A strengthening sheet bonding and positioning device and method for precisely manufacturing composite material tensile and compressive test specimens

Abstract

The present invention discloses a reinforcing sheet bonding and positioning device and method for precisely manufacturing composite material tensile and compressive test specimens. A limiting strip is provided on the upper surface of a flat base, and a lead screw track is arranged above the limiting strip; a long-side stopper and a reinforcing sheet connecting block are respectively connected to the lead screw track and are movable on the flat base through the lead screw track; the number of long-side stoppers is two, and short-side stoppers are slidably arranged on the inner side walls of the two long-side stoppers; the reinforcing sheet connecting block includes a first reinforcing sheet connecting block and a second reinforcing sheet connecting block, and both reinforcing sheet connecting blocks are connected with a reinforcing sheet stopper and a reinforcing sheet positioning and bonding device. The device and method can realize the pasting of reinforcing sheets of different types and specifications of composite material test specimens, assist in quickly preparing specimens with reinforcing sheets, simplify the reinforcing sheet pasting process, reduce the cost of the reinforcing sheet pasting tooling, and improve the pasting efficiency and the machining dimensional accuracy of the specimen reinforcing sheets.

Description

Technical Field

[0001] The present invention belongs to the technical field of general tooling, and particularly relates to a bonding and positioning device and method for accurately manufacturing a reinforcing sheet of a composite material tensile and compression specimen. Background Art

[0002] When testing the mechanical properties of composite material specimens at the specimen level, whether it is a tensile test specimen or a compression test specimen of the composite material, when testing according to national standards or foreign standards, it is necessary to paste a reinforcing sheet to ensure an effective failure mode during the test. For example, when preparing a tensile strength specimen (ASTM D3039) and a compression strength specimen (SACMA SRM1), it is necessary to paste a reinforcing sheet, and according to the thickness change of the test piece, the size, thickness and type of the reinforcing sheet are all different. In particular, the size difference between the tensile strength reinforcing sheet and the compression strength reinforcing sheet is relatively large.

[0003] The existing reinforcing sheet pasting devices and methods usually design special reinforcing sheet pasting tooling for different specimen types and specimen sizes respectively. The tooling is only applicable to the pasting of reinforcing sheets for specific types of test pieces, and is only applicable to the preparation of test pieces with specific sizes and thicknesses of reinforcing sheets. The versatility is poor, the quantity and size of the prepared specimens are limited, the process is complex, and the cost is relatively high. First of all, the reinforcing sheet pasting tooling designed for tensile specimens is not applicable to the pasting of reinforcing sheets for compression strength composite material test pieces. Special tooling needs to be designed for different types of test pieces, and the cost is relatively high. At the same time, most of the existing tooling uses upper and lower closing molds, which are difficult to clean and the process is complex. Whether using a film adhesive or an adhesive for pasting the reinforcing sheet, the thickness of the adhesive layer needs to be manually calculated and controlled by the thickness of the reinforcing sheet and the mold gap. The thickness of the reinforcing sheet is limited by the mold size, and it is difficult to ensure the thickness and uniformity of the adhesive layer. In addition, the existing tooling does not have a unified positioning reference, and the quality of pasting the reinforcing sheet depends greatly on the operator, which brings difficulties to the subsequent finishing and cutting of the test piece, and it is difficult to ensure the machining accuracy of the final test piece. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems that the existing reinforcing sheet pasting device is only applicable to the preparation of test pieces with specific sizes and thicknesses of reinforcing sheets, with poor versatility, limited quantity and size of the prepared specimens, complex process and high cost; in addition, the existing tooling does not have a unified positioning reference, and the quality of pasting the reinforcing sheet depends greatly on the operator, which brings difficulties to the subsequent finishing and cutting of the test piece, and it is difficult to ensure the machining accuracy of the final test piece.

[0005] To achieve the object of the present invention, the present invention discloses a bonding and positioning device for a reinforcing sheet for precisely manufacturing a composite tension-compression specimen, including a flat base, a long-side stopper, a short-side stopper, a reinforcing sheet connecting block, a reinforcing sheet stopper, and a reinforcing sheet positioning and bonding device; a limiting strip is provided on the upper surface of the flat base, and a screw rod track is provided above the limiting strip; the long-side stopper and the reinforcing sheet connecting block are respectively connected to the screw rod track and can be moved on the flat base through the screw rod track; the number of long-side stoppers is two, and short-side stoppers are slidably provided on the inner side walls of the two long-side stoppers; the reinforcing sheet connecting block includes a first reinforcing sheet connecting block and a second reinforcing sheet connecting block, and both reinforcing sheet connecting blocks are connected with a reinforcing sheet stopper and a reinforcing sheet positioning and bonding device;

