CT detection atlas acquisition method and defect comparison method

Abstract

Provided are a CT detection atlas acquisition method for obtaining a plurality of sets of atlas cards for evaluating defects of a composite component, comprising the following steps: partitioning the composite component according to the thickness of the composite component to form a plurality of comparison regions; collecting a plurality of sets of three-dimensional pore map data of components of the same structure as the component to be detected, and converting the plurality of sets of three-dimensional pore maps into a plurality of sets of two-dimensional maps in different comparison regions; sorting and grading the two-dimensional maps according to the pore distribution density, and selecting one two-dimensional map in each pore distribution density grade and each comparison region as a comparison two-dimensional atlas card. Also provided is a CT detection defect comparison method, which can quantitatively judge the pore group density by directly comparing the defect data of the composite component with the comparison two-dimensional atlas card, thereby realizing accurate evaluation of the product.

Description

Technical Field

[0001] This invention relates to the field of scanning, and more specifically to the field of non-destructive testing of composite fan blades for aero-engines. Background Technology

[0002] Advanced aero-engines extensively utilize carbon fiber reinforced resin matrix composites to replace metal materials in order to achieve weight reduction, especially in cold-end components such as fan blades, casings, and nacelles. Carbon fiber weaving combined with resin transfer molding (RTM) can be applied to fan blades with variable curvature, large thickness, and complex structural shapes. As a critical rotating component, the internal quality evaluation of fan blades is crucial. A major defect present in liquid-molded parts is porosity; the density and location of these pores have varying impacts on the blade's strength and lifespan.

[0003] Ultrasonic testing is commonly used for non-destructive testing of composite materials. However, the variable curvature and thickness of fan blades significantly affect ultrasonic attenuation, complicating evaluation. The internal weaving structure also significantly impacts the accuracy of porosity assessment due to ultrasonic reflection, refraction, and absorption. Fluctuations in surface quality and dimensional shape further complicate ultrasonic testing. Therefore, industrial computerized tomography (ICT) is primarily used for the internal quality inspection and evaluation of woven composite fan blades. ICT refers to nuclear imaging technology applied in industry, which, without damaging the object being inspected, clearly, accurately, and intuitively displays the internal structure, composition, material, and defects of the object in the form of two-dimensional or three-dimensional tomographic images.

[0004] While a single pore may have a relatively small impact on a blade, the influence of a large number of pores is significant. Therefore, characterizing a single pore is not very meaningful; a comprehensive evaluation of all pores in the blade is necessary. The complex structure of woven composite blades makes it difficult to statistically record specific defect information, especially when numerous small pores exist. The statistical recording of their size, quantity, and distribution becomes crucial for quantitative evaluation of the blade. Although CT scans can accurately identify the location, size, and morphology of individual defects, the impact of a single defect, especially a small pore, on the part is relatively small. Therefore, the statistical significance of statistically analyzing the characteristics of a single defect is limited. Conversely, pore clusters, especially densely packed pore clusters, have a significant impact on the blade's strength, such as fatigue performance, necessitating a comprehensive quantitative evaluation of all defects. Summary of the Invention

[0005] One objective of this invention is to provide a method for obtaining CT scan atlases, which can prepare CT scan comparison atlases suitable for composite components, facilitating comparative analysis of composite components.

[0006] To achieve the above-mentioned destination CT detection atlas acquisition method for obtaining multiple sets of atlas cards for evaluating defects in composite components, the method includes the following steps: S1. Dividing the composite component into multiple comparison areas according to its thickness; S2. Collecting multiple sets of three-dimensional pore map data of the composite component, and converting the multiple sets of three-dimensional pore maps into multiple sets of two-dimensional maps in different comparison areas; S3. Sort and classifying the two-dimensional maps according to the pore distribution density, and selecting one two-dimensional map in each pore distribution density level and each comparison area as a comparison two-dimensional atlas card.

[0007] In one or more embodiments, the comparison two-dimensional map card is arbitrarily selected from multiple sets of two-dimensional maps at each pore distribution density level.

[0008] In one or more embodiments, the comparison two-dimensional map card is determined by two-dimensional maps of median pore density from multiple sets of two-dimensional maps at each pore distribution density level.

[0009] In one or more embodiments, a densely distributed area of ​​pores is framed in the selected two-dimensional image to form a comparison two-dimensional atlas card.

[0010] In one or more embodiments, the composite component is a blade, and the comparison area includes the blade body area, the root extension area, and the tenon area.

