Method for predicting off-axis tensile strength of fiber web reinforced ECC composite material
By using uniaxial tensile tests and functional relationship calculations, the tensile strength of fiber-woven mesh reinforced high-ductility cementitious composite materials at arbitrary off-axis angles is predicted, solving the problem of the inability to predict off-axis load conditions in existing technologies, and realizing efficient and accurate structural analysis and design.
Patent Information
- Application Number
- CN202511593150.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-03
- Publication Date
- 2026-03-20
AI Technical Summary
Existing technologies cannot effectively predict the tensile strength of fiber-reinforced high-ductility cementitious composites (TR-ECC) under eccentric loading conditions, making them unsuitable for complex structural design and calculation.
The axial tensile strength of fiber-woven mesh reinforced high-ductility cementitious composite material was obtained by uniaxial tensile test. The off-axis tensile strength at non-zero off-axis angle was measured. The undetermined coefficients were calculated using functional relationships to predict the tensile strength at any off-axis angle. The prediction results were then input into a finite element model for structural analysis.
It enables the prediction of off-axis tensile strength of TR-ECC based on a small amount of experimental data, reducing costs, improving prediction accuracy and model adaptability, and supporting rapid structural analysis and optimization.
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Figure CN121709101A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of new building materials, and particularly relates to a method for predicting the off-axis tensile strength of fiber mesh reinforced ECC composite materials. BACKGROUND
[0002] In recent years, the fiber woven mesh reinforced high ductility cement-based composite material (TR-ECC) has attracted widespread attention in the fields of building lightweight design and existing building structure reinforcement due to its beneficial mechanical properties / good durability and excellent crack control capability. Obtaining the strength of TR-ECC is a key basic step for the design and application of TR-ECC structures. The existing strength prediction model is only applicable to the case where TR-ECC is subjected to axial loading, that is, the loading direction is consistent with the fiber bundle direction in the fiber woven mesh. However, in actual engineering, due to the complexity of the load and the complexity of the structure surface, it is almost inevitable to have an off-axis load condition in which the main direction of the load and the fiber bundle direction in the TR-ECC form a certain angle. Under the off-axis load, the tensile strength of TR-ECC changes with the off-axis angle.
[0003] At present, there is no TR-ECC tensile strength prediction model applicable to the off-axis condition, so it is also impossible to effectively establish the change rule of the tensile strength of TR-ECC with the off-axis angle, and it is naturally impossible to be applied to the structural design and calculation of the off-axis condition. Of course, users can directly obtain relevant mechanical parameters through off-axis load tests. However, the actual off-axis angle is constantly changing, and it is impossible to test any situation. How to effectively solve the above defects is a technical problem faced by the field. SUMMARY
[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a method for predicting the off-axis tensile strength of fiber mesh reinforced ECC composite materials, which realizes the prediction of the tensile strength of TR-ECC under any off-axis angle with a small amount of test data.
[0005] To solve the above technical problems, the technical solutions adopted by the present application are as follows:
[0006] The axial tensile strength of the fiber woven mesh reinforced high ductility cement-based composite material TR-ECC is obtained through a uniaxial tensile test along the warp direction of the fiber woven mesh;
[0007] The off-axis tensile strength of TR-ECC under at least one non-zero off-axis angle is determined through a test;
[0008] Based on the axial tensile strength and the off-axis tensile strength, the undetermined coefficient is calculated according to the functional relationship between the off-axis tensile strength of TR-ECC and the off-axis angle;
[0009] The angle between the load direction in the TR-ECC structure to be predicted and the warp direction of the fiber woven mesh is determined.
[0010] Substitute the axial tensile strength, the undetermined coefficient, and the included angle to obtain the functional relationship after obtaining the undetermined coefficient, and predict the off-axis tensile strength of TR-ECC.
[0011] The predicted off-axis tensile strength is used as a key parameter and input into the TR-ECC structural analysis finite element model for structural analysis, design, and optimization.
