Method and tool for measuring fiber volume fraction of flanged barrel-shaped composite workpiece

Abstract

According to the method and the tool for measuring the fiber volume fraction of the flanged barrel-shaped composite workpiece, the mass of the flanged barrel-shaped composite workpiece is measured through a tension sensor, then the flanged barrel-shaped composite workpiece is immersed into water, buoyancy borne by the flanged barrel-shaped composite workpiece is measured through the sensor, and the volume of the workpiece is calculated; according to the method, the average density of the composite part is calculated, and the average fiber volume fraction of the flanged barrel-shaped composite part can be calculated by combining the density of a fiber body and the density of a resin matrix which are used for preparing the flanged barrel-shaped composite part, so that the measurement of the average fiber volume fraction of the flanged barrel-shaped composite part is realized. According to the method, the fiber volume fraction of the flanged barrel-shaped composite workpiece can be measured, and compared with a measurement method in the prior art, the measurement method provided by the invention is higher in result accuracy and more visual in test result.

Description

Technical Field

[0001] The invention relates to the technical field of composite material part measuring equipment, and more specifically to a fiber volume fraction measuring method and a measuring tool for a barrel-shaped composite material part with a flange. Background Art

[0002] When measuring the average fiber volume fraction of the entire composite material part, it is necessary to measure the total mass and total volume of the part and then calculate the average bulk density of the part. Then, the average fiber volume fraction of the entire part is calculated based on the bulk density of the reinforcing fibers in the composite material and the bulk density of the resin matrix in the composite material.

[0003] When measuring the volume of composite parts, if the optical fitting method is used to scan the entire surface of the part, for large and complex surface components, it is necessary to scan different areas of the large and complex surface components in turn to form scanning models of each area, and then fit the scanning models of multiple areas through the corresponding fitting software to form an overall model, and then calculate the volume of the component based on the overall model. There is a deviation between the model formed by fitting and the actual model. The larger the volume of the component, the more areas need to be scanned and the more times the fitting is required. Therefore, the measurement deviation increases with the increase of the part volume, and the deviation is closely related to the disturbance of the on-site measurement state. Therefore, for large and complex surface components, the measurement results have a large deviation problem. If the part has a processing hole (such as a sound lining hole), the light may not be able to penetrate the processing hole due to the small hole during scanning, which leads to the failure to scan these processing holes during scanning, which also affects the accuracy of the measurement results. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The technical problem to be solved by the present invention is that when the existing optical fitting method is used to measure the fiber volume fraction of a large complex profile component, the measurement result has a large deviation value and low accuracy.

[0006] (II) Technical solution

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a method for measuring the fiber volume fraction of a flanged barrel-shaped composite part, comprising the following steps:

[0009] Fixed tension sensors are respectively installed on the traction ropes connected to multiple hanging point positions of the flanged barrel-shaped composite material part, and the multiple hanging point positions are arranged on the same horizontal plane;

[0010] One end of the traction rope is connected to the lifting point, and the other end of the traction rope is connected to the lifting device. The length direction of the traction rope is parallel to the Z direction of the flanged barrel-shaped composite part, and the lifting device is provided with a distance measuring sensor;

[0011] The lifting device lifts the flanged barrel-shaped composite material part through the traction rope, and measures and calculates the mass Mp of the flanged barrel-shaped composite material part through the tension sensor;

[0012] The flanged barrel-shaped composite material part is hoisted into the annular water tank, and the flanged barrel-shaped composite material part is kept at a preset distance from the bottom of the annular water tank;

[0013] Filling water into the annular water tank until the water surface completely covers the top surface of the flanged barrel-shaped composite member, measuring the buoyancy of the flanged barrel-shaped composite member by a tension sensor, marking the position where the traction rope is submerged in the water, and calculating the volume Vp of the flanged barrel-shaped composite member according to the buoyancy;

[0014] Calculate the average density of the flanged barrel composite part

[0015] According to the fiber density ρ f and the resin matrix density ρ r The average fiber volume fraction V of the flanged barrel composite part is calculated as follows: fm .

[0016] Preferably, the mass Mp of the flanged barrel-shaped composite part is calculated by the following formula:

[0017]

[0018] Among them, G t Represents the total tension measured by multiple tension sensors, G n It represents the tension value of a single hanging point measured by the tension sensor at the nth hanging point, where g is the acceleration due to gravity.

