CN117434162A - Test block and method for quantitative evaluation of mechanical edge delamination defects of composite material - Google Patents
Test block and method for quantitative evaluation of mechanical edge delamination defects of composite material Download PDFInfo
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- 238000012360 testing method Methods 0.000 title claims abstract description 220
- 230000007547 defect Effects 0.000 title claims abstract description 199
- 239000002131 composite material Substances 0.000 title claims abstract description 92
- 238000000034 method Methods 0.000 title claims abstract description 50
- 230000032798 delamination Effects 0.000 title claims abstract description 33
- 238000011158 quantitative evaluation Methods 0.000 title claims description 15
- 238000003754 machining Methods 0.000 claims abstract description 23
- 238000001514 detection method Methods 0.000 claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 claims abstract description 15
- 238000011156 evaluation Methods 0.000 claims abstract description 13
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- 229920001343 polytetrafluoroethylene Polymers 0.000 description 4
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- 238000004088 simulation Methods 0.000 description 4
- 239000002356 single layer Substances 0.000 description 4
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/30—Arrangements for calibrating or comparing, e.g. with standard objects
Abstract
The invention discloses a test block and a method for quantitatively evaluating mechanical edge delamination defects of a composite material. The test block is made of the same material as the composite material workpiece to be tested, wherein at least one tip-like defect is prefabricated at the edge of the test block. The invention also relates to a method for manufacturing the test block for quantitatively evaluating the mechanical edge delamination defect of the composite material and a method for quantitatively evaluating the mechanical edge delamination defect of the composite material. The invention can accurately simulate the defect signal, improve the sensitivity of the ultrasonic detection of the defect signal of the machining edge, and establish the test capability of the high-precision nondestructive evaluation of the machining edge, thereby ensuring the reliability and the safety of the composite material in application.
Description
Technical Field
The invention relates to the technical field of nondestructive testing, in particular to a test block and a method for quantitatively evaluating mechanical edge delamination defects of a composite material.
Background
At present, the aluminum alloy in the Boeing B787 only accounts for 20 percent, and the composite material consumption is up to 50 percent; the composite material in the air passenger a350 has a 53% ratio. Under the international background of civil engineering, the composite material is widely applied to the aerospace field by virtue of the advantages of small specific gravity, high specific strength, large specific modulus, fatigue resistance and the like. With the continuous emergence of new processes and new structural composite material components, higher requirements on the manufacturing quality safety of civil engineering are required.
In order to meet the connection and assembly requirements of composite material components, a large amount of machining such as cutting, milling, drilling and the like is needed after the composite material is molded, but the defects of layering and the like are very easy to generate during machining due to the fact that the composite material has large anisotropy and poor interlayer binding force, and the machining damages are mostly in the structure and are difficult to detect. Most of composite material machine parts belong to key bearing structures such as wings, rudders and the like, if the damage tolerance control or monitoring is not carried out in time, the fatigue strength of structural parts is easily affected, and great hidden danger is brought to the service performance and the flight safety of an aircraft, so that the problem of the quality of the edges of the composite material machine parts is required to be paid attention to.
At present, a composite material test block simulates layering mainly by embedding single-layer or double-layer polytetrafluoroethylene, but the single-layer or double-layer film is easy to misplacement and deviation during layering, particularly the machining edge is easy to add, so that the defect position and size cannot be ensured; in addition, the field process staff always adopts a conventional ultrasonic test block to scan the edge area of the machining part by using the detection sensitivity established in the middle area of the flat plate, but the mode is only used for extracting the layering signals of the machining edge without representing the method because of strong noise interference of the machining edge, so that the real source of the defect signals cannot be judged.
Therefore, how to provide a test block and a method for quantitatively evaluating the mechanical edge delamination defect of the composite material is a technical problem to be solved by the person skilled in the art.
Disclosure of Invention
The invention provides a test block and a method for quantitatively evaluating the mechanical edge layering defects of a composite material, which can accurately simulate defect signals, improve the sensitivity of ultrasonic detection of the mechanical edge defects, establish the test capability of high-precision nondestructive evaluation of the mechanical edge, and further guarantee the reliability and safety of the composite material in application.
