A method for monitoring the weaving angle of carbon fiber fabric based on resistance measurement

Abstract

The present application relates to a kind of carbon fiber fabric weaving angle monitoring methods based on resistance measurement, comprising the following process steps:1), carbon fiber fabric weaving uses annular radial weaving device, by controlling weaving parameter and weaving process to weave carbon fiber fabric;2), using four metal rollers as measurement electrode, using mechanical arm control electrode measurement position;3), by input current, obtain voltage value, according to the voltage value calculated from measurement resistance value of measurement position;4), according to resistance value and previously measured angle and resistance relationship diagram are contrasted, obtain the fabric angle of current measurement position;5), compare the measured fabric angle and the angle of set weaving parameter, confirm whether the current fabric weaving process is correct.The present application uses sensing method to carry out real-time online monitoring, can effectively real-time monitoring of weaving angle under the premise of guaranteeing not to affect normal preparation of carbon fiber fabric.

Description

Technical field

[0001] The present invention relates to a method for monitoring the weaving angle of a fabric, in particular to a method for monitoring the weaving angle of a carbon fiber fabric based on resistance measurement, and belongs to the technical field of non-destructive testing. [Background Technology]

[0002] Carbon fiber reinforced composite materials have advantages such as no creep, high temperature resistance, corrosion resistance, and small expansion coefficient, which give them strong competitive advantages in harsh environments such as density, stiffness, and chemical resistance. They are currently widely used in many fields such as aerospace, chemical industry, automobiles, and wind power generation.

[0003] However, during the production process of carbon fiber woven composite materials, the weaving angle of the final fabric will deviate from the initially set weaving angle parameters. This difference in weaving angle will have a significant impact on the performance of the final carbon fiber composite material. If the weaving angle cannot be detected during the weaving process, it will pose a safety hazard. Currently, the main methods for detecting the weaving angle of carbon fiber fabrics are online or offline optical detection methods, such as stereophotometry and machine vision. However, optical detection has high requirements for ambient light and is not suitable for use in actual production environments such as factories.

[0004] Therefore, in order to solve the above problems, it is necessary to provide an innovative carbon fiber fabric weaving angle monitoring method based on resistance measurement to overcome the above defects in the prior art. [Summary of the invention]

[0005] In order to solve the above problems, the purpose of the present invention is to provide a carbon fiber fabric weaving angle monitoring method based on resistance measurement, which adopts a sensing method to perform real-time online measurement, and can effectively monitor the weaving angle in real time without affecting the normal preparation of the carbon fiber fabric.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for monitoring the braiding angle of carbon fiber fabric based on resistance measurement, which includes the following process steps:

[0007] 1) Carbon fiber fabric weaving adopts an annular radial weaving device, and the carbon fiber fabric is woven by controlling the weaving parameters and weaving process;

[0008] 2) Four metal rollers are used as measuring electrodes, and a robotic arm is used to control the measuring position of the electrodes;

[0009] 3) By inputting current, a voltage value is obtained, and the resistance value at the measurement location is calculated based on the measured voltage value;

[0010] 4) comparing the resistance value calculated in step 3) with the angle and resistance relationship diagram obtained from the previous measurement to determine the fabric angle at the current measurement position;

[0011] 5) Compare the measured fabric angle with the angle of the set weaving parameters to confirm whether the current fabric weaving process is correct.

[0012] The carbon fiber fabric weaving angle monitoring method based on resistance measurement of the present invention is further as follows: in the step 1), the annular radial weaving device includes a spindle, a guide ring and a core shaft, which has 72 bias yarns and 36 axial yarns, the bias yarns are grouped in pairs, each group corresponds to two spindles, and carbon fiber of model T700 12k is used; the spindles are evenly arranged on the annular radial weaving device according to the required number; the inner diameter of the guide ring is 300 mm; the core shaft maintains the tension of the carbon fiber, determines the shape of the fabric and fixes the position of the fabric; the carbon fiber is woven on the surface of the core shaft through the guide ring.

[0013] The carbon fiber fabric weaving angle monitoring method based on resistance measurement of the present invention is further as follows: the weaving parameters include the number of carbon fiber bundles, the number of spindle heads, the weaving angle and the weaving speed; during the weaving process, the core shaft is controlled by manipulating the robotic arm, and the weaving angle is adjusted based on the initial depth, rotation speed and expected feed speed.

[0014] The carbon fiber fabric weaving angle monitoring method based on resistance measurement of the present invention is further as follows: Step 2) is specifically: four inverted olive-shaped roller electrodes are placed on four bearings with fixed relative distances on the manipulator platform, and a current source capable of generating milliampere current is connected to the two outer roller electrodes, and the output current is set to 100mA; the positive and negative poles of the voltmeter are connected to the two inner roller electrodes in the same direction as the current source.

