Metal structure limit blasting load prediction method and related device

Abstract

The invention discloses a metal structure limit blasting load prediction method and a related device, and relates to the technical field of material science and engineering application, and the method comprises the steps: determining an experiment stress-strain curve based on a first experiment tension-displacement curve, randomly selecting a plurality of first data points in a plastic stage and a stress rising stage of the experimental stress-strain curve, performing interpolation processing on the plurality of first data points to obtain an extrapolated stress-strain curve, obtaining a first simulated tension-displacement curve based on the extrapolated stress-strain curve and finite element simulation, and performing continuous iteration to obtain a second simulated tension-displacement curve; the first simulation tension-displacement curve is matched with the first experiment tension-displacement curve, an optimized extrapolation stress-strain curve is obtained, the optimized extrapolation stress-strain curve serves as the material constitutive relation of the metal structure, and the limit blasting load of the metal structure is determined through finite element simulation. According to the method, the limit blasting load of the metal structure can be accurately predicted at any temperature.

Description

Technical Field

[0001] The present application relates to the technical field of materials science and engineering applications, and particularly relates to a method for predicting the ultimate bursting load of a metal structure and related devices. Background Art

[0002] A metal structure refers to metal components, metal parts, precision metal structural parts, etc. mainly made of metals such as iron, steel, or aluminum through manufacturing and processing. The related metal structure safety assessment methods mainly rely on static stress analysis and traditional destructive tests, which can provide certain reference value under normal temperature conditions. However, in the face of high-temperature environments, these traditional methods are difficult to accurately simulate and predict the actual behavior of metal structures, making it extremely difficult to accurately predict the ultimate bursting load. Summary of the Invention

[0003] The purpose of the present application is to provide a method for predicting the ultimate bursting load of a metal structure and related devices, which can accurately predict the ultimate bursting load of a metal structure at any temperature.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] In the first aspect, the present application provides a method for predicting the ultimate bursting load of a metal structure, and the method for predicting the ultimate bursting load of a metal structure includes:

[0006] Obtain the first experimental tensile force-displacement curve obtained from a uniaxial tensile experiment on a first uniaxial tensile specimen with a central notch; the first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted;

[0007] Based on the first experimental tensile force-displacement curve, determine the experimental stress-strain curve, and randomly select multiple first data points in the plastic stage and stress rising stage of the experimental stress-strain curve;

[0008] Perform interpolation processing on the multiple first data points to obtain an extrapolated stress-strain curve, and use the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen to perform finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve;

[0009] Judge whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, delete the first data point with the largest strain value among the multiple first data points in the current iteration to obtain the multiple first data points in the next iteration, and return to the step of "performing interpolation processing on the multiple first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve;

[0010] Taking the optimized extrapolated stress-strain curve as the material constitutive relation of the metal structure to be predicted, perform a finite element simulation on the pressure-bearing process of the metal structure to be predicted to determine the ultimate bursting load of the metal structure to be predicted.

[0011] Optionally, perform interpolation processing on multiple first data points to obtain an extrapolated stress-strain curve, specifically including: performing interpolation processing on multiple first data points by using the cubic spline interpolation method to obtain an extrapolated stress-strain curve;

[0012] Wherein, when performing interpolation, the value range of the interpolation stress value is [yield strength, extrapolated target stress].

[0013] Optionally, determine whether the first simulated tensile-displacement curve matches the first experimental tensile-displacement curve, specifically including:

[0014] Randomly select multiple second data points on the first simulated tensile-displacement curve, and randomly select multiple third data points on the first experimental tensile-displacement curve to form multiple data point pairs; the data point pairs include corresponding second data points and third data points, and the displacements in the corresponding second data points and third data points have the same value;

[0015] For each of the data point pairs, calculate the difference between the value of the tensile force in the second data point of the data point pair and the value of the tensile force in the third data point of the data point pair to obtain the difference of the data point pair;

[0016] Calculate the sum value of the differences of all the data point pairs to obtain the total deviation;

[0017] Determine whether the total deviation is less than a preset deviation. If so, the first simulated tensile-displacement curve matches the first experimental tensile-displacement curve; if not, the first simulated tensile-displacement curve does not match the first experimental tensile-displacement curve.

[0018] Optionally, taking the optimized extrapolated stress-strain curve as the material constitutive relation of the metal structure to be predicted, perform a finite element simulation on the pressure-bearing process of the metal structure to be predicted to determine the ultimate bursting load of the metal structure to be predicted, specifically including:

[0019] Establish a finite element model of the metal structure to be predicted;

[0020] Taking the optimized extrapolated stress-strain curve as the material constitutive relation of the finite element model, apply a continuously increasing single load to the finite element model to perform a finite element simulation on the pressure-bearing process of the metal structure to be predicted; the single load is internal pressure;

[0021] At each time step of the finite element simulation, calculate the strain and stress triaxiality of each element in the finite element model; for each of the elements, determine the fracture strain based on the stress triaxiality, and determine whether the strain is greater than the fracture strain. If so, end the finite element simulation, and use the value of the single load corresponding to the current time step as the predicted ultimate bursting load of the metal structure.

