SMAF-ECC fiber stress calculation method based on multi-seam cracking effect
By establishing a method for calculating the fiber stress of SMAF-ECC under the multi-slit cracking effect, the inaccuracy of the fiber stress-crack width relationship under the traditional single-slit assumption is solved, and high-precision prediction of SMAF-ECC material under multi-slit cracking conditions is achieved, supporting its design and evaluation in seismic structures and self-healing components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN UNIV OF SCI & TECH
- Filing Date
- 2025-12-23
- Publication Date
- 2026-05-12
AI Technical Summary
Existing mechanical models of fiber stress-crack width relationship are mostly based on the single crack assumption, which cannot accurately reflect the real mechanical behavior of shape memory alloy fiber reinforced engineered cementitious composite (SMAF-ECC) under multi-crack cracking conditions, leading to inaccuracies in crack control and durability assessment.
This paper presents a method for calculating the stress of SMAF-ECC fibers based on the multi-crack effect. By obtaining material parameters, the strain and stress of shape memory alloy fibers are calculated. Considering the cumulative width of multiple cracks, a correlation model between fiber strain and crack width is established to reflect the real mechanical behavior of SMAF-ECC materials under multi-crack conditions.
It significantly improves the accuracy and reliability of fiber stress calculation, enabling more precise prediction of fiber stress corresponding to multiple crack widths, and supports the refined design and performance evaluation of SMAF-ECC materials in seismic structures and self-healing components.
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Figure CN122019913A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of materials properties technology, and in particular to a method for calculating stress in SMAF-ECC fibers based on the multi-slit cracking effect. Background Technology
[0002] By incorporating shape memory alloy fibers (SMAF) into engineering cement-based composites (ECC), a novel composite material, namely shape memory alloy fiber reinforced engineering cement-based composite (SMAF-ECC), is prepared. This composite material not only possesses the multi-crack effect of ECC but also utilizes the superelasticity of SMAF to close micro-cracks in the ECC matrix and reduce its residual strain. As a typical fiber-reinforced cement-based composite material, SMAF-ECC is widely used in civil engineering due to its excellent self-healing properties and high ductility.
[0003] In the design and durability assessment of concrete structures, crack width control is crucial. Crack width not only affects the load-bearing capacity of the structure but also directly relates to steel corrosion and the service life of the structure. Therefore, studying the fiber stress-crack width relationship of SMAF-ECC materials has significant reference value for concrete structure design. Under tension, SMAF-ECC often exhibits a multi-crack pattern, forming densely distributed microcracks with small spacing (typically 1-5 mm). Multiple microcracks exist within the length of a single SMAF, causing the fiber stress-matrix crack width relationship to differ significantly from the mechanical model under the traditional single-crack assumption.
[0004] Currently, most mechanical models for the fiber stress-crack width relationship are based on the single-crack assumption, which assumes that only one crack exists within the length of a single fiber. Such mechanical models cannot accurately reflect the relationship between SMAF stress and the width of multiple cracks in the ECC matrix. Therefore, there is an urgent need for a fiber stress-crack width calculation method that can accurately describe the multi-crack effect to improve the reliability of crack control and the accuracy of durability assessment. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a method for calculating the stress of SMAF-ECC fibers based on the multi-slit cracking effect, so as to solve the above-mentioned technical problem.
[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: a method for calculating the stress of SMAF-ECC fibers based on the multi-crack effect, comprising: obtaining material parameters of the material to be tested, wherein the material parameters are parameters describing the mechanical behavior of the material to be tested; calculating the strain of the shape memory alloy fibers in the material to be tested according to the material parameters and a preset multi-crack width, thereby obtaining the shape memory alloy fiber strain; wherein the preset multi-crack width characterizes the sum of the opening widths of all cracks in the material to be tested that intersect with the shape memory alloy fibers; and calculating the stress of the shape memory alloy fibers based on the constitutive relationship of the shape memory alloy fibers, according to the material parameters and the shape memory alloy fiber strain.
