A bamboo winding pipeline production quality testing system

Abstract

The present invention discloses a bamboo-wound pipe production quality testing system comprising a first testing unit, a second testing unit, a third testing unit, and a testing terminal. The first testing unit, the second testing unit, and the third testing unit are respectively connected to the testing terminal. The first testing unit tests the ultimate pressure of the bend of the bamboo-wound pipe under test. The second testing unit tests whether there is leakage inside the bamboo-wound pipe under test. The third testing unit tests the surface crack image of the bamboo-wound pipe under test. The first testing unit, the second testing unit, and the third testing unit transmit the test results to the testing terminal. The testing terminal determines whether the quality of the bamboo-wound pipe under test meets the requirements based on the received test information.

Description

Technical Field

[0001] This invention relates to the field of testing, and more particularly to a bamboo-wound pipe production quality testing system. Background Technology

[0002] Bamboo-wound composite material is a novel bio-based composite material formed by winding bamboo strips or bundles as reinforcing phases and thermosetting resin as matrix. Bamboo-wound pipes made from this material have advantages such as light weight, high strength, corrosion resistance, and low carbon footprint, and are increasingly widely used in municipal water supply and drainage, farmland irrigation, and oil and gas transportation.

[0003] While bamboo-wound pipes are considered an environmentally friendly and economical option, they have several limitations in practical applications. The primary issue is their poor safety; their pressure resistance is significantly lower than that of metal pipes, posing risks of cracking and bursting. Secondly, bamboo-wound materials are highly absorbent and prone to moisture absorption, leading to a rapid decline in performance and even collapse or breakage, severely impacting the pipe's lifespan. Furthermore, these pipes are susceptible to insect infestation, requiring special attention to pest control over long-term use to prevent serious aging problems. Additionally, bamboo-wound pipes are prone to cracking under high temperatures, posing a significant threat to their lifespan.

[0004] Currently, the production of bamboo-wound pipes typically includes processes such as bamboo strip preparation, resin impregnation, winding, curing, demolding, and finishing. During production, the quality of the pipe directly determines its safety and service life. Existing technologies primarily rely on the following methods to test the production quality of bamboo-wound pipes:

[0005] Finished product sampling inspection: After the pipes have completely cured and been demolded, samples are randomly selected according to a certain proportion for hydrostatic testing, external pressure load testing, or endoscopic inspection. This method is an offline inspection and cannot provide real-time feedback on quality defects during the production process. Once defective products are discovered, a large amount of raw materials and labor time have often been wasted, and it is difficult to trace the specific production stage where the quality problem occurred.

[0006] Single-parameter testing: Some production lines are equipped with single-parameter monitoring methods, such as weighing to determine whether the quality per unit length of pipe meets the standard, or measuring the outer diameter of the pipe manually. However, the quality of bamboo-wound pipes is a multi-dimensional indicator, including but not limited to the uniformity of bamboo strip distribution, the tightness of the bonding between winding layers, the degree of resin curing, and the presence of internal defects such as air bubbles, delamination, or wrinkles. A single physical dimension or weight test is insufficient to comprehensively assess the overall quality of the pipe.

[0007] Manual judgment based on experience: During the winding process, operators mainly rely on visual observation and tactile assessment of the bamboo strips to judge tension, and adjust process parameters based on experience. This subjective judgment method has significant uncertainties, making it difficult to achieve standardized and precise control, and it cannot penetrate to detect potential defects inside the pipe and in its deep structure.

[0008] In summary, existing technologies lack a comprehensive system for efficiently and non-destructively testing multiple key quality indicators of bamboo-wound pipes. Therefore, designing a testing system capable of real-time monitoring and evaluation of the internal structure and surface condition of bamboo-wound pipes has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0009] The bamboo-wound pipe production quality testing system provided by the present invention includes a first testing unit, a second testing unit, a third testing unit, and a testing terminal, wherein the first testing unit, the second testing unit, and the third testing unit are respectively connected to the testing terminal.