[0006] When bonding the reinforcing sheet, first place the composite tension-compression specimen on the upper surface of the flat base, and abut one side of the composite tension-compression specimen against the limiting strip to achieve the positioning of the first side of the composite tension-compression specimen; move the long-side stoppers through the screw rod track, and the two long-side stoppers respectively achieve the positioning of the other two sides of the composite tension-compression specimen. Then, slide the short-side stoppers on the inner side walls of the long-side stoppers, and the two short-side stoppers complete the positioning of the last side of the composite tension-compression specimen; then, move the two reinforcing sheet connecting blocks to the preset positions through the screw rod track. The preset positions are pre-calculated according to the sizes of the composite tension-compression specimen and the reinforcing sheet used; after the first reinforcing sheet connecting block and the second reinforcing sheet connecting block move to the preset positions, the reinforcing sheet stoppers respectively connected to the first reinforcing sheet connecting block and the second reinforcing sheet connecting block enclose two reinforcing sheet bonding areas with the limiting strip, the long-side stoppers, and the short-side stoppers. Subsequently, place the reinforcing sheet into the reinforcing sheet bonding area, and the reinforcing sheet positioning and bonding device connected to the reinforcing sheet connecting block is used to achieve the bonding of the reinforcing sheet of the composite tension-compression specimen.

[0007] Further, the reinforcing sheet positioning and bonding device includes a pressing plate and a lifting mechanism; the lifting mechanism is connected to the reinforcing sheet connecting block, and the pressing plate is connected to the lifting mechanism. When the two reinforcing sheet connecting blocks move to the preset positions, the pressing plate can just be located directly above the reinforcing sheet bonding area; the lifting mechanism drives the pressing plate to move up and down through a motor or an electric motor. When the pressing plate presses down, the reinforcing sheet can be bonded to the composite tension-compression specimen.

[0008] Further, a pressure sensor is provided below the pressing plate. The pressure sensor is electrically connected to the main control chip and can send the real-time pressure received by the pressing plate to the main control chip; the main control chip is electrically connected to the lifting mechanism and is used to send an action instruction to the lifting mechanism; when bonding, the main control chip controls the lifting mechanism to move downward, and the pressure sensor monitors the pressure received by the pressing plate in real time; when the pressure received by the pressing plate reaches the preset value, the main control chip sends a rising instruction to the lifting mechanism to complete the bonding of the reinforcing sheet of the composite tension-compression specimen and realize the reset of the pressing plate.

[0009] Further, the bonding pressure of the reinforcing sheet is preset by the main control chip, and the magnitude of the bonding pressure is:

[0010] F = σ × S

[0011] In the formula, F is the bonding force, with the unit of Newton (N); σ is the bonding stress of the bonding adhesive or adhesive film, with the unit of Pascal (Pa); S is the area of the bonding surface of the reinforcing sheet, with the unit of square meter (m 2 .

[0012] Further, the limiting strip is arranged on one side of the upper surface of the flat base and is of the same length as the flat base; the lead screw track is a double-layer track, and the lower layer track is connected to the two long side stoppers; sliding grooves are provided on the inner side walls between the long side stoppers, and the two short side stoppers are respectively slidably arranged in the sliding grooves of the two long side stoppers.

[0013] Further, the reinforcing sheet connecting block is of an L-shaped structure and is connected to the upper layer of the lead screw track; the lifting mechanism is arranged below one side of the reinforcing sheet connecting block close to the short side stopper, and a pressing plate is arranged on one side of the lifting mechanism close to the short side stopper and is parallel to the flat base; on one side of the two reinforcing sheet connecting blocks close to each other, reinforcing sheet stoppers are respectively arranged parallel to the long side stoppers and extend out.

