Large-volume high-strength concrete wall temperature field analysis method and equipment

Abstract

The invention provides a mass high-strength concrete wall temperature field analysis method and device, and relates to the technical field of civil engineering, and the method comprises the steps: S1, constructing a temperature field mathematical model of a to-be-measured concrete wall; s2, the actually measured temperature of each temperature measuring point of the sample plate concrete wall is obtained; s3, iteratively solving and optimizing the temperature field mathematical model through a finite element method and each actually measured temperature to obtain an optimal thermodynamic parameter; s4, the optimal thermodynamic parameters are substituted into the temperature field mathematical model, and the optimal temperature field of the to-be-measured concrete wall is obtained through calculation. According to the method, mathematical modeling, finite element analysis, experimental verification and parameter optimization technologies are fused, so that the engineering problems of accurately predicting and controlling the temperature distribution of the concrete wall, preventing temperature cracks and the like are realized, and the durability and the safety of the mass concrete structure are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and particularly relates to a method and device for analyzing the temperature field of a large-volume high-strength concrete wall. Background Technique

[0002] In large-scale infrastructure construction, such as high-rise buildings, water conservancy and hydropower projects, nuclear power plants, etc., large-volume high-strength concrete walls, as key load-bearing and protective structures, their performance stability is crucial. However, due to the limited heat conduction performance of concrete materials and the release of hydration heat during the construction process, the temperature inside the concrete rises sharply, while the outside is affected by the ambient temperature more slowly, forming a significant temperature difference between the inside and outside. This temperature difference effect will not only cause uneven stress distribution inside the concrete, but may also induce temperature cracks, seriously affecting the integrity and durability of the structure.

[0003] Traditional temperature field analysis methods mostly rely on empirical formulas or simplified models, and it is difficult to accurately reflect the complex and variable heat conduction process of large-volume concrete walls. In addition, for high-strength concrete, there are significant differences in its thermal properties (such as thermal conductivity, thermal expansion coefficient, etc.) compared with ordinary concrete, further increasing the difficulty of temperature field analysis. Therefore, it is particularly important to develop a method that can comprehensively consider the characteristics of concrete materials, construction conditions and environmental factors and accurately simulate the temperature field change of large-volume high-strength concrete walls.

[0004] In recent years, with the rapid development of computer technology and numerical analysis methods, finite element analysis has become a powerful tool for solving complex engineering problems. By constructing an accurate mathematical model and optimizing parameters in combination with experimental data, it is possible to achieve refined simulation and prediction of the temperature field of concrete walls. However, for the specific characteristics of large-volume high-strength concrete walls, how to reasonably construct a mathematical model, efficiently implement finite element analysis and accurately optimize thermodynamic parameters are still hot and difficult issues in current research. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method and device for analyzing the temperature field of a large-volume high-strength concrete wall, which are used to solve the technical problem that the existing temperature field analysis methods cannot optimize the thermodynamic parameters for large-volume high-strength concrete walls.

[0006] The present invention provides a method for analyzing the temperature field of a large-volume high-strength concrete wall, including the steps of:

[0007] S1: Construct a mathematical model of the temperature field of the concrete wall to be measured;

[0008] S2: Obtain the measured temperatures of each temperature measurement point of the sample concrete wall;

[0009] S3: Solve and optimize the temperature field mathematical model through the finite element method and each measured temperature to obtain the optimal thermodynamic parameters;

[0010] S4: Substitute the optimal thermodynamic parameters into the temperature field mathematical model and calculate to obtain the optimal temperature field of the concrete wall to be measured.

[0011] Preferably:

[0012] The expression of the temperature field mathematical model is:

[0013]

[0014] where t is time, x is the coordinate in the thickness direction, z is the coordinate in the height direction, k, ρ, c are respectively the thermal conductivity, density and specific heat capacity of the concrete wall, m' is the concrete heat source attenuation coefficient, T 0 is the temperature at the time of pouring, T e is the ambient temperature, H is the height of the concrete wall, B is the thickness of the concrete wall, K' is the adiabatic temperature rise of the concrete, h 1 is the heat transfer coefficient on the top surface of the concrete wall, h 2 is the heat transfer coefficient on the side surface of the concrete wall, h 3 is the heat transfer coefficient on the bottom surface of the concrete wall.