[0010] Preferably, the first detection unit tests the ultimate pressure of the bend in the bamboo-wound pipe under test, the second detection unit tests whether there is leakage inside the bamboo-wound pipe under test, and the third detection unit tests the surface crack image of the bamboo-wound pipe under test. The first, second, and third detection units transmit the test results to the detection terminal, and the detection terminal judges whether the quality of the bamboo-wound pipe under test meets the requirements based on the received test information.

[0011] Preferably, the detection terminal stores a pressure threshold for the bend. If the received ultimate pressure of the bamboo-wound pipe under test is less than the pressure threshold, the detection terminal determines that the quality of the bamboo-wound pipe under test is unqualified. If the information received by the detection terminal indicates that there is a leak in the bamboo-wound pipe under test, the quality of the bamboo-wound pipe under test is determined to be unqualified. If the image information received by the detection terminal indicates that the surface cracks of the bamboo-wound pipe under test exceed a preset range (which can be physical quantities that characterize the size of the crack, such as length or width), the bamboo-wound pipe under test is determined to be unqualified.

[0012] Preferably, specifically, the first detection unit tests the ultimate pressure P of the bamboo-wound pipe bend to be tested, and the ultimate pressure of the bamboo-wound pipe bend to be tested is adjusted by a geometric correction factor f. ge ,Right now

[0013]

[0014] Among them, P b This is the straight pipe pressure parameter of the bamboo-wound pipe to be tested. This parameter is determined by the bamboo material.

[0015] Then there is,

[0016]

[0017] Where k is the curvature correction coefficient, and R is the bending radius of the bamboo-wound pipe to be tested. Let r be the bending angle of the bamboo-wound pipe bend to be tested, and r be the average radius of the bamboo-wound pipe bend to be tested.

[0018] Then there is,

[0019]

[0020] Where D is the outer diameter of the bamboo-wound pipe to be tested, and t is the pipe wall thickness.

[0021] Then there is,

[0022]

[0023] Where, d max The maximum defect depth of the bamboo-wrapped pipe bend to be tested.

[0024] Then there is,

[0025]

[0026] Where L is the length of the straight section of the bamboo-wound pipe to be tested, and d is the depth of the elbow defect in the bamboo-wound pipe to be tested. It is the ultimate tensile strength of bamboo materials.

[0027] Preferably, the pressure wave is measured using two fiber optic pressure sensors mounted on the bamboo-wound pipe to be tested, and the leak location is determined by the time difference required for the pressure wave to reach the sensor.

[0028] When a leak occurs at leak point 1, the time it takes for the negative pressure wave to reach pressure gauge 1 and pressure gauge 2 from leak point 1 is... .

[0029] Then there is,

[0030]

[0031] Then there is,

[0032]

[0033] Wherein, the negative pressure wave velocity is v, the velocity of the fluid in the bamboo-wound pipe is μ, the distance between pressure gauge 2 and pressure gauge 1 is L, and the distance between pressure gauge 1 and leakage point 1 is L1.

[0034] Then there is,

[0035]

[0036] During the test, the liquid in the bamboo-wound pipe does not flow, so the value of μ is 0 m / s. Therefore, the above equation can be simplified to:

[0037]

[0038] If the location of leak point 1 is required, then the location must also be known. and The value of .

[0039] Then there is,

[0040]

[0041]

[0042]

[0043] In the test, it was obtained through actual measurement. The value is determined by causing a leak at leak point 2. The time it takes for the negative pressure wave to travel from leak point 2 to pressure gauges 1 and 2 is [value missing]. .

[0044] Preferably, during actual testing, the pressure signal is affected by noise, resulting in signal spikes. This invention can also use wavelet transform to denoise the signal, selecting the sym8 wavelet basis for denoising the pressure signal, which significantly reduces the spikes. The singularity of the pressure signal from pressure gauge 2 is calculated using wavelet transform, the original signal is decomposed using wavelet transform, and then the signal is reconstructed at a given layer.