[0019] Preferably, the volume Vp of the flanged barrel-shaped composite part is calculated according to the following formula:

[0020]

[0021] Among them, G t Represents the total tension measured by multiple tension sensors, T t represents the total tensile force measured by multiple tensile sensors when the water surface completely covers the top surface of the flanged barrel-shaped composite member, ρ w It represents the density of water at the corresponding measurement environment temperature, g is the acceleration due to gravity, V L Indicates the volume of the portion of the towing rope that is submerged in water.

[0022] Preferably, the fiber average volume fraction is calculated according to the following formula:

[0023]

[0024] Preferably, the method further comprises the following steps:

[0025] When water is poured into the annular water tank, the water is poured at intervals of a certain liquid level after the water contacts the flanged barrel-shaped composite member. After the reading of the tension sensor is stable, the value of each tension sensor is read to obtain the sensor measurement value T at the i-th water level. i , where i is a positive integer;

[0026] Calculate the volume of the flanged barrel composite part submerged in water at each water level

[0027] The height between two adjacent water surfaces is a cutting section. The flanged barrel-shaped composite material part has a plurality of interconnected cutting sections along the Z direction. The measured volume of each cutting section is △vi=v i+1 -v i ;

[0028] The measured volume Δvi of each cutting section is combined with the theoretical volume of the digital model of the flanged barrel-shaped composite part in the corresponding cutting section to obtain the deviation value between the measured thickness of each cutting section and the theoretical thickness of the digital model.

[0029] Preferably, the method further comprises the following steps:

[0030] The theoretical volume △Vt of each cutting section is measured according to the three-dimensional digital model of the workpiece, and compared with the measured volume △Vi corresponding to each cutting section. Since the workpiece is manufactured according to the set fiber path, the deviation of the fiber volume fraction of each cutting section is mainly caused by the thickness of the workpiece, that is, △Vi / △Vt=di / dt, where dt is the theoretical thickness, and the measured average thickness di of each cutting section is calculated. Since the fiber volume fraction is a function of the thickness di, the fiber volume fraction at different thicknesses is measured experimentally, and the corresponding fiber volume fraction f(di) within a certain thickness range is fitted, and then the Z-direction fiber measurement volume fraction △V of each cutting section can be obtained. fm Then, the average density △ρi of the corresponding cutting section is calculated according to the measured volume fraction of the Z-direction fiber in each cutting section, and the total mass m of the flanged barrel-shaped composite part is calculated according to the measured volume △vi and the average density △ρi of each cutting section. 估 =∑(△ρi×△vi), m 估 Compared with Mp, the credibility of the measurement data of each cutting section is evaluated.

[0031] Preferably, the evaluation of the credibility of the measurement data of each cutting section comprises the following steps:

[0032] When m 估 When the value of Mp is within the preset deviation range, the measurement data of each cutting section is credible;

[0033] When m 估 When the value of Mp exceeds the preset deviation range, the measurement data of each cutting section is not credible.

[0034] In the second aspect, the present invention also provides a measuring tool for implementing the fiber volume fraction measurement method of the flanged barrel-shaped composite part described in any one of the above technical solutions, comprising a lifting device, a plurality of tension sensors, a traction rope and an annular water tank; the lifting device is used to lift the flanged barrel-shaped composite part along the Z direction, and the lifting device is provided with a distance measuring sensor; a plurality of tension sensors are arranged on the traction rope connected to the lifting device; the traction rope is used to connect the lifting device and the flanged barrel-shaped composite part; the annular water tank is used to accommodate the flanged barrel-shaped composite part and water.

[0035] Preferably, it further comprises a moving assembly, which is connected to the lifting device and is used to drive the lifting device to move along the X direction and the Y direction.

[0036] Preferably, the height of the annular water tank is higher than the height of the flanged barrel-shaped composite part.

