An auxiliary preparation tool for large-thickness composite material compression specimen

Abstract

The application relates to the technical field of large-thickness composite material laminated plate testing, and discloses an auxiliary preparation tool for a large-thickness composite material compression sample, which comprises a bottom plate, a first frame, a second frame, a first positioning assembly and a first positioning bolt; in the vertical direction, the first frame and the second frame are oppositely and spacedly arranged, the first frame or the second frame is arranged on the bottom plate, the first frame is arranged around one end of the sample and is spaced from the one end of the sample, and the second frame is arranged around the other end of the sample and is spaced from the other end of the sample; in the vertical direction, one end of the first positioning assembly is connected with the first frame, and the other end of the first positioning assembly is connected with the second frame; the first positioning bolt is threadedly matched with the first positioning assembly so as to selectively abut against the sample in the first direction, and the first direction is perpendicular to the vertical direction. The auxiliary preparation tool according to the application improves the preparation quality of the compression sample.

Description

Technical Field

[0001] This application relates to the field of testing technology for thick composite laminates, and in particular to an auxiliary tooling for preparing thick composite compression specimens. Background Technology

[0002] Deep-sea equipment is trending towards larger sizes and greater diving depths. Pressure structures are the main load-bearing components of deep-sea equipment such as submersibles and underwater vehicles. The extreme service requirements of large size and great diving depth pose significant challenges to lightweight technology for deep-sea pressure structures. Under the external pressure environment of deep-sea applications, compressive stress exists within the shell of composite pressure structures. The compressive properties of the composite laminates are primarily relied upon to meet the external pressure load-bearing requirements of the pressure structure.

[0003] The testing methods for the compressive properties of composite materials include using uniaxial compression specimens with reinforcing plates at both ends, bonding the reinforcing plates to the composite laminate, and using specially designed compression test fixtures to transfer the compressive load at the end of the testing machine to the test section of the specimen through pure shear or shear-end coupling loading methods. However, due to the limited shear load bearing capacity of the adhesive layer between the reinforcing plates and the specimen, the existing thin composite plate specimens are no longer suitable for the uniaxial compression test requirements of thick composite laminates.

[0004] In related technologies, the quality of compression specimen preparation has a significant impact on the accuracy and reliability of uniaxial compression test data for thick composite laminates. How to improve the quality of compression specimen preparation is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides an auxiliary preparation tool for uniaxial compression test specimens of thick composite laminates, which improves the quality of the compression specimen preparation.

[0006] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide an auxiliary preparation fixture for a thick composite material compression specimen, including a base plate, a first frame, a second frame, a first positioning component, and a first positioning bolt; the first frame and the second frame are arranged opposite to each other and spaced apart in the vertical direction, the first frame or the second frame is disposed on the base plate, the first frame surrounds one end of the specimen and is spaced apart from one end of the specimen, and the second frame surrounds the other end of the specimen and is spaced apart from the other end of the specimen; in the vertical direction, one end of the first positioning component is connected to the first frame, and the other end of the first positioning component is connected to the second frame; the first positioning bolt is threadedly engaged with the first positioning component to selectively abut against the specimen in a first direction, the first direction being perpendicular to the vertical direction.

[0007] The auxiliary preparation tooling for thick composite compression specimens proposed in the first aspect of this application facilitates the filling of mixtures between the first frame and the specimen and between the second frame and the specimen to reinforce the specimen. Compared with the traditional method of pasting reinforcing sheets, there is no weak layer at the bonding interface, the interface bonding force is stronger, the preparation quality of the specimen is effectively improved, and it is easy to manufacture, easy to disassemble, and recyclable.

[0008] Optionally, there are two first positioning components, arranged on both sides of the sample along the first direction, and each first positioning component is provided with a first positioning bolt.

[0009] In the above scheme, the above structure helps to make the gap between the sample and the first frame and the second frame uniform and consistent, thereby improving the preparation quality of the sample.

[0010] Optionally, the first positioning component includes a first positioning plate and a second positioning plate. In the vertical direction, one end of the first positioning plate is connected to the first frame, one end of the second positioning plate is connected to the second frame, and the distance between the other ends of the first and second positioning plates is adjustable. Both the first and second positioning plates are provided with first positioning bolts.