[0011] Another objective of this invention is to provide a CT defect comparison method that can quantitatively evaluate the internal quality of blades by region, effectively improving the efficiency of quality judgment and sorting in the batch production stage of composite components.

[0012] The CT defect comparison method for achieving the above objectives is used to evaluate the defects of composite components and includes the following steps: S4. Obtaining a comparison two-dimensional map card using the above-mentioned CT image acquisition method; S5. Performing strength analysis on each comparison area of ​​the composite component at any porosity distribution density level to determine the acceptance level of each comparison area that can pass the strength analysis; S6. Comparing the CT defect two-dimensional map of any comparison area of ​​the composite component to be tested with the comparison two-dimensional map card of the same comparison area at each of the porosity distribution density levels to obtain the defect level of the composite component to be tested in that comparison area.

[0013] In one or more embodiments, the acceptance level is between the minimum pore distribution density level and the maximum pore distribution density level. If the acceptance level is equal to the minimum pore distribution density level or the maximum pore distribution density level, the amount of three-dimensional pore map data collected is increased, and steps S2-S4 are repeated.

[0014] In one or more embodiments, the acceptance level is the median level between the minimum pore density level and the maximum pore density level.

[0015] The aforementioned CT inspection image acquisition method, by dividing composite components of different thicknesses into zones, avoids the influence of structural factors such as thickness, and realizes the conversion of three-dimensional defects into two-dimensional images. These images are then transformed into two-dimensional image cards that can be directly identified, interpreted, and compared, facilitating subsequent comparison work. The aforementioned CT inspection defect comparison method, by directly comparing the defect data of composite components with the comparison two-dimensional image cards, can quantitatively determine the density of pore groups, thereby achieving accurate evaluation of the product's internal structure and improving the efficiency of quality judgment and sorting during the batch production stage of blades. Attached Figure Description

[0016] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a flowchart of a CT defect comparison method.

[0018] Figure 2 This is a schematic diagram of the blade partitioning.

[0019] Figures 3A-3F It is a two-dimensional map card comparing the pore distribution density levels under the comparison area of ​​the leaf blade.

[0020] Figures 4A-4F It is a two-dimensional map card comparing the pore distribution density levels under the leaf root comparison area.

[0021] Figures 5A-5F It is a two-dimensional comparison chart card showing the density distribution of pores under different levels in the tenon comparison area.

[0022] Figure 6 This is a flowchart of a specific embodiment of a CT defect comparison method. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0024] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0025] Composite material components, also known as composite parts, often contain porosity due to manufacturing processes, affecting manufacturing quality. Taking fan blades as an example, as critical rotating components, the internal quality evaluation of fan blades is crucial. However, while a single pore may have a small impact on the blade, the influence of a large number of pores cannot be ignored. Therefore, simply characterizing a single pore is not very meaningful; a holistic evaluation of all pores in the blade is necessary. Factors such as pore density and location all affect the blade's strength and lifespan.

[0026] The CT inspection atlas acquisition method described in this disclosure is used to obtain multiple sets of atlas cards for evaluating defects in composite components. During use, the test results of the composite components are compared with standard atlas cards to directly determine the porosity and blade quality grade. Considering the characteristics of the three-dimensional woven RTM molding process, porosity is defined as a predominantly abundant defect.

[0027] Combination Figure 1 or Figure 6 As shown in the flowchart, the method for obtaining CT scan atlases includes the following steps.

[0028] First, in step S1, the component to be tested is divided into multiple comparison areas according to its thickness. For example, if the composite component is a blade, the blade is divided into three comparison areas: blade body area A, root area B, and tenon area C, based on its thickness. Blade body area A is the thinner comparison area, while tenon area C is the thicker one. Dividing the comparison areas according to thickness avoids considering the thickness dimension, thus transforming the three-dimensional porosity into a two-dimensional model. Since each comparison involves areas of the same thickness, the influence of the thickness dimension on porosity comparison can be ignored, thereby converting the three-dimensional porosity map into a two-dimensional map.