[0007] The beneficial effects of this invention are as follows: By establishing a fiber strain calculation model that considers the cumulative width of multiple cracks, this invention achieves high-precision prediction from crack information to fiber stress. Compared with the traditional single-crack model, this method fully reflects the true mechanical behavior of SMAF-ECC materials under multi-crack conditions, significantly improving the accuracy and reliability of fiber stress calculation.
[0008] Based on the above technical solution, the present invention can be further improved as follows.
[0009] Further, the step of calculating the strain of the shape memory alloy fibers in the material under test based on the material parameters and the preset multi-crack width, to obtain the strain of the shape memory alloy fibers, includes: Based on the material parameters and the preset multi-crack width, the strain of the shape memory alloy fiber in the material under test is calculated using a first formula to obtain the strain of the shape memory alloy fiber. The first formula is: ; in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
[0010] Furthermore, the calculation of shape memory alloy fiber stress based on the constitutive relation of the shape memory alloy fiber, according to the material parameters and the strain of the shape memory alloy fiber, includes: Based on the material parameters and the strain of the shape memory alloy fiber, the stress of the shape memory alloy fiber is calculated using a second formula, which is: ; in, For shape memory alloy fiber stress, For shape memory alloy fiber strain, The elastic modulus of austenite. This represents the deformation modulus during the "yield plateau" stage of the normal martensitic transformation. This is the martensitic elastic modulus. This represents the strain value at the onset of stress-induced martensitic transformation. This represents the strain value at the end of the stress-induced martensitic phase transformation. Parameters for controlling the sharpness of martensitic hardening corners. Parameters used to control the sharpness of the hysteresis curve corners.
[0011] Furthermore, the parameters for controlling the sharpness of the martensitic hardening corner and the parameters for controlling the sharpness of the hysteresis curve corner are determined in the following manner: A uniaxial tensile test was performed on a single shape memory alloy fiber to obtain stress-strain data. Based on the stress-strain data, the parameters for controlling the sharpness of the martensitic hardening corner and the parameters for controlling the sharpness of the hysteresis curve corner are determined by nonlinear least squares method.
[0012] Furthermore, the preset multi-crack width is obtained in the following way: Obtain the matrix strain of the material under test; Based on the matrix strain and the material parameters, the preset multi-crack width is calculated using a third formula, which is: ; in, For the preset multi-crack width, For matrix strain, This refers to the tensile length of the shape memory alloy fiber. The strain is the matrix cracking strain.
[0013] Furthermore, both the matrix strain and the matrix cracking strain were measured by uniaxial tensile tests on SMAF-ECC specimens.
[0014] To address the aforementioned technical problems, this invention also provides a SMAF-ECC fiber stress calculation device based on the multi-slit cracking effect, comprising: The parameter acquisition module is used to acquire the material parameters of the material to be tested, wherein the material parameters are parameters describing the mechanical behavior of the material to be tested; The strain calculation module is used to calculate the strain of the shape memory alloy fiber in the material under test based on the material parameters and the preset multi-crack width, so as to obtain the strain of the shape memory alloy fiber. The preset multi-crack width represents the sum of the opening widths of all cracks in the material under test that intersect with the shape memory alloy fiber; The stress calculation module is used to calculate the stress of the shape memory alloy fiber based on the constitutive relation of the shape memory alloy fiber, according to the material parameters and the strain of the shape memory alloy fiber.
[0015] Based on the above technical solution, the present invention can be further improved as follows.
[0016] Furthermore, the strain calculation module includes: The strain calculation unit is used to calculate the strain of the shape memory alloy fibers in the material under test based on the material parameters and a preset multi-crack width, using a first formula to obtain the strain of the shape memory alloy fibers. The first formula is: ; in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
[0017] To address the aforementioned technical problems, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described above.