[0011] In the above scheme, the above structure can be adapted to thick composite material samples of different lengths and specifications, and can meet the end reinforcement preparation requirements of samples of various sizes without changing the tooling, thus greatly improving the versatility of the tooling.

[0012] Optionally, the first positioning component further includes an adjusting member, which includes a slide rail, a slider, and a locking member. The slide rail is fixed to the first positioning plate and extends in a vertical direction, the slider is fixed to the second positioning plate and slidably disposed on the slide rail, and the locking member passes through the slider and can optionally abut against the slide rail.

[0013] In the above scheme, the above structure can be quickly adapted to thick composite material samples of different lengths and specifications, and the adjustment process is simple, efficient and reliable in positioning.

[0014] Optionally, the adjusting component also includes a fixing frame, which surrounds and is fixedly connected to the slide rail. In the vertical direction, one end of the fixing frame is fixed to the first positioning plate, and the other end of the fixing frame is slidably disposed on the second positioning plate.

[0015] In the above solution, the fixed frame can effectively protect and support the slide rail, preventing deformation and displacement of the slide rail during long-term use, ensuring smooth sliding and accurate positioning of the slider, and improving the rigidity and stability of the entire adjustment structure.

[0016] Optionally, the locking element passes through the fixed frame and the slider and optionally abuts against the slide rail.

[0017] In the above scheme, the above structure can make the overall positioning more robust and reliable, which not only improves the positional accuracy after adjustment, but also enhances the structural rigidity, and further improves the quality of the sample.

[0018] Optionally, the outer peripheral surface of the first positioning bolt is provided with a first scale extending in a first direction.

[0019] In the above scheme, the above structure can realize the visualization and quantitative precise adjustment of the lateral positioning distance of the sample, and the operator can directly screw the positioning bolt to the set position according to the scale.

[0020] Optionally, the auxiliary preparation tooling also includes a second positioning component and a second positioning bolt. In the vertical direction, one end of the second positioning component is connected to the first frame, and the other end of the second positioning component is connected to the second frame. The second positioning bolt is threadedly engaged with the second positioning component to selectively abut the sample along the second direction, with the first direction, the second direction, and the vertical direction being perpendicular to each other.

[0021] In the above scheme, the above structure can ensure that the gap between the sample and the upper and lower frames is uniform and symmetrical, so that the molding thickness and structural morphology of the resin and quartz sand mixture at both ends are highly consistent, thereby improving the preparation quality of the sample.

[0022] Optionally, the second positioning component includes a third positioning plate and a fourth positioning plate. In the vertical direction, the third positioning plate is disposed on the first frame and the fourth positioning plate is disposed on the second frame. Both the third positioning plate and the fourth positioning plate are provided with second positioning bolts.

[0023] In the above scheme, the above structure can achieve synchronous clamping and positioning of the sample at multiple points in the second direction, which can further constrain the deflection and tilt of the sample in the horizontal direction, so that the thick sample is subjected to more uniform force and has a more stable posture in the height direction.

[0024] Optionally, the outer peripheral surface of the second positioning bolt is provided with a second scale extending in a second direction.

[0025] In the above scheme, the operator can intuitively and accurately control the clamping distance to ensure that the sample is completely centered in the tooling, so that the gap between the sample and the frame is uniform and consistent, thereby improving the quality of sample preparation.

[0026] The beneficial effects of this application are: it facilitates filling the mixture between the first frame and the specimen and between the second frame and the specimen to reinforce the specimen. Compared with the traditional method of pasting reinforcing sheets, there is no weak layer at the bonding interface, the interface bonding force is stronger, the quality of specimen preparation is effectively improved, and it is easy to manufacture, easy to disassemble, and recyclable. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the auxiliary preparation tooling in some embodiments of this application; Figure 2 This is a schematic diagram of the overall structure of the auxiliary preparation tooling in some embodiments of this application from another angle.