[0029] Step S2 then proceeds to collect three-dimensional pore map data of multiple sets of composite components, i.e., multiple sets of three-dimensional pore map data of components with the same structure as the composite component to be tested. For example, this could involve collecting CT pore 3D distribution maps of different defect densities on composite fan blades of the same configuration, or obtaining sufficient pore distribution data through trial production data or historical data from the testing process. Height data in the three-dimensional pore maps is not considered in different comparison areas, thus converting multiple sets of three-dimensional pore maps into multiple sets of two-dimensional maps. An embodiment of the two-dimensional map is shown below. Figure 3A As shown, this only shows the pore distribution within the length and width range. It is understandable that if the composite component is another component with a relatively large thickness, the smaller length or width can be ignored, and the thickness and width or thickness and length can be used as the dimensional standard of the two-dimensional diagram to compare the positions in two dimensions.

[0030] Continuing with step S3, the two-dimensional images are sorted and graded according to the density of pore distribution. In multiple sets of two-dimensional images, the density of pore distribution varies for each region. The multiple sets of two-dimensional images are arranged from low to high or high to low according to the degree of defect density, and the number of levels is defined, classifying the multiple sets of two-dimensional images into corresponding levels. For example, 50 sets of two-dimensional pore distribution images of the blades are obtained. For the 60 sets of two-dimensional pore distribution images within the blade body, they are sorted from low to high according to the degree of defect density, and the density is divided into 6 levels, where level 0 represents very few pores and level 5 is the most severe. Therefore, the pore density levels in the blade body are LM0 to LM5, and each level includes 10 two-dimensional pore distribution images. These 10 two-dimensional pore distribution images represent the pore density distribution of the same level and have similar pore density distributions. For the 60 sets of two-dimensional pore distribution images within the tenon section, they are sorted from low to high according to the degree of defect density, and the density is divided into 6 levels, such as... Figures 5A to 5F As shown, the pore density levels in the tenon area range from LP0 to LP5.

[0031] For each pore density level and each comparison region, select one two-dimensional map as a comparison two-dimensional map card. For example, among the above 10 two-dimensional pore distribution maps, select one two-dimensional pore distribution map of the leaf blade as a comparison two-dimensional map card. For example, for the third level of the leaf blade... Figure 3C This is the final selected comparison two-dimensional map card. It is understood that in some embodiments, the comparison two-dimensional map card is arbitrarily selected from multiple sets of two-dimensional maps at each pore density level. Since the distribution density within the same pore density level is relatively close, the differences between the two-dimensional maps within the same level can be ignored, and any one can be selected as the final comparison two-dimensional map card. In other embodiments, the comparison two-dimensional map card can also be determined from the two-dimensional map with the median pore density among multiple sets of two-dimensional maps at each pore density level. Selecting a pore density at the median value is more accurate.

[0032] In the selected two-dimensional image, a densely distributed area of ​​pores is outlined to form a comparison two-dimensional atlas card. In subsequent single comparisons, the outlined densely distributed area of ​​pores is focused on, and a defect image with characteristic size structure or scale is extracted to outline the dense area. This defines standard atlases for different zones and different density levels, and the test data is directly compared with the outlined area.

[0033] Based on the above introduction to CT inspection image acquisition methods, we can also understand a CT inspection defect comparison method for evaluating and comparing defects in composite components. This method can simply and quantitatively evaluate the internal quality of blades by region, effectively improving the efficiency of quality judgment and sorting in the batch production stage of composite components.

[0034] Continue to refer to Figure 1 As illustrated in the flowchart, after obtaining the comparison two-dimensional map card through steps S1-S3, step S4 is performed to conduct a strength analysis on any comparison area of ​​the composite component at any porosity distribution density level, determining the acceptance level of each comparison area that can pass the strength analysis. For example, if the strength analysis is passed, the acceptance levels for the blade area, root extension area, and tenon area are determined to be LM3, LN2, and LP3, respectively.

[0035] Specifically, strength analysis is performed on composite components at each porosity density level to determine the acceptance requirements for the defect density level of each zone. The acceptance level is the porosity density level that meets the strength assessment. For example, after dividing the density into 6 levels, the blade area at the 3rd porosity density level meets the strength assessment requirements. Porosity density levels higher than this level indicate denser pores and will not meet the strength assessment requirements. Porosity density levels lower than this level indicate more porous pores, and given that the 3rd level already meets the assessment requirements, there is a greater probability that the strength assessment requirements will be met.