[0045] Preferably, specifically, the third inspection unit tests the surface crack image of the bamboo-wound pipe to be tested. The third inspection unit includes an image acquisition device and an image processing device, which are connected in sequence to a testing terminal. The image acquisition device is used to acquire image information of the surface of the bamboo-wound pipe to be tested and transmits the acquired image information to the image processing device. The image processing device processes the received image information and then transmits it to the testing terminal.

[0046] Specifically, starting with the image acquired by the image acquisition device, for various window sizes... ,

[0047] The image processing device passes the input image and the standard image through a guided filter. This filter models the local relationship between the input image and the standard image using linear coefficients a and b to output an image that is O.

[0048] Then there is,

[0049]

[0050] The values ​​of a and b are in the range of size The calculation is performed within a local window, where:

[0051]

[0052] in, and These represent the mean values ​​within the windows of the input image I and the standard image G, respectively. The variance of the input image I. It is a parameter that controls the smoothness, and is used by a guided filter. Basic and detail feature layers are obtained at all scales, and these binary weight maps are refined by guided filtering to ensure spatial smoothness and continuity.

[0053] The bamboo-wound pipe production quality testing system provided by this invention performs comprehensive testing of bamboo-wound pipes from the inside out through three-dimensional inspection. Specifically, the ultimate pressure test of elbows is verified through full-scale pressure tests on defective pipes, introducing a modified expression and combining it with the original model to evaluate the ultimate pressure of pipe elbows; internal leakage detection can directly mark leakage points; and surface crack detection can obtain crack information on the pipe surface through clear images. Therefore, the bamboo-wound pipe production quality testing system provided by this invention is more accurate and comprehensive than existing technologies. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the bamboo-wound pipe bend to be tested according to the present invention;

[0055] Figure 2 This is a geometric schematic diagram of the bamboo-wound pipe bend to be tested according to the present invention;

[0056] Figure 3 This is a finite element mesh configuration diagram of the bend with external defects at the outer arc of the bamboo-wound pipe to be tested according to the present invention.

[0057] Figure 4 This is a schematic diagram illustrating the principle of the bamboo-wound pipe leakage test of the present invention.

[0058] Figure 5 The image shows a comparison of the pressure signal before and after filtering in the leakage test of the bamboo-wound pipe of the present invention (the top image is before filtering, and the bottom image is after filtering).

[0059] Figure 6 This is the d3 layer reconstruction curve of the pressure gauge 2 signal of the present invention. Detailed Implementation

[0060] The bamboo-wound pipe production quality testing system provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0061] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and systems according to various embodiments of this disclosure. It should be noted that each block in the block diagram may represent a module, segment, or portion of code, which may include one or more executable instructions for implementing the logical functions specified in the various embodiments. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, may be implemented using a dedicated hardware-based system that performs the specified functions or operations, or using a combination of dedicated hardware and computer instructions.

[0062] The terms "comprising," "including," and similar terms used should be understood as open-ended, meaning "including / including but not limited to," indicating that other contents may also be included. The same reference numerals used in the embodiments and accompanying drawings indicate the same or similar components or structural features. Furthermore, when describing a component as being disposed on another component, it means that a component is directly disposed on the other component, or a component is indirectly disposed on the other component, i.e., one or more components are disposed between the two components. Conversely, when describing a component as being directly disposed on another component, it means that there are no other components between the two components.

[0063] Bamboo-wound pipes (also known as bamboo-wound composite pipes) are circular tubular composite materials made primarily of bamboo, using thermosetting resin as an adhesive, and processed through a mechanical winding process.

[0064] The bamboo-wound pipe production quality testing system includes a first testing department, a second testing department, a third testing department, and a testing terminal, wherein the first testing department, the second testing department, and the third testing department are respectively connected to the testing terminal.

[0065] Specifically, the first testing unit tests the ultimate pressure of the bend in the bamboo-wound pipe under test, the second testing unit tests whether there is leakage inside the bamboo-wound pipe under test, and the third testing unit tests the surface crack image of the bamboo-wound pipe under test. The first, second, and third testing units transmit the test results to the testing terminal, which judges whether the quality of the bamboo-wound pipe under test meets the requirements based on the received test information.