[0018] To address the aforementioned technical problems, the present invention also provides a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described above. Attached Figure Description
[0019] Figure 1 This is a flowchart of the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect of the present invention. Figure 2 This is a schematic diagram of the fitting of parameters g and n for an SMAF with a diameter of 0.2 mm; Figure 3 This is a schematic diagram of the fitting of parameters g and n for an SMAF with a diameter of 0.5 mm. Figure 4 This is a schematic diagram of the fitting of parameters g and n for an SMAF with a diameter of 1.0 mm. Figure 5 A comparison of simulated and calculated curves of fiber stress-crack width for dog bone specimens with S-0.2-0.15. Figure 6A comparison of simulated and calculated curves of fiber stress-crack width for dog bone specimens with S-0.2-0.25 thickness; Figure 7 A comparison of simulated and calculated curves of fiber stress-crack width for dog bone specimens with S-0.2-0.35. Figure 8 A comparison of simulated and calculated curves of fiber stress-crack width for dog bone specimens with S-0.5-0.35 thickness; Figure 9 A comparison of simulated and calculated curves of fiber stress-crack width for a dog bone specimen with S-1.0-0.35. Figure 10 This is a schematic diagram of the SMAF-ECC fiber stress calculation device based on the multi-slit cracking effect of the present invention; Figure 11 This is a schematic diagram of the electronic device of the present invention. Detailed Implementation
[0020] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0021] Example 1 like Figure 1 As shown, this embodiment provides a method for calculating the stress of SMAF-ECC fibers based on the multi-slit cracking effect (including steps S101 to S103), including: S101. Obtain the material parameters of the material to be tested. The material parameters are parameters that describe the mechanical behavior of the material to be tested.
[0022] The material to be tested refers to the SMAF-ECC composite material to be tested. Specifically, the material parameters include matrix cracking strain, tensile length of shape memory alloy fibers, austenitic elastic modulus, deformation modulus at the "yield plateau" stage of the martensitic positive phase transformation, martensitic elastic modulus, strain value at the start of stress-induced martensitic phase transformation, strain value at the end of stress-induced martensitic phase transformation, parameters controlling the sharpness of the martensitic hardening corner, parameters controlling the sharpness of the hysteresis curve corner, and matrix strain.
[0023] S102. Based on the material parameters and the preset multi-crack width, the strain of the shape memory alloy fiber in the test material is calculated to obtain the strain of the shape memory alloy fiber; wherein, the preset multi-crack width represents the sum of the opening widths of all cracks in the test material intersecting with the shape memory alloy fiber.
[0024] Optionally, in the embodiments, strain calculation is performed on the shape memory alloy fibers in the material to be tested based on material parameters and preset multi-crack widths to obtain the strain of the shape memory alloy fibers, including: Based on the material parameters and the preset multi-crack width, the strain of the shape memory alloy fibers in the test material is calculated using the first formula, which is: ; in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
[0025] Based on the multi-crack steady-state cracking characteristics of ECC during the strain hardening stage, optionally, in the embodiments, the preset multi-crack width is obtained by: obtaining the matrix strain of the material to be tested; and calculating the preset multi-crack width using a third formula based on the matrix strain and material parameters. The third formula is as follows: ; in, For the preset multi-crack width, For matrix strain, This refers to the tensile length of the shape memory alloy fiber. The strain is the matrix cracking strain.
[0026] The third formula above is one method for calculating the total cumulative width of multiple cracks. Other methods can also be used to obtain the width of multiple cracks.
[0027] S103. Based on the constitutive relationship of shape memory alloy fibers, calculate the stress of shape memory alloy fibers according to material parameters and shape memory alloy fiber strain.
[0028] Optionally, in the embodiments, based on the constitutive relation of the shape memory alloy fiber, the stress of the shape memory alloy fiber is calculated according to the material parameters and the strain of the shape memory alloy fiber, including: Based on the material parameters and the strain of the shape memory alloy fiber, the stress of the shape memory alloy fiber is calculated using the second formula, which is: ; in, For shape memory alloy fiber stress, For shape memory alloy fiber strain, The elastic modulus of austenite. This represents the deformation modulus during the "yield plateau" stage of the normal martensitic transformation. This is the martensitic elastic modulus. This represents the strain value at the onset of stress-induced martensitic transformation. This represents the strain value at the end of the stress-induced martensitic phase transformation. Parameters for controlling the sharpness of martensitic hardening corners. Parameters used to control the sharpness of the hysteresis curve corners.