According to one aspect of the present invention, there is provided a test block for quantitative evaluation of composite machine-applied edge delamination defects, the test block being composed of the same material as a composite workpiece to be inspected, wherein at least one kind of tip defects is preformed at the edge of the test block.
Further, the tail end of the tip-like defect is an isosceles trapezoid, and the edge end of the test block of the tip-like defect is rectangular.
Further, the transverse short side dimension of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 6 mm; the transverse long side of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 9 mm; the longitudinal dimension of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 9 mm; wherein the longitudinal dimension of the isosceles trapezoid is the distance from the tip-like defect end to the test block edge.
Further, the at least one tip-like defect is spatially located differently.
Further, prefabricating at least three tip-like defects at the edge of the test block; wherein, the space position of the first tip-like defect is at least two fiber layers away from the upper surface of the test block; the space position of the second tip-like defect is the same as the distance from the upper surface of the test block and the distance from the lower surface of the test block; the third tip-like defect is spatially located at least two fiber layers from the lower surface of the test block.
According to another aspect of the present invention, there is provided a method for manufacturing a test block for quantitative evaluation of a composite machine-edge delamination defect, the method comprising:
determining the number of layers, the laying angle and the laying sequence of fiber layers in the test block according to the attribute of the detected composite material workpiece;
determining the number, shape, size and spatial position of the tip-like defects in the test block according to the layering detection requirements of the detected composite material workpiece;
sequentially laying the fiber layers according to the number of layers, the laying angle and the laying sequence of the fiber layers to form a laminated plate;
preprocessing the laminated plate to obtain an intermediate test block;
determining technological parameters of laser processing equipment according to the shape, the size and the space position of the quasi-tip defect in the test block;
and processing the intermediate test block according to the technological parameters to obtain a target test block.
Further, the preprocessing includes: placing the laminated plate in a tool for vacuum sealing and bagging, and curing and forming in an autoclave to obtain an initial test block; and processing the initial test block according to a preset size to obtain an intermediate test block.
Further, after the intermediate test block is processed according to the process parameters to obtain a target test block, the manufacturing method further includes: and performing metering test and correction on the shape, the size and the space position of the quasi-tip defect in the target test block.
According to another aspect of the present invention, there is provided a method for quantitative evaluation of mechanical edge delamination defects of a composite material, characterized in that the method comprises:
obtaining a test block to be verified; wherein the test block to be verified is the test block according to any one of claims 1 to 5, which is manufactured according to the method according to any one of the preceding claims 6 to 8;
carrying out ultrasonic scanning on the test block to be verified, and determining an ultrasonic scanning result of the tip-like defect in the test block to be verified;
and if the test block meets the preset evaluation capability requirement according to the ultrasonic scanning result, quantitatively evaluating the mechanical edge delamination defect of the composite material through the test block.
Furthermore, according to the ultrasonic scanning result, if a layering reflected wave signal or an image abnormality prompt exists at the point-like defect position of the corresponding shape, size and space position in the test block to be verified, the evaluation capability of the ultrasonic system on the mechanical edge layering defect of the composite material can be determined.
According to the technical scheme provided by the embodiment of the invention, the defect signal can be accurately simulated, the sensitivity of the mechanical edge ultrasonic detection defect signal is improved, the test capability of the mechanical edge high-precision nondestructive evaluation is established, and the reliability and the safety of the composite material in application are further ensured.
It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a test block for quantitative evaluation of mechanical edge delamination defects of a composite material according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a tip-like defect according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a spatial location of a tip-like defect according to an embodiment of the present invention;
FIG. 4 is a flowchart of a method for manufacturing a test block for quantitative evaluation of mechanical edge delamination defects of a composite material according to an embodiment of the present invention;
FIG. 5 is a flowchart of a method for quantitative evaluation of mechanical edge delamination defects of a composite material according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," "third," "intermediate," and "target" in the description and claims of the present invention and the above-described drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The embodiment of the invention provides a test block for quantitatively evaluating the composite material machining edge layering defect, which is applicable to the condition of quantitatively evaluating the composite material machining edge layering defect so as to accurately simulate and evaluate the composite material machining edge layering defect; the method is also suitable for the research and cutter development stage of the mechanical processing technology to optimize the mechanical processing technology parameters and the performance of the elevator and the components; the method is also suitable for part processing stage to monitor and evaluate quality, improve on-site part processing efficiency and quality, and ensure quality safety of key structural parts. The test block for quantitatively evaluating the mechanical edge delamination defects of the composite material consists of the same material as that of a tested composite material workpiece, and at least one type of tip defects are prefabricated on the edge of the test block.