[0015] Preferably, step S3 is specifically:

[0016] S31: Construct an objective function, initialize the values of the thermodynamic parameters and the number of iterations u, and the initial value of u is 1;

[0017] S32: Enter the u-th iteration, input the thermodynamic parameters into the temperature field mathematical model, solve the temperature field mathematical model through the finite element method to obtain the temperature field, and obtain the simulated temperature of each temperature measurement point through the temperature field;

[0018] S33: Calculate the value of the objective function through the thermodynamic parameters, each simulated temperature and each measured temperature;

[0019] S34: Update the values of the thermodynamic parameters through the Nelder-Mead algorithm, and let u = u + 1;

[0020] S35: Repeat steps S32 - S34 until the change in the value of the objective function is less than the preset value, and take the thermodynamic parameters that make the value of the objective function the smallest as the optimal thermodynamic parameters.

[0021] Preferably:

[0022] The expression of the thermodynamic parameters is: (K', h 1 , h 2 , h 3 ).

[0023] Preferred:

[0024] The expression of temperature field is: T(x,z,t).

[0025] Preferred:

[0026] The calculation formula of the objective function J is:

[0027]

[0028] in, is the simulated temperature of the jth temperature measurement point at the i-th time point, is the measured temperature of the jth temperature measuring point at the i-th time point.

[0029] A storage medium stores instructions and data for implementing the temperature field analysis method for large-volume high-strength concrete walls.

[0030] A temperature field analysis device for a large volume high strength concrete wall comprises: a processor and a storage medium; the processor loads and executes instructions and data in the storage medium to implement the temperature field analysis method for a large volume high strength concrete wall.

[0031] The present invention has the following beneficial effects:

[0032] According to the characteristics of large-volume high-strength concrete walls, a temperature field mathematical model was specifically constructed, and the temperature field mathematical model was iteratively solved and optimized through the finite element method and measured temperature, to achieve continuous optimization of thermodynamic parameters, and finally obtain the optimal thermodynamic parameters, and obtain the optimal temperature field based on the optimal thermodynamic parameters. By integrating mathematical modeling, finite element analysis, experimental verification and parameter optimization technology, it is possible to accurately predict and control the temperature distribution of concrete walls, prevent engineering problems such as temperature cracks, and improve the durability and safety of large-volume concrete structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of a method according to an embodiment of the present invention;

[0034] Figure 2 This is the layout diagram of the temperature measurement points for the sample wall temperature measurement test;

[0035] Figure 3 Comparison between the measured temperature value and the numerical simulation value;

[0036] Figure 4 The temperature cloud diagram of the sample wall at different times;

[0037] Figure 5 is the effect of the concrete wall thickness B on the core-surface temperature difference in the plane z = 2m;

[0038] Figure 6The influence of the environmental temperature Te on the core-surface temperature difference at the plane of z = 2m;

[0039] Figure 7 Schematic diagram of the operation of the hardware device according to the embodiment of the present invention;

[0040] The implementation, functional features, and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0041] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] Referring to Figure 1 , the present invention provides a method for analyzing the temperature field of a large-volume high-strength concrete wall, including the steps of:

[0043] S1: Construct a mathematical model of the temperature field of the concrete wall to be measured;

[0044] As an embodiment:

[0045] The expression of the mathematical model of the temperature field is:

[0046]

[0047] where t is time, x is the coordinate in the thickness direction, z is the coordinate in the height direction, k, ρ, c are the thermal conductivity, density, and specific heat capacity of the concrete wall respectively, m' is the attenuation coefficient of the concrete heat source, T 0 is the temperature at the time of pouring, T e is the environmental temperature, H is the height of the concrete wall, B is the thickness of the concrete wall, K' is the adiabatic temperature rise of the concrete, h 1 is the heat transfer coefficient of the top surface of the concrete wall, h 2 is the heat transfer coefficient of the side surface of the concrete wall, h 3 is the heat transfer coefficient of the bottom surface of the concrete wall.