[0037] (III) Beneficial effects

[0038] The above technical solution of the present invention has at least the following advantages:

[0039] 1. In the present invention, the mass of the flanged barrel-shaped composite part is measured by a tension sensor, and the volume of the flanged barrel-shaped composite part is calculated by immersing the flanged barrel-shaped composite part in water to measure the buoyancy it receives, and then the average density of the flanged barrel-shaped composite part can be calculated. Combined with the density of the fiber body and the density of the resin matrix used to prepare the flanged barrel-shaped composite part, the average fiber volume fraction of the flanged barrel-shaped composite part can be calculated, and then the average fiber volume fraction of the flanged barrel-shaped composite part can be measured. The method provided by the present invention is particularly suitable for measuring the average fiber volume fraction of large-sized complex-surface parts. Compared with the optical fitting method, it does not require multiple scanning and fitting of the parts, and the test results have a smaller deviation from the actual value and a higher accuracy.

[0040] 2. In the present invention, compared with the method of calculating the volume of a workpiece by reverse modeling using an optical scanning method, when the measurement method provided by the present invention is used to measure a workpiece with a processing hole thereon, water can smoothly enter the processing hole, so that the volume measurement is not affected by the processing hole of the workpiece, the measurement operation and data processing are simpler, and the result accuracy is higher.

[0041] 3. In the present invention, the entire measurement process is mainly achieved through a tension sensor. Since the tension sensor is an easily available third-party standard measuring instrument, the tension sensor can be selected and used by the party entrusting the measurement, and the test results can be directly displayed on the tension sensor, which is intuitive. For large-scale parts, multiple small-range tension sensors can be used for measurement. The deviation range of each calibrated tension sensor is calibrated, and the deviation range is estimable when multiple tension sensors are measured in parallel. Therefore, compared with the method of calculating the volume of the part by reverse modeling using an optical scanning method, the test process of the present invention can be intuitively reflected through the readings of the tension sensor and the corresponding calculation formula, and is more credible. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be 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 paying creative work.

[0043] Figure 1 It is a schematic flow chart of a method for measuring the fiber volume fraction of a flanged barrel-shaped composite part provided in an embodiment of the present invention.

[0044] Figure 2 It is a schematic structural diagram of a flanged barrel-shaped composite part provided in an embodiment of the present invention.

[0045] Figure 3 It is a structural schematic diagram of an annular water tank provided in an embodiment of the present invention.

[0046] Figure 4 It is a schematic diagram of the structure of the measuring tool provided in an embodiment of the present invention.

[0047] The reference numerals in the figures are:

[0048] 100. Flanged barrel-shaped composite part; 110. Tension sensor; 120. Distance sensor; 200. Towing rope; 300. Annular water tank; 400. Mechanism frame; 500. X-axis crossbeam guide rail; 600. Y-axis moving crossbeam; 700. Lifting device. DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0050] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0051] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0053] like Figure 4 As shown, the embodiment of the present invention provides a measuring tool for implementing a fiber volume fraction measurement method of a flanged barrel-shaped composite part 100. It should be noted that, as Figure 2 The flanged barrel-shaped composite component 100 shown is a resin-based composite component, and the reinforcement is a textile fiber (specifically, it can be a carbon fiber textile fiber), and its components include a resin material for forming a resin matrix and a fiber material for forming a reinforcement. The actual size of the flanged barrel-shaped composite component 100 is relatively large, and it is barrel-shaped as a whole and has a flanged structure. The measuring tool includes a lifting device 700, a plurality of tension sensors 110, a traction rope 200, and an annular water tank 300; the lifting device 700 is used to lift the flanged barrel-shaped composite component 100 along the Z direction; the plurality of tension sensors 110 are arranged on the traction rope 200 connected to the lifting device 700; the traction rope 200 is used to connect the lifting device 700 and the flanged barrel-shaped composite component 100; the annular water tank 300 (such as Figure 3) is used to accommodate the flanged barrel-shaped composite part 100 and water. It should be noted that the specific structural form of the lifting device 700 is not limited in this application, and it can be a linear servo module, or a crane, a hoist, a servo linear electric cylinder, etc. In this embodiment, the lifting device 700 is preferably a servo linear electric cylinder, and the output end of the linear electric cylinder is connected to the traction rope 200.