It will be appreciated that the composite member is primarily in the form of a laminate, and that the mismatch in ply stiffness due to the inconsistent lay-up direction of the fibre plies in the composite material induces higher ply stresses and is therefore highly susceptible to damage, such as delamination, from low energy impacts during manufacture, assembly and service of the laminate. However, the conventional embedded single-layer or double-layer polytetrafluoroethylene is adopted to simulate layering, but the single-layer or double-layer film is easy to misplacement and deviation during layering, particularly the edge is machined, so that the defect position and size cannot be ensured.
The test block for quantitatively evaluating the mechanical edge delamination defect of the composite material consists of the same material as that of the detected composite material workpiece. In order to ensure that the test block can accurately quantitatively evaluate the layering defects of the detected composite material workpiece, on one hand, the material properties of each fiber layer in the test block and the detected composite material workpiece are required to be the same; on the other hand, the layering sequence and the layering direction of each fiber layer in the test block and the tested composite material workpiece are required to be the same; in addition, the type, orientation and number of prepregs used for the test block and the composite workpiece being inspected are also the same.
FIG. 1 is a schematic diagram of a test block for quantitative evaluation of mechanical edge delamination defects of a composite material according to an embodiment of the present invention. As shown in fig. 1, at least one kind of tip defects 120 are preformed at the edges of the test block 110. It should be noted that fig. 1 is only for illustrating the positional relationship between the test block 110 and the tip-like defect 120, and is not used for characterizing the shape of the tip-like defect 120; in addition, the shape of the tip-like defect 120 is also not limited to the shape shown in fig. 1.
In an embodiment of the invention, at least one type of tip defects is prefabricated on the edge of the test block to simulate the mechanical edge delamination defects of the composite material. The tip-like defect 120 may be a tip-like defect having a width gradually narrowed inward from the edge of the test block 110. Illustratively, the shape of the tip-like defect 120 may be a single triangular shape, a trapezoidal shape, a semi-elliptical shape, or a semi-circular shape; the shape may be a trapezoid or rectangle, or a combination of a triangle, trapezoid, semi-ellipse, or semicircle; the shape of the tip-like defect 120 may be determined according to actual requirements, and is not limited.
Optionally, the end of the tip-like defect is isosceles trapezoid, and the edge end of the test block of the tip-like defect is rectangular.
Fig. 2 is a schematic diagram of a tip-like defect according to an embodiment of the present invention. As shown in FIG. 2, A is the block edge and B is the tip-like defect. The tail end of the quasi-tip defect B is isosceles trapezoid, and the edge end of the test block is rectangular. The tip-like defect B provided by the embodiment of the invention can realize the control of the size of the tip-like defect by adjusting the size of each part in the tip-like defect. The arrangement has the advantages that the tail end is isosceles trapezoid, the edge end of the test block is rectangular and similar to the shape of the tip defect, the common morphological characteristics of the mechanical edge layering defect of the composite material can be displayed, and the method has certain representative significance.
Optionally, the dimension of the transverse short side of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 6 mm; the transverse long side of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 9 mm; a longitudinal dimension greater than or equal to 0.5 millimeters and less than or equal to 9 millimeters; wherein the longitudinal dimension is the distance from the tip-like defect end to the test block edge end.
As shown in FIG. 2, the isosceles trapezoid has a transverse short side dimension W 1 The transverse long side of the isosceles trapezoid is W 2 The longitudinal dimension is L. The device has the advantages that the size of the simulated mechanical edge delamination defect of the composite material is clear, the coverage range is wide, and a plurality of selection ranges, especially tiny delamination defects, are provided for quantitative analysis of different size delamination of the detected composite material workpiece.