[0029] The stress-strain relationship of SMAF follows the Graesser-Cozzarelli constitutive model. This method establishes the relationship between fiber stress and crack width through two core formulas: the first is the SMAF strain calculation formula, which incorporates the width of multiple cracks generated by ECC multi-cracking into the strain calculation, reflecting the steady-state cracking characteristics of ECC multi-cracking; the second is the SMAF stress calculation formula, which couples the deformation modulus and characteristic strain of the austenitic and martensitic phase transformation stages of SMAF, reflecting the stress change law during the SMAF phase transformation process.
[0030] This method overcomes the limitations of traditional single-crack models in describing stress transfer mechanisms in real crack systems by simultaneously considering the phase transformation nonlinearity of SMAF materials and the multi-crack characteristics of ECC. It can provide a reliable method for the refined design and performance evaluation of SMAF-ECC materials in seismic structures, deformation control, and self-healing components.
[0031] Optionally, in the embodiments, the parameters for controlling the sharpness of the martensitic hardening corner and the parameters for controlling the sharpness of the hysteresis curve corner are determined by: performing a uniaxial tensile test on a single shape memory alloy fiber to obtain stress-strain data; and determining the parameters for controlling the sharpness of the martensitic hardening corner and the parameters for controlling the sharpness of the hysteresis curve corner using a nonlinear least squares method based on the stress-strain data.
[0032] Nonlinear least squares is a commonly used data fitting method that finds the optimal parameters by minimizing the sum of squared errors between the model's predicted values and the actual observed values.
[0033] Both matrix strain and matrix cracking strain are determined based on the steady-state cracking characteristics of ECC materials. Optionally, in the embodiments, both matrix strain and matrix cracking strain are measured by uniaxial tensile tests on SMAF-ECC specimens.
[0034] Among them, the SMAF-ECC specimen is a standard specimen made of a composite material with the exact same composition and proportions as the material being tested. The uniaxial tensile test is a national standard test method conforming to the tensile properties of fiber-reinforced cementitious composites.
[0035] To verify the accuracy and rationality of the SMAF-ECC fiber stress-crack width calculation method, this example uses uniaxial tensile test data of SMAF-ECC composite material (specimen S-1.0-0.35) with a polyvinyl alcohol (PVA) fiber volume content of 2%, an SMAF diameter of 1.0 mm, and an SMAF volume content of 0.35%.
[0036] Depend on Figure 4 The relevant material parameters are as follows: ; .
[0037] Based on the above material parameters, this method is used to calculate the stress of shape memory alloy fibers corresponding to different multi-crack widths.
[0038] Table 1 Comparison of Calculated and Simulated SMAF Stress Values for Specimen S-1.0-0.35 The data in Table 1 show that the calculated value of S-1.0-0.35 of the specimen is in good agreement with the simulated value, with an average error of less than 3%.
[0039] Table 2 Specimen Parameters Similarly, the calculations for each specimen in Table 2 are performed separately. The calculated fiber stress values for the remaining specimens can be obtained and compared sequentially with the simulated values, such as... Figures 2 to 9 As shown, the calculated SMAF stress values agree well with the finite element simulation values, with errors between the calculated and simulated values both within 5%. This demonstrates the rationality of the method proposed in this example.
[0040] This method, combined with the multi-crack behavior of SMAF-ECC materials, establishes a more accurate fiber stress-crack width calculation model. Based on the development of multiple cracks within the length of a single SMAF fiber, this method fully considers the width of multiple cracks in the material. The resulting fiber stress-crack width model better reflects actual engineering conditions and can more accurately calculate the SMAF stress corresponding to the width of multiple cracks, providing a foundation for the prediction and design of the mechanical properties of SMAF-ECC composite materials.
