A concrete beam damage repair method and system based on shape alloy drive

Abstract

This invention relates to the field of structural monitoring and repair technology, and in particular to a method and system for repairing concrete beam damage based on shape memory alloy (MMA) driven by shape memory alloys. The method includes the following steps: obtaining material property parameters of a shape memory alloy; obtaining model parameters using the material property parameters; obtaining the strain relationship of the shape memory alloy based on the model parameters; obtaining the relationship between the damage strain of the concrete beam and the shape memory alloy based on the strain relationship; repairing the concrete beam damage based on the shape memory alloy's driving force; and describing the repair using an expression. This invention introduces shape memory alloys into the repair of concrete beam damage, conducts a detailed study of the repair principle, and provides a complete theoretical basis and strong technical support for the practical engineering application of shape memory alloys in bridge structures. Furthermore, the method described in this invention has a certain degree of versatility for the matrix material.

Description

Technical Field

[0001] The invention relates to the technical field of structure monitoring and repairing, and in particular to a method and system for repairing concrete beam damage based on shape alloy driving. Background Art

[0002] The generation and expansion of cracks in bridge structures has always been one of the difficult problems that need to be solved urgently in civil engineering. Due to shrinkage, hydration heat and temperature changes, the physical structure of the bridge changes during operation, which will inevitably produce cracks. The generation, expansion and even penetration of cracks will directly affect the waterproofness, durability and bearing capacity of the bridge, greatly increasing the risk of safety accidents. Therefore, it is very necessary to take measures to control the generation and expansion of cracks in bridge structures.

[0003] Shape memory alloy materials have many excellent properties such as shape memory effect, pseudo-elasticity, high strength ratio, corrosion resistance and wear resistance, so shape memory alloys and their composite materials have attracted widespread attention in the field of smart material research; in order to control the generation and expansion of concrete cracks, industry experts have proposed combining shape memory alloy materials with concrete materials to inhibit the generation and expansion of concrete cracks, and at the same time repair the cracks through their shape memory effect; however, existing related research mainly characterizes the mechanical properties of materials through experimental tests and numerical simulations, and has not conducted in-depth research on the crack monitoring theory of shape memory alloy materials under different initial states, and there is no effective method for damage repair of shape memory alloy-driven concrete beams.

[0004] The present invention proposes a method and system for repairing concrete beam damage based on shape memory alloy drive. The present invention reasonably optimizes the structural conditions of shape memory alloys and concrete beams in actual engineering, considers the influence of temperature and load on the resistance characteristics and recovery strain drive of shape memory alloys, repairs the damage of concrete beams under the drive of shape memory alloys, and evaluates the repair effect. Moreover, since the method does not involve too much material properties of concrete, it has certain versatility for matrix materials. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a concrete beam damage repair method and system based on shape alloy drive.

[0006] In order to achieve the above-mentioned purpose, in the first aspect, the present invention provides a method for repairing concrete beam damage based on shape alloy drive, the method comprising the following steps: obtaining material characteristic parameters of shape memory alloy; obtaining model parameters using the material characteristic parameters; obtaining the strain relationship of the shape memory alloy according to the model parameters; obtaining the change relationship between the concrete beam damage strain and the shape memory alloy according to the strain relationship; repairing the concrete beam damage based on the drive of the shape memory alloy, and describing the repair situation using an expression. The present invention proposes to repair the damage of concrete beams based on shape memory alloy drive, conducts a detailed study on the damage monitoring and repair mechanism of concrete beams, proposes a concrete beam damage monitoring and repair theory, and realizes relatively accurate concrete beam crack damage monitoring, damage repair and repair effect evaluation.

[0007] Optionally, the material characteristic parameters of the shape memory alloy are obtained, including: measuring the martensitic elastic modulus, austenitic elastic modulus, Poisson's ratio and maximum phase transformation strain; obtaining the redirected critical stress; obtaining the phase transformation critical temperature of the shape memory alloy; measuring the thermal expansion coefficient of the martensitic and austenitic shape memory alloys; calculating the stress influence coefficient of the martensitic and austenitic shape memory alloys; and obtaining initial parameters related to the resistivity of the shape memory alloy. The present invention obtains the material characteristic parameters of the shape memory alloy and comprehensively describes the mechanical performance characteristics of the shape memory alloy material based on the obtained characteristic parameters. The characteristic parameters have important use value in subsequent theoretical research and practical applications, and provide strong data support for the method steps of the present invention.

