg (300) is placed between the third clamping plate (103) and the fourth clamping plate (104) and clamped by tightening screws. The three-dimensional fabric prepreg (300) and the fixing mechanism are placed directly below the needle (203) of the needle puncture driving force testing mechanism; Close valves B (210) and C (212), and open valve D (213); then, open valve A (208), and when the needle (203) starts to move, record the pressure P1 of pressure gauge A (209); when the needle (203) moves to pass through the three-dimensional fabric prepreg (300), record the pressure P2 of pressure gauge A (209); Close valves A (208) and D (213), open valve C (212); then open valve B (210), and close valve B (210) when piston (201) rises to the starting position; Based on the recorded pressure P1, the thrust F when the needle (203) passes through the three-dimensional fabric prepreg (300) is calculated; Based on the calculated thrust F, the evaluation results of the sewing process of the three-dimensional fabric prepreg (300) are given; when F≤5N, the sewing process evaluation result is excellent; when 5N<F≤10N, the sewing process evaluation result is good; when 10N<F, the sewing process evaluation result is poor.

9. The method according to claim 8, characterized in that, F = S*(P2-P1); where S represents the area of ​​the circular region on the upper surface of the piston (201).

10. The method according to claim 9, characterized in that, By controlling the opening of valve A (208) or valve B (210), the movement speed of needle (203) is ensured to be 0.5 to 2.0 mm / s.

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