[0041] This method accurately reflects the stress evolution of SMAF in ECC matrix as the width of distributed cracks develops. Compared with traditional single-crack models, this method has the following significant advantages: First, by coupling the phase transition nonlinear constitutive model of SMAF material with the geometric coordination relationship of multi-crack cracking in ECC, it realizes a multi-scale series connection from the microscopic behavior of materials to the macroscopic response of components; second, it can accurately describe the stress redistribution and collaborative working mechanism of fibers among multiple cracks, significantly improving the prediction accuracy of the mechanical behavior of composite materials in the strain hardening stage; third, the physical meaning of the model parameters is clear and easy to calibrate, providing a reliable basis for the refined design and performance evaluation of SMAF-ECC materials in seismic structures, deformation control, and self-healing components, effectively promoting the development of engineering applications of this type of intelligent composite material.
[0042] Example 2 like Figure 10 As shown, this embodiment provides a SMAF-ECC fiber stress calculation device 200 based on the multi-slit cracking effect, including: The parameter acquisition module 201 is used to acquire the material parameters of the material to be tested, which are parameters describing the mechanical behavior of the material to be tested. The strain calculation module 202 is used to calculate the strain of the shape memory alloy fiber in the material to be tested based on the material parameters and the preset multi-crack width, and to obtain the strain of the shape memory alloy fiber. Among them, the preset multi-crack width characterizes the sum of the opening widths of all cracks in the test material intersecting with the shape memory alloy fiber; The stress calculation module 203 is used to calculate the stress of shape memory alloy fibers based on the constitutive relation of the shape memory alloy fibers, according to the material parameters and the strain of the shape memory alloy fibers.
[0043] Optionally, in an embodiment, the strain calculation module 202 includes: The strain calculation unit is used to calculate the strain of the shape memory alloy fibers in the material under test based on material parameters and a preset multi-crack width, using a first formula to obtain the strain of the shape memory alloy fibers. The first formula is: ; in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
[0044] Optionally, in an embodiment, the stress calculation module 203 includes: The stress calculation unit is used to calculate the stress of the shape memory alloy fiber based on the material parameters and the strain of the shape memory alloy fiber, using a second formula: ; in, For shape memory alloy fiber stress, For shape memory alloy fiber strain, The elastic modulus of austenite. This represents the deformation modulus during the "yield plateau" stage of the normal martensitic transformation. This is the martensitic elastic modulus. This represents the strain value at the onset of stress-induced martensitic transformation. This represents the strain value at the end of the stress-induced martensitic phase transformation. Parameters for controlling the sharpness of martensitic hardening corners. Parameters used to control the sharpness of the hysteresis curve corners.
[0045] Optionally, in the embodiments, the parameters controlling the sharpness of the martensitic hardening corner and the parameters controlling the sharpness of the hysteresis curve corner are determined in the following manner: A uniaxial tensile test was performed on a single shape memory alloy fiber to obtain stress-strain data. Based on stress-strain data, the parameters controlling the sharpness of the martensitic hardening corner and the parameters controlling the sharpness of the hysteresis curve corner are determined by nonlinear least squares method.
[0046] Optionally, in the embodiments, the preset multi-crack width is obtained in the following way: Obtain the matrix strain of the material to be tested; Based on the matrix strain and material parameters, the preset multi-crack width is calculated using the third formula, which is: ; in, For the preset multi-crack width, For matrix strain, This refers to the tensile length of the shape memory alloy fiber. The strain is the matrix cracking strain.
[0047] Optionally, in the embodiments, both the matrix strain and the matrix cracking strain are measured by uniaxial tensile testing of SMAF-ECC specimens.