[0012] Preferably, the off-axis tensile strength of TR-ECC at at least one non-zero off-axis angle is determined by test, wherein the non-zero off-axis angle is 45°.
[0013] Preferably, the undetermined coefficients are calculated based on the functional relationship between TR-ECC tensile strength and off-axis angle, wherein the functional relationship is as follows:
[0014] ;
[0015] in, For TR-ECC axial tensile strength, denoted as 45° off-axis tensile strength of TR-ECC, where k is an undetermined coefficient.
[0016] Preferably, the functional relationship after obtaining the undetermined coefficients is as follows:
[0017] ;
[0018] in, The off-axis angle of TR-ECC, The off-axis angle is The off-axis tensile strength of TR-ECC.
[0019] Preferably, it is used to calculate undetermined coefficients. of and The corresponding TR-ECC structure needs to be aligned with the off-axis angle to be predicted. The TR-ECC has the same structure, which includes: using the same ECC matrix, fiber woven mesh, number of fiber woven mesh layers, and fiber woven mesh spacing; only the fiber woven mesh laying angle, stretching direction, and the angle between the fiber woven mesh and the fiber woven mesh are different. different.
[0020] Preferably, the matrix in TR-ECC is high-ductility cement ECC or conventional concrete.
[0021] Preferably, when TR-ECC off-axis tensile strength data with two or more non-zero off-axis angles are available, the undetermined coefficients are adjusted to minimize the average dispersion between the predicted off-axis tensile strength calculated using the aforementioned functional relationship and the off-axis tensile strength measured by existing experiments.
[0022] Preferably, when the TR-ECC bias stretching strength data of two or more non-zero bias angle are obtained, the bias stretching strength is substituted into the function relationship respectively to obtain corresponding multiple undetermined coefficients, the undetermined coefficients corresponding to any bias angle are calculated by an interpolation method, and the TR-ECC bias stretching strength under any bias angle is calculated by substituting the undetermined coefficients into the function relationship.
[0023] In addition, the application provides an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed, the steps of the method are implemented.
[0024] Finally, the application provides a computer readable storage medium, which stores a computer program, wherein when the program is executed by a processor, the steps of the method are implemented.
[0025] Compared with the prior art, the application has the following technical effects:
[0026] (1) The bias stretching strength prediction method of the fiber mesh reinforced ECC composite material provided by the application can predict the TR-ECC bias stretching strength based on a small amount of test data, solves the problem that the prior art can only obtain the stretching strength under each bias angle through test and cannot predict the TR-ECC stretching strength under other angles, overcomes the problem that the existing theoretical model is only applicable to the axial stretching working condition and is not applicable to the bias load working condition, and significantly reduces the cost and improves the efficiency compared with the direct test measurement method.
[0027] (2) When multiple bias angle test data are obtained, the application adjusts the undetermined coefficient k value to minimize the dispersion degree of the prediction result and the test data, or dynamically determines the k value under different angles by using an interpolation method, significantly improves the prediction accuracy and model adaptability, ensures that the prediction result is closer to the actual value when the data is sufficient, and reduces the necessity of relying on a large number of tests.
[0028] (3) The application inputs the predicted bias stretching strength as a key parameter into a finite element model, supports rapid structure analysis and optimization, and provides an efficient and reliable technical means for the engineering application of the TR-ECC material in a complex stress structure. BRIEF DESCRIPTION OF DRAWINGS
[0029] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, illustrate the application together with the embodiments thereof, and explain the application without limiting the application.
[0030] Figure 1This invention relates to a flowchart of a method for predicting the off-axis tensile strength of fiber mesh reinforced ECC composite materials.
[0031] Figure 2 These are TR-ECC tensile stress-strain curves under different off-axis angles according to embodiments of the present invention. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0033] Example 1: This example uses carbon fiber woven mesh reinforced ECC matrix TR-ECC as an example. Based on the tensile strength of TR-ECC at 0° and 45°, the tensile strength of TR-ECC at any off-axis angle is predicted, with reference to... Figure 1 The specific steps are as follows:
[0034] S1: Obtain the axial tensile strength of TR-ECC by uniaxial tensile test along the warp direction (0°) of the fiber woven mesh. .