[0029] [Explanation of Markings in the Attached Images] 100. Base plate; 200. First Framework; 300. Second Frame; 400. First positioning component; 410. First positioning plate; 420. Second positioning plate; 500, First positioning bolt; 510, First scale; 600. Adjusting component; 610. Slide rail; 620. Slider; 630. Locking component; 640. Fixing frame; 700. Second positioning component; 710. Third positioning plate; 720. Fourth positioning plate; 800. Second positioning bolt; 810. Second scale; 900, Sample; Z, vertical direction; X, primary direction; Y, secondary direction. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0032] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] Driven by advancements in deep-sea and deep-earth exploration, deep-sea equipment is trending towards larger sizes and greater diving depths. Pressure structures are the main load-bearing components of deep-sea equipment such as submersibles and underwater vehicles. The extreme service requirements of large size and great diving depth pose significant challenges to lightweighting technologies for deep-sea pressure structures. Compared to high-strength steel and titanium alloys, carbon fiber composite materials offer advantages such as high specific strength, high specific modulus, fatigue resistance, and strong design flexibility, making them a crucial choice for solving the challenge of lightweighting deep-sea pressure structures.

[0035] In deep-sea pressure environments, compressive stress exists within the shell of composite pressure-resistant structures. The compressive properties of the composite laminates are crucial for meeting the external pressure load requirements. Testing methods for the compressive properties of composite materials primarily employ uniaxial compression specimens with reinforcing plates at both ends. These reinforcing plates are bonded to the composite laminates using adhesive bonding. A specially designed compression test fixture is used, and the compressive load from the test chamber end is transferred to the test section of the specimen via pure shear or shear-end coupling loading methods. Due to the shear strength limit of the adhesive layer between the reinforcing plates and the specimen, and limitations imposed by the specimen's size, large shear loads cannot be transferred. Therefore, the thickness of the composite laminates suitable for existing specimens generally does not exceed 12 mm. However, extreme service conditions such as large dimensions and deep diving depths have led to a significant increase in the thickness of composite pressure-resistant structure shells. For example, the shell thickness of the Haiyi glider exceeds 20 mm, and the shell thickness of the TITAN deep-sea submersible exceeds 100 mm, classifying them as thick (≥20 mm) composite laminate structures.

[0036] Compared with common thin-plate composite materials, thick composite materials have the characteristics of large thickness and high test load in uniaxial compression test specimens. Since the shear load bearing capacity of the adhesive layer between the reinforcing sheet and the specimen is limited, the existing thin-plate composite material specimens are no longer suitable for the uniaxial compression test requirements of thick composite laminates.

[0037] Meanwhile, the quality of compression specimen preparation has a significant impact on the accuracy and reliability of uniaxial compression test data for thick composite laminates. Appropriate auxiliary preparation tooling is crucial for improving the quality of compression specimens for thick composite laminates. Therefore, how to improve the quality of compression specimen preparation is a pressing technical problem that needs to be solved.

[0038] Therefore, in order to improve the quality of compression test specimen preparation, this application proposes an auxiliary tooling for preparing thick composite material compression test specimens, such as... Figure 1 As shown, it includes a base plate, a first frame, a second frame, a first positioning component, and a first positioning bolt.

[0039] Along the vertical direction, the first frame and the second frame are arranged opposite to each other and spaced apart. The first frame or the second frame is set on the base plate. The first frame surrounds one end of the sample and is spaced apart from one end of the sample, and the second frame surrounds the other end of the sample and is spaced apart from the other end of the sample.

[0040] Specifically, the space between the first frame and the sample can be filled with a mixture of de-bubbling resin and quartz sand, and the mixture is cured to strengthen one end of the sample. The space between the second frame and the sample can be filled with a mixture of de-bubbling resin and quartz sand, and the mixture is cured to strengthen the other end of the sample.

[0041] This facilitates the formation of a strong, integrated bond between the reinforcing material and the specimen. Compared to traditional adhesive reinforcing sheets, there is no weak bonding layer at the interface, resulting in stronger interfacial adhesion. Quartz sand enhances the hardness and compressive strength of the cured reinforcing layer, while the resin ensures the wetting and bonding of the reinforcing layer to the composite matrix. The combination effectively disperses stress at the specimen ends, preventing premature crushing and end-face breakage in thick specimens due to stress concentration. Simultaneously, pre-degassing of the mixture prevents defects such as pores and looseness within the reinforcing layer, preventing stress concentration at these defects and subsequent cracking, thus improving the reliability of end reinforcement.