[0048] In some embodiments, the SMAF-ECC fiber stress calculation device 200 based on the multi-slit cracking effect of the present invention can be implemented in a combination of hardware and software. As an example, the SMAF-ECC fiber stress calculation device 200 based on the multi-slit cracking effect of the present invention can be a processor in the form of a hardware decoding processor, which is programmed to execute the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect of the present invention. For example, the processor in the form of a hardware decoding processor can be one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), or other electronic components.
[0049] The modules described in the embodiments of this invention can be implemented in software or hardware. The names of the modules are not, in some cases, limiting the scope of the module itself.
[0050] Example 3 like Figure 11 As shown, this embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described in Embodiment 1.
[0051] In other words, an electronic device according to an embodiment of the present invention may include, but is not limited to: a processor and a memory; the memory is used to store computer programs; the processor is used to execute the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect shown in any embodiment of the present invention by calling the computer program.
[0052] In one alternative embodiment, an electronic device is provided, such as Figure 11 As shown, Figure 11 The illustrated electronic device 300 includes a processor 301 and a memory 303. The processor 301 and the memory 303 are connected, for example, via a bus 302. Optionally, the electronic device 300 may further include a transceiver 304, which can be used for data interaction between the electronic device and other electronic devices, such as sending and / or receiving data. It should be noted that in practical applications, the transceiver 304 is not limited to one type, and the structure of the electronic device 300 does not constitute a limitation on the embodiments of the present invention.
[0053] Processor 301 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 301 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.
[0054] Bus 302 may include a path for transmitting information between the aforementioned components. Bus 302 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 302 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 11 The bus 302 is represented by only one thick line, but this does not mean that there is only one bus or one type of bus.
[0055] The memory 303 may be a ROM (Read Only Memory) or other type of static storage device capable of storing static information and instructions, RAM (Random Access Memory) or other type of dynamic storage device capable of storing information and instructions, or an EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto.
[0056] The memory 303 is used to store application code (computer program) for executing the present invention, and its execution is controlled by the processor 301. The processor 301 is used to execute the application code stored in the memory 303 to implement the content shown in the foregoing method embodiments.
[0057] Among them, electronic devices can also be terminal devices, which can be any device that can install applications, including at least one of smartphones, tablets, laptops, desktop computers, smart speakers, smartwatches, smart TVs, and smart in-vehicle devices.
[0058] It should be noted that, Figure 11 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.
[0059] Example 4 This embodiment provides a non-transitory computer-readable storage medium that stores computer instructions for causing a computer to execute the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described in Embodiment 1.
[0060] Alternatively, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, a floppy disk, and an optical data storage device, etc.
[0061] In an exemplary embodiment, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the aforementioned SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect.
[0062] Computer program code for performing the operations of this invention can be written in one or more programming languages or a combination thereof, including object-oriented programming languages such as Java, Smalltalk, and C++, and conventional procedural programming languages such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).
[0063] It should be understood that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.
[0064] The computer-readable storage medium provided in this invention can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EEPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.
[0065] The aforementioned computer-readable storage medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the method shown in the above embodiments.
[0066] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.
[0067] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and represent a limitation on a specific order or sequence. Where appropriate, the order of use for similar objects can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that shown or described.
[0068] Those skilled in the art will recognize that this invention can be implemented as a system, method, or computer program product. Therefore, this invention can be specifically implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, this invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.
[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A method for calculating stress in SMAF-ECC fibers based on the multi-slit cracking effect, characterized in that, include: Obtain the material parameters of the material to be tested, wherein the material parameters are parameters describing the mechanical behavior of the material to be tested; Based on the material parameters and the preset multi-crack width, the strain of the shape memory alloy fiber in the material under test is calculated to obtain the strain of the shape memory alloy fiber. The preset multi-crack width represents the sum of the opening widths of all cracks in the material under test that intersect with the shape memory alloy fiber; Based on the constitutive relation of shape memory alloy fibers, the stress of shape memory alloy fibers is calculated according to the material parameters and the strain of the shape memory alloy fibers.