[0008] Optionally, the obtaining of model parameters based on the material characteristic parameters includes: representing the model parameters related to the phase change; describing a first change law of the volume fraction of non-twinned martensite during the redirection process; and describing a second change law of the volume fraction of martensite during the phase change process. The present invention obtains model parameters based on the material characteristic parameters of the shape memory alloy, improves the rigor and reliability of the process steps, and can better understand the performance changes of the shape memory alloy material during the phase change strain process, and lays a theoretical data foundation for subsequent research.

[0009] Optionally, obtaining the strain relationship of the shape memory alloy according to the model parameters includes: constructing a model according to the obtained model parameters; and obtaining the strain relationship of the shape memory alloy using the model. The present invention deduces the strain relationship of the shape memory alloy under certain conditions through the constructed model, which not only strengthens the systematicness and logic of the method flow, but also accurately describes the physical strain characteristics of the shape memory alloy, lays a solid foundation for in-depth research on the mechanical behavior of shape memory alloy materials, and also provides a theoretical basis for structural design and performance optimization in practical engineering applications, greatly enhancing the academic value and application prospects of theoretical research.

[0010] Optionally, the step of obtaining the strain relationship of the shape memory alloy by using the model specifically includes:

[0011]

[0012] Among them, ε S is the current strain of the shape memory alloy material, ε0 is the initial strain of the shape memory alloy material, σ is the current stress of the shape memory alloy material, σ0 is the initial stress of the shape memory alloy material, E S is the elastic modulus of the shape memory alloy material, α S is the thermal expansion coefficient of the shape memory alloy material, T is the current ambient temperature, T0 is the initial ambient temperature, ε L is the maximum phase transformation strain, ξ S is the current volume fraction of non-twinned martensite, ξ S0 The present invention uses an expression to clearly describe the strain relationship of the shape memory alloy material under certain conditions, and uses a formula to visually visualize the physical behavior of the shape memory alloy material, thereby improving the feasibility of subsequent theoretical research and enhancing the feasibility and practical value of the method of the present invention.

[0013] Optionally, the method of obtaining the variation relationship between the damage strain of the concrete beam and the shape memory alloy according to the strain relationship includes: using an expression to represent the resistance characteristic parameters of the shape memory alloy; and establishing the variation relationship between the damage strain of the concrete beam and the shape memory alloy according to the resistance characteristic parameters. The present invention links the damage strain generated by the concrete beam during the stress process with the resistance variation characteristics of the shape memory alloy, which not only broadens the technical path of structural monitoring, but also significantly improves the practicality of the method. By constructing a relationship between the two, the corresponding relationship between strain and resistance change is quantified with a clear expression, which enhances the rigor of the method and provides data support and theoretical basis for engineering structure damage warning, safety assessment and repair decision-making.

[0014] Optionally, establishing a relationship between the damage strain of the concrete beam and the change of the shape memory alloy according to the resistance characteristic parameter specifically includes:

[0015]

[0016] Among them, ε F is the damage strain of the concrete beam, ΔR is the relative change value of the resistance of the shape memory alloy, Δδ is the relative change rate of resistivity, v is the Poisson's ratio, σ C is the stress of the concrete beam, E C is the elastic modulus of the concrete beam, α C is the thermal expansion coefficient of the concrete beam, T is the current ambient temperature, T0 is the initial ambient temperature, R is the current resistance value of the shape memory alloy, and R0 is the initial resistance value of the shape memory alloy. The present invention accurately interprets the intrinsic relationship between the damage strain of the concrete beam and the resistance characteristics of the shape memory alloy with an expression, which is intuitive and easy to understand, with a simple and rigorous process, significantly improving the accuracy and practicality of the method, and providing a new choice for monitoring methods and material research in practical engineering applications.