[0042] Meanwhile, the first and second frames can form circumferential restraints on the resin and quartz sand mixture, preventing material outflow and collapse during filling, ensuring uniform thickness and regular shape of the reinforcing layers at both ends, and ensuring that the force-bearing surface is flat and uniform during subsequent test clamping, avoiding eccentric loading due to dimensional deviations of the reinforcing layers.

[0043] The fixed internal gaps and uniform positioning of the first and second frames help maintain consistency in the filling amount and curing posture of the mixture, avoiding individual differences such as uneven thickness of the reinforcing layer and large positioning deviation during manual preparation.

[0044] Meanwhile, the support structure of the base plate and frame can ensure that the sample maintains a vertical posture throughout the curing process, and will not tilt or shift due to the weight of the thick sample. This effectively reduces the sample scrap rate caused by posture deviation and internal defects in the reinforcing layer, and steadily improves the finished product qualification rate.

[0045] The tooling is a rigid, split structure. After the mixture has solidified, it can be easily demolded. The frame, base plate and other components are undamaged and can be repeatedly recycled.

[0046] In some specific embodiments, the first and second frames are solidified together with the mixture to further enhance the structural strength. In other words, the first and second frames can not only play an auxiliary role in preparation, but also play a role in strengthening the sample.

[0047] In the vertical direction, one end of the first positioning component is connected to the first frame, and the other end of the first positioning component is connected to the second frame; the first positioning bolt is threadedly engaged with the first positioning component to selectively abut against the sample in a first direction, which is perpendicular to the vertical direction.

[0048] Understandably, the first positioning component can ensure the coaxiality and relative positional accuracy of the first and second frames, which helps to reduce the problem of asymmetry of the reinforcing material cured at both ends of the specimen, and avoids deformation or misalignment of the frame fixed at one end due to the lateral pressure of the mixture and the self-weight of the thick specimen. This effectively reduces the additional bending moment in the subsequent compression test and improves the accuracy of the test data.

[0049] The first positioning component provides a mounting carrier for the first positioning bolt. The reference surface of the threaded engagement remains perpendicular to the vertical direction, ensuring that the bolt tightening direction acts strictly along the horizontal radial direction on the specimen, preventing the tightening force from generating a vertical component that could cause the specimen to lift or tilt. At the same time, the tightening reaction force can be transmitted to the overall frame through the positioning component for closed-loop dissipation, avoiding local stress that could cause frame deformation, and maintaining stable positioning accuracy even after long-term repeated use.

[0050] When in use, after placing the sample into the first frame and the second frame, screw the first positioning bolt inward until the first positioning bolt abuts against the sample.

[0051] In some embodiments, such as Figure 1 and Figure 2 As shown, there are two first positioning components. Along the first direction, the two first positioning components are arranged on both sides of the sample, and each first positioning component is provided with a first positioning bolt.

[0052] In other words, the two first positioning components can clamp the sample from both sides in the first direction, which can not only ensure that the sample is accurately centered in the tooling and that the circumferential gap between the sample and the first and second frames is uniform, ensuring that the end reinforcement layer of the subsequently filled resin-quartz sand mixture is uniform in thickness and well-formed after curing, but also effectively constrain the horizontal displacement and rotation of the sample during the entire process of mixture pouring and curing, avoiding the tilting and misalignment of the sample due to unilateral force, thus significantly improving the preparation quality of thick composite material compression samples.

[0053] Meanwhile, the bidirectional symmetrical clamping can make the sample more evenly stressed, effectively preventing local pressure damage to the sample. Moreover, the structure has stronger adaptability and can meet the centering positioning requirements of samples with different cross-sectional sizes, further improving the versatility and preparation stability of the tooling.

[0054] Specifically, the first positioning component is fixed on the outer peripheral surface of the first frame and the second frame, and the first positioning bolt extends inward through the corresponding first positioning component to abut against the outer surface of the sample.

[0055] In some embodiments, such as Figure 1 and Figure 2 As shown, the first positioning component includes a first positioning plate and a second positioning plate. In the vertical direction, one end of the first positioning plate is connected to the first frame, and one end of the second positioning plate is connected to the second frame. The distance between the other ends of the first positioning plate and the other ends of the second positioning plate is adjustable. Both the first positioning plate and the second positioning plate are provided with first positioning bolts.

