A method, system and apparatus for evaluating the performance of a composite panel in a tensile test

Abstract

The application discloses a kind of composite plate tensile test performance evaluation method, system and device, and composite plate includes base material, complex material and the adhesive layer between base material and complex material, it is characterized in that, composite plate tensile strength appointed coefficient k is introduced, according to the predetermined use of the composite plate to be evaluated determines the value of multiple composite plate tensile strength appointed coefficient k that satisfies evaluation requirement.The application gives a kind of more accurate evaluation composite plate tensile performance method, system and device, realize composite plate tensile strength theoretical value and sample test result evaluation classification are unified.Under the condition of composite plate global composite ratio, obtain continuous tensile strength theoretical value curve when taking certain appointed coefficient k, so that composite plate tensile performance grade division can be more accurate and continuous.According to the reasonable composite plate tensile strength grade division of use environment, reduce composite plate unqualified rate, improve economic benefit.

Description

Technical Field

[0001] This invention relates to a method, system, and apparatus for evaluating the tensile performance of composite material plates, belonging to the technical field of metallurgical methods, systems, and apparatus for testing the physical and chemical properties of metals. Background Technology

[0002] Some structures require layering two or more metals or non-metals to control costs or achieve specific performance characteristics. Examples include welding copper alloys to the surface of structural steel; in shipbuilding and marine engineering, using lightweight metals for the upper structure and economical steel for the lower structure to control the center of gravity; and connecting different metals with metal composite plates. In other engineering applications, non-metallic materials are bonded to the surface of metallic materials to achieve specific functions. In engineering applications and physicochemical performance testing, the tensile properties of composite plates need to be evaluated and graded to accurately assess the applicable engineering environment. The application environment of composite plates varies, and the required tensile property grades also differ. For example, composite plates used for transition joints, flanges, and other applications involving structural strength require relatively high tensile strength grades. Composite plates where the composite material is a design strength component, such as tube sheets and buffer pads, which contribute less to structural strength, also require relatively high tensile strength grades. Composite plates where the composite material is not a design strength component, such as anti-corrosion linings, require relatively moderate tensile strength grades. If the composite material is not used as a structural or functional component in the design, such as for decorative purposes, the composite board must have a relatively low level of tensile strength.

[0003] In Section 5, "Tensive Test," of GB / T 6396-2008 "Test Methods for Mechanical and Technological Properties of Composite Steel Plates," the calculation and rounding of various strengths in the processing of test results shall be performed in accordance with the relevant provisions of GB / T 228. There are many methods for preparing composite plates, such as rolled composite plates, exploded composite plates, and welded composite plates. Because dissimilar metals are bonded together, the metals at the bonding surface are not homogeneous or uniform due to differences in metal crystal structure and the influence of heat and stress. Therefore, the tensile properties of a single dissimilar metal cannot be used to evaluate the test results of the composite plate. Furthermore, the tensile mechanical properties of the composite and the substrate are different, and the tensile properties are significantly affected by the thickness (composite ratio) of the composite and the substrate. Therefore, a more accurate method, system, and apparatus for evaluating the tensile properties of composite plates is needed to achieve consistency between the theoretical value of the tensile strength of composite plates and the evaluation and grading of test specimen results.

[0004] The yield strength or tensile strength R measured in the tensile mechanical property test of composite steel plates as described in Section 9, Chapter 3, Part 1 of the "Materials and Welding Specifications of China Classification Society" (2018) refers to the tensile mechanical property test of composite steel plates. M It should be no less than according to The calculated value only provides one level of acceptance or rejection, and the evaluation result does not describe the different tensile property requirements for composite panels in different applications. GB / T228 and the "China Classification Society Materials and Welding Specifications" stipulate that the evaluation value for tensile test results is the base material R... M R-value or equivalent linear calculation of composite plate M This value makes it impossible to accurately classify the tensile properties of composite panels under different usage conditions. For example, composite panels used for decoration, etc., are classified according to the above R values. M Acceptance testing significantly improved the tensile properties of the decorative composite panels while still meeting the required tensile performance, thus indirectly increasing their cost. Furthermore, since composite panels produced in batches inevitably exhibit some fluctuation in tensile properties, as described above (R...). M Inevitably, defective products will be found during the acceptance process, resulting in waste of the produced composite boards and reducing the company's profits. Summary of the Invention

[0005] The technical problem this invention aims to solve is: the accuracy of evaluating the tensile properties of composite boards is reduced, the evaluation results of tensile properties are singular, and the evaluation results of the tensile properties of composite boards have a low degree of matching with the actual needs of the use environment.