[0017] Optionally, the repair of concrete beam damage based on the drive of the shape memory alloy, and the use of expressions to describe the repair situation, include: applying a load on the concrete beam until damage strain appears in the concrete beam structure; removing the load and increasing the temperature, so that the non-twinned martensite undergoes an austenite phase transformation so that the shape memory alloy gradually returns to its original state; based on the shape memory alloy driving to repair the damage strain of the concrete beam, and using expressions to describe the repair situation of the concrete beam damage. The present invention uses shape memory alloys to repair the damage of concrete beams, and uses expressions to describe the repair situation, quantifies the repair process, and makes the repair effect intuitively presented, which helps to understand the repair process and enhances the feasibility of theoretical research.

[0018] Optionally, the repairing the damage strain of the concrete beam based on the shape memory alloy driving and describing the repairing condition of the concrete beam damage by using an expression specifically includes:

[0019]

[0020] Among them, ε F is the damage strain of the concrete beam, σ S is the critical stress at which phase transformation begins, E A is the austenite elastic modulus of the shape memory alloy material, ξ is the volume fraction of martensite, E M is the martensite elastic modulus of shape memory alloy material, σ C is the stress of the concrete beam, E C is the elastic modulus of concrete, εL is the maximum phase transformation strain, ξ S is the volume fraction of non-twinned martensite during reorientation, ξ S0 is the initial volume fraction of non-twinned martensite, α S is the thermal expansion coefficient of the shape memory alloy material, α C is the thermal expansion coefficient of the concrete beam, T is the current ambient temperature, and T0 is the initial ambient temperature. The present invention uses an expression to quantify the effect of shape memory alloy repairing concrete beams, which not only simplifies the operation process, but also intuitively displays the repair situation, so that engineering and technical personnel can grasp the repair situation in time, take targeted measures in time, improve the repair efficiency and quality, and enhance the value of engineering application.

[0021] In the second aspect, the present invention provides a concrete beam damage repair system based on shape alloy drive, the system executes the concrete beam damage repair method based on shape alloy drive provided by the present invention, the system includes an input device, an output device, a processor and a memory, and its gain lies in: the hardware facilities integrated by the present invention have excellent performance, the input device, the output device, the processor and the memory are interconnected, the information transmission between the various components is smooth, and an efficient information processing system is constructed through the interaction of multiple hardware facilities. The system of the present invention utilizes the unique physical properties of shape memory alloys to achieve accurate repair of concrete beam crack damage, and intuitively displays the repair situation through expressions and graphic data, which has important reference value for engineering and technical personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a method for repairing concrete beam damage based on shape alloy drive according to an embodiment of the present invention;

[0023] Figure 2 The stress-strain curve of the embodiment of the present invention in the austenite state;

[0024] Figure 3 is a stress-strain curve in the martensitic state of an embodiment of the present invention;

[0025] Figure 4 is a differential scanning calorimetry curve of an embodiment of the present invention;

[0026] Figure 5 A comparison diagram of monitoring status results of an embodiment of the present invention;

[0027] Figure 6 A comparison diagram of the repair status results of an embodiment of the present invention;

[0028] Figure 7 This is a framework diagram of a concrete beam damage repair system based on shape alloy drive according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0030] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0031] See also Figure 1 An embodiment of the present invention provides a method for repairing concrete beam damage based on shape alloy drive, the method comprising the following steps:

[0032] S1. Obtain material characteristic parameters of shape memory alloy.

[0033] Among them, S1 specifically includes the following steps:

[0034] S11. Determine the martensite elastic modulus, austenite elastic modulus, Poisson's ratio and maximum phase transformation strain.

[0035] For details, see Figure 2 , at a certain temperature, a uniaxial tensile test is carried out on the shape memory alloy in the austenite state to obtain the stress-strain curve in the austenite state.

[0036] Furthermore, based on the stress-strain curve in the austenite state, the martensite elastic modulus, the austenite elastic modulus, the Poisson's ratio and the maximum phase transformation strain are obtained.

[0037] S12. Obtain the critical stress of redirection.

[0038] For details, see Figure 3 , at a certain temperature, a uniaxial tensile test is carried out on the shape memory alloy in the martensitic state to obtain the stress-strain curve in the martensitic state.