[0022] Optionally, when applying a continuously increasing single load to the finite element model, the method for predicting the ultimate bursting load of the metal structure further includes: based on the actual stress condition of the metal structure to be predicted, applying a load that remains unchanged and is different from the type of the single load to the finite element model.

[0023] Optionally, determining the fracture strain based on the stress triaxiality specifically includes: using the stress triaxiality as an input, and determining the fracture strain by using a pre-determined fracture strain-stress triaxiality relationship.

[0024] Wherein, the method for determining the fracture strain-stress triaxiality relationship includes:

[0025] Obtain the second experimental tensile force-displacement curves obtained by performing single tensile experiments on each notched second uniaxial tensile specimen; the second uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted, and the notches of different second uniaxial tensile specimens are different;

[0026] For each of the second uniaxial tensile specimens, determine the fracture moment based on the second experimental tensile force-displacement curve corresponding to the second uniaxial tensile specimen, use the optimized extrapolated stress-strain curve as the material constitutive relationship of the second uniaxial tensile specimen, perform finite element simulation on the uniaxial tensile process of the second uniaxial tensile specimen, and when the time step of the finite element simulation reaches the fracture moment, calculate the stress triaxiality simulation value and strain simulation value at the center of the minimum width section of the second uniaxial tensile specimen;

[0027] Perform fitting on the stress triaxiality simulation values and strain simulation values corresponding to all the second uniaxial tensile specimens to obtain a fracture strain-stress triaxiality relationship.

[0028] In a second aspect, the present application provides a device for predicting the ultimate bursting load of a metal structure, and the device for predicting the ultimate bursting load of the metal structure includes:

[0029] An acquisition module, configured to acquire the first experimental tensile force-displacement curve obtained by performing a single tensile experiment on a first uniaxial tensile specimen with a notch at the center; the first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted;

[0030] A selection module, configured to determine an experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly select a plurality of first data points during the plastic stage and the stress rising stage of the experimental stress-strain curve;

[0031] A simulation module, configured to perform interpolation processing on the plurality of first data points to obtain an extrapolated stress-strain curve, and use the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen, and perform finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve;

[0032] An optimization module, configured to determine whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, delete the first data point with the largest strain value among the plurality of first data points in the current iteration to obtain the plurality of first data points in the next iteration, and return to the step of "performing interpolation processing on the plurality of first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve;

[0033] A prediction module, configured to use the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, perform finite element simulation on the pressure-bearing process of the metal structure to be predicted, and determine the ultimate bursting load of the metal structure to be predicted.

[0034] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the above metal structure ultimate bursting load prediction method.

[0035] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above metal structure ultimate bursting load prediction method is implemented.

[0036] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, the above metal structure ultimate bursting load prediction method is implemented.

[0037] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0038] The present application provides a method and related device for predicting the ultimate bursting load of a metal structure. The first experimental tensile force-displacement curve obtained from a uniaxial tension experiment on a first uniaxial tension specimen with a notch in the center is acquired. Based on the first experimental tensile force-displacement curve, the experimental stress-strain curve is determined. Multiple first data points are randomly selected in the plastic stage and stress rising stage of the experimental stress-strain curve, interpolation processing is performed on the multiple first data points to obtain an extrapolated stress-strain curve, and the extrapolated stress-strain curve is used as the material constitutive relationship of the first uniaxial tension specimen. The uniaxial tension process of the first uniaxial tension specimen is simulated by finite element to obtain the first simulated tensile force-displacement curve. It is judged whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve. If so, the currently iterated extrapolated stress-strain curve is recorded as the optimized extrapolated stress-strain curve. The optimized extrapolated stress-strain curve is used as the material constitutive relationship of the metal structure to be predicted, and the pressure-bearing process of the metal structure to be predicted is simulated by finite element to determine the ultimate bursting load of the metal structure to be predicted. The present application realizes that the reason why the ultimate bursting load of the metal structure cannot be accurately simulated in a high-temperature environment is that the stress-strain curve obtained at this time is not the real stress-strain curve. Therefore, the present application first optimizes the stress-strain curve. No matter what temperature it is, as long as a uniaxial tension experiment is carried out at this temperature, and then the subsequent process of comparing simulation and experiment is carried out, the optimized extrapolated stress-strain curve can be obtained. Subsequently, the optimized extrapolated stress-strain curve is used as the material constitutive relationship of the metal structure, and the ultimate bursting load of the metal structure can be obtained through finite element simulation, so that the ultimate bursting load of the metal structure can be accurately predicted at any temperature. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is an application environment diagram of a method for predicting the ultimate bursting load of a metal structure provided in Embodiment 1 of the present application.

[0041] Figure 2 It is a flow chart of a method for predicting the ultimate bursting load of a metal structure provided in Embodiment 1 of the present application.