[0054] like Figure 4 As shown, in one embodiment, a moving assembly is further included, and the moving assembly is connected to the lifting device, and is used to drive the lifting device to move along the X direction and the Y direction. Specifically, the moving assembly includes a mechanism frame 400, an X-direction beam guide rail 500, and a Y-direction moving beam 600. The X-direction beam guide rail is installed in the X direction of the mechanism frame 400, and a plurality of Y-direction moving beams 600 that can move along the X direction are installed on the X-direction beam guide rail 500. A lifting device 700 that can move along the Z direction is installed on each Y-direction moving beam 600, and the lifting device 700 can move on the Y-direction moving beam 600. Specifically, in this embodiment, the X direction corresponds to the X-axis direction of the three-dimensional spatial coordinate system, the Y direction corresponds to the Y-axis direction of the three-dimensional spatial coordinate system, and the Z direction corresponds to the Z-axis direction of the three-dimensional spatial coordinate system. By setting up the moving assembly, the lifting device can be driven to move in the xy plane. In conjunction with the Z-direction movement of the lifting device, the flanged barrel-shaped composite part 100 can be lifted and transported to a designated position in the three-dimensional space of the mechanism frame 400.

[0055] In one embodiment, the height of the annular water tank 300 is higher than the height of the flanged barrel-shaped composite product 100, so that the annular water tank 300 can accommodate the entire flanged barrel-shaped composite product 100, and the water surface can completely cover the top surface of the flanged barrel-shaped composite product 100 when water is poured into the annular water tank 300.

[0056] like Figure 1 As shown, the embodiment of the present invention provides a method for measuring the fiber volume fraction of a flanged barrel-shaped composite part, which is used to measure Figure 2 The fiber volume fraction of the flanged barrel-shaped composite product 100 shown includes the following steps:

[0057] Distance sensors 120 are respectively installed on multiple lifting devices 700, and the distance between the end face of the lifting device 700 and the Y-direction moving crossbeam 600 is measured to ensure that multiple lifting point positions are set on the same horizontal plane; specifically, when the lifting device 700 lifts the flanged barrel-shaped composite part 100, it can ensure that the bottom surface of the flanged barrel-shaped composite part 100 is always perpendicular to the Z direction, that is, the height direction of the flanged barrel-shaped composite part 100 is parallel to the Z direction. More specifically, before installing and fixing the tension sensor, it is first necessary to determine the number of lifting point positions and the specifications of the tension sensor used according to the geometric dimensions and estimated weight of the flanged barrel-shaped composite part 100. Then the tension sensor needs to be calibrated, a calibration range is selected within the range of the tension sensor, several calibration measurement points are selected within the calibration range, and the tension sensor is measured at the corresponding calibration measurement points using standard weights. Multiple tension sensors are electrically connected to the industrial control computer, and the measurement error of the tension sensor is compensated by setting a corresponding program in the industrial control computer. The remaining measurement points within the calibration range are calculated and compensated using linear interpolation of the calibration point measurement point error. Furthermore, multiple distance sensors 120 (the position of the distance sensor 120 is set as shown in FIG. 1 ) can be set on the lifting device 700. Figure 3 As shown in the figure, after the flanged barrel-shaped composite material part 100 is lifted, the lifting device corresponding to each lifting point position is driven to move along the Z direction, so as to adjust the value of each distance measuring sensor 120 to the specified value, thereby realizing that multiple lifting point positions are set on the same horizontal plane. In this embodiment, it is preferred to use a small-range tension sensor for measurement. The small-range tension sensor has a small deviation range and is easy to accurately calibrate. Multiple calibrated small-range tension sensors are used for measurement in parallel, and the deviation of positive and negative fluctuations is partially offset, thereby improving the accuracy of volume measurement of the flanged barrel-shaped composite material part 100.

[0058] One end of the traction rope 200 is connected to the flanged barrel-shaped composite part 100, and the other end of the traction rope 200 is connected to the tension sensor 110 on the lifting device. The length direction of the traction rope is parallel to the Z direction of the flanged barrel-shaped composite part 100. The lifting device is provided with a distance sensor 120, and the distance sensor 120 is used to measure the distance between the end face of the lifting device 700 and the Y-direction moving beam 600. Specifically, the lower hook of the tension sensor is connected to the traction rope, and the two ends of the traction rope are lifting rings. The multiple traction ropes used to lift the flanged barrel-shaped composite part 100 adopt the same length specification. One end of the traction rope passes through the flanged barrel-shaped composite part from the bottom of the flanged barrel-shaped composite part and then passes through the inside of the flanged barrel-shaped composite part, and is hoisted on the lower hook of the tension sensor together with the lifting ring at the other end of the traction rope, thereby realizing the hoisting and fixing of the flanged barrel-shaped composite part. More specifically, the traction rope is preferably a steel wire rope or a steel cable, and a rubber sleeve or a polytetrafluoroethylene sleeve is provided at the position in contact with the flanged barrel-shaped composite part to separate the traction rope from the flanged barrel-shaped composite part to prevent the traction rope from damaging the flanged barrel-shaped composite part during the lifting process. The traction rope is made of a material that is not wetted by water.