[0039] Furthermore, the redirected critical stress is obtained based on the stress-strain curve in the martensitic state.

[0040] S13. Obtaining the phase transition critical temperature of the shape memory alloy.

[0041] For details, see Figure 4 , the differential scanning calorimetry curve was obtained using differential scanning calorimetry.

[0042] Furthermore, the phase transformation critical temperature of the shape memory alloy is obtained by observing the valley peak start and end data of the differential scanning calorimetry curve.

[0043] S14. Measure the coefficient of thermal expansion of martensitic and austenitic shape memory alloys.

[0044] Specifically, the thermal expansion coefficients of the martensitic and austenitic shape memory alloys are measured using a fully automatic thermal expansion instrument.

[0045] S15. Calculate the stress influence coefficients of martensitic and austenitic shape memory alloys.

[0046] Specifically, under certain temperature conditions, the measured data is calculated by a processor to further obtain the stress influence coefficient of the martensite and austenite shape memory alloys, and the calculation process includes:

[0047]

[0048] Among them, C M is the stress influence coefficient of martensitic shape memory alloy, σ Ms is the critical stress for the onset of martensitic transformation, T A is temperature, M s is the phase transition critical temperature obtained by differential scanning calorimetry, C A is the stress influence coefficient of austenitic shape memory alloy, σ As is the critical stress for the start of austenite transformation, A s is the phase transition critical temperature obtained by differential scanning calorimetry.

[0049] S16. Obtaining initial parameters related to the resistivity of the shape memory alloy.

[0050] Specifically, the relevant initial parameters are obtained by measuring the resistivity of the shape memory alloy at four different temperatures. The parameter calculation formula includes:

[0051]

[0052] Among them, δ1, δ2, δ3, and δ4 are the resistivities measured at temperatures T1, T2, T3, and T4, respectively. T1, T2, T3, and T4 are four different temperatures.M1 , C M2 , C A1 , C A2 is the initial parameter related to resistivity.

[0053] In this embodiment, the physical meanings of the relevant parameters of the shape memory alloy material are shown in Table 1:

[0054] Table 1 Significance of relevant parameters of shape memory alloy materials

[0055]

[0056] Specifically, the values ​​of the relevant parameters of the shape memory alloy material are shown in Table 2:

[0057] Table 2 Values ​​of relevant parameters of shape memory alloy materials

[0058]

[0059] S2. Obtain model parameters using the material characteristic parameters.

[0060] Among them, S2 specifically includes the following steps:

[0061] S21. Representing the model parameters related to the phase change.

[0062] Specifically, the model parameters of the phase change are expressed using a weighted average method, including:

[0063] E S =E A +ξ(E M -E A )

[0064] α S =α A +ξ(α M -α A )

[0065] Among them, E S is the elastic modulus of the shape memory alloy material, E A is the elastic modulus of austenite, ξ is the volume fraction of martensite, E M is the elastic modulus of martensite, α S is the thermal expansion coefficient of the shape memory alloy material, α A is the thermal expansion coefficient of austenite, α M is the thermal expansion coefficient of martensite.

[0066] S22. Describe the first law of variation of the volume fraction of non-twinned martensite during the reorientation process.

[0067] Specifically, the first change law is described using a function of stress and temperature, including:

[0068]

[0069] Among them, ξ S is the volume fraction of non-twinned martensite during reorientation, ξ S0 is the initial volume fraction of non-twinned martensite, is the critical stress at the beginning of the redirection process, is the critical stress at the end of the redirection process, σ is the current stress of the shape memory alloy material, C M is the stress influence coefficient of martensite, T is the current ambient temperature, M s is the critical temperature of phase transformation of shape memory alloy.

[0070] S23. Describe the second law of change of the volume fraction of martensite during phase transformation.

[0071] Specifically, the second variation law is expressed using a function of stress and temperature, including:

[0072]

[0073] Among them, ξ is the volume fraction of martensite during phase transformation, ξ0 is the initial volume fraction of martensite, α A is the thermal expansion coefficient of austenite of shape memory alloy material, T is the current ambient temperature, A s is the critical temperature of the phase transition of the shape memory alloy, σ is the current stress of the shape memory alloy material, C A is the stress influence coefficient of austenite.