Optionally, the at least one tip-like defect is spatially located differently.
Wherein the spatial location may be a depth location or a planar location of the tip-like defect in the test block. Specifically, a preset spatial position of at least one tip-like defect may be set in the test block, and the tip-like defect is prefabricated according to the preset spatial position. The method includes the steps of setting preset space positions of three tip-like defects in a test block, wherein the preset space positions of the three tip-like defects are located at different position depths of the same test block, so that detection effects of layering defects of different depths of the test block are obtained.
In addition, the test block covers the machined edge without any simulation defect, and the machined edge is used as a reference, so that the detection result of whether the simulation layering defect exists or not can be compared and analyzed, and the extraction of the edge layering defect signal is facilitated.
Optionally, prefabricating at least three tip-like defects at the edge of the test block; wherein, the space position of the first tip-like defect is at least two fiber layers away from the upper surface of the test block; the space position of the second tip-like defect is the same as the distance from the upper surface of the test block and the distance from the lower surface of the test block; the third tip-like defect is spatially located at least two fiber layers from the lower surface of the test block.
Preferably, the first tip-like defect is spatially located two or three fiber layers from the upper surface of the test block; the third tip-like defect is spatially located two or three fiber layers from the upper surface of the test block.
Fig. 3 is a schematic diagram of a kind of spatial location of tip defects according to an embodiment of the present invention. As shown in fig. 3, six preset spatial positions, respectively R1, R2, S1, S2, T1 and T2, are set at different edges of the same test block. Wherein R1 and R2 are first tip-like defects, and three fiber layers are arranged on the space positions of the first tip-like defects from the upper surface of the test block; s1 and S2 are second tip-like defects, and the distance between the space position of the second tip-like defects and the upper surface of the test block is the same as the distance between the space position of the second tip-like defects and the lower surface of the test block; t1 and T2 are third tip-like defects, which are spatially located 3 fiber layers from the lower surface of the block.
In the embodiment of the invention, the spatial positions of the first tip-like defect, the second tip-like defect and the third tip-like defect can be determined according to the actual thickness of the test block.
The advantage of this arrangement is that by arranging the tip-like defects at different spatial locations in the test block, respectively, the detection of delamination defects at different spatial locations of the test block can be effectively covered.
The embodiment of the invention provides a test block for quantitatively evaluating mechanical edge delamination defects of a composite material, which consists of the same material as a tested composite material workpiece, wherein at least one type of tip defects are prefabricated at the edge of the test block. Through the technical means, the defect signal can be accurately simulated, the sensitivity of the ultrasonic detection of the defect signal of the machined edge is improved, and the test capability of the high-precision nondestructive evaluation of the machined edge is established, so that the reliability and the safety of the composite material in application are ensured.
The embodiment of the invention also provides a manufacturing method of the test block for quantitatively evaluating the mechanical edge delamination defect of the composite material. FIG. 4 is a flowchart of a method for manufacturing a test block for quantitative evaluation of mechanical edge delamination defects of a composite material according to an embodiment of the present invention, as shown in FIG. 4, the method includes:
s410, determining the number of fiber layers, the laying angle and the laying sequence of the fiber layers in the test block according to the attribute of the detected composite material workpiece.
The properties of the inspected composite workpiece may include, among other things, the thickness of the inspected composite workpiece, the number of fiber layers, the lay-up angle, and the lay-up order. The number of fiber layers in the test block can be determined according to the thickness of the composite material workpiece to be detected. For example, if the thickness of the composite workpiece to be inspected is 2.96 mm and the thickness of the fiber layer is 0.185 mm, the number of fiber layers in the test block is 16. The angle of lay-up of each fiber layer in the test block may be the angle between the fiber direction of each layer and the manufacturing reference coordinate axis. The laying angle and the laying sequence of each fiber layer in the test block can be determined according to the laying angle and the laying sequence of each fiber layer in the tested composite material workpiece.
Preferably, based on the laying angle and the laying sequence of each fiber layer in the tested composite material workpiece, the fiber layers in the test block are determined to be laid in the crossed four laying directions of 0 DEG, +45 DEG, -45 DEG and 90 DEG, so that bending and impact damage can be avoided.