[0042] Figure 3 It is a schematic diagram of non-uniform deformation caused by necking phenomenon in a high-temperature environment provided in Embodiment 1 of the present application.

[0043] Figure 4Schematic diagram of the first uniaxial tension specimen with a notch in the center provided in Embodiment 1 of the present application.

[0044] Figure 5 Schematic diagram for comparison of stress-strain curves provided in Embodiment 1 of the present application.

[0045] Figure 6 Schematic diagram of the extrapolated stress-strain curve provided in Embodiment 1 of the present application.

[0046] Figure 7 Schematic diagram for comparison of stress-strain curves obtained through experiments and extrapolation provided in Embodiment 1 of the present application.

[0047] Figure 8 Schematic diagram for comparison of the tensile-displacement curve provided in Embodiment 1 of the present application.

[0048] Figure 9 Schematic diagram of the tensile-shear specimen provided in Embodiment 1 of the present application; wherein, Figure 9 (a) in it is the front view of the tensile-shear specimen, Figure 9 (b) in it is the top view of the tensile-shear specimen, Figure 9 (c) in it is the schematic diagram of the E-E section in the front view of the tensile-shear specimen.

[0049] Figure 10 Schematic diagram of the notched round bar specimen provided in Embodiment 1 of the present application.

[0050] Figure 11 Schematic diagram for determining the fracture moment provided in Embodiment 1 of the present application.

[0051] Figure 12 Schematic diagram of the simulation results of the second uniaxial tension specimen provided in Embodiment 1 of the present application; wherein, Figure 12 (a) in it is the schematic diagram of plastic strain, Figure 12 (b) in it is the schematic diagram of stress triaxiality.

[0052] Figure 13 Schematic diagram of the fitting of fracture strain and stress triaxiality provided in Embodiment 1 of the present application.

[0053] Figure 14 Schematic diagram of the finite element model of the pressure vessel provided in Embodiment 1 of the present application; wherein, Figure 14 (a) in it is the three-dimensional view, Figure 14 (b) in it is the contour map.

[0054] Figure 15 Schematic diagram of the functional modules of a device for predicting the ultimate bursting load of a metal structure provided in Embodiment 2 of the present application.

[0055] Figure 16Schematic diagram of a computer device provided in Embodiment 3 of this application. Detailed implementation manners

[0056] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0057] Embodiment 1

[0058] The method for predicting the ultimate bursting load of a metal structure provided in the embodiments of this application can be applied to an application environment as Figure 1 shown. Among them, the terminal communicates with the server through the network. The data storage system can store the data that the server needs to process. The data storage system can be set separately, integrated on the server, or placed on the cloud or other servers. The terminal can send the prediction request to be processed to the server. After receiving the prediction request to be processed, for the prediction request to be processed, the server obtains the first experimental tensile force-displacement curve obtained from the tensile test of the first uniaxial tensile specimen with a notch in the center; determines the experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly selects multiple first data points in the plastic stage and stress rising stage of the experimental stress-strain curve; performs interpolation processing on the multiple first data points to obtain an extrapolated stress-strain curve, and uses the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen, and performs a finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve; determines whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, deletes the first data point with the largest strain value among the multiple first data points in the current iteration to obtain the multiple first data points in the next iteration, and returns to the step of "performing interpolation processing on the multiple first data points"; if so, records the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve; uses the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, and performs a finite element simulation on the pressure-bearing process of the metal structure to be predicted to determine the ultimate bursting load of the metal structure to be predicted. The server can feedback the prediction result of the ultimate bursting load for the prediction request to the terminal.

[0059] In addition, in some embodiments, the method for predicting the ultimate bursting load of a metal structure can also be implemented separately by the server or the terminal. For example, the terminal can directly process the prediction request to be processed, or the server can obtain the prediction request to be processed from the data storage system and process the prediction request to be processed.

[0060] Among them, the terminal can be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc., and the portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0061] In an exemplary embodiment, as Figure 2 shown, a method for predicting the ultimate blasting load of a metal structure is provided. This method is executed by a computer device, and specifically can be executed alone by a computer device such as a terminal or a server, or can be jointly executed by a terminal and a server. In the embodiments of the present application, taking this method applied to Figure 1 the server in as an example for illustration, it includes the following steps.

[0062] Step S1, obtain the first experimental tensile force-displacement curve obtained from a uniaxial tensile test on a first uniaxial tensile specimen with a notch at the center; the first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted.

[0063] Step S2, determine the experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly select multiple first data points in the plastic stage and stress rising stage of the experimental stress-strain curve.

[0064] Step S3, perform interpolation processing on the multiple first data points to obtain an extrapolated stress-strain curve, and use the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen, and perform finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve.

[0065] Step S4, determine whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, delete the first data point with the largest strain value among the multiple first data points in the current iteration to obtain the multiple first data points in the next iteration, and return to the step of "performing interpolation processing on the multiple first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve.

[0066] Step S5, use the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, and perform finite element simulation on the pressure-bearing process of the metal structure to be predicted to determine the ultimate blasting load of the metal structure to be predicted.