[0014] To achieve the purpose of the present invention, the present invention also discloses a method for accurately bonding and positioning the reinforcing sheet of the composite material tensile and compressive specimen, including the following steps:

[0015] Step 1: Place the composite material tensile and compressive specimen closely against the limiting strip on the flat base, and rotate the lower layer lead screw of the lead screw track to clamp the long sides of the composite material tensile and compressive specimen with the two long side stoppers;

[0016] Step 2: Slide the short side stoppers in the two long side stoppers to clamp the short sides of the composite material tensile and compressive specimen;

[0017] Step 3: Rotate the upper layer lead screw of the lead screw track to move the two reinforcing sheet connecting blocks to the preset positions, so that the reinforcing sheet stoppers enclose a reinforcing sheet bonding area with the limiting strip, the long side stoppers and the short side stoppers;

[0018] Step 4: Paste the reinforcing sheet with the bonding adhesive or adhesive film evenly applied on the bonding area position of the composite material tensile and compressive specimen, and the reinforcing sheet should be pasted exactly along the reinforcing sheet stopper;

[0019] Step 5: Use the pressing plate of the reinforcing sheet positioning and bonding device to press down through the lifting mechanism. After completion of bonding, cure the composite material tensile and compressive specimen with the reinforcing sheet bonded, and finally lift the pressing plate to reset and take out the specimen with the reinforcing sheet bonded.

[0020] Compared with the prior art, the remarkable progress of the present invention lies in: 1) The present device and method can realize the pasting of reinforcement sheets for composite material specimens of different types and specifications, and assist in the rapid preparation of specimens with reinforcement sheets; 2) Simplify the reinforcement sheet pasting process, reduce the cost of the reinforcement sheet pasting tooling, and improve the pasting efficiency and the machining dimensional accuracy of the specimen reinforcement sheet.

[0021] To more clearly illustrate the functional characteristics and structural parameters of the present invention, the following further explains in conjunction with the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 is a schematic structural diagram of a reinforcement sheet bonding and positioning device for precisely manufacturing composite material tensile and compressive specimens;

[0024] Figure 2 is a schematic flowchart of a method for precisely manufacturing a reinforcement sheet bonding and positioning of composite material tensile and compressive specimens;

[0025] The reference numerals in the drawings are: flat base 1, long side stop block 2, short side stop block 3, first reinforcement sheet connecting block 41, second reinforcement sheet connecting block 42, reinforcement sheet stop block 5, reinforcement sheet positioning and bonding device 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0027] As Figure 1 shown, a limit strip is provided on the upper surface of the flat base 1, and a lead screw track is provided above the limit strip; the long side stop block 2 and the reinforcement sheet connecting block are respectively connected to the lead screw track and are moved on the flat base 1 through the lead screw track; the number of the long side stop blocks 2 is two, and short side stop blocks 3 are slidably arranged on the inner side walls of the two long side stop blocks 2; the reinforcement sheet connecting block includes a first reinforcement sheet connecting block 41 and a second reinforcement sheet connecting block 42, and both reinforcement sheet connecting blocks are connected with a reinforcement sheet stop block 5 and a reinforcement sheet positioning and bonding device 6.

[0028] As Figure 2 shown, a method for precisely manufacturing a reinforcement sheet bonding and positioning of composite material tensile and compressive specimens includes the following steps:

[0029] Step 1: Place the composite material tensile and compressive test piece closely against the limit strip on the flat base, and rotate the lower screw of the screw rod track to clamp the long sides of the composite material tensile and compressive test piece with the two long side blocks.

[0030] Step 2: Slide the short side block in the two long side blocks to clamp the short side of the composite material tensile and compressive test piece.

[0031] Step 3: Rotate the upper screw of the screw rod track to move the two reinforcing sheet connecting blocks to the preset positions, so that the reinforcing sheet block, the limit strip, the long side block, and the short side block enclose a reinforcing sheet bonding area.

[0032] Step 4: Paste the reinforcing sheet evenly coated with bonding adhesive or pasted with adhesive film on the position of the reinforcing sheet bonding area of the composite material tensile and compressive test piece. The reinforcing sheet should be pasted exactly along the reinforcing sheet block.

[0033] Step 5: Use the pressing plate of the reinforcing sheet positioning and bonding device to press down through the lifting mechanism. After the bonding is completed, cure the composite material tensile and compressive test piece with the bonded reinforcing sheet. Finally, lift the pressing plate to reset and take out the test piece with the reinforcing sheet bonded.

[0034] Example 1

[0035] The size of the rectangular glass fiber-reinforced composite material tensile test piece is 250 mm × 25 mm, the size of a single reinforcing sheet is 56 mm × 25 mm, the bonding stress of the two-component bonding adhesive used is 0.56 MPa, the curing temperature is 75 °C, and the curing time is 2 h.