S420, determining the number, shape, size and spatial position of the tip-like defects in the test block according to the layering detection requirements of the detected composite material workpiece.
The layering detection requirement of the detected composite material workpiece can be the detection capability or the signal sensitivity of layering defects.
Wherein, the shape of the tip-like defect in the test block can be a defect similar to a tip type, the width of which gradually narrows from the edge end of the test block to the inner defect. By way of example, the shape of the tip-like defect may be a single triangular shape, a trapezoidal shape, a semi-elliptical shape, or a semi-circular shape; the shape may be a trapezoid or rectangle, or a combination of a triangle, trapezoid, semi-ellipse, or semicircle; and the method can also be determined according to actual requirements.
The size of the tip-like defects in the test block can be determined according to the actual layering detection requirement. The number of the tip-like defects in the test block is at least three, wherein the tip-like defects in the test block need to be related to different depth positions, and the specific depth positions can be determined according to the actual layering detection requirements.
The spatial position of the tip-like defect in the test block can be the depth position or the plane position of the tip-like defect in the test block. Specifically, a preset spatial position of at least one tip-like defect may be set in the test block, and the tip-like defect is prefabricated according to the preset spatial position. The method includes the steps of setting preset space positions of three tip-like defects in a test block, wherein the preset space positions of the three tip-like defects are located at different position depths of the same test block, so that detection effects of layering defects of different depths of the test block are obtained.
And S430, sequentially laying the fiber layers according to the number of layers, the laying angle and the laying sequence of the fiber layers to form a laminated plate.
Wherein, the laminated board is a whole structure board which is formed by stacking and bonding a plurality of unidirectional fiber layers according to a certain layering sequence and layering angles.
In the embodiment of the invention, the fiber layers are sequentially paved according to the determined pavement angle and the determined pavement sequence to form the laminated board, and the control instruction can be issued to the paving equipment, so that the paving equipment performs paving according to the received control instruction; or generating and displaying a control instruction, and sequentially laying the fiber layers according to the determined laying angle and the determined laying sequence by a worker to form the laminated plate according to the displayed control instruction.
S440, preprocessing the laminated plate to obtain an intermediate test block.
The intermediate test block can be a test block meeting the preset size and the preset mechanical property standard. It can be understood that the laminated board formed by sequentially laying the fiber layers according to the layer number, the laying angle and the laying sequence still has differences in the size and the performance of the standard test block, and the laminated board needs to be processed through certain pretreatment to obtain the middle test block meeting the preset standard.
Wherein, the pretreatment can be a treatment mode for changing the size and mechanical property of the laminated board. The physical properties of the laminate may include, among others, the dimensions of the laminate, stiffness, strength, compliance, or thermal wet stress. It will be appreciated that if it is desired to change the dimensions of the laminate, the laminate may be machined to obtain intermediate test blocks of a predetermined size; if it is desired to change the thermal-wet stress of the laminate, the temperature and time for curing the laminate can be adjusted.
In the embodiment of the invention, the laminated board is preprocessed to obtain the intermediate test block, and the preprocessing equipment can preprocess the laminated board according to the received control instruction by issuing the control instruction to the preprocessing equipment; control instructions may be generated and displayed, and the operator may preprocess the laminate according to the displayed control instructions.
Optionally, the preprocessing includes: placing the laminated plate in a tool for vacuum sealing and bagging, and curing and forming in an autoclave to obtain an initial test block; and processing the initial test block according to a preset size to obtain an intermediate test block.
The initial test block is a test block obtained after the mechanical properties of the laminated plate are adjusted, and the middle test block is a test block obtained after the initial test block is adjusted in size.
In the embodiment of the invention, the laminated plate is placed in process equipment for vacuum sealing, which is beneficial to removing air and volatile matters; and then placing the vacuum-sealed and bagged laminated plate into an autoclave, and completing heating, pressurizing and curing of the laminated plate according to the preset temperature and the preset pressure.