[0048] Specifically, k, ρ, c are taken according to the "Code for Design of Concrete Structures", m' is taken as 1.1, the value range of K' is [0, 80] °C, and h 1 has a value range of [0, 60] W / (m 2 ·K), h 2 has a value range of [0, 60] W / (m 2 ·K), h 3 has a value range of [0, 60] W / (m 2 ·K); W is the unit watt, m is the unit meter, and K is the unit kelvin.

[0049] Taking a large-volume high-strength concrete wall as an example, its dimensions are 10m (length) × 4m (height) × 1m (thickness), and it is poured with C70 concrete, with the pouring temperature being 30°C.

[0050] The expression of the temperature field mathematical model is:

[0051]

[0052] In the formula, referring to the "Code for Design of Concrete Structures", the thermal conductivity k of concrete is taken as 2.9444 W / (m·K), the specific heat capacity c of concrete is taken as 960 J / (kg·K), and the density ρ of concrete is taken as 2400 kg / m³.

[0053] S2: Obtain the measured temperatures of each temperature measurement point on the sample concrete wall;

[0054] As an example, taking the above large-volume high-strength concrete wall as an example, a temperature measurement test of the sample wall is carried out. Three temperature measurement points are set on the temperature measurement plane. As Figure 2 shown, the coordinates of temperature measurement point P1 are (x, z) = (0, H - 10 cm), the coordinates of temperature measurement point P2 are (x, z) = (0, H / 2), and the coordinates of temperature measurement point P3 are (x, z) = (0, 10 cm). After pouring the concrete, the temperature data and ambient temperature data are recorded every 6 hours for a total of 150 hours. The temperature data of the three temperature measurement points are respectively expressed as a time series data set: {T P1 (t i )}, {T P2 (t i )}, {T P3 (t i )}, where t i represents the i-th time point (i = 0, 1, 2,..., 25). The temperature data of the temperature measurement points and the ambient temperature data are shown in Table 1.

[0055] Table 1 Temperature data of temperature measurement points and ambient temperature

[0056]

[0057] S3: Iteratively solve and optimize the temperature field mathematical model through the finite element method and each measured temperature to obtain the optimal thermodynamic parameters;

[0058] As an example,

[0059] Step S3 is specifically:

[0060] S31: Construct an objective function, initialize the values of the thermodynamic parameters and the number of iterations u, and the initial value of u is 1;

[0061] Specifically:

[0062] The expression of the thermodynamic parameters is: (K’, h 1 , h 2 , h 3 ).

[0063] S32: Enter the u-th iteration, input the thermodynamic parameters into the temperature field mathematical model, solve the temperature field mathematical model by the finite element method to obtain the temperature field, and obtain the simulated temperature of each temperature measurement point through the temperature field;

[0064] Specifically:

[0065] The expression of the temperature field is: T(x, z, t).

[0066] S33: Calculate the value of the objective function through the thermodynamic parameters, each simulated temperature and each measured temperature;

[0067] Specifically:

[0068] The calculation formula of the objective function J is:

[0069]

[0070] Where, is the simulated temperature of the j-th temperature measurement point at the i-th time point, is the measured temperature of the j-th temperature measurement point at the i-th time point.

[0071] S34: Update the value of the thermodynamic parameters through the Nelder-Mead algorithm, and let u = u + 1;

[0072] S35: Repeat steps S32 - S34 until the change in the value of the objective function is less than the preset value, and take the thermodynamic parameters that make the value of the objective function the smallest as the optimal thermodynamic parameters.

[0073] Specifically, taking the above-mentioned large-volume high-strength concrete wall mixing as an example, the optimal thermodynamic parameters (K’, h1, h2, h3) = (70.1 °C, 27.8 W / (m 2 ·K), 7.6 W / (m 2 ·K), 5.6 W / (m 2 ·K)). The optimization effect is shown in Figure 3 , and the corresponding temperature field is shown in Figure 4 .

[0074] S4: Substitute the optimal thermodynamic parameters into the temperature field mathematical model to calculate the optimal temperature field of the concrete wall to be measured.

[0075] Specifically, according to the optimal thermodynamic parameters, study the influence of the concrete wall thickness B on the core-surface temperature difference of the concrete wall, as shown in Figure 5 ; and study the influence of the ambient temperature Te on the core-surface temperature difference of the concrete wall, as shown inFigure 6 as shown

[0076] Please refer to Figure 7 , Figure 7 which is a schematic diagram of the operation of the hardware device according to an embodiment of the present invention. The hardware device specifically includes: a large-volume high-strength concrete wall temperature field analysis device 401, a processor 402, and a storage medium 403.