[0006] To address the aforementioned technical problems, one technical solution of the present invention provides a method for evaluating the tensile performance of a composite material plate. The composite material plate includes a substrate, a composite material, and an adhesive layer located between the substrate and the composite material. The method is characterized by comprising the following steps:

[0007] Step 1: Introduce the tensile strength convention factor k of the composite plate and establish the theoretical value R of the equivalent tensile strength of the composite plate. M The functional relationship between the tensile strength coefficient k of the composite plate and the thickness t of the composite material;

[0008] Step 2: Determine the values ​​of the tensile strength convention coefficient k for multiple composite panels that meet the evaluation requirements based on the intended use of the composite panel to be evaluated;

[0009] Step 3: Using the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite plate... M In the coordinate plane corresponding to the horizontal and vertical axes, based on the values ​​of the multiple composite plate tensile strength convention coefficients k determined in step 2 and the functional relationship obtained in step 1, multiple tR values ​​are obtained. M Curves, all tR M The curve divides the entire coordinate plane into different grade division regions, and different grade division regions correspond to different tensile strength evaluation grades.

[0010] Step 4: Prepare a tensile specimen on the composite plate to be evaluated and measure the composite thickness t0 of the tensile specimen.

[0011] Step 5: After conducting the tensile test, process the tensile test results to obtain the measured value R0 of the tensile strength of the composite board.

[0012] Step 6: Using the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite plate... M The point (t0, R0) is marked on the coordinate plane corresponding to the horizontal and vertical axes. The grade division area where the point (t0, R0) is located is obtained, and the corresponding tensile strength evaluation grade is given.

[0013] Preferably, in step 1, the functional relationship is:

[0014]

[0015] In the formula, T is the total thickness of the tensile specimen, R is the theoretical value of the tensile strength of the composite material, and R B This represents the theoretical value of the tensile strength of the substrate.

[0016] Preferably, in step 2, multiple values ​​of the tensile strength coefficient k of the composite board are taken according to the various usage environments of the composite board to be evaluated, and each value of the tensile strength coefficient k of the composite board corresponds to a usage environment.

[0017] Preferably, in step 4, the tensile specimen is a full-thickness plate specimen or a plate specimen that has been thinned during processing.

[0018] Preferably, if the tensile specimen is a thinned plate-shaped specimen, both sides of the tensile specimen are machined so that the thickness ratio between the composite material and the substrate material is the same as before.

[0019] Preferably, in the tensile specimen, the thickness of the composite metal is not less than 3 mm.

[0020] Preferably, in step 5, if the test result is invalid after the tensile test, the process returns to step 4 to re-prepare the tensile specimen for testing until a valid test result is obtained, and then the measured value R0 of the tensile strength of the composite plate is obtained.

[0021] Another technical solution of the present invention is to provide a tensile test performance evaluation system for composite material plates, characterized in that it includes:

[0022] The evaluation grading module is based on the value of the tensile strength coefficient k for different composite panels, combined with the theoretical value of the equivalent tensile strength R of the composite panel. M The functional relationship between the tensile strength coefficient k of the composite plate and the thickness t of the composite material is given by the composite thickness t and the theoretical value R of the equivalent tensile strength of the composite plate. M Multiple tR lines are obtained in the coordinate plane corresponding to the horizontal and vertical axes. M Curves, all tR MThe curve divides the entire coordinate plane into different grade division regions, and different grade division regions correspond to different tensile strength evaluation grades.