[0066] Specifically, the detection terminal stores the pressure threshold of the bend. If the received ultimate pressure of the bamboo-wound pipe under test is less than the pressure threshold, the detection terminal judges that the quality of the bamboo-wound pipe under test is unqualified. If the information received by the detection terminal indicates that there is a leak in the bamboo-wound pipe under test, the quality of the bamboo-wound pipe under test is judged to be unqualified. If the image information received by the detection terminal indicates that the surface cracks of the bamboo-wound pipe under test exceed the preset range (which can be physical quantities that characterize the size of the crack, such as length value and width value), the bamboo-wound pipe under test is judged to be unqualified.

[0067] Specifically, the detection terminal can be a mobile phone, a portable computer, or other device with storage, processing, and information receiving functions.

[0068] It should be noted that the bamboo winding pipe production quality testing system provided by this invention can test not only newly produced bamboo winding pipes, but also bamboo winding pipes that have been put into use, thereby facilitating user use and maintenance.

[0069] like Figure 1 As shown in the figure, it is a schematic diagram of the bend of the bamboo-wound pipe to be tested. D is the outer diameter of the bamboo-wound pipe to be tested, R is the bending radius of the bamboo-wound pipe to be tested, and L is the length of the straight pipe section of the bamboo-wound pipe to be tested. In order to reduce the adverse effects of boundary conditions, the straight pipe length is generally more than four times the outer diameter of the bend in the design.

[0070] like Figure 2 As shown, the geometric parameters of a bamboo-wound pipe elbow with a semi-elliptical defect are described. The maximum defect length in the longitudinal direction of the elbow is related to the plane angle γ, while the defect width along the circumference is determined by the angle β. t is the pipe wall thickness, and d is the defect depth of the elbow. A three-dimensional view of the elbow defect is shown below. Figure 3 As shown.

[0071] Specifically, the first testing unit tests the ultimate pressure P of the bamboo-wound pipe bend under test. The ultimate pressure of the bamboo-wound pipe bend under test is adjusted by a geometric correction factor f. ge ,Right now

[0072]

[0073] Among them, P b This is the straight pipe pressure parameter of the bamboo-wound pipe to be tested. This parameter is determined by the bamboo material.

[0074] Then there is,

[0075]

[0076] Where k is the curvature correction coefficient, and R is the bending radius of the bamboo-wound pipe to be tested. Let r be the bending angle of the bamboo-wound pipe bend to be tested, and r be the average radius of the bamboo-wound pipe bend to be tested.

[0077] Then there is,

[0078]

[0079] Where D is the outer diameter of the bamboo-wound pipe to be tested, and t is the pipe wall thickness.

[0080] Then there is,

[0081]

[0082] Where, d max The maximum defect depth of the bamboo-wrapped pipe bend to be tested.

[0083] Then there is,

[0084]

[0085] Where L is the length of the straight section of the bamboo-wound pipe to be tested, and d is the depth of the elbow defect in the bamboo-wound pipe to be tested. It is the ultimate tensile strength of bamboo materials.

[0086] It should be noted that the existing model was developed for rectangular corrosion profiles, and its application to elliptical defects has not been fully studied. Elliptical defects, however, more accurately reflect naturally occurring quality problems in bamboo-wound pipe bends. This model was validated through full-scale pressure tests on defective pipes. A modified expression was introduced and combined with the original model to assess the ultimate pressure of the pipe bend. The above-mentioned ultimate pressure calculation model for the tested bamboo-wound pipe bend is based on a recalibrated model using existing technology. Statistical analysis of the model errors related to the straight pipe pressure test model using full-scale pressure test results from pipes with actual defects shows that the calculation model provided by this invention has higher prediction accuracy than existing technologies.