[0074] S3. Obtaining a strain relationship of the shape memory alloy according to the model parameters.

[0075] Among them, S3 specifically includes the following steps:

[0076] S31, constructing a model according to the obtained model parameters.

[0077] Specifically, in this embodiment, the model has the following assumptions:

[0078] The concrete beam and the shape memory alloy material are well bonded and will not slip.

[0079] When the concrete beam structure is subjected to axial tensile stress, the shape memory alloy material is deformed, and the shape memory alloy is not directly affected by external forces.

[0080] In the model described in the method of the present invention, the mutual transformation between twinned martensite and non-twinned martensite under other circumstances is ignored.

[0081] S32. Obtaining a strain relationship of the shape memory alloy using the model.

[0082] Specifically, a model is constructed according to the obtained model parameters to describe the strain of the shape memory alloy under thermal conditions. The strain relationship includes:

[0083]

[0084] Among them, ε S is the current strain of the shape memory alloy material, ε0 is the initial strain of the shape memory alloy material, σ is the current stress of the shape memory alloy material, σ0 is the initial stress of the shape memory alloy material, E S is the elastic modulus of the shape memory alloy material, α S is the thermal expansion coefficient of the shape memory alloy material, T is the current ambient temperature, T0 is the initial ambient temperature, ε L is the maximum phase transformation strain, ξ S is the current volume fraction of non-twinned martensite, ξ S0 is the volume fraction of initial non-twinned martensite.

[0085] S4. Obtaining a variation relationship between the damage strain of the concrete beam and the shape memory alloy according to the strain relationship.

[0086] Wherein, S4 specifically includes the following steps:

[0087] S41. Using an expression to represent the resistance characteristic parameters of the shape memory alloy.

[0088] Specifically, the resistance characteristics of the shape memory alloy are described using the material characteristic parameters of the shape memory alloy, including:

[0089]

[0090] Among them, δ S is the resistivity of the shape memory alloy material, δ A is the resistivity of austenite, ξ is the volume fraction of martensite, δ M is the resistivity of martensite, C M1 , C M2 , C A1 , C A2 is the initial parameter related to resistivity, T is the current ambient temperature, Δδ is the relative change rate of resistivity, and δ0 is the resistivity in the initial state.

[0091] S42. Establishing a relationship between the damage strain of the concrete beam and the change of the shape memory alloy according to the resistance characteristic parameter.

[0092] It should be noted that there are no constraints at both ends of the shape memory alloy-concrete beam structure. The initial state of the shape memory alloy is twinned martensite or austenite, which gradually transforms into non-twinned martensite during the application of tensile load. The strain relationship is as follows, including:

[0093] ε S =ε C =ε E +ε F +ε T

[0094] Among them, ε S is the shape memory alloy strain, ε C is the concrete beam strain, ε E is the elastic strain, ε F is the damage strain, ε T For thermal strain.

[0095] Specifically, under the action of temperature and load, according to the resistance characteristic parameters of the obtained shape memory alloy, the relationship between the damage strain of the concrete beam and the resistance characteristic of the shape memory alloy is obtained, including:

[0096]

[0097] Among them, ε F is the damage strain of the concrete beam, ΔR is the relative change value of the resistance of the shape memory alloy, Δδ is the relative change rate of resistivity, v is the Poisson's ratio, σ C is the stress of the concrete beam, E C is the elastic modulus of the concrete beam, α C is the thermal expansion coefficient of the concrete beam, T is the current ambient temperature, T0 is the initial ambient temperature, R is the current resistance value of the shape memory alloy, and R0 is the initial resistance value of the shape memory alloy.

[0098] For further information, see Figure 5 The solid line portion is the monitoring status result obtained by using the relationship between the damage strain of the concrete beam and the resistance characteristics of the shape memory alloy.

[0099] S5. Repair the damage of the concrete beam based on the driving of the shape memory alloy, and use expressions to describe the repair situation.

[0100] Specifically, a load is first applied to the concrete beam until damage strain appears in the concrete beam structure, and then the load is removed and the temperature is increased. The non-twinned martensite undergoes an austenite phase transformation, causing the shape memory alloy to gradually return to its original state. Finally, the damage strain of the concrete beam is repaired based on the shape memory alloy, and an expression is used to describe the repair of the concrete beam damage.