Further, the initial test block is processed according to a preset size to obtain an intermediate test block, wherein the preset size can be determined according to actual requirements. The machining method may be a machining method by a tool having machining performance such as a numerical control machine tool or a grinding machine.
S450, determining the technological parameters of the laser processing equipment according to the shape, the size and the space position of the similar tip defects in the test block.
It will be appreciated that defects in the test block are typically simulated using pre-buried single or double layer polytetrafluoroethylene, but single or double layer polytetrafluoroethylene films are prone to misalignment during layering. According to the embodiment of the invention, the defects in the test block are simulated and prefabricated through the laser processing equipment.
The process parameters of the laser processing device can be laser power, repetition frequency, pulse width or laser scanning speed of the laser processing device. By selecting the optimal laser processing parameters according to the shape, size and spatial position of the tip-like defects in the test block, the defect signals can be more accurately simulated.
S460, processing the intermediate test block according to the technological parameters to obtain a target test block.
The target test block can be a test block with the quantitative evaluation capability of the mechanical edge delamination defect of the composite material.
Specifically, the determined shape, size and space position of the similar tip defect are led into a photoetching machine, and the laser beam is utilized to precisely focus the micro size, and the target test block is obtained by gradually etching from the edge end of the test block to the defect end.
In the embodiment of the invention, the laser processing equipment can be controlled to process the intermediate test block according to the technological parameters by generating the control instruction to obtain the target test block.
The arrangement has the advantages that on one hand, the laser processing operation is simple, the processing precision and efficiency are high, the size and the space position of the tip-like defects can be ensured, and particularly, the defects with complex morphology can be obtained; on the other hand, since the laser processing apparatus has non-contact property, the machining of the tip-like defect on the intermediate test block by the laser processing apparatus does not generate additional mechanical stress on the intermediate test block and the target test block.
The embodiment of the invention provides a manufacturing method of a test block for quantitatively evaluating the mechanical edge delamination defect of a composite material, which comprises the steps of determining the number of layers, the laying angle and the laying sequence of fiber layers in the test block according to the attribute of a detected composite material workpiece; determining the number, shape, size and space position of the similar tip defects in the test block according to the layering detection requirement of the detected composite material workpiece; sequentially laying the fiber layers according to the number of layers, the laying angle and the laying sequence of the fiber layers to form a laminated plate; preprocessing the laminated plate to obtain an intermediate test block; determining technological parameters of laser processing equipment according to the shape, the size and the space position of the quasi-tip defect in the test block; and processing the intermediate test block according to the technological parameters to obtain a target test block. According to the technical scheme, the precision and the accuracy of layering defect simulation in the test block can be improved, and the operation is simple and convenient.
In the above technical solution, optionally, after the intermediate test block is processed according to the process parameter to obtain a target test block, the manufacturing method further includes: and performing metering test and correction on the shape, the size and the space position of the quasi-tip defect in the target test block.
In order to ensure that the quasi-tip defects can accurately display layering defects in the detected composite material workpiece, the shape, the size and the spatial position of the quasi-tip defects in the target test block need to be measured and corrected. For example, the shape, size and spatial position of the tip-like defect in the target test block can be measured and tested by an industrial CT detection system, and if the measured shape, size or spatial position is inconsistent with the preset shape, size and spatial position, the tip-like defect in the target test block can be processed and corrected again by laser processing equipment. The advantage of setting like this is that can carry out accurate correction to layering defect's in the test block shape, size and spatial position, can ensure the size position accuracy of class tip defect, more accurate simulation defect signal.
The embodiment of the invention also provides a method for quantitatively evaluating the composite material machining edge layering defect, which can be suitable for quantitatively evaluating the composite material machining edge layering defect so as to accurately evaluate the composite material machining edge layering defect. Fig. 5 is a flowchart of a method for quantitatively evaluating an edge delamination defect of a composite material according to an embodiment of the present invention, as shown in fig. 5, the method includes:
s510, acquiring a test block to be verified.
The test block to be verified is made of the same material as the detected composite material workpiece, and at least one tip defect is prefabricated at the edge of the test block to be verified.
Optionally, the end of the tip defect is isosceles trapezoid, and the edge end of the test block of the tip defect is rectangular.