[0015] The carbon fiber fabric weaving angle monitoring method based on resistance measurement of the present invention is further as follows: the specific method of the robotic arm controlling the measurement position of the electrode is: when the fabric weaving angle monitoring is not required, the robotic arm platform is controlled to move the roller electrode away from the fabric and the core shaft; when the fabric weaving angle monitoring is required, the robotic arm platform is controlled to make the roller electrode tangent to the fabric surface, and then monitor.

[0016] The carbon fiber fabric weaving angle monitoring method based on resistance measurement of the present invention can also be: in the step 4), the process of establishing the angle and resistance relationship diagram is as follows: the parallel resistance between the electrodes determined by the carbon fiber bundle angle is defined as R, and a relationship curve related to the weaving angle is established through the change of R.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The carbon fiber fabric weaving angle monitoring method of the present invention adopts the resistance measurement method. Compared with the currently commonly used non-destructive testing methods, the resistance measurement method does not require other sensors for measurement. It completes self-sensing through its own conductive properties, and can complete the detection conveniently and quickly.

[0019] 2. The carbon fiber fabric weaving angle monitoring method of the present invention can be used directly during the carbon fiber weaving process. Without affecting the normal preparation of the carbon fiber fabric, it can monitor online whether the actual weaving angle meets the design standards, providing real-time information feedback for the intelligent production of composite materials.

Brief Description of the Drawings

[0020] Figure 1 Schematic diagram of the circular radial braiding device used in step 1) of the present invention.

[0021] Figure 2 Schematic diagram of step 2) of the present invention using four metal rollers as measuring electrodes.

[0022] Figure 3 It is a schematic diagram when the roller electrode is away from the fabric and the core shaft.

[0023] Figure 4 This is a schematic diagram of the roller electrode, fabric, and core shaft being tangent.

[0024] Figure 5 This is a schematic diagram of the current path in carbon fiber fabric when the weaving angle is 45°.

[0025] Figure 6 This is a schematic diagram of the current path in carbon fiber fabric when the weaving angle is 60°.

[0026] Figure 7 It is a schematic diagram illustrating the resistance values ​​of the present invention. [Specific implementation method]

[0027] Please refer to the instruction manual Figure 1 To the attached Figure 7 As shown, the present invention is a method for monitoring the braiding angle of carbon fiber fabric based on resistance measurement, which includes the following process steps:

[0028] 1) Carbon fiber fabric is woven using a circular radial weaving device 1, which controls weaving parameters and weaving process to weave carbon fiber fabric.

[0029] The annular radial braiding device 1 is composed of several parts including a spindle 2, a guide ring 3 and a core shaft 4. It has 72 bias yarns and 36 axial yarns. The bias yarns are grouped in pairs, and each group corresponds to two spindles. It uses carbon fiber model T700 12k.

[0030] Furthermore, the spindles 2 are evenly arranged on the annular radial braiding device 1 in the required number. The guide ring 3 has an inner diameter of 300 mm. The mandrel 4 maintains the tension of the carbon fibers 6, determines the shape of the fabric, and secures the fabric in place. The carbon fibers 6 are braided on the surface of the mandrel 4 via the guide ring 3.

[0031] The braiding parameters include the number of carbon fiber tows, the number of spindles, the braiding angle, and the braiding speed. Once the braiding parameters are determined, the motor is started to weave. Mandrel 4 in the braiding device determines the fabric shape. Mandrel 4 and guide ring 3 maintain carbon fiber tension, determine the fabric braiding angle, and secure the fabric position. Mandrel 4 is controlled by a manipulator, adjusting the braiding angle based on the initial depth, rotational speed, and estimated feed rate.

[0032] 2) Four metal rollers are used as measuring electrodes 10 (as a pair of current input sources and a pair of voltage measurement sources), and a robotic arm is used to control the measuring position of the electrodes.

[0033] Specifically, four inverted olive-shaped roller electrodes 10 were placed on four fixed bearings on a manipulator platform 11. A current source 7 capable of generating milliampere-level current was connected to the two outer roller electrodes 10, with the output current set to 100 mA. The positive and negative poles of a voltmeter 9 were connected to the inner two roller electrodes 10 in the same direction as the current source.

[0034] The specific method of using the robotic arm to control the measurement position of the electrode is: when the fabric weaving angle monitoring is not required, the robotic arm platform 11 is controlled to move the roller electrode 10 away from the fabric 8 and the core shaft 4; when the fabric weaving angle monitoring is required, the robotic arm platform 11 is controlled to make the roller electrode 10 tangent to the surface of the fabric 8 for monitoring.

[0035] 3) By inputting current, the voltage value is obtained, and the resistance value at the measurement location is calculated based on the measured voltage value and Ohm's law.