[0067] By implementing the above steps S1 to S5, in this embodiment, the material constitutive relationship of the metal structure to be predicted can be optimized first. Regardless of the temperature, as long as this temperature is used during the uniaxial tension experiment, the optimized material constitutive relationship of the metal structure to be predicted at this temperature can be obtained, which is conducive to more accurately predicting the ultimate bursting load at this temperature subsequently. Thus, the ultimate bursting load of the metal structure can be accurately predicted at any temperature, with high precision and a wide application range.

[0068] Next, a detailed introduction to the method for predicting the ultimate bursting load of the metal structure used in this embodiment is given:

[0069] (1) Optimization of the material constitutive relationship under the condition of a fixed temperature (any temperature).

[0070] The uniaxial tension experiment for measuring the material constitutive relationship (i.e., the stress-strain curve, which is the curve of the change of stress with strain) usually measures the displacement value (which can also be called the opening displacement) of two fixed points (the parallel section between the two fixed points is the gauge section) through an extensometer, and then divides it by the original length to calculate the strain value, and divides the directly measured tensile force value by the initial cross-sectional area to calculate the stress value. The result of the strain value and stress value obtained from the experiment is actually the average value within the gauge section. However, due to the presence of the necking phenomenon, the average value within the gauge section does not represent the true stress-strain relationship at a certain point in the necking region. Under normal temperature conditions, the non-uniform deformation caused by the necking phenomenon only occurs in a relatively small local area, but under high temperature conditions, the non-uniform deformation caused by the necking phenomenon will occur in a larger area, such as Figure 3 shown, which results in the fact that after the necking phenomenon occurs, the result of the strain value and stress value measured through the uniaxial tension experiment is very inaccurate, and it is very difficult to simulate this deformation state through finite element technology.

[0071] As Figure 4 shown, it is the first uniaxial tension specimen with a central notch. The shape and size of the first uniaxial tension specimen are arbitrary, as long as it is ensured that the first uniaxial tension specimen is the uniaxial tension specimen corresponding to the metal structure to be predicted, and the first uniaxial tension specimen has a central notch, that is, a notch at the central position, which can bring stress concentration. Through the central notch, the non-uniform deformation can be concentrated in a relatively small area. In this way, by simulating this process through finite element and continuously adjusting the stress-strain curve, when the first simulated tensile force-displacement curve obtained by simulation is relatively consistent with the first experimental tensile force-displacement curve obtained by the uniaxial tension experiment, the true stress-strain curve of the material (i.e., the metal structure to be predicted) can be approximately obtained.

[0072] Specifically, as Figure 5 shown, the blue solid line is the material stress-strain curve measured after the uniaxial tension experiment on the smooth specimen (i.e., Figure 5The solid orange line is the true stress-strain curve obtained by assuming that the specimen undergoes uniform deformation, and is also the experimental stress-strain curve obtained after the single-pull test of the first single-pull specimen (i.e. Figure 5 The green dotted line is the true stress-strain curve of the material in the experimental stress-strain curve when it is in the plastic stage and the true stress is in the rising stage (i.e. Figure 5 The green dotted data is extracted, and the data volume is kept within 20 data points by sampling every other point, as shown in the first group of data in Table 1. x represents strain and y represents stress. In order to adapt to different finite element software, for example, some finite element software requires input of stress-plastic strain curve, so the strain value can be converted into plastic strain value (plastic strain ε peeq = strain ε T -Stress σ T / elastic modulus E).

[0073] Table 1 Selected data points

[0074]

[0075] According to experimental observation and data analysis, for the single-pull test, the single-pull specimen does not undergo uneven deformation as soon as it enters the plastic stage, but undergoes a certain amount of uniform deformation before undergoing uneven deformation. However, the moment when uniform deformation is converted to uneven deformation is not clear, so the last data point of the first group of data is deleted to form the second group of data, and the last data point of the second group of data is deleted to form the third group of data, and so on, to obtain the fourth and fifth groups of data. For each group of data, the cubic spline interpolation method is used to infer the growth trend of the curve formed. Specifically, the interpolation function in the matlab software can be used, such as: ε peeq = interp1(x, y, s, 'spline') to calculate, where ε peeq is the extrapolated strain value, s is the extrapolated stress value, 'spline' represents cubic spline interpolation, and s can be set to: σ s (Yield Strength): n (Data Interval): σ b (Extrapolated target stress, the value of which can be manually adjusted by comparing the first simulated tension-displacement curve with the first experimental tension-displacement curve), specifically refers to taking the data interval points as the value interval within the range of [yield strength, extrapolated target stress] to obtain multiple extrapolated stress values, and then substituting them into the above interpolation function to obtain the extrapolated strain value corresponding to each extrapolated stress value, such as Figure 6 As shown, the red data points are the extrapolated stress values ​​and extrapolated strain values ​​obtained by extrapolating the second group of data in Table 1 using the interpolation function, and the extrapolated stress-strain curve can be further determined.