[0059] The lifting device lifts the flanged barrel-shaped composite part 100 through the traction rope 200, and measures and calculates the mass Mp of the flanged barrel-shaped composite part 100 through the tension sensor; specifically, when calculating Mp, the deadweight of the traction rope 200 needs to be removed, which can be done by setting the value of the tension zero position displayed by the tension sensor to the deadweight of the traction rope 200 when debugging the tension sensor. Alternatively, when calculating the final Mp value, the deadweight of the traction rope 200 is subtracted from the value displayed by the tension sensor.

[0060] The flanged barrel-shaped composite member 100 is hoisted into the annular water tank 300 , and the flanged barrel-shaped composite member 100 maintains a preset distance from the bottom of the annular water tank 300 , so as to ensure that the flanged barrel-shaped composite member 100 is in a suspended state.

[0061] Pour water into the annular water tank 300 until the water surface completely covers the top surface of the flanged barrel-shaped composite member 100, measure the buoyancy of the flanged barrel-shaped composite member 100 through a tension sensor, mark the position where the traction rope 200 is immersed in the water surface, and calculate the volume Vp of the flanged barrel-shaped composite member 100 according to the buoyancy;

[0062] Calculate the average density of the flanged barrel composite part 100

[0063] According to the fiber density ρ f and the resin matrix density ρ r The average fiber volume fraction V of the flanged barrel composite part 100 is calculated as follows: fmCompared with the optical scanning method that calculates the volume of the workpiece through reverse modeling, the optical scanning method sometimes misses the processed holes on the workpiece (such as the acoustic lining holes), which finally causes the measured volume of the workpiece to be greater than the actual volume of the workpiece. This measurement method uses water to measure the volume of the workpiece. Water can smoothly enter the processed holes, so that the volume measurement is not affected by the processed holes of the workpiece, the measurement operation and data processing are simpler, and the results are more accurate.

[0064] In one embodiment, the mass Mp of the flanged barrel-shaped composite part 100 is calculated by the following formula:

[0065]

[0066] Among them, G t Represents the total tension measured by multiple tension sensors, G n It represents the tension value of a single hanging point measured by the tension sensor at the nth hanging point, where g is the acceleration due to gravity.

[0067] In one embodiment, the volume Vp of the flanged barrel-shaped composite part 100 is calculated according to the following formula:

[0068]

[0069] Among them, G t Represents the total tension measured by multiple tension sensors, T t represents the total tension measured by multiple tension sensors when the water surface completely covers the top surface of the flanged barrel-shaped composite component 100, ρ w It represents the density of water at the corresponding measurement environment temperature, g is the acceleration due to gravity, V L Indicates the volume of the part of the traction rope 200 submerged in the water. Since the traction rope is made of a material that is not wetted by water, its volume will not change when it is immersed in water. Specifically, we can measure the volume VL of the part of the traction rope submerged in the water by sinking the part of the traction rope submerged in the water into a measuring cylinder filled with water and measuring the volume VL of the part of the traction rope submerged in the water by the scale difference corresponding to the height of the water level in the measuring cylinder.