[0056] The vertical spacing between the first and second positioning plates is adjustable, which can accommodate thick composite material samples of different lengths and specifications. It can meet the end reinforcement preparation needs of various sizes of samples without changing the tooling, greatly improving the versatility of the tooling.

[0057] Meanwhile, both the upper and lower split positioning plates are equipped with first positioning bolts, which can achieve multi-point lateral tightening and positioning at different positions in the height direction of the sample. This ensures that the sample remains vertically centered throughout the process, effectively preventing the long strip sample from tilting or shaking during the filling and curing process. It also makes the sample more uniformly stressed, avoiding local deformation or damage caused by single-point positioning, and further improving the quality of sample preparation.

[0058] In some embodiments, such as Figure 1 and Figure 2 As shown, the first positioning component also includes an adjusting member, which includes a slide rail, a slider, and a locking member. The slide rail is fixed to the first positioning plate and extends in the vertical direction. The slider is fixed to the second positioning plate and slidably disposed on the slide rail. The locking member passes through the slider and can be selectively abutted against the slide rail.

[0059] It enables stepless, smooth, and precise vertical adjustment of the first and second positioning plates, allowing for rapid adaptation to thick composite material samples of varying lengths. The adjustment process is simple, efficient, and reliable. The smooth sliding fit prevents jamming or misalignment during adjustment, ensuring accurate alignment of the upper and lower positioning plates. The locking mechanism reliably locks the slider and slide rail after adjustment, preventing loosening or displacement during sample filling and curing. This ensures the stability of the positioning structure, thereby guaranteeing the molding accuracy of the reinforcing layers at both ends of the sample and the overall shape and position accuracy of the sample. This further enhances the flexibility of the tooling and the quality of sample preparation.

[0060] In some embodiments, such as Figure 1 and Figure 2 As shown, the adjusting component also includes a fixing frame, which surrounds the slide rail and is fixedly connected to the slide rail. In the vertical direction, one end of the fixing frame is fixed to the first positioning plate, and the other end of the fixing frame is slidably disposed on the second positioning plate.

[0061] The fixed frame provides effective protection and support for the slide rail, preventing deformation and displacement during long-term use, ensuring smooth sliding and precise positioning of the slider, and improving the rigidity and stability of the entire adjustment structure. On the other hand, the fixed frame is fixed vertically to the first positioning plate and can slide relative to the second positioning plate, further constraining the relative movement direction of the two positioning plates, preventing swaying and misalignment during adjustment, and ensuring that the first and second positioning plates always remain parallel and aligned, which helps improve ease of use and sample preparation quality.

[0062] In a specific embodiment, the fixed frame can be constructed as a square frame, and the slide rail is disposed inside the square frame with its two ends fixedly connected to the square frame respectively. That is to say, the slide rail can be fixed to the first positioning plate through the square frame. Both the first positioning plate and the second positioning plate are provided with slide grooves that cooperate with the square frame, which helps to improve the positional accuracy of the first positioning plate and the second positioning plate.

[0063] In some embodiments, the locking element passes through the fixed frame and the slider and can optionally abut against the slide rail. On the one hand, it can simultaneously lock the second positioning plate, the slider, and the fixed frame onto the slide rail, making the overall positioning more secure and reliable, and effectively preventing slippage or loosening due to force during filling and curing; on the other hand, the fixed frame can provide support for the locking part, preventing local deformation of the slider or slide rail during locking, ensuring uniform and stable locking force, which not only improves the positional accuracy after adjustment, but also enhances the structural rigidity, further improving the sample quality.

[0064] In some embodiments, such as Figure 1 and Figure 2 As shown, the outer circumferential surface of the first positioning bolt is provided with a first scale extending along a first direction. This enables visualized, quantitative, and precise adjustment of the lateral positioning distance of the sample. Operators can directly screw the positioning bolt to the set position according to the scale, without relying on experience or additional measuring tools for comparison. This ensures that the sample is accurately centered within the fixture, making the gap between the sample and the frame uniform. It also significantly improves the consistency of positioning between different samples in the same batch, reduces human error, improves the molding accuracy of the end reinforcement layer and the repeatability of sample preparation, and facilitates rapid adaptation to samples with different cross-sectional dimensions, further improving the ease of use and preparation efficiency of the fixture.