[0023] Tensile specimen preparation module: used to prepare tensile specimens on the composite plate to be evaluated;

[0024] Data measurement module: used to measure the thickness t0 of the composite material before the tensile test.

[0025] Tensile testing module: used to obtain the measured tensile strength R0 of the composite plate after the tensile test.

[0026] Grading module: Based on the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite board. M The point (t0, R0) is marked on the coordinate plane corresponding to the horizontal and vertical axes. The grade division area where the point (t0, R0) is located is obtained, and the corresponding tensile strength evaluation grade is given according to the grade division area.

[0027] Preferably, the functional relationship is:

[0028]

[0029] In the formula, T is the total thickness of the tensile specimen, R is the theoretical value of the tensile strength of the composite material, and R B This represents the theoretical value of the tensile strength of the substrate.

[0030] Another technical solution of the present invention is to provide an electronic device, characterized in that it includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the above-described method for evaluating the tensile performance of composite material plates.

[0031] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0032] 1) Provide a more accurate method, system and device for evaluating the tensile properties of composite plates, so as to unify the theoretical value of the tensile strength of composite plates with the evaluation and classification of the test results of the specimens.

[0033] 2) Under the condition of the composite ratio of the entire composite board, a continuous theoretical tensile strength curve is obtained when a certain agreed coefficient k is taken, so that the tensile performance grade classification of the composite board can be more accurate and continuous.

[0034] 3) Classify composite panels according to the tensile strength grade of the application environment to reduce the failure rate of composite panels and improve economic efficiency. Attached Figure Description

[0035] Figure 1 This is a front view of a tensile specimen;

[0036] Figure 2 This is a top view of a tensile specimen.

[0037] Figure 3 For the composite material thickness t and tensile strength R M Relationship diagram;

[0038] Figure 4 This is a flowchart for the evaluation process of composite board grades.

[0039] In the diagram: 1—Substrate;

[0040] 2—Composite materials;

[0041] 3—Adhesive layer;

[0042] T—sample thickness;

[0043] t b —Substrate thickness;

[0044] t — composite material thickness;

[0045] B—Sample width;

[0046] L0—Original gauge length of the tensile specimen;

[0047] Lc—parallel length of the tensile specimen;

[0048] L—Length of the tensile specimen;

[0049] R B —The substrate is specified with a minimum yield strength, non-proportional elongation strength, or theoretical tensile strength.

[0050] R — The theoretical value of the minimum specified yield strength, non-proportional elongation strength, or tensile strength of the composite material;

[0051] R M —The theoretical values ​​of equivalent yield strength, non-proportional elongation strength, or tensile strength are specified for composite steel plates;

[0052] R0—Measured value of yield strength, non-proportional elongation strength, or tensile strength of composite steel plate;

[0053] k——A convention coefficient for the theoretical value of the equivalent yield strength, non-proportional elongation strength, or tensile strength of the composite steel plate that meets the usage conditions.

[0054] R M1 —When the coefficient k = 1 and the thickness of the composite plate is t1, the theoretical value of the equivalent yield strength, non-proportional elongation strength, or tensile strength of the composite steel plate is specified.

[0055] R M2—When the agreed coefficient k = k2, 1 > k2 > k3 and the thickness of the composite plate is t1, the theoretical value of the equivalent yield strength, non-proportional elongation strength or tensile strength of the composite steel plate is specified.

[0056] R M3 When the agreed coefficient k = k3, k2 > k3 > k4 and the thickness of the composite plate is t1, the theoretical value of the equivalent yield strength, non-proportional elongation strength or tensile strength of the composite steel plate is specified.

[0057] R M4 When the agreed coefficient k = k4, k4 > kx, and the thickness of the composite plate is t1, the theoretical values ​​of the equivalent yield strength, non-proportional elongation strength, or tensile strength of the composite steel plate are specified.