Optionally, the transverse short sides of the waist-trapezoids have a dimension greater than or equal to 0.5 millimeters and less than or equal to 6 millimeters; the transverse long side of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 9 mm; a longitudinal dimension greater than or equal to 0.5 millimeters and less than or equal to 9 millimeters; wherein the longitudinal dimension is the distance from the end of the tip defect to the edge of the test block.
Optionally, the at least one tip-like defect is spatially located differently.
Optionally, prefabricating at least three tip-like defects at the edge of the test block; wherein the first tip-like defect is spatially located at least two fiber layers from the upper surface of the test block; the second tip-like defect is spaced from the upper surface of the block by the same distance as the lower surface of the block; the third tip-like defect is spatially located at least two fiber layers from the lower surface of the block.
Further, the method for manufacturing the test block to be verified can be realized by the following steps: determining the number of layers, the laying angle and the laying sequence of fiber layers in the test block according to the attribute of the detected composite material workpiece; determining the number, shape, size and space position of the similar tip defects in the test block according to the layering detection requirement of the detected composite material workpiece; sequentially laying the fiber layers according to the number of layers, the laying angle and the laying sequence of the fiber layers to form a laminated plate; preprocessing the laminated plate to obtain an intermediate test block; determining technological parameters of laser processing equipment according to the shape, the size and the space position of the quasi-tip defect in the test block; and processing the intermediate test block according to the technological parameters to obtain a target test block, namely the test block to be verified.
S520, carrying out ultrasonic scanning on the test block to be verified, and determining an ultrasonic scanning result of the tip-like defect in the test block to be verified.
The ultrasonic scanning mode can be ultrasonic A scanning, phased array scanning or characteristic C scanning. And determining an ultrasonic scanning result of the quasi-tip defect in the test block to be verified by carrying out ultrasonic scanning on the defect position in the test block to be verified.
In the embodiment of the invention, ultrasonic scanning is carried out on the test block to be verified, the sensitivity of a composite material machining edge good region can be established by selecting a probe with a certain frequency and a certain size and completing parameter setting of an ultrasonic scanning system, tip-like defects in the test block to be verified are detected by the sensitivity, and the ultrasonic scanning result of the tip-like defects in the test block to be verified is determined.
Wherein the ultrasound scan result may be an attenuation or amplitude of the ultrasound waves.
And S530, determining the evaluation capability of the corresponding detection ultrasonic system on the mechanical edge layering defect of the composite material if layering reflected wave signals or image abnormality prompts exist at the defect-like positions of the corresponding shape, size and space position in the test block to be verified according to the ultrasonic scanning result.
The preset evaluation capability requirement can be a preset attenuation rate of an ultrasonic reflection signal, a preset ratio of an abnormal image area in an ultrasonic scanning result to a layering defect area in a test block to be verified, or a parameter capable of reflecting a layering defect quantitative standard in the test block to be verified. The comparison of the embodiment of the invention is not limited.
In the embodiment of the invention, based on an ultrasonic scanning result, if a test block to be verified meets the preset attenuation rate of an ultrasonic reflection signal or the ratio of the area of an abnormal image area in the ultrasonic scanning result to the area of a layering defect area in the test block to be verified is in a preset ratio range, quantitative evaluation of the composite material machining edge layering defect is performed through the test block to be verified.
Optionally, according to the ultrasonic scanning result, if a layered reflected wave signal or an image abnormality prompt exists at the similar defect position of the corresponding shape, size and space position in the test block to be verified, the evaluation capability of the ultrasonic system on the mechanical edge layered defect of the composite material can be determined.
The abnormal result of the test block to be verified can be prompted according to the comparison result of the ultrasonic scanning result of the non-defective test block and the ultrasonic scanning result of the test block to be verified. Wherein the layered reflected wave signal may be an amplitude display or an image display of the ultrasonic reflected signal. In the embodiment of the invention, if the ultrasonic scanning result has a layered reflected wave signal or an image abnormality prompt, the test block to be verified is determined to meet the requirement of the preset evaluation capability.