2. The method for calculating SMAF-ECC fiber stress based on multi-slit cracking effect according to claim 1, characterized in that, The step of calculating the strain of the shape memory alloy fibers in the material under test based on the material parameters and the preset multi-crack width, to obtain the strain of the shape memory alloy fibers, includes: Based on the material parameters and the preset multi-crack width, the strain of the shape memory alloy fiber in the material under test is calculated using a first formula to obtain the strain of the shape memory alloy fiber. The first formula is: ； in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
3. The method for calculating SMAF-ECC fiber stress based on multi-slit cracking effect according to claim 1, characterized in that, The constitutive relation based on shape memory alloy fibers, and the calculation of shape memory alloy fiber stress according to the material parameters and the shape memory alloy fiber strain, includes: Based on the material parameters and the strain of the shape memory alloy fiber, the stress of the shape memory alloy fiber is calculated using a second formula, which is: ； in, For shape memory alloy fiber stress, For shape memory alloy fiber strain, The elastic modulus of austenite. This represents the deformation modulus during the "yield plateau" stage of the normal martensitic transformation. This is the martensitic elastic modulus. This represents the strain value at the onset of stress-induced martensitic transformation. This represents the strain value at the end of the stress-induced martensitic phase transformation. Parameters for controlling the sharpness of martensitic hardening corners. Parameters used to control the sharpness of the hysteresis curve corners.
4. The method for calculating SMAF-ECC fiber stress based on multi-slit cracking effect according to claim 3, characterized in that, The parameters controlling the sharpness of the martensitic hardening corner and the parameters controlling the sharpness of the hysteresis curve corner are determined in the following manner: A uniaxial tensile test was performed on a single shape memory alloy fiber to obtain stress-strain data. Based on the stress-strain data, the parameters for controlling the sharpness of the martensitic hardening corner and the parameters for controlling the sharpness of the hysteresis curve corner are determined by nonlinear least squares method.
5. The method for calculating SMAF-ECC fiber stress based on multi-slit cracking effect according to claim 1, characterized in that, The preset multi-crack width is obtained in the following way: Obtain the matrix strain of the material under test; Based on the matrix strain and the material parameters, the preset multi-crack width is calculated using a third formula, which is: ； in, For the preset multi-crack width, For matrix strain, This refers to the tensile length of the shape memory alloy fiber. The strain is the matrix cracking strain.
6. The method for calculating SMAF-ECC fiber stress based on multi-slit cracking effect according to claim 5, characterized in that, Both the matrix strain and the matrix cracking strain were measured by uniaxial tensile tests on SMAF-ECC specimens.
7. A SMAF-ECC fiber stress calculation device based on the multi-slit cracking effect, characterized in that, include: The parameter acquisition module is used to acquire the material parameters of the material to be tested, wherein the material parameters are parameters describing the mechanical behavior of the material to be tested; The strain calculation module is used to calculate the strain of the shape memory alloy fiber in the material under test based on the material parameters and the preset multi-crack width, so as to obtain the strain of the shape memory alloy fiber. The preset multi-crack width represents the sum of the opening widths of all cracks in the material under test that intersect with the shape memory alloy fiber; The stress calculation module is used to calculate the stress of the shape memory alloy fiber based on the constitutive relation of the shape memory alloy fiber, according to the material parameters and the strain of the shape memory alloy fiber.
8. The SMAF-ECC fiber stress calculation device based on the multi-slit cracking effect according to claim 7, characterized in that, The strain calculation module includes: The strain calculation unit is used to calculate the strain of the shape memory alloy fibers in the material under test based on the material parameters and a preset multi-crack width, using a first formula to obtain the strain of the shape memory alloy fibers. The first formula is: ； in, For shape memory alloy fiber strain, The strain is the matrix cracking strain. This refers to the tensile length of the shape memory alloy fiber. The preset multi-crack width.
9. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described in any one of claims 1 to 6.
10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to execute the SMAF-ECC fiber stress calculation method based on the multi-slit cracking effect as described in any one of claims 1 to 6.