[0036] In some embodiments, the acceptance level should be between the minimum porosity distribution density level and the maximum porosity distribution density level. If the acceptance level is equal to either the minimum porosity distribution density level (0) or the maximum porosity distribution density level (5), it indicates that none of the porosity distribution density levels cover both quality levels. In this case, the process should return to step S2, increase the amount of data collected for the three-dimensional porosity map, and repeat steps S2-S4 until the acceptance level falls between the minimum and maximum porosity distribution density levels. Preferably, the acceptance level is the median level between the minimum and maximum porosity distribution density levels, ensuring that the porosity distribution density levels cover component quality across various scenarios.

[0037] Proceeding to step S5, the CT defect 2D image of any comparison area of ​​the composite component to be inspected is compared with the comparison 2D image card of the same comparison area under each pore distribution density level to determine the defect level of the composite component to be inspected in that comparison area. For example, for the blade area, the blade porosity measurement data of the composite blade is compared with... Figures 3A to 3F The comparison of the two-dimensional atlas cards at each level is shown. When the pore distribution data are more similar... Figures 3A to 3F When comparing any two-dimensional map card, the porosity level of the blade region of the composite blade can be considered as the level corresponding to that card. Furthermore, based on whether this level is an assessment level, it can be determined whether the quality of the blade region of the composite blade meets the verification standards. Similarly, for the root extension region, the porosity measurement data of the root extension region of the composite blade will be compared with... Figures 4A to 4F The comparison of the two-dimensional atlas cards at each level is shown. When the pore distribution data are more similar... Figures 4A to 4F When comparing any two-dimensional map card, the porosity level of the root extension zone of the composite blade can be regarded as the level of the card. Then, based on whether the level is the assessment level, it can be determined whether the quality of the root extension zone of the composite blade meets the verification standard.

[0038] When evaluating complex fan blades, the densest area in a two-dimensional defect distribution map of the same region is compared with the bounding area in a standard map to determine the porosity level. This method or rule can simply and effectively use pore groups, especially highly dense pore groups, as the quality evaluation standard, thereby enabling a comprehensive quantitative evaluation of all defects. By preparing CT inspection comparison maps for comparison with composite materials, the density of pore groups can be quantitatively determined, thus achieving accurate evaluation of the product's internal structure and significantly improving the efficiency of quality judgment and sorting in the batch production stage of composite components.

[0039] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0040] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A CT inspection map acquisition method for obtaining a map sheet for evaluating defects of a composite material part, characterized in that, Includes the following steps: S1. Divide the composite component into multiple comparison areas according to its thickness; S2. Collect three-dimensional pore map data of multiple sets of composite components, and convert multiple sets of three-dimensional pore maps into multiple sets of two-dimensional maps in different comparison areas; S3. Sort and classify the two-dimensional images according to the size of the pore distribution density, and select one two-dimensional image for each pore distribution density level and each comparison area as a comparison two-dimensional image card.

2. The CT scan atlas acquisition method as described in claim 1, characterized in that, The comparison two-dimensional map card is obtained by randomly selecting from multiple sets of two-dimensional maps at each pore distribution density level.

3. The CT scan atlas acquisition method as described in claim 1, characterized in that, The comparison two-dimensional map card is determined by the two-dimensional map of the median pore density in multiple sets of two-dimensional maps under each pore distribution density level.

4. The CT scan atlas acquisition method as described in claim 1, characterized in that, In the selected two-dimensional image, a region with dense pore distribution is framed to form a comparison two-dimensional atlas card.

5. The CT scan atlas acquisition method as described in claim 1, characterized in that, The composite component is a blade, and the comparison area includes the blade body area, the root extension area, and the tenon area.

6. A CT defect comparison method for evaluating and comparing defects in composite components, characterized in that, Includes the following steps: A comparison two-dimensional atlas card is obtained using the CT detection atlas acquisition method as described in any one of claims 1-5; S4. Perform strength analysis on any comparison area of ​​the composite component at any porosity distribution density level, and determine the acceptance level of each comparison area that can pass the strength analysis. S5. Compare the CT defect 2D image of any comparison area of ​​the composite component to be tested with the comparison 2D image card of the same comparison area under each pore distribution density level to obtain the defect level of the composite component to be tested in that comparison area.

7. The CT defect comparison method as described in claim 6, characterized in that, The acceptance level is between the minimum pore distribution density level and the maximum pore distribution density level. If the acceptance level is equal to the minimum pore distribution density level or the maximum pore distribution density level, the amount of three-dimensional pore map data collected is increased, and steps S2-S4 are repeated.

8. The CT defect comparison method as described in claim 7, characterized in that, The acceptance level is the median level between the minimum pore density level and the maximum pore density level.

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