[0076] The extrapolated stress-strain curves of the first to fifth groups of data in Table 1 are respectively used as the material constitutive relationship of the uniaxial tensile process of the first uniaxial tensile specimen with a central notch shown as follows. When the first simulated tensile force-displacement curve obtained by simulation is in good agreement with the first experimental tensile force-displacement curve obtained by experiment, it is considered as the appropriate stress-strain curve, as shown in Figure 4 and Figure 7 and Figure 8 shown.

[0077] At this time, in this embodiment, the optimization process of the material constitutive relationship includes:

[0078] (1) Obtain the first experimental tensile force-displacement curve obtained from the uniaxial tensile experiment on the first uniaxial tensile specimen with a central notch. The first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted.

[0079] (2) Determine the experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly select multiple first data points in the plastic stage and stress rising stage (i.e., the stage where stress increases with the increase of strain) of the experimental stress-strain curve. The first data points include the stress value and the strain value.

[0080] (3) Perform interpolation processing on the multiple first data points to obtain the extrapolated stress-strain curve, and use the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen to perform finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain the first simulated tensile force-displacement curve.

[0081] Performing interpolation processing on the multiple first data points to obtain the extrapolated stress-strain curve specifically includes: using the cubic spline interpolation method to perform interpolation processing on the multiple first data points to obtain the extrapolated stress-strain curve. Among them, when performing interpolation, the value range of the interpolation stress value (i.e., the extrapolated stress value) is [yield strength, extrapolated target stress].

[0082] (4) Determine whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, delete the first data point with the largest strain value among the multiple first data points in the current iteration to obtain the multiple first data points in the next iteration, and return to the step of "performing interpolation processing on the multiple first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve.

[0083] Determine whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve, specifically including: randomly select multiple second data points on the first simulated tensile force-displacement curve, and randomly select multiple third data points on the first experimental tensile force-displacement curve to form multiple data point pairs. A data point pair includes a corresponding second data point and a third data point. Both the second data point and the third data point include the value of the tensile force and the value of the displacement. The values of the displacements in the corresponding second data point and third data point are the same; for each data point pair, calculate the difference between the value of the tensile force in the second data point of the data point pair and the value of the tensile force in the third data point of the data point pair to obtain the difference of the data point pair; calculate the sum of the differences of all data point pairs to obtain the total deviation; determine whether the total deviation is less than the preset deviation. If so, the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, the first simulated tensile force-displacement curve does not match the first experimental tensile force-displacement curve.

[0084] (2) The correlation between the stress triaxiality and the fracture strain under a fixed temperature condition.

[0085] Conduct uniaxial tensile experiments on second uniaxial tensile specimens with different notches covering different stress states, measure the tensile force values and the displacement values within the gauge section of the specimen (select a section of the second uniaxial tensile specimen according to the actual situation and include the parallel section of the notch area) to obtain the second experimental tensile force-displacement curve of each second uniaxial tensile specimen. The second uniaxial tensile specimens are as Figure 9 and Figure 10 shown. The notches of different second uniaxial tensile specimens are different, which may be different notch types or different notch positions, to simulate different stress states. The size and shape of the second uniaxial tensile specimens are arbitrary, as long as the second uniaxial tensile specimens are the uniaxial tensile specimens corresponding to the metal structure to be predicted.

[0086] For each second uniaxial tensile specimen, based on the actual size of the second uniaxial tensile specimen used in the uniaxial tensile experiment, establish a finite element model of the second uniaxial tensile specimen, use the optimized extrapolated stress-strain curve obtained in (1) as the material constitutive relationship of the finite element model of the second uniaxial tensile specimen, use finite element technology to simulate the uniaxial tensile process of the second uniaxial tensile specimen, and extract the tensile force value and the displacement value of the gauge section during the uniaxial tensile process. Set the turning point (which can be determined manually) where the second experimental tensile force-displacement curve obtained from the experiment drops rapidly as the fracture moment of the second uniaxial tensile specimen, as the red dot shown in Figure 11 Extract the stress triaxiality simulation value and the plastic strain simulation value at the center of the specimen cross-section (select the cross-section with the minimum width) in the finite element simulation result at the fracture moment, as shown in Figure 12 shown.

[0087] The stress triaxiality simulation values and plastic strain simulation values obtained from different second uniaxial tensile specimens are statistically recorded in Figure 13Among them, further fitting is carried out to obtain the fracture strain-stress triaxiality relationship: ε f =-0.7957·η + 1.833, where ε f is the fracture strain and η is the stress triaxiality.

[0088] At this time, in this embodiment, the method for determining the fracture strain-stress triaxiality relationship includes:

[0089] (1) Obtain the second experimental tensile force-displacement curves obtained by separately conducting tensile tests on each notched second uniaxial tensile specimen. The second uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted, and the notches of different second uniaxial tensile specimens are different.