[0036] 4) Compare the resistance value calculated in step 3) with the angle and resistance relationship diagram obtained from the previous measurement to obtain the fabric angle at the current measurement position.

[0037] The process of establishing the angle and resistance relationship diagram obtained by previous measurements is as follows: the parallel resistance between the electrodes determined by the angle of the carbon fiber tow is defined as R, and the relationship curve related to the braiding angle is established through the change of R.

[0038] 5) Compare the measured fabric angle with the angle of the set weaving parameters to confirm whether the current fabric weaving process is correct.

[0039] The reason why the resistance of the fabric changes with the weaving angle is that the current path changes, e.g. Figure 3As shown, Figure 5 represents the current path when the fabric with a measuring angle of 45°, wherein the resistance is composed of four resistances R1, R2, R3, R4 in parallel circuit. Figure 6 represents the fabric with an angle of 60°, when the resistance measurement is performed, the resistance in the circuit is R5, R6, R7, R8, R9, R10 six resistances in parallel, and R7, R8, R9 belong to a piece of resistance, R6, R8, R10 belong to a piece of resistance, essentially the circuit belongs to three resistances in parallel. The more the number of resistances in parallel in the parallel resistance, the smaller the total resistance, so it can be concluded that as the weaving angle of the fabric decreases, the fabric resistance decreases.

[0040] Because the carbon fiber fabric itself is woven by overlapping each other through the warp and weft, its surface is not flat, but has a periodic fluctuation, so the measured resistance value is not a fixed resistance value, but a periodic waveform value, which can be shown as Figure 7 . Figure 4 The middle curve represents the fabric resistance curve of 45° weaving angle, and the * curve represents the fabric resistance curve of 60° weaving angle. The peak value of 45° fabric resistance is lower than that of 60° fabric. At the same time, from the comparison of Figure 5 and Figure 6 It can be seen that the 60° fabric has more yarns in the same distance, and the fabric is more compact, so the change period of 60° fabric is smaller than that of 45° fabric. Therefore, the weaving angle of the current detected fabric can be judged by the peak value and period in the waveform value.

[0041] The above specific embodiments are only the preferred embodiments of the present application, and do not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for monitoring the braiding angle of carbon fiber fabrics based on resistance measurement, characterized in that: The process steps include: 1) Carbon fiber fabric weaving adopts an annular radial weaving device, and the carbon fiber fabric is woven by controlling the weaving parameters and weaving process; 2) Use four metal rollers as measurement electrodes, and use a robotic arm to control the measurement position of the electrodes. Specifically, place four inverted olive-shaped roller electrodes on four fixed bearings on the robotic platform. Connect a current source capable of generating milliampere current to the two outer roller electrodes, with the output current set to 100mA. Connect the positive and negative poles of a voltmeter to the inner two roller electrodes in the same direction as the current source. The specific method of the robot arm controlling the measuring position of the electrode is as follows: when the fabric weaving angle monitoring is not required, the robot arm platform is controlled to move the roller electrode away from the fabric and the core shaft; when the fabric weaving angle monitoring is required, the robot arm platform is controlled to make the roller electrode tangent to the fabric surface for monitoring; 3) By inputting current, a voltage value is obtained, and the resistance value at the measurement location is calculated based on the measured voltage value; 4) comparing the resistance value calculated in step 3) with the angle and resistance relationship diagram obtained from the previous measurement to determine the fabric angle at the current measurement position; 5) Compare the measured fabric angle with the angle of the set weaving parameters to confirm whether the current fabric weaving process is correct.

2. The method for monitoring the braiding angle of carbon fiber fabric based on resistance measurement according to claim 1, wherein: In step 1), the annular radial weaving device includes spindles, a guide ring, and a core shaft, which has 72 bias yarns and 36 axial yarns, with the bias yarns grouped in pairs, each group corresponding to two spindles, and uses carbon fiber model T70012k; the spindles are evenly arranged on the annular radial weaving device according to the required number; the inner diameter of the guide ring is 300 mm; the core shaft maintains the tension of the carbon fiber, determines the shape of the fabric, and fixes the position of the fabric; the carbon fiber is woven on the surface of the core shaft through the guide ring.

3. The method for monitoring the braiding angle of carbon fiber fabric based on resistance measurement according to claim 2, wherein: The weaving parameters include the number of carbon fiber tows, the number of spindle heads, the weaving angle and the weaving speed; during the weaving process, the core shaft is controlled by manipulating the robotic arm, and the weaving angle is adjusted based on the initial depth, rotation speed and expected feed speed.

4. The method for monitoring the braiding angle of carbon fiber fabric based on resistance measurement according to claim 1, wherein: In step 4), the process of establishing the angle and resistance relationship diagram is as follows: the parallel resistance between the electrodes determined by the angle of the carbon fiber tow is defined as R, and a relationship curve related to the braiding angle is established by the change of R.

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