[0058] kx represents the theoretical value R of the composite steel plate's specified equivalent yield strength, non-proportional elongation strength, or tensile strength when the composite plate thickness is t1. MX This is a convention coefficient representing the maximum unacceptable value for the current grade classification. Detailed Implementation

[0059] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0060] A method for evaluating the tensile performance of a composite material plate according to an exemplary embodiment includes the following steps:

[0061] Step 1: Prepare several tensile specimens from the composite plate to be evaluated according to recognized standards. The tensile specimens should generally be full-thickness plate specimens; however, if the plate thickness is too large or due to limitations in the testing machine's capacity, the tensile specimens may be machined to reduce their thickness. Both sides of the tensile specimens should be machined to maintain the original thickness ratio between the composite material and the substrate material, but the thickness of the composite metal should not be reduced to less than 3 mm.

[0062] like Figure 1 , 2 As shown, the tensile specimen includes a substrate 1, a composite material 2, and an adhesive layer 3 located between the substrate 1 and the composite material 2. The total thickness of the tensile specimen is denoted as T, and the thickness of the substrate 1 is denoted as t. b The thickness of composite material 2 is denoted as t, the width of the tensile specimen is denoted as B, the original gauge length of the tensile specimen is denoted as L0, the parallel length of the tensile specimen is denoted as Lc, and the specimen length of the tensile specimen is denoted as L.

[0063] Step 2: Measure the total thickness T of the tensile specimen, the thickness t of the composite material, and the thickness t of the substrate. b=Tt. The cross-sectional area of ​​the tensile specimen is calculated as S = S1 + S2, where S1 = t × B and S2 = (Tt) × B.

[0064] Based on the theoretical value of the tensile strength R of the substrate B And the theoretical value of the tensile strength R of the composite material, and the theoretical value of the equivalent linear tensile strength R of the composite plate according to the accepted standard. c This can be derived from equation (1):

[0065]

[0066] Step 3: Based on the actual situation and the different usage environments of the composite board, introduce a conventional coefficient k for the tensile strength of the composite board. When the tensile test result R0 of the tensile specimen is greater than the theoretical value R of the equivalent linear tensile strength of the composite board... C When multiplied by the conventional tensile strength coefficient k of the composite board, the tensile strength of the composite board meets the requirements for certain environmental applications. In this case, the tensile strength test result R0 is greater than R. M The requirements are met in a timely manner.

[0067] When the tensile strength coefficient k = 1, the theoretical value of the equivalent tensile strength R of the composite plate is... M R is the theoretical value of the equivalent linear tensile strength of the composite plate obtained from equation (1). C .

[0068] When the tensile strength coefficient k of the composite plate is not equal to 1, the theoretical value of the equivalent tensile strength R of the composite plate is... M For R M =kR C .

[0069] When k < 1, the theoretical value of the equivalent tensile strength R of the composite plate is specified. M The tensile test result shows that R0 is greater than R. M This can be described as when R0≥R M At that time, the tensile strength test results met the requirements. When the total thickness T is constant, the theoretical value of the equivalent linear tensile strength R of the composite plate changes with the thickness t of the composite material. C It also changes. For any composite plate with a defined tensile strength coefficient k, when t = 0, R... M =R B When t = T, R M =R, therefore, when k≠1, R M The thickness t of the composite material is non-linear.

[0070] For any tensile strength coefficient k of a composite plate, with the boundary condition t=0, R M =R B When t = T, R M =R. When t = t1, for different k, the corresponding R... MThe values ​​are different, t1 represents the expected thickness of the composite material required for the composite board. This is determined by satisfying the boundary conditions and the continuous R value corresponding to any k. M When k≠1, R M The relationship with t can be fitted as a linear equation in two variables as shown in equation (2):

[0071] R M =At 2 +Bt+C (2)

[0072] When t = 0:

[0073] C=R B (3)

[0074] When t = T:

[0075] R = AT 2 +BT+R B (4)

[0076] when hour:

[0077] 2R M =k(R) B +R) (5)

[0078] There is also equation (1) and when Shi Zhi:

[0079] 2R M =k(R) B +R) (6)

[0080] From equations (3), (4), (5), and (6), we know that:

[0081]

[0082] In equation (7), T, R, R B All are known constants, R M It depends only on the value of k and t.