[0036] Place the rectangular glass fiber-reinforced composite material tensile test piece on the flat base, with one side against the limit strip, adjust the long side block and the short side block to closely adhere to the composite material tensile test piece. According to the size of the rectangular glass fiber-reinforced composite material tensile test piece of 250 mm × 25 mm and the size of a single reinforcing sheet of 56 mm × 25 mm, adjust the positions of the first reinforcing sheet connecting block and the second reinforcing sheet connecting block to enclose the reinforcing sheet bonding area. Then place the reinforcing sheet evenly coated with the two-component bonding adhesive on one side in the bonding area. Set the bonding force of the reinforcing sheet through the main control chip:

[0037] F = σ × S = 0.56 × 10 6 × 56 × 10 -3 × 25 × 10 -3 = 784 N

[0038] Use the pressing plate of the reinforcing sheet positioning and bonding device to press down through the lifting mechanism. After the bonding is completed, cure the composite material tensile and compressive test piece with the bonded reinforcing sheet. Then lift the pressing plate to reset to complete the pasting of the reinforcing sheet on the glass fiber-reinforced composite material tensile test piece.

[0039] Example 2

[0040] The size of the rectangular carbon fiber reinforced composite compression specimen is 80 mm × 13 mm, the size of a single reinforcing patch is 47 mm × 13 mm, the bonding stress of the adhesive film used is 1.2 MPa, the curing temperature is 120 °C, and the curing time is 3 h.

[0041] Place the rectangular carbon fiber reinforced composite compression specimen on the flat base, with one side against the limit strip. Adjust the long-side block and short-side block to be in close contact with the composite compression specimen. According to the size of the rectangular carbon fiber reinforced composite compression specimen being 80 mm × 13 mm and the size of a single reinforcing patch being 47 mm × 13 mm, adjust the positions of the first reinforcing patch connecting block and the second reinforcing patch connecting block to enclose the reinforcing patch bonding area, and then place the reinforcing patch evenly coated with the adhesive film on the bonding area. Set the bonding force of the reinforcing patch through the main control chip:

[0042] F = σ × S = 1.2×10 6 ×37.5×10 -3 ×13×10 -3 = 585 N

[0043] Use the pressing plate of the reinforcing patch positioning and bonding device to press down through the lifting mechanism. After completion of bonding, cure the composite compression specimen bonded with the reinforcement, and then lift the pressing plate to reset, completing the pasting of the reinforcing patch on the carbon fiber reinforced composite compression specimen.

[0044] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or sequence between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0045] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bonding and positioning device for strengthening sheets of a composite material tensile and compressive specimen fabricated precisely, characterized in that It includes a flat base (1), long-side stoppers (2), short-side stoppers (3), reinforcing plate connecting blocks, reinforcing plate stoppers (5), and a reinforcing plate positioning and bonding device (6); on the upper surface of the flat base (1), there are limit bars, and above the limit bars, there is a lead screw track; the long-side stoppers (2) and the reinforcing plate connecting blocks are respectively connected to the lead screw track and can move on the flat base (1) through the lead screw track; the number of the long-side stoppers (2) is two, and short-side stoppers (3) are slidably arranged on the inner side walls of the two long-side stoppers (2); the reinforcing plate connecting blocks include a first reinforcing plate connecting block (41) and a second reinforcing plate connecting block (42), and both of the two reinforcing plate connecting blocks are connected with a reinforcing plate stopper (5) and a reinforcing plate positioning and bonding device (6). When bonding the reinforcing plate, first place the composite material tensile and compressive specimen on the upper surface of the flat base (1), and press one side of the composite material tensile and compressive specimen against the limit bar to position the first side of the composite material tensile and compressive specimen; move the long-side stoppers (2) through the lead screw track, and the two long-side stoppers (2) respectively position the other two sides of the composite material tensile and compressive specimen. Then, slide the short-side stoppers (3) on the inner side walls of the long-side stoppers (2), and the two short-side stoppers (3) complete the positioning of the last side of the composite material tensile and compressive specimen; then, move the two reinforcing plate connecting blocks to the preset position through the lead screw track, and the preset position is pre-calculated according to the dimensions of the composite material tensile and compressive specimen and the reinforcing plate used; after the first reinforcing plate connecting block (41) and the second reinforcing plate connecting block (42) move to the preset position, the reinforcing plate stoppers (5) respectively connected to the first reinforcing plate connecting block (41) and the second reinforcing plate connecting block (42) enclose two reinforcing plate bonding areas with the limit bar, the long-side stoppers (2), and the short-side stoppers (3). Subsequently, place the reinforcing plate into the reinforcing plate bonding area, and the reinforcing plate positioning and bonding device (6) connected to the reinforcing plate connecting block realizes the bonding of the reinforcing plate to the composite material tensile and compressive specimen.