[0090] (2) For each second uniaxial tensile specimen, determine the fracture moment based on the second experimental tensile force-displacement curve corresponding to the second uniaxial tensile specimen. Use the optimized extrapolated stress-strain curve as the material constitutive relationship of the second uniaxial tensile specimen, conduct a finite element simulation on the uniaxial tensile process of the second uniaxial tensile specimen, and when the time step of the finite element simulation reaches the fracture moment, calculate the stress triaxiality simulation value and strain simulation value at the center of the minimum width section of the second uniaxial tensile specimen.

[0091] (3) Fit the stress triaxiality simulation values and strain simulation values corresponding to all second uniaxial tensile specimens to obtain the fracture strain-stress triaxiality relationship.

[0092] (3) Prediction of the ultimate burst load under fixed temperature conditions.

[0093] Establish a finite element model of the metal structure, use the optimized extrapolated stress-strain curve obtained in (1) as the material constitutive relationship of the finite element model of the metal structure, apply an increasing internal pressure load to the finite element model of the metal structure, calculate the plastic strain and stress triaxiality of each element in the finite element model of the metal structure, determine the fracture strain based on the stress triaxiality. When the plastic strain ε peeq > fracture strain ε f , it is considered that the metal structure fails, and the internal pressure load value at this time is the ultimate burst load. The specific judgment criterion is: ε f =-0.7957·η + 1.833. When ε peeq > ε f , the material fails and fracture occurs.

[0094] To accelerate the simulation speed, in this embodiment, only the plastic strain and stress triaxiality of each element in the notch area (determined manually according to experience) of the finite element model of the metal structure can be calculated.

[0095] At this time, in this embodiment, the optimized extrapolated stress-strain curve is used as the material constitutive relation of the metal structure to be predicted, and the finite element simulation is carried out on the pressure-bearing process of the metal structure to be predicted to determine the ultimate bursting load of the metal structure to be predicted.

[0096] Among them, using the optimized extrapolated stress-strain curve as the material constitutive relation of the metal structure to be predicted, and carrying out finite element simulation on the pressure-bearing process of the metal structure to be predicted to determine the ultimate bursting load of the metal structure to be predicted specifically includes:

[0097] (1) Establish a finite element model of the metal structure to be predicted.

[0098] The metal structure can be a pressure vessel, and the finite element model of the pressure vessel is as Figure 14 shown.

[0099] (2) Using the optimized extrapolated stress-strain curve as the material constitutive relation of the finite element model, apply a continuously increasing single load to the finite element model to carry out finite element simulation on the pressure-bearing process of the metal structure to be predicted, and the single load is the internal pressure.

[0100] When applying a continuously increasing single load to the finite element model, the method for predicting the ultimate bursting load of the metal structure in this embodiment further includes: based on the actual stress situation of the metal structure to be predicted, applying a load that remains unchanged and is different from the type of the single load to the finite element model.

[0101] (3) At each time step of the finite element simulation, calculate the strain and stress triaxiality of each element in the finite element model; for each element, determine the fracture strain based on the stress triaxiality, and judge whether the strain is greater than the fracture strain. If so, end the finite element simulation, and use the value of the single load corresponding to the current time step as the ultimate bursting load of the metal structure to be predicted.

[0102] Determining the fracture strain based on the stress triaxiality specifically includes: using the stress triaxiality as the input and determining the fracture strain by using the pre-determined fracture strain-stress triaxiality relation.

[0103] In this embodiment, the metal structure can be any structural member made of metal materials. For example, a pressure vessel, specifically a notched pressure vessel. Pressure vessels play a crucial role in key industrial fields such as chemical engineering, petroleum, and energy. Their safety directly affects the safety of the production process and the lives and property of the public. With the rapid development of industrial technology, the operating environment faced by pressure vessels has become increasingly complex. Especially under extreme conditions such as high temperature and high pressure, any minor manufacturing notch or material aging may lead to catastrophic consequences. In recent years, explosion accidents of pressure vessels caused by fires or local high temperatures have occurred frequently, not only causing huge economic losses but also posing a serious threat to social public safety. To effectively address this severe challenge, it is necessary to strengthen the design, manufacturing, maintenance, and inspection standards of pressure vessels to ensure their reliability and safety under various extreme conditions. At the same time, develop advanced monitoring technologies and prediction models to identify potential risk factors in a timely manner, prevent accidents, and ensure industrial production and public safety. Existing pressure vessel safety assessment methods mainly rely on static stress analysis and traditional destructive tests, which can provide certain reference values under normal temperature conditions. However, in the face of fire or high-temperature environments, these traditional methods are difficult to accurately simulate and predict the actual behavior of pressure vessels. For notched pressure vessels generated during manufacturing or use, the current assessment methods are usually limited to compliance evaluations that meet regulatory requirements and do not deeply study their ultimate load-bearing capacity, especially their specific performance under high-temperature conditions, making it extremely difficult to accurately predict the ultimate load.