[0101] The repair status of the heating repair process is represented by expressions, including:

[0102]

[0103] Among them, ε F is the damage strain of the concrete beam, σ S is the critical stress at which phase transformation begins, E A is the austenite elastic modulus of the shape memory alloy material, ξ is the volume fraction of martensite, E M is the martensite elastic modulus of shape memory alloy material, σ C is the stress of the concrete beam, E C is the elastic modulus of concrete, ε L is the maximum phase transformation strain, ξ S is the volume fraction of non-twinned martensite during reorientation, ξ S0 is the initial volume fraction of non-twinned martensite, α S is the thermal expansion coefficient of the shape memory alloy material, α C is the thermal expansion coefficient of the concrete beam, T is the current ambient temperature, and T0 is the initial ambient temperature.

[0104] For further information, see Figure 6 The solid line portion is the repair status result obtained by using the repair condition expression of the temperature increase repair process.

[0105] S6. Use finite element analysis software to perform numerical simulation on the method of the present invention to obtain numerical simulation results, which include:

[0106] See also Figure 5 The dotted part shown is the monitoring status result of the numerical simulation.

[0107] See also Figure 6 The dotted part shown is the repair status result of numerical simulation.

[0108] S7. Compare the results obtained by the method of the present invention with the numerical simulation results thereof, and evaluate the effect of the method of the present invention.

[0109] Wherein, S7 specifically includes the following steps:

[0110] S71, see Figure 5 ,The monitoring status results obtained by the two methods were compared.

[0111] Specifically, when predicting and evaluating the expansion of crack damage, the resistance changes of the two are well consistent, thereby verifying that the method of the present invention can effectively monitor the status of the shape memory alloy and concrete beam under the action of thermal-mechanical coupling, and at the same time illustrating that the method of the present invention has good results.

[0112] S72, see Figure 6 ,The repair status results obtained by the two methods were compared.

[0113] Specifically, the comparison results show that the two methods are consistent in predicting and evaluating the repair of concrete beam crack damage, which verifies that the method of the present invention can effectively repair the damage of concrete beams based on shape memory alloys, and at the same time, it can make a good prediction and evaluation of the repair effect, indicating that the method of the present invention has a good presentation effect.

[0114] See also Figure 7 In an optional embodiment, in order to efficiently execute the concrete beam damage repair method based on shape alloy drive provided by the present invention, the present invention provides a concrete beam damage repair system based on shape alloy drive, the system includes an input device, an output device, a processor and a memory, the hardware facilities are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute the specific steps of the embodiment of the concrete beam damage repair method based on shape alloy drive provided by the present invention. The concrete beam damage repair system based on shape alloy drive provided by the present invention has a complete structure, objective stability, and can efficiently execute the concrete beam damage repair method based on shape alloy drive provided by the present invention, thereby improving the overall applicability and practical application ability of the present invention.