The method has the advantages that whether the test block to be verified has the capability of quantitatively evaluating the mechanical edge layering defect of the composite material can be quickly and intuitively determined by observing whether layering reflected wave signals or image abnormity prompts exist in the ultrasonic scanning result.
The embodiment of the invention provides a method for quantitatively evaluating mechanical edge delamination defects of a composite material, which comprises the steps of obtaining a test block to be verified; carrying out ultrasonic scanning on the test block to be verified, and determining an ultrasonic scanning result of the tip-like defect in the test block to be verified; and according to an ultrasonic scanning result, if a layered reflected wave signal or an image abnormality prompt exists at the similar defect position of the corresponding shape, size and space position in the test block to be verified, determining the evaluation capability of the ultrasonic system on the mechanical edge layered defect of the composite material. According to the technical scheme, the defect signal can be accurately simulated, the sensitivity of the ultrasonic detection of the defect signal of the machined edge is improved, the test capability of the high-precision nondestructive evaluation of the machined edge is established, and the reliability and the safety of the composite material in application are further ensured.
It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.
The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims (9)
1. A test block for quantitative evaluation of composite material machining edge delamination defects, the test block being composed of the same material as a composite material workpiece to be inspected, characterized in that at least one type of tip defects is preformed in the edge of the test block.
2. The test block of claim 1, wherein the tip-like defect ends are isosceles trapezoids and the edge ends of the test block are rectangular.
3. The test block of claim 2, wherein the isosceles trapezoid has a transverse short side dimension greater than or equal to 0.5 mm and less than or equal to 6 mm; the transverse long side of the isosceles trapezoid is greater than or equal to 0.5 mm and less than or equal to 9 mm; a longitudinal dimension greater than or equal to 0.5 millimeters and less than or equal to 9 millimeters; wherein the longitudinal dimension is the distance from the tip-like defect end to the test block edge end.
4. The test block of claim 1, wherein the at least one type of tip defect is spatially located differently.
5. The test block of claim 4, wherein at least three tip-like defects are preformed in the edge of the test block; wherein,
the first tip-like defect is spatially located at least two fiber layers from the upper surface of the test block;
the space position of the second tip-like defect is the same as the distance from the upper surface of the test block and the distance from the lower surface of the test block;
the third tip-like defect is spatially located at least two fiber layers from the lower surface of the test block.
6. A method for manufacturing a test block for quantitative evaluation of mechanical edge delamination defects of a composite material, the method comprising:
determining the number of layers, the laying angle and the laying sequence of fiber layers in the test block according to the attribute of the detected composite material workpiece;
determining the number, shape, size and spatial position of the tip-like defects in the test block according to the layering detection requirements of the detected composite material workpiece;
sequentially laying the fiber layers according to the number of layers, the laying angle and the laying sequence of the fiber layers to form a laminated plate;
preprocessing the laminated plate to obtain an intermediate test block;
determining technological parameters of laser processing equipment according to the shape, the size and the space position of the quasi-tip defect in the test block;
and processing the intermediate test block according to the technological parameters to obtain a target test block.
7. The method of manufacturing according to claim 6, wherein the pretreatment process comprises:
placing the laminated plate in a tool for vacuum sealing and bagging, and curing and forming in an autoclave to obtain an initial test block;
and processing the initial test block according to a preset size to obtain an intermediate test block.
8. The method of manufacturing according to claim 6, further comprising, after processing the intermediate test block according to the process parameters to obtain a target test block:
and performing metering test and correction on the shape, the size and the space position of the similar tip defects in the target test block.
9. A method for quantitative evaluation of composite machining edge delamination defects, the method comprising:
obtaining a test block to be verified; wherein the test block to be verified is the test block according to any one of claims 1 to 5, which is manufactured according to the method according to any one of the preceding claims 6 to 8;
carrying out ultrasonic scanning on the test block to be verified, and determining an ultrasonic scanning result of the tip-like defect in the test block to be verified;
and according to an ultrasonic scanning result, if a layering reflected wave signal or an image abnormality prompt exists at the point-like defect position of the corresponding shape, size and space position in the test block to be verified, determining the evaluation capability of the ultrasonic system on the mechanical edge layering defect of the composite material.
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