[0077] A large-volume high-strength concrete wall temperature field analysis device 401: The large-volume high-strength concrete wall temperature field analysis device 401 implements the large-volume high-strength concrete wall temperature field analysis method.

[0078] Processor 402: The processor 402 loads and executes the instructions and data in the storage medium 403 to implement the large-volume high-strength concrete wall temperature field analysis method.

[0079] Storage medium 403: The storage medium 403 stores instructions and data; the storage medium 403 is used to implement the large-volume high-strength concrete wall temperature field analysis method.

[0080] It should be noted that in this article, the terms "including", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article, or system. Without more limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article, or system including that element.

[0081] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments. Among the several unit claims listing several devices, several of these devices may be specifically embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order and these words can be interpreted as identifiers.

[0082] The above is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A temperature field analysis method for a large volume high-strength concrete wall, characterized in that: Includes steps: S1: Construct the mathematical model of the temperature field of the concrete wall to be tested; S2: Obtain the measured temperature of each temperature measuring point of the sample concrete wall; S3: The temperature field mathematical model is iteratively solved and optimized through the finite element method and each measured temperature to obtain the optimal thermodynamic parameters; S4: Substitute the optimal thermodynamic parameters into the temperature field mathematical model to calculate and obtain the optimal temperature field of the concrete wall to be tested.

2. The temperature field analysis method for a large volume high strength concrete wall according to claim 1 is characterized in that: The expression of the temperature field mathematical model is: Among them, t is time, x is the thickness direction coordinate, z is the height direction coordinate, k, ρ, c are the thermal conductivity, density and specific heat capacity of the concrete wall, m' is the concrete heat source attenuation coefficient, T0 is the mold entry temperature, T e is the ambient temperature, H is the height of the concrete wall, B is the thickness of the concrete wall, K' is the adiabatic temperature rise of the concrete, h1 is the heat exchange coefficient of the top surface of the concrete wall, h2 is the heat exchange coefficient of the side surface of the concrete wall, and h3 is the heat exchange coefficient of the bottom surface of the concrete wall.

3. The temperature field analysis method of large volume high strength concrete wall according to claim 2 is characterized in that: Step S3 is specifically as follows: S31: construct the objective function, initialize the value of the thermodynamic parameter and the number of iterations u, and the initial value of u is 1; S32: Entering the uth iteration, inputting the thermodynamic parameters into the temperature field mathematical model, solving the temperature field mathematical model by the finite element method to obtain the temperature field, and obtaining the simulated temperature of each temperature measuring point by the temperature field; S33: Obtaining the value of the objective function by calculating the thermodynamic parameters, each simulated temperature and each measured temperature; S34: Update the value of the thermodynamic parameter by Nelder-Mead algorithm, and set u=u+1; S35: Repeat steps S32-S34 until the change in the value of the objective function is less than a preset value, and take the thermodynamic parameter that minimizes the value of the objective function as the optimal thermodynamic parameter.

4. The temperature field analysis method for a large volume high strength concrete wall according to claim 3 is characterized in that: The expression of thermodynamic parameters is: (K', h1, h2, h3).

5. The temperature field analysis method for a large volume high strength concrete wall according to claim 3 is characterized in that: The expression of temperature field is: T(x,z,t).

6. The temperature field analysis method for a large volume high strength concrete wall according to claim 3 is characterized by: The calculation formula of the objective function J is: in, is the simulated temperature of the jth temperature measurement point at the i-th time point, is the measured temperature of the jth temperature measuring point at the i-th time point.

7. A storage medium, characterized in that: The storage medium stores instructions and data for implementing the temperature field analysis method for large-volume high-strength concrete walls as described in any one of claims 1 to 6.

8. A temperature field analysis device for large-volume high-strength concrete walls, characterized by: include: Processor and storage medium; the processor loads and executes instructions and data in the storage medium to implement the temperature field analysis method of large-volume high-strength concrete wall as described in any one of claims 1 to 6.

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