[0035] S2: The TR-ECC 45° off-axis tensile strength is obtained through a 45° off-axis tensile test (the tensile direction is at a 45° angle to the warp direction of the fiber woven mesh).
[0036] S3: Will and Substitute into the following formula to calculate the undetermined coefficients. .
[0037]
[0038] S4: Determine the load on the TR-ECC structure to be predicted and the warp angle of the fiber woven mesh. .
[0039] S5: Adjust the off-axis angle and S3 calculated Substituting into the following formula, the off-axis angle is calculated as follows: TR-ECC off-axis tensile strength :
[0040]
[0041] S6: Calculate the off-axis angle TR-ECC off-axis tensile strength under operating conditions The parameters are input as key parameters into the TR-ECC structural analysis finite element model for structural analysis, design, and optimization.
[0042] Furthermore, it is used to calculate the undetermined coefficients. of and The corresponding TR-ECC structure needs to be aligned with the off-axis angle to be predicted. TR-ECC has the same structure, specifically, it uses the same ECC matrix, fiber woven mesh, number of fiber woven mesh layers, and fiber woven mesh spacing. The only difference is the fiber woven mesh laying angle and the angle between the stretching direction and the fiber woven mesh. different.
[0043] Furthermore, in steps S2 and S3, if 45° off-axis stretching data is missing, 15° and 30° data can be used to calculate the undetermined coefficient k. When there is a choice, data closer to 45° should be selected for calculation.
[0044] Furthermore, if only the tensile strength of TR-ECC under 0° operating conditions is considered... and TR-ECC in-plane shear strength The undetermined coefficients can then be approximately calculated using the following formula. :
[0045]
[0046] Furthermore, the matrix in TR-ECC can be either high-ductility cement (ECC) or conventional concrete.
[0047] Furthermore, if sufficient experimental data is available, i.e., TR-ECC off-axis tensile strength data with two or more off-axis angles (for example, having...) If so, it can be adjusted. Value, making the adoption Off-axis tensile strength calculated by formula Compared with the off-axis tensile strength measured by existing experiments The minimum average dispersion is used to determine a reasonable value for k. The superscript exp in the text represents experimental data.
[0048] Furthermore, if sufficient experimental data is available, i.e., TR-ECC off-axis tensile strength data with two or more off-axis angles (for example, having...) The off-axis tensile strength can be substituted into the equation. Calculate Then, linear interpolation and nonlinear interpolation methods are used to calculate the angle at any given angle. Then Substitution Used to calculate the off-axis tensile strength of TR-ECC at any off-axis angle. .
[0049] Specifically, in the present embodiment:
[0050] (1) Obtain the axial tensile strength of TR-ECC by uniaxial tensile test along the warp direction (0°) of the fiber woven net , from the stress-strain curve shown in FIG. 1. Figure 2
[0051] (2) Obtain the 45° bias tensile strength of TR-ECC by 45° bias tensile test (the tensile direction is 45° to the warp direction of the fiber woven net) , from the stress-strain curve shown in FIG. 2. Figure 2
[0052] (3) Substitute σ 0 and σ 45 into the following formula to calculate the undetermined coefficient a: .
[0053]
[0054] (4) Measure the load and the fiber woven net warp angle of two TR-ECC structures to be predicted , which are 15° and 30° respectively.
[0055] (5) Substitute the bias angle θ and σ 0 into the following formula to calculate the TR-ECC bias tensile strength when the bias angle is θ: :
[0056]
[0057] The calculated σ θ is , .
[0058] The corresponding tensile strength test value obtained from the stress-strain curve shown in FIG. 3 is Figure 2 , , and the prediction errors are about 3.6% and 5.5% respectively, proving that the bias tensile strength prediction method proposed in the present application has sufficient prediction accuracy. Embodiment 2: The present embodiment proposes an electronic device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that when the computer program is executed, the steps of the method as described in the present application are implemented.