[0104] Therefore, this embodiment proposes an innovative method for predicting the ultimate bursting load of notched pressure vessels under high-temperature conditions, aiming to solve the above problems (i.e., the limitations of existing pressure vessel safety assessment methods under extreme conditions such as high temperature and high pressure), especially for the problem of predicting the ultimate bursting load of notched pressure vessels. This method combines numerical simulation, physical experiments, and data analysis techniques, and can accurately predict the structural response of pressure vessels under high-temperature conditions and their failure loads under different working conditions, ensuring the accuracy and reliability of the prediction. It not only provides a powerful tool for accident investigation, helps to deeply understand the root causes of accidents, but also provides a scientific basis for the design optimization, material selection, and safety standard formulation of pressure vessels. It helps to improve the safety level of the entire industry, reduce the risk of accidents, and thus protect public safety and promote sustainable development, effectively prevent accidents, ensure industrial production and public safety, and reduce economic losses and environmental risks.

[0105] This embodiment can be designed for the field of accident investigation, and can predict the failure load of explosion accidents of notched pressure vessels in fire scenarios through numerical simulation technology, and can also deeply explore the load-bearing capacity of pressure vessels under extreme conditions.

[0106] The present application also provides an application scenario, which applies the above-mentioned metal structure ultimate bursting load prediction method. Specifically, the metal structure ultimate bursting load prediction method provided in this embodiment can be applied to the pressure vessel design scenario. The pressure vessel design scenario includes a prediction link and a design link. The prediction link is used to predict the ultimate bursting load of the pressure vessel, and the design link is used to design the pressure vessel based on the ultimate bursting load. The metal structure ultimate bursting load prediction method provided in this embodiment belongs to the prediction link.

[0107] Embodiment 2

[0108] Based on the same inventive concept, the embodiment of the present application also provides a metal structure ultimate bursting load prediction device for implementing the above-mentioned metal structure ultimate bursting load prediction method. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the following metal structure ultimate bursting load prediction device can refer to the limitations on the metal structure ultimate bursting load prediction method in the above text, and will not be repeated here.

[0109] In an exemplary embodiment, as Figure 15 shown, a metal structure ultimate bursting load prediction device is provided. The metal structure ultimate bursting load prediction device includes:

[0110] An acquisition module M1, configured to acquire a first experimental tensile force-displacement curve obtained from a uniaxial tensile experiment on a first uniaxial tensile specimen with a central notch; the first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted.

[0111] A selection module M2, configured to determine an experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly select a plurality of first data points in the plastic stage and stress rising stage of the experimental stress-strain curve.

[0112] A simulation module M3, configured to perform interpolation processing on a plurality of first data points to obtain an extrapolated stress-strain curve, and use the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen to perform a finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve.

[0113] An optimization module M4, configured to determine whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, delete the first data point with the largest strain value among the plurality of first data points in the current iteration to obtain the plurality of first data points in the next iteration, and return to the step of "performing interpolation processing on a plurality of first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve.

[0114] The prediction module M5 is used to take the optimized extrapolated stress-strain curve as the material constitutive relation of the metal structure to be predicted, perform finite element simulation on the pressure-bearing process of the metal structure to be predicted, and determine the ultimate bursting load of the metal structure to be predicted.

[0115] Example 3

[0116] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as shown in Figure 16 the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a method for predicting the ultimate bursting load of a metal structure.

[0117] Those skilled in the art can understand that Figure 16 the structure shown in is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0118] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the method for predicting the ultimate bursting load of a metal structure in Example 1.

[0119] Example 4

[0120] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by the processor, it implements the method for predicting the ultimate bursting load of a metal structure in Example 1.

[0121] Example 5

[0122] In an exemplary embodiment, a computer program product is provided, including a computer program which, when executed by a processor, implements the method for predicting the ultimate blasting load of a metal structure in Embodiment 1.

[0123] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0124] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0125] In this article, specific examples are used to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, based on the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for predicting the ultimate blasting load of a metal structure, characterized in that The method for predicting the ultimate blasting load of the metal structure includes: Obtaining a first experimental tensile force-displacement curve obtained from a uniaxial tensile test on a first uniaxial tensile specimen with a central notch; the first uniaxial tensile specimen is the uniaxial tensile specimen corresponding to the metal structure to be predicted; Determining an experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly selecting a plurality of first data points in the plastic stage and stress rising stage of the experimental stress-strain curve; Performing interpolation processing on the plurality of first data points to obtain an extrapolated stress-strain curve, and using the extrapolated stress-strain curve as the material constitutive relationship of the first uniaxial tensile specimen to perform finite element simulation on the uniaxial tensile process of the first uniaxial tensile specimen to obtain a first simulated tensile force-displacement curve; Judging whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, deleting the first data point with the largest strain value among the plurality of first data points in the current iteration to obtain the plurality of first data points in the next iteration, and returning to the step of "performing interpolation processing on the plurality of first data points"; if so, recording the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve; Using the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, performing finite element simulation on the pressure-bearing process of the metal structure to be predicted, and determining the ultimate blasting load of the metal structure to be predicted.