[0070] In one embodiment, the average fiber volume fraction is calculated according to the following formula:

[0071]

[0072] In one embodiment, the following steps are also included:

[0073] When water is poured into the annular water tank, the water is poured at a certain liquid level after the water contacts the flanged barrel-shaped composite part 100. After the tension sensor reading is stable, the value of each tension sensor is read to obtain the sensor measurement value T at the i-th water level. i, where i is a positive integer;

[0074] Calculate the volume of the flanged barrel composite part 100 submerged in water at each water level

[0075] The height between two adjacent water surfaces is a cutting section. The flanged barrel-shaped composite material product 100 has a plurality of interconnected cutting sections along the Z direction. The measured volume of each cutting section is △vi=v i+1 -v i ;

[0076] The measured volume △vi of each cutting section is combined with the theoretical volume of the digital model of the flanged barrel-shaped composite part 100 in the corresponding cutting section to obtain the deviation value of the measured thickness of each cutting section and the theoretical thickness of the digital model. It should be noted that the digital model of the flanged barrel-shaped composite part 100 refers to a digital three-dimensional model designed and drawn by three-dimensional software before the production of the flanged barrel-shaped composite part 100. The theoretical volume of the corresponding cutting section can be calculated by the corresponding three-dimensional software. When the measured volume of the corresponding cutting section is greater than the theoretical volume of its digital model, it can be explained that the actual thickness of the corresponding cutting section is greater than the theoretical thickness on the digital model; conversely, when the measured volume of the corresponding cutting section is less than the theoretical volume of its digital model, it can be explained that the actual thickness of the corresponding cutting section is less than the theoretical thickness on the digital model. Then, we can estimate the deviation ratio of the thickness of the corresponding cutting section and the theoretical thickness of the digital model according to the deviation ratio of the measured volume of each cutting section and the theoretical volume of the digital model, and then evaluate the thickness deviation value of each cutting section. For the flanged barrel-shaped composite part 100 formed of the resin-based composite material in this embodiment, the number of layers of the fiber body fabric in the corresponding cutting section is defined by design, that is, the fiber content of the fiber body fabric in the corresponding cutting section is certain, and the reason for the difference between the actual thickness of the cutting section and the theoretical thickness of the digital model is the thickness of the composite material. When the composite material of the corresponding cutting section is thicker, it means that the proportion of the resin material in the cutting section is greater, and the Z-direction fiber volume fraction (the proportion of the fiber body fabric) of the cutting section is smaller, and then the value of the Z-direction fiber measured volume fraction of each cutting section can be derived according to the deviation ratio between the thickness of the corresponding cutting section and the theoretical thickness of the digital model, and the Z-direction fiber theoretical volume fraction designed in the digital model.

[0077] In one embodiment, the following steps are also included:

[0078] The theoretical volume △Vt of each cutting section is measured according to the three-dimensional digital model of the workpiece, and compared with the measured volume △Vi corresponding to each cutting section. Since the workpiece is manufactured according to the set fiber path, the deviation of the fiber volume fraction of each cutting section is mainly caused by the thickness of the workpiece, that is, △Vi / △Vt=di / dt, where dt is the theoretical thickness, and the measured average thickness di of each cutting section is calculated. Since the fiber volume fraction is a function of the thickness di, the fiber volume fraction at different thicknesses is measured experimentally, and the corresponding fiber volume fraction f(di) within a certain thickness range is fitted, and then the Z-direction fiber measurement volume fraction △V of each cutting section can be obtained. fm Then, the average density △ρi of the corresponding cutting section is calculated according to the measured volume fraction of the Z-direction fiber in each cutting section, and the total mass m of the flanged barrel composite part 100 is calculated according to the measured volume △vi and the average density △ρi of each cutting section. 估 =∑(△ρi×△vi), m 估 Compared with Mp, the credibility of the measured data of each cutting section is evaluated. Specifically, the average density △ρi is calculated by the following formula: △ρi=V1ρ f +(1-V1)ρ r ; where ρ f is the fiber density, ρ r is the resin matrix density, and V1 is the volume fraction of the fiber measured in the Z direction.

[0079] In one embodiment, evaluating the credibility of the measurement data of each cutting section includes the following steps:

[0080] When m 估 When the value of Mp is within the preset deviation range, the measurement data of each cutting section is credible;

[0081] When m 估 When the value of Mp exceeds the preset deviation range, the measurement data of each cutting section is not credible. Specifically, the preset deviation range can determine its specific value according to the actual design requirements and the corresponding structural form. In this embodiment, the preset deviation range can be preferably ±1%.