2. The bonding and positioning device for the reinforcement sheet of the composite material tensile and compressive specimen fabricated precisely according to claim 1, wherein The reinforcing plate positioning and bonding device (6) includes a pressing plate and a lifting mechanism; the lifting mechanism is connected to the reinforcing plate connecting block, and the pressing plate is connected to the lifting mechanism. When the two reinforcing plate connecting blocks move to the preset position, the pressing plate can just be located directly above the reinforcing plate bonding area; the lifting mechanism drives the pressing plate to move up and down through a motor or an electric motor. When the pressing plate presses down, it can bond the reinforcing plate to the composite material tensile and compressive specimen.

3. The bonding and positioning device for the reinforcement sheet of the composite material tensile and compressive specimen fabricated precisely according to claim 2, characterized in that, A pressure sensor is arranged below the pressing plate, and the pressure sensor is electrically connected to the main control chip and can send the real-time pressure received by the pressing plate to the main control chip; the main control chip is electrically connected to the lifting mechanism and is used to send action instructions to the lifting mechanism; when bonding, the main control chip controls the lifting mechanism to move downward, and the pressure sensor monitors the pressure received by the pressing plate in real time; when the pressure received by the pressing plate reaches the preset value, the main control chip sends a rising instruction to the lifting mechanism, completes the bonding of the reinforcing plate to the composite material tensile and compressive specimen, and realizes the reset of the pressing plate.

4. The bonding and positioning device for the reinforcement sheet of the composite material tensile and compressive specimen fabricated precisely according to claim 3, characterized in that, The bonding pressure of the reinforcing plate is preset through the main control chip, and the magnitude of the bonding pressure is: F = σ × S Wherein, F is the adhesion force with the unit of N; σ is the adhesion stress of the adhesive or adhesive film with the unit of Pa; S is the area of the bonding surface of the reinforcing sheet with the unit of m 2 .

5. The strengthening sheet bonding and positioning device for precisely manufacturing a composite material tensile and compressive test piece according to claim 2, wherein, The limiting strip is arranged on one side of the upper surface of the flat base (1) and has the same length as the flat base (1); the lead screw track is a double-layer track, and the lower layer track is connected to the two long side stoppers (2); sliding grooves are formed on the inner side walls between the two long side stoppers (2), and the two short side stoppers (3) are respectively slidably arranged in the sliding grooves of the two long side stoppers (2).

6. The strengthening sheet bonding and positioning device for precisely manufacturing a composite material tensile and compressive test piece according to claim 5, characterized in that, The reinforcing sheet connecting block is of an L-shaped structure and is connected to the upper layer of the lead screw track; the lifting mechanism is arranged below one side of the reinforcing sheet connecting block close to the short side stopper (3), and a pressing plate is arranged parallel to the flat base (1) on one side of the lifting mechanism close to the short side stopper (3); on one side of the two reinforcing sheet connecting blocks close to each other, reinforcing sheet stoppers (5) are respectively arranged to extend parallel to the long side stoppers (2).

7. A method for bonding and positioning the reinforcement sheet of a composite tensile and compressive specimen with high precision. The method is based on the device for bonding and positioning the reinforcement sheet of a composite tensile and compressive specimen according to any one of claims 2-6, and is characterized in that It includes the following steps: Step 1: Place the composite material tensile and compressive specimen closely against the limiting strip on the flat base (1), and rotate the lower layer lead screw of the lead screw track to clamp the long sides of the composite material tensile and compressive specimen with the two long side stoppers (2). Step 2: Slide the short side stoppers (3) in the two long side stoppers (2) to clamp the short sides of the composite material tensile and compressive specimen. Step 3: Rotate the upper layer lead screw of the lead screw track to move the two reinforcing sheet connecting blocks to a preset position, so that the reinforcing sheet stoppers (5) enclose a reinforcing sheet bonding area with the limiting strip, the long side stoppers (2), and the short side stoppers (3). Step 4: Paste the reinforcing sheet evenly coated with bonding glue or pasted with a glue film at the position of the reinforcing sheet bonding area of the composite material tensile and compressive specimen, and the reinforcing sheet should be pasted exactly along the reinforcing sheet stoppers (5). Step 5: Use the pressing plate of the reinforcing sheet positioning and bonding device (6) to press down through the lifting mechanism. After the bonding is completed, cure the composite material tensile and compressive specimen with the bonded reinforcement. Finally, lift the pressing plate to reset and take out the specimen with the reinforcing sheet bonded.

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