[0115] In summary, the method of the present invention provides a method and system for repairing concrete beam damage based on shape alloy drive, which introduces shape memory alloy materials into the repair of concrete beam damage, fully considers the thermal coupling effect, and combines the mechanics and thermodynamics theory of composite materials to construct a method and system for monitoring and repairing cracks in shape memory alloy-concrete beams. The method of the present invention is easy to understand, simple to calculate, small in workload, and convenient for engineering application. It provides a theoretical basis and technical support for the further engineering application of shape memory alloys and their composite materials in bridge structures. In addition, the method of the present invention does not involve too much the material properties of concrete beams, and therefore has a certain versatility for the matrix material.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for repairing concrete beam damage based on shape alloy drive, characterized in that: The steps include: Obtaining material characteristic parameters of shape memory alloy; Obtaining model parameters using the material characteristic parameters; Obtaining a strain relationship of the shape memory alloy according to the model parameters; Obtaining a variation relationship between the damage strain of the concrete beam and the shape memory alloy according to the strain relationship; Repairing the concrete beam damage based on the driving of the shape memory alloy, and describing the repairing situation using an expression; The obtaining of material characteristic parameters of the shape memory alloy comprises: Determine the elastic modulus of martensite, elastic modulus of austenite, Poisson's ratio and maximum phase transformation strain; Obtain the critical stress for redirection; Obtaining the phase transition critical temperature of the shape memory alloy; Measure the thermal expansion coefficient of martensitic and austenitic shape memory alloys; Calculate the stress influence coefficients of martensitic and austenitic shape memory alloys; Obtaining initial parameters related to the resistivity of the shape memory alloy; The method of obtaining model parameters by using the material characteristic parameters comprises: representing the model parameters related to the phase change; Describe the first law of variation of the volume fraction of non-twinned martensite during reorientation; Describe the second law of change of martensite volume fraction during phase transformation; The strain relationship of the shape memory alloy is obtained according to the model parameters, comprising: Constructing a model according to the obtained model parameters; Using the model to obtain a strain relationship of the shape memory alloy; The method of obtaining the strain relationship of the shape memory alloy by using the model specifically includes: in, is the current strain of the shape memory alloy material, is the initial strain of the shape memory alloy material, is the current stress of the shape memory alloy material, is the initial stress of the shape memory alloy material, is the elastic modulus of the shape memory alloy material, is the thermal expansion coefficient of the shape memory alloy material, is the current ambient temperature, is the initial ambient temperature, is the maximum phase transformation strain, is the current volume fraction of non-twinned martensite, is the volume fraction of initial non-twinned martensite.

2. The method for repairing concrete beam damage based on shape alloy drive according to claim 1 is characterized in that: The step of obtaining a change relationship between the damage strain of the concrete beam and the shape memory alloy according to the strain relationship includes: An expression is used to represent the resistance characteristic parameter of the shape memory alloy; A relationship between the damage strain of the concrete beam and the change of the shape memory alloy is established according to the resistance characteristic parameter.

3. The method for repairing concrete beam damage based on shape alloy drive according to claim 2 is characterized in that: The step of establishing a relationship between the damage strain of the concrete beam and the change of the shape memory alloy according to the resistance characteristic parameter specifically includes: in, is the damage strain of the concrete beam, is the relative change in resistance of the shape memory alloy, is the relative change rate of resistivity, is Poisson's ratio, is the stress on the concrete beam, is the elastic modulus of the concrete beam, is the thermal expansion coefficient of the concrete beam, is the current ambient temperature, is the initial ambient temperature, is the current resistance value of the shape memory alloy, is the initial resistance value of shape memory alloy.

4. The method for repairing concrete beam damage based on shape alloy drive according to claim 2 is characterized in that: The repairing of the concrete beam damage based on the driving of the shape memory alloy and describing the repairing situation by using an expression include: Applying a load to the concrete beam until damage strain occurs in the concrete beam structure; The load is removed and the temperature is increased, so that the non-twinned martensite undergoes an austenite phase transformation, and the shape memory alloy gradually returns to its original state; The damage strain of the concrete beam is repaired based on the shape memory alloy, and the repair condition of the concrete beam damage is described using an expression.

5. The method for repairing concrete beam damage based on shape alloy drive according to claim 4 is characterized in that: The method of repairing the damage strain of the concrete beam based on the shape memory alloy driving and describing the repairing condition of the concrete beam damage by using an expression specifically includes: in, is the damage strain of the concrete beam, is the critical stress at which phase transformation begins, is the austenite elastic modulus of the shape memory alloy material, is the volume fraction of martensite, is the martensite elastic modulus of the shape memory alloy material, is the stress on the concrete beam, is the elastic modulus of concrete, is the maximum phase transformation strain, is the volume fraction of non-twinned martensite during the reorientation process, is the initial volume fraction of non-twinned martensite, is the thermal expansion coefficient of the shape memory alloy material, is the thermal expansion coefficient of the concrete beam, is the current ambient temperature, is the initial ambient temperature.

6. A concrete beam damage repair system based on shape alloy drive, characterized in that: The system includes an input device, an output device, a processor and a memory, wherein the input device, the output device, the processor and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute the concrete beam damage repair method based on shape alloy drive as described in any one of claims 1 to 5.

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