[0083] Step 3: Based on the various usage environments of the composite board, select multiple sets of values ​​for the tensile strength coefficient k that meet the tensile strength value conditions, and obtain the following... Figure 3 The multiple R lines shown M Curves relating the composite thickness t. Multiple curves divide the coordinate system as follows: Figure 3 Here are a few examples of districts. Figure 3 As shown, when the thickness t of the composite material is a certain value, the measured value of the tensile specimen is R0. The coordinates of the measured value in the coordinate system are (t, R0). The area where the measured value coordinate point is located is the tensile performance evaluation level of the composite board, which can be used in an acceptable environment.

[0084] The composite board grade evaluation process based on the above method includes the following steps:

[0085] S1: Determine the value of the tensile strength convention factor k of multiple composite panels that meet the evaluation requirements based on the intended use of the composite panel.

[0086] S2: Based on the theoretical minimum tensile strength R specified for composite materials and the theoretical minimum tensile strength R specified for base materials. B The total thickness T of the tensile specimen and the theoretical equivalent tensile strength R of multiple composite plates were plotted. M Regarding the curves for the composite thickness t, multiple curves divide the coordinate system into different grade division regions. The horizontal and vertical axes of the coordinate system represent the theoretical value of the equivalent tensile strength R of the composite plate, respectively. M And the thickness t of the composite material.

[0087] S3: Prepare tensile specimens on the composite plate to be evaluated according to recognized standards.

[0088] S4: Measure the total thickness T of the tensile specimen and the thickness t of the composite material.

[0089] S5: Perform a tensile test. If the test result is invalid, return to step S3 to re-prepare a tensile specimen for testing.

[0090] S6: Process the tensile test results to obtain the effective measured value R0.

[0091] S7: Mark the point (t, R0) in the coordinate system, obtain the grade division zone where the point (t, R0) is located, and give the evaluation grade of the corresponding division zone.

[0092] S8: Based on the grade division area obtained in step S7, mark the tensile strength grade of the composite board.

[0093] The present invention also provides a tensile performance evaluation system for composite material plates, comprising:

[0094] Evaluation grade classification module: Based on the value of the tensile strength convention coefficient k of different composite plates, combined with the theoretical value of the equivalent tensile strength R of the composite plate shown in formula (7). M The functional relationship between the tensile strength coefficient k of the composite plate and the thickness t of the composite material is given by the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite plate. M To obtain multiple tR lines in the coordinate plane of the horizontal and vertical axes M Curves, all tR M The curve divides the entire coordinate plane into different grade division regions, with each grade division region corresponding to a different tensile strength assessment grade.

[0095] Tensile specimen preparation module: used to prepare tensile specimens on the composite plate to be evaluated.

[0096] Data measurement module: used to measure the composite thickness t0 of the tensile specimen before the tensile test.

[0097] Tensile test module: used to obtain the measured tensile strength R0 of the composite plate after the tensile test.

[0098] Grading module: Based on the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite board. M Mark the point (t0, R0) on the coordinate plane of the horizontal and vertical axes to obtain the grade division area where the point (t0, R0) is located, and then give the corresponding tensile strength evaluation grade according to the grade division area.

[0099] Embodiments of the present invention also provide an electronic device, including a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When executed by the processor, the program or instructions implement the steps of the composite material plate tensile test performance evaluation method described above. All implementations in the above method embodiments are applicable to the embodiments of this electronic device and can achieve the same technical effects.