[0065] In some embodiments, such as Figure 1 and Figure 2 As shown, the auxiliary preparation tooling also includes a second positioning component and a second positioning bolt. In the vertical direction, one end of the second positioning component is connected to the first frame, and the other end of the second positioning component is connected to the second frame. The second positioning bolt is threadedly engaged with the second positioning component to selectively abut the sample along the second direction, with the first direction, the second direction, and the vertical direction being perpendicular to each other.

[0066] This design enables precise bidirectional and omnidirectional positioning and centering fine-tuning of the sample in the horizontal plane, avoiding horizontal offset, rotation, and swaying of the sample. Compared with single-direction positioning, it effectively solves the problems of poor centering accuracy and skewed posture caused by the large self-weight and uneven force of thick composite material samples.

[0067] In a specific embodiment, the sample is square, and the first positioning component and the first positioning bolt can clamp the sample from the width direction, while the second positioning component and the second positioning bolt can clamp the sample from the thickness direction.

[0068] It can ensure that the gap between the sample and the upper and lower frames is uniform and symmetrical, so that the molding thickness and structural morphology of the resin and quartz sand mixture at both ends are highly consistent, eliminating the problem of sample structure asymmetry caused by unilateral wall thickness deviation and improving the sample preparation quality.

[0069] In addition, the bidirectional independently adjustable positioning structure has stronger adaptability and can be compatible with thick composite material samples of different cross-sectional specifications, further broadening the tooling adaptability range and improving the tooling versatility and the stability and accuracy of sample batch preparation.

[0070] In some embodiments, such as Figure 1 and Figure 2 As shown, the second positioning component includes a third positioning plate and a fourth positioning plate. In the vertical direction, the third positioning plate is disposed on the first frame and the fourth positioning plate is disposed on the second frame. Both the third positioning plate and the fourth positioning plate are provided with second positioning bolts.

[0071] In the above scheme, the third positioning plate and the fourth positioning plate are respectively set on the first frame and the second frame, and each is equipped with a second positioning bolt. This enables the sample to be simultaneously clamped and positioned at multiple points in the second direction, which can further constrain the deflection and tilt of the sample in the horizontal direction. This makes the force on the thick sample in the height direction more uniform and the posture more stable. It effectively avoids the sample from tilting or shaking during the filling and curing process of the resin and quartz sand mixture. It ensures that the sample axis is always consistent with the center axis of the tooling, thereby ensuring that the thickness of the reinforcing layer at both ends is uniform and the molding is regular, and improving the shape and position accuracy and preparation quality of the sample.

[0072] In some embodiments, the outer circumferential surface of the second positioning bolt is provided with a second scale extending along a second direction. Operators can intuitively and precisely control the tightening distance, ensuring the specimen is perfectly centered within the fixture and that the gap between the specimen and the frame is uniform. Simultaneously, it significantly improves the repeatability and consistency of positioning for specimens in the same batch, reduces human error, ensures uniform thickness and regular forming of the end reinforcement layer, and further enhances the preparation accuracy and reliability of test data for thick composite material compression specimens.

[0073] In a specific embodiment, the auxiliary tooling also includes a release cloth and a sealing strip. The release cloth is laid on the base plate, the first frame is detachably set on the release cloth, and the sealing strip is located between the outer peripheral surface of the first frame and the release cloth.

[0074] During use, the first and second frames are used to increase the pressure area and end face strength, protecting the sample end face and reducing the risk of damage during pressure.

[0075] Both the first and second frames are constructed as square metal frames. A sealing strip is attached to the gap between the square metal frame and the release cloth to prevent the subsequent resin and quartz sand mixture from overflowing from the gap between the release cloth and the metal frame.

[0076] Along the second direction, two first positioning components are spaced apart, meaning there are a total of four first positioning components on both sides of the first and second frames. Adjust the position of the slider on the slide rail according to the length of the sample. Ensure the outer surface of the upper and lower rectangular metal frames is level with the upper and lower surfaces of the sample (using a spirit level or large flat plate), and then lock the slider.