[0087] like Figure 4 As shown, the negative pressure wave velocity is v, the fluid velocity in the bamboo-wound pipe under test is μ, and the distance between pressure gauge 2 and pressure gauge 1 is L. The distance between pressure gauge 1 and leak point 1 is L1. The distance between pressure gauge 2 and leak point 1 is L2. The second detection unit tests whether there is a leak in the bamboo-wound pipe under test. When a leak occurs in the bamboo-wound pipe under test, the fluid at the leak point flows out rapidly, and the pressure drops. Due to the pressure difference, the fluid on both sides of the leak point replenishes the leak point. This process propagates upstream and downstream to the leak point, which is equivalent to a negative pressure wave propagating at a certain speed at the leak point. Two fiber optic grating pressure sensors installed on the bamboo-wound pipe under test measure the pressure wave, and the leak location is determined by the time difference required for the pressure wave to reach the sensor.

[0088] When a leak occurs at leak point 1, the time it takes for the negative pressure wave to reach pressure gauge 1 and pressure gauge 2 from leak point 1 is... .

[0089] Then there is,

[0090]

[0091] Then there is,

[0092]

[0093] Wherein, the negative pressure wave velocity is v, the velocity of the fluid in the bamboo-wound pipe is μ, the distance between pressure gauge 2 and pressure gauge 1 is L, and the distance between pressure gauge 1 and leakage point 1 is L1.

[0094] Then there is,

[0095]

[0096] During the test, the liquid in the bamboo-wound pipe does not flow, so the value of μ is 0 m / s. Therefore, the above equation can be simplified to:

[0097]

[0098] If the location of leak point 1 is required, then the location must also be known. and The value of .

[0099] Then there is,

[0100]

[0101]

[0102]

[0103] In the test, it was obtained through actual measurement. The value is determined by causing a leak at leak point 2. The time it takes for the negative pressure wave to travel from leak point 2 to pressure gauges 1 and 2 is [value missing]. .

[0104] Specifically, in actual testing, the pressure signal is affected by noise, resulting in signal spikes. This invention can also use wavelet transform to denoise the signal, selecting the sym8 wavelet basis to denoise the pressure signal, significantly reducing the spikes in the pressure signal (e.g., Figure 5 (As shown). Figure 6The diagram illustrates the singularity of the pressure signal from pressure gauge 2 calculated using wavelet transform. The original signal is decomposed using wavelet transform, and then reconstructed at a given level. Among all reconstructed signals, the reconstructed signal at level d3 shows the best response to abrupt changes in the original signal. The point where the leakage inflection point stops can be found in the figure; the x-coordinate of the inflection point where the leakage begins is:

[0105]

[0106] Specifically, the third inspection unit tests images of surface cracks in the bamboo-wound pipe under test. The third inspection unit includes an image acquisition device and an image processing device, which are connected sequentially to a testing terminal. The image acquisition device acquires image information of the surface of the bamboo-wound pipe under test and transmits the acquired image information to the image processing device. The image processing device processes the received image information and then transmits it to the testing terminal.

[0107] Specifically, starting with the image acquired by the image acquisition device, for various window sizes... ,

[0108] The image processing device passes the input image and the standard image through a guided filter. This filter models the local relationship between the input image and the standard image using linear coefficients a and b to output an image that is O.

[0109] Then there is,

[0110]

[0111] The values ​​of a and b are in the range of size The calculation is performed within a local window, where:

[0112]

[0113] in, and These represent the mean values ​​within the windows of the input image I and the standard image G, respectively. The variance of the input image I. It is a parameter that controls the smoothness, and is used by a guided filter. Basic and detail feature layers are obtained at all scales, and these binary weight maps are refined by guided filtering to ensure spatial smoothness and continuity.

[0114] The bamboo-wound pipe production quality testing system provided by this invention performs comprehensive testing of bamboo-wound pipes from the inside out through three-dimensional inspection. Specifically, the ultimate pressure detection of elbows is verified through full-scale pressure tests on defective pipes, introducing a modified expression and combining it with the original model to evaluate the ultimate pressure of pipe elbows; internal leakage detection can directly mark leakage points; and surface crack detection can obtain crack information on the pipe surface through clear images. Therefore, the bamboo-wound pipe production quality testing system provided by this invention is more accurate and comprehensive than existing technologies.