[0100] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the tensile performance of a composite material plate, the composite material plate comprising a substrate, a composite material, and an adhesive layer located between the substrate and the composite material, characterized in that, Includes the following steps: Step 1: Introduce the tensile strength convention factor k of the composite plate and establish the theoretical value R of the equivalent tensile strength of the composite plate. M The functional relationship between the tensile strength coefficient k of the composite plate and the thickness t of the composite material; Step 2: Determine the values ​​of the tensile strength convention coefficient k for multiple composite panels that meet the evaluation requirements based on the intended use of the composite panel to be evaluated; Step 3: Using the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite plate... M In the coordinate plane corresponding to the horizontal and vertical axes, based on the values ​​of the multiple composite plate tensile strength convention coefficients k determined in step 2 and the functional relationship obtained in step 1, multiple tR values ​​are obtained. M Curves, all tR M The curve divides the entire coordinate plane into different grade division regions, and different grade division regions correspond to different tensile strength evaluation grades. Step 4: Prepare a tensile specimen on the composite plate to be evaluated and measure the composite thickness t0 of the tensile specimen. Step 5: After conducting the tensile test, process the tensile test results to obtain the measured value R0 of the tensile strength of the composite board. Step 6: Using the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite plate... M The point (t0, R0) is marked on the coordinate plane corresponding to the horizontal and vertical axes. The grade division area where the point (t0, R0) is located is obtained, and the corresponding tensile strength evaluation grade is given.

2. The method for evaluating the tensile performance of composite material plates as described in claim 1, characterized in that, In step 1, the functional relationship is: In the formula, T is the total thickness of the tensile specimen, R is the theoretical value of the tensile strength of the composite material, and R B This represents the theoretical value of the tensile strength of the substrate.

3. The method for evaluating the tensile performance of composite material plates as described in claim 1, characterized in that, In step 2, multiple values ​​of the tensile strength coefficient k of the composite board are taken according to the various usage environments of the composite board to be evaluated, and each value of the tensile strength coefficient k of the composite board corresponds to a usage environment.

4. The method for evaluating the tensile performance of composite material plates as described in claim 1, characterized in that, In step 4, the tensile specimen is a full-thickness plate specimen or a plate specimen that has been thinned by processing.

5. The method for evaluating the tensile performance of composite material plates as described in claim 4, characterized in that, If the tensile specimen is a plate-shaped specimen that has been thinned, then both sides of the tensile specimen are machined so that the thickness ratio between the composite material and the substrate material is the same as before.

6. The method for evaluating the tensile performance of composite material plates as described in claim 5, characterized in that, In the tensile specimen, the thickness of the composite metal is not less than 3 mm.

7. The method for evaluating the tensile performance of composite material plates as described in claim 1, characterized in that, In step 5, if the test result is invalid after the tensile test, return to step 4 to re-prepare the tensile specimen and conduct the test until a valid test result is obtained, and then obtain the measured value R0 of the tensile strength of the composite plate.

8. A tensile performance evaluation system for composite material plates, characterized in that, include: The evaluation grading module is based on the value of the tensile strength coefficient k for different composite panels, combined with the theoretical value of the equivalent tensile strength R of the composite panel. M The functional relationship between the tensile strength coefficient k of the composite plate and the thickness t of the composite material is given by the composite thickness t and the theoretical value R of the equivalent tensile strength of the composite plate. M Multiple tR lines are obtained in the coordinate plane corresponding to the horizontal and vertical axes. M Curves, all tR M The curve divides the entire coordinate plane into different grade division regions, and different grade division regions correspond to different tensile strength evaluation grades. Tensile specimen preparation module: used to prepare tensile specimens on the composite plate to be evaluated; Data measurement module: used to measure the thickness t0 of the composite material before the tensile test. Tensile testing module: used to obtain the measured tensile strength R0 of the composite plate after the tensile test. Grading module: Based on the composite thickness t and the theoretical value of the equivalent tensile strength R of the composite board. M The point (t0, R0) is marked on the coordinate plane corresponding to the horizontal and vertical axes. The grade division area where the point (t0, R0) is located is obtained, and the corresponding tensile strength evaluation grade is given according to the grade division area.

9. The composite material plate tensile test performance evaluation system as described in claim 8, characterized in that, The functional relationship is as follows: In the formula, T is the total thickness of the tensile specimen, R is the theoretical value of the tensile strength of the composite material, and R B This represents the theoretical value of the tensile strength of the substrate.

10. An electronic device, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, which, when executed by the processor, implement the steps of the composite material plate tensile test performance evaluation method as described in claim 1.

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