[0082] The following is a specific example to illustrate the Figure 2 The fiber volume fraction measurement method of the flanged barrel composite part shown in the figure is described, and the specific implementation steps are as follows:

[0083] Step 1: The estimated weight of the flanged barrel-shaped composite part 100 is 150 kg. Four tension sensors with a range of 50 kg are selected to measure its weight.

[0084] Step 2: Before measuring, calibrate the tension sensor within the range of 5kg to 45kg, select a calibration range within the measuring range of the tension sensor, select several calibration measurement points within the calibration range, measure the sensor at the corresponding calibration measurement points with standard weights, compensate for the measurement error of the tension sensor in the industrial control computer program settings, and calculate and compensate the remaining measurement points within the calibration range using linear interpolation of the calibration point measurement error.

[0085] Step 3, move the lifting device in the measuring tool to the top of the flanged barrel-shaped composite part 100, install the tension sensor, connect the hook of the tension sensor to the hook connected to the end of the traction rope, and pass one end of the traction rope from the bottom of the flanged barrel-shaped composite part around the flanged barrel-shaped composite part and then through the inside of the flanged barrel-shaped composite part, and hoist it together with the lifting ring at the other end of the traction rope on the hook below the tension sensor, thereby realizing the hoisting and fixation of the flanged barrel-shaped composite part.

[0086] Step 4: Turn on the linear servo module on the lifting device to lift the flanged barrel-shaped composite part 100, read the distance value of the distance sensor at each lifting point, and adjust the values ​​of all distance sensors to the specified values ​​after fine-tuning.

[0087] Step 5, read the value of the tension sensor at each lifting point, G1, G2, G3, G4 are 1#: 360.4N, 2# 434.1N, 3# 415.4N, 4# 322.4N respectively, record them in the industrial control computer, remove the weight of the lifting rope and the traction rope, and calculate the mass Mp of the flanged barrel composite part 100 to be 156.11kg.

[0088] Step 6: Remove the support frame, move the annular water tank 300 to the bottom of the flanged barrel-shaped composite part 100, and control the flanged barrel-shaped composite part 100 to move slowly downward through the synchronous action of the linear servo module until the flanged barrel-shaped composite part 100 completely enters the annular water tank 300, and the bottom of the flanged barrel-shaped composite part 100 maintains a certain distance from the annular water tank 300.

[0089] Step 7: Pour water into the annular water tank 300 until the water surface completely covers the upper end surface of the flanged barrel-shaped composite component 100, mark the traction rope 200, and read the tension sensor values ​​at this time: 1#: 160.0N, 2# 153.1N, 3# 132.8N, 4# 118.8N, respectively. The water temperature in the annular water tank 300 is 20°C, and the density of the water therein is ρ w 0.9982kg / m 3 , remove the volume V of the traction rope L After that, the volume Vp of the flanged barrel-shaped composite part 100 is calculated to be 98.82L.

[0090] Step 8: Calculate the average volume density ρ of the flanged barrel composite part 100 m 1.579 g / cm 3 , from the carbon fiber body density ρ f 1.787 g / cm 3 , resin matrix density ρ r 1.245g / cm 3 , the average fiber volume fraction V of the flanged barrel composite part 100 is calculated fm It is 61.62%.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for measuring the fiber volume fraction of a flanged barrel-shaped composite part, characterized in that: The following steps are involved: Fixed tension sensors are respectively installed on the traction ropes connected to multiple hanging point positions of the flanged barrel-shaped composite material part, and the multiple hanging point positions are arranged on the same horizontal plane; One end of the traction rope is connected to the lifting point, and the other end of the traction rope is connected to the lifting device. The length direction of the traction rope is parallel to the Z direction of the flanged barrel-shaped composite part, and the lifting device is provided with a distance measuring sensor; The lifting device lifts the flanged barrel-shaped composite material part through the traction rope, and measures and calculates the mass Mp of the flanged barrel-shaped composite material part through the tension sensor; The flanged barrel-shaped composite material part is hoisted into the annular water tank, and the flanged barrel-shaped composite material part is kept at a preset distance from the bottom of the annular water tank; Filling water into the annular water tank until the water surface completely covers the top surface of the flanged barrel-shaped composite member, measuring the buoyancy of the flanged barrel-shaped composite member by a tension sensor, marking the position where the traction rope is submerged in the water, and calculating the volume Vp of the flanged barrel-shaped composite member according to the buoyancy; Calculate the average density of the flanged barrel composite part According to the fiber density ρ f and the resin matrix density ρ r The average fiber volume fraction V of the flanged barrel composite part is calculated as follows: fm .

2. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 1, characterized in that: The mass Mp of the flanged barrel-shaped composite part is calculated by the following formula: Among them, G t Represents the total tension measured by multiple tension sensors, G n It represents the tension value of a single hanging point measured by the tension sensor at the nth hanging point, where g is the acceleration due to gravity.

3. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 2, characterized in that: The volume Vp of the flanged barrel-shaped composite part is calculated according to the following formula: Among them, G t Represents the total tension measured by multiple tension sensors, T t represents the total tensile force measured by multiple tensile sensors when the water surface completely covers the top surface of the flanged barrel-shaped composite member, ρ w It represents the density of water at the corresponding measurement environment temperature, g is the acceleration due to gravity, V L Indicates the volume of the portion of the towing rope that is submerged in water.

4. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 3, characterized in that: The fiber average volume fraction is calculated according to the following formula:

5. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 3, characterized in that: The following steps are also included: When water is poured into the annular water tank, the water is poured at a certain liquid level after the water contacts the flanged barrel-shaped composite member. After the tension sensor reading is stable, the value of each tension sensor is read to obtain the sensor measurement value T at the i-th water level. i , where i is a positive integer; Calculate the volume of the flanged barrel composite part submerged in water at each water level The height between two adjacent water surfaces is a cutting section. The flanged barrel-shaped composite material part has a plurality of interconnected cutting sections along the Z direction. The measured volume of each cutting section is △vi=v i+1 -v i ; The measured volume Δvi of each cutting section is combined with the theoretical volume of the digital model of the flanged barrel-shaped composite part in the corresponding cutting section to obtain the deviation value between the measured thickness of each cutting section and the theoretical thickness of the digital model.

6. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 5, characterized in that: The following steps are also included: The theoretical volume △Vt of each cutting section is measured according to the three-dimensional digital model of the workpiece, and compared with the measured volume △Vi corresponding to each cutting section. Since the workpiece is manufactured according to the set fiber path, the deviation of the fiber volume fraction of each cutting section is mainly caused by the thickness of the workpiece, that is, △Vi / △Vt=di / dt, where dt is the theoretical thickness, and the measured average thickness di of each cutting section is calculated. Since the fiber volume fraction is a function of the thickness di, the fiber volume fraction at different thicknesses is measured experimentally, and the corresponding fiber volume fraction f(di) within a certain thickness range is fitted, and then the Z-direction fiber measurement volume fraction △V of each cutting section can be obtained. fm Then, the average density △ρi of the corresponding cutting section is calculated according to the measured volume fraction of the Z-direction fiber in each cutting section, and the total mass m of the flanged barrel-shaped composite part is calculated according to the measured volume △vi and the average density △ρi of each cutting section. 估 =∑(△ρi×△vi), m 估 Compared with Mp, the credibility of the measurement data of each cutting section is evaluated.

7. The method for measuring the fiber volume fraction of a flanged barrel-shaped composite part according to claim 6, characterized in that: The credibility of the measurement data of each cutting section is evaluated, comprising the following steps: When m 估 When the value of Mp is within the preset deviation range, the measurement data of each cutting section is credible; When m 估 When the value of Mp exceeds the preset deviation range, the measurement data of each cutting section is not credible.

8. A measuring tool for implementing the fiber volume fraction measurement method of a flanged barrel-shaped composite part according to any one of claims 1 to 7, characterized in that: include: A lifting device, used for lifting the flanged barrel-shaped composite part along the Z direction, wherein the lifting device is provided with a distance measuring sensor; A plurality of tension sensors are arranged on the traction rope connected to the lifting device; A traction rope, used to connect the lifting device and the flanged barrel-shaped composite part; The annular water tank is used to contain the flanged barrel-shaped composite material component and water.

9. The measuring tool according to claim 8, characterized in that: Also includes: The moving assembly is connected to the lifting device and is used to drive the lifting device to move along the X direction and the Y direction.

10. The measuring tool according to claim 8, characterized in that: The height of the annular water tank is higher than the height of the flanged barrel-shaped composite member.

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