[0115] Finally, it should be reiterated that the constituent elements / components described in the foregoing embodiments of the present invention are merely illustrative examples and are not intended to limit the scope of the present invention. Substitutions or variations of other equivalent components should be within the scope of protection of the present invention.

Claims

1. A bamboo-wrapped pipe production quality test system, characterized by, The bamboo-wound pipe production quality testing system includes a first testing unit, a second testing unit, a third testing unit, and a testing terminal, wherein the first testing unit, the second testing unit, and the third testing unit are respectively connected to the testing terminal; The first detection unit tests the ultimate pressure of the bend in the bamboo-wound pipe under test, the second detection unit tests whether there is leakage inside the bamboo-wound pipe under test, and the third detection unit tests the surface crack image of the bamboo-wound pipe under test. The first detection unit, the second detection unit, and the third detection unit transmit the test results to the detection terminal, and the detection terminal determines whether the quality of the bamboo-wound pipe under test meets the requirements based on the received test information.

2. The bamboo-winding pipe production quality test system according to claim 1, characterized in that, The first detection part tests the limit pressure P of the bamboo winding pipeline elbow to be tested, and the limit pressure of the bamboo winding pipeline elbow to be tested is corrected by a geometric correction factor f ge That is P b is the straight pipe pressure parameter of the bamboo winding pipeline to be tested; Then there is, Wherein, k is the curvature correction coefficient, R is the bending radius of the bamboo winding pipeline to be measured, is the bending angle of the elbow of the bamboo winding pipeline to be measured, and r is the average radius of the elbow of the bamboo winding pipeline to be measured. Then there is, Where D is the outer diameter of the bamboo-wound pipe to be tested, and t is the pipe wall thickness; Then there is, wherein d max is the maximum defect depth of the bamboo winding pipe elbow to be tested; Then there is, Wherein, L is the length of the straight pipe section of the bamboo winding pipeline to be tested, d is the defect depth of the elbow of the bamboo winding pipeline to be tested, is the ultimate tensile strength of the bamboo material.

3. The bamboo-wound pipe production quality testing system according to claim 1, characterized in that, Two fiber grating pressure sensors are installed on the bamboo winding pipeline to be tested, when the first leakage point leaks, the time for the negative pressure wave to reach the pressure gauge 1 and the pressure gauge 2 from the first leakage point is ; Then there is, Then there is, Wherein, the negative pressure wave velocity is v, the velocity of the fluid in the bamboo-wound pipe to be tested is μ, the distance between pressure gauge 2 and pressure gauge 1 is L, and the distance between pressure gauge 1 and the first leak point is L1. Then there is, During the test, the liquid in the bamboo-wound pipe does not flow, so the value of μ is 0 m / s. Therefore, the above equation can be simplified to: If the position of the first leak point is required, the values of and must be known simultaneously; Then there is, In the test, a leak was caused at the second leak point. The time it took for the negative pressure wave to reach pressure gauge 1 and pressure gauge 2 from the second leak point was... .

4. The bamboo-wound pipe production quality testing system according to claim 3, characterized in that, The singularity of the pressure signal from pressure gauge 2 is calculated using wavelet transform, the original signal is decomposed by wavelet, and then the signal is reconstructed at a given level.

5. The bamboo-wound pipe production quality testing system according to claim 1, characterized in that, The third detection unit tests the surface crack image of the bamboo-wound pipe to be tested. The third detection unit includes an image acquisition device and an image processing device. The image acquisition device, the image processing device and the detection terminal are connected in sequence. The image acquisition device is used to acquire the surface image information of the bamboo-wound pipe to be tested and transmit the acquired image information to the image processing device. The image processing device processes the received image information and then transmits it to the detection terminal. Starting with images acquired by the image acquisition device, for various window sizes... The image processing device passes the input image and the standard image through a guided filter. This filter models the local relationship between the input image and the standard image using linear coefficients a and b to output an image that is O. Then there is, The values ​​of a and b are in the range of size The calculation is performed within a local window, where: in, and These represent the mean values ​​within the windows of the input image I and the standard image G, respectively. The variance of the input image I. It is a parameter that controls the smoothness.

Images