[0077] The heads of the first and second positioning bolts are equipped with thick, disc-shaped rubber pads, which better secure the specimen while reducing damage to the specimen surface. Initially, the "zero mark" of the positioning bolt is aligned with the outer surface of the corresponding positioning plate, and the rubber pad is in the same vertical plane as the inner surface of the metal frame. The specimen must be centered in the auxiliary fixture, and the positioning bolt should be screwed in according to the calculated mark.

[0078] The thick composite material specimen is placed vertically in the center of a square metal frame, with rubber discs for the width and thickness positioning bolts attached to its sides. A mixture of resin and quartz sand is filled between the metal frames at both ends of the specimen and the thick composite material specimen (the mixture needs to have internal air bubbles removed first). It is then placed in an oven for curing. After the mixture has fully solidified, the sealing strip is removed and the specimen is demolded.

[0079] Rotate this auxiliary preparation fixture 180 degrees up and down. Place the square metal frame on the other side onto the release cloth. Then repeat the operation on the other end face of the sample.

[0080] After the mixture at both ends of the sample has fully solidified, the prepared sample can be obtained by removing the first positioning component and the second positioning component.

[0081] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. An auxiliary tooling for preparing thick composite material compression specimens, characterized in that, include: Base plate; A first frame and a second frame are arranged vertically, with the first frame and the second frame facing each other and spaced apart. The first frame or the second frame is disposed on the base plate. The first frame surrounds one end of the sample and is spaced apart from one end of the sample, and the second frame surrounds the other end of the sample and is spaced apart from the other end of the sample. A first positioning component, along the vertical direction, has one end connected to the first frame and the other end connected to the second frame; A first positioning bolt, which is threadedly engaged with the first positioning assembly, is used to selectively abut against the sample in a first direction perpendicular to the vertical direction.

2. The auxiliary preparation tooling according to claim 1, characterized in that, There are two first positioning components. Along the first direction, the two first positioning components are disposed on both sides of the sample, and each first positioning component is provided with the first positioning bolt.

3. The auxiliary preparation tooling according to claim 2, characterized in that, The first positioning component includes a first positioning plate and a second positioning plate. Along the vertical direction, one end of the first positioning plate is connected to the first frame, and one end of the second positioning plate is connected to the second frame. The distance between the other ends of the first positioning plate and the other ends of the second positioning plate is adjustable. Both the first positioning plate and the second positioning plate are provided with the first positioning bolt.

4. The auxiliary preparation tooling according to claim 3, characterized in that, The first positioning component further includes an adjusting member, which includes a slide rail, a slider, and a locking member. The slide rail is fixed to the first positioning plate and extends along the vertical direction. The slider is fixed to the second positioning plate and slidably disposed on the slide rail. The locking member passes through the slider and can be selectively abutted against the slide rail.

5. The auxiliary preparation tooling according to claim 4, characterized in that, The adjusting component also includes a fixing frame, which surrounds the slide rail and is fixedly connected to the slide rail. Along the vertical direction, one end of the fixing frame is fixed to the first positioning plate, and the other end of the fixing frame is slidably disposed on the second positioning plate.

6. The auxiliary preparation tooling according to claim 5, characterized in that, The locking element passes through the fixed frame and the slider and can optionally abut against the slide rail.

7. The auxiliary preparation tooling according to claim 1, characterized in that, The outer circumferential surface of the first positioning bolt is provided with a first scale extending along the first direction.

8. The auxiliary preparation tooling according to claim 1, characterized in that, The auxiliary preparation tooling also includes a second positioning component and a second positioning bolt. Along the vertical direction, one end of the second positioning component is connected to the first frame, and the other end of the second positioning component is connected to the second frame. The second positioning bolt is threadedly engaged with the second positioning component to selectively abut the sample along a second direction, wherein the first direction, the second direction, and the vertical direction are perpendicular to each other.

9. The auxiliary preparation tooling according to claim 8, characterized in that, The second positioning component includes a third positioning plate and a fourth positioning plate. Along the vertical direction, the third positioning plate is disposed on the first frame, and the fourth positioning plate is disposed on the second frame. Both the third positioning plate and the fourth positioning plate are provided with the second positioning bolt.

10. The auxiliary preparation tooling according to claim 8, characterized in that, The outer circumferential surface of the second positioning bolt is provided with a second scale extending along the second direction.

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