[0059]
[0060] Embodiment 3: This embodiment provides a computer readable storage medium, which stores a computer program, characterized in that the program, when executed by a processor, implements the steps of the method according to the present application.
[0061] It should be noted that the processing procedures of embodiments 2-3 correspond to the specific steps of the method provided in embodiment 1 of the present application, and have the corresponding function modules and beneficial effects of the execution method. Technical details not described in detail in this embodiment can be referred to the method provided in embodiment 1 of the present application.
[0062] In the context of the present application, the machine-readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the above. More specific examples of machine-readable storage media can include one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical storage devices, magnetic storage devices, or any suitable combination of the above.
[0063] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present application shall fall within the scope of the present application.
Claims
1. A method for predicting the off-axis tensile strength of fiber mesh reinforced ECC composite materials, characterized in that, Includes the following steps: The axial tensile strength of TR-ECC, a fiber-woven mesh reinforced high-ductility cementitious composite material, was obtained by uniaxial tensile testing along the warp direction of the fiber-woven mesh. The off-axis tensile strength of TR-ECC at at least one non-zero off-axis angle was determined by test. Based on axial tensile strength and off-axis tensile strength, the undetermined coefficients are calculated according to the functional relationship between TR-ECC off-axis tensile strength and off-axis angle. Determine the angle between the load direction and the warp direction of the fiber braided mesh in the TR-ECC structure to be predicted; Substitute the axial tensile strength, the undetermined coefficient, and the included angle to obtain the functional relationship after obtaining the undetermined coefficient, and predict the off-axis tensile strength of TR-ECC. The predicted off-axis tensile strength is used as a key parameter and input into the TR-ECC structural analysis finite element model for structural analysis, design, and optimization.
2. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 1, characterized in that, The off-axis tensile strength of TR-ECC at at least one non-zero off-axis angle of 45° was determined by test.
3. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 2, characterized in that, The undetermined coefficients were calculated based on the functional relationship between TR-ECC tensile strength and off-axis angle, as follows: ； in, For TR-ECC axial tensile strength, denoted as 45° off-axis tensile strength of TR-ECC, where k is an undetermined coefficient.
4. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 3, characterized in that, The functional relationship after obtaining the undetermined coefficients is as follows: ； in, The off-axis angle of TR-ECC, The off-axis angle is The off-axis tensile strength of TR-ECC.
5. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 4, characterized in that, Used to calculate undetermined coefficients of and The corresponding TR-ECC structure needs to be aligned with the off-axis angle to be predicted. The TR-ECC has the same structure, which includes: using the same ECC matrix, fiber woven mesh, number of fiber woven mesh layers, and fiber woven mesh spacing; only the fiber woven mesh laying angle, stretching direction, and the angle between the fiber woven mesh and the fiber woven mesh are different. different.
6. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 1, characterized in that, The matrix in TR-ECC is either high-ductility cement ECC or conventional concrete.
7. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 1, characterized in that, When TR-ECC off-axis tensile strength data with two or more non-zero off-axis angles are available, the undetermined coefficients are adjusted to minimize the average dispersion between the predicted off-axis tensile strength calculated using the aforementioned functional relationship and the off-axis tensile strength measured by existing experiments.
8. The method for predicting the off-axis tensile strength of a fiber mesh reinforced ECC composite material according to claim 1, characterized in that, When TR-ECC off-axis tensile strength data with two or more non-zero off-axis angles are available, the off-axis tensile strength is substituted into the function relationship to calculate the corresponding multiple undetermined coefficients. The undetermined coefficients corresponding to any off-axis angle are calculated by interpolation. The undetermined coefficients are then substituted into the function relationship to calculate the TR-ECC off-axis tensile strength at any off-axis angle.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is executed, it implements the steps of the method as described in any one of claims 1 to 8.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 8.