2. The method for predicting the ultimate bursting load of a metal structure according to claim 1, wherein Performing interpolation processing on the plurality of first data points to obtain an extrapolated stress-strain curve, specifically including: performing interpolation processing on the plurality of first data points by using the cubic spline interpolation method to obtain an extrapolated stress-strain curve; Wherein, when performing interpolation, the value range of the interpolated stress value is [yield strength, extrapolated target stress].

3. The method for predicting the ultimate blasting load of a metal structure according to claim 1, wherein Judging whether the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve specifically includes: Randomly selecting a plurality of second data points on the first simulated tensile force-displacement curve, and randomly selecting a plurality of third data points on the first experimental tensile force-displacement curve to form a plurality of data point pairs; the data point pairs include corresponding second data points and third data points, and the displacements in the corresponding second data points and third data points have the same value; For each of the data point pairs, calculating the difference between the value of the tensile force in the second data point of the data point pair and the value of the tensile force in the third data point of the data point pair to obtain the difference of the data point pair; Calculating the sum value of the differences of all the data point pairs to obtain the total deviation; Judging whether the total deviation is less than a preset deviation, if so, the first simulated tensile force-displacement curve matches the first experimental tensile force-displacement curve; if not, the first simulated tensile force-displacement curve does not match the first experimental tensile force-displacement curve.

4. The method for predicting the ultimate blasting load of a metal structure according to claim 1, wherein Using the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, performing finite element simulation on the pressure-bearing process of the metal structure to be predicted, and determining the ultimate blasting load of the metal structure to be predicted, specifically including: Establishing a finite element model of the metal structure to be predicted; Using the optimized extrapolated stress-strain curve as the material constitutive relation of the finite element model, a continuously increasing single load is applied to the finite element model to perform a finite element simulation on the pressure-bearing process of the metal structure to be predicted; the single load is an internal pressure; At each time step of the finite element simulation, the strain and stress triaxiality of each element in the finite element model are calculated; for each element, the fracture strain is determined based on the stress triaxiality, and it is judged whether the strain is greater than the fracture strain. If so, the finite element simulation is terminated, and the value of the single load corresponding to the current time step is used as the ultimate burst load of the metal structure to be predicted.

5. The method for predicting the ultimate blasting load of a metal structure according to claim 4, wherein, When applying a continuously increasing single load to the finite element model, the method for predicting the ultimate burst load of the metal structure further includes: based on the actual stress condition of the metal structure to be predicted, applying a load that remains unchanged and is different from the type of the single load to the finite element model.

6. The method for predicting the ultimate bursting load of a metal structure according to claim 4, wherein Determining the fracture strain based on the stress triaxiality specifically includes: taking the stress triaxiality as the input and using a pre-determined fracture strain-stress triaxiality relationship formula to determine the fracture strain; Among them, the method for determining the fracture strain-stress triaxiality relationship formula includes: Obtaining the second experimental tensile force-displacement curves obtained by performing single tensile experiments on each second single tensile specimen with a notch; the second single tensile specimen is the single tensile specimen corresponding to the metal structure to be predicted, and the notches of different second single tensile specimens are different; For each of the second single tensile specimens, the fracture moment is determined based on the second experimental tensile force-displacement curve corresponding to the second single tensile specimen. Using the optimized extrapolated stress-strain curve as the material constitutive relation of the second single tensile specimen, the uniaxial tensile process of the second single tensile specimen is subjected to finite element simulation, and when the time step of the finite element simulation reaches the fracture moment, the stress triaxiality simulation value and strain simulation value at the center of the minimum width section of the second single tensile specimen are calculated; Performing fitting on the stress triaxiality simulation values and strain simulation values corresponding to all the second single tensile specimens to obtain a fracture strain-stress triaxiality relationship formula.

7. A device for predicting the ultimate blasting load of a metal structure, characterized in that, The device for predicting the ultimate burst load of the metal structure includes: An acquisition module, configured to acquire the first experimental tensile force-displacement curve obtained by performing a single tensile experiment on a first single tensile specimen with a notch at the center; the first single tensile specimen is the single tensile specimen corresponding to the metal structure to be predicted; A selection module, configured to determine an experimental stress-strain curve based on the first experimental tensile force-displacement curve, and randomly select a plurality of first data points in the plastic stage and stress rising stage of the experimental stress-strain curve; A simulation module, configured to perform interpolation processing on the plurality of first data points to obtain an extrapolated stress-strain curve, and using the extrapolated stress-strain curve as the material constitutive relation of the first single tensile specimen, perform a finite element simulation on the uniaxial tensile process of the first single tensile specimen to obtain a first simulated tensile force-displacement curve; An optimization module, configured to determine whether the first simulated tensile-displacement curve matches the first experimental tensile-displacement curve; if not, delete the first data point with the largest strain value among the multiple first data points in the current iteration to obtain the multiple first data points in the next iteration, and return to the step of "performing interpolation processing on the multiple first data points"; if so, record the extrapolated stress-strain curve in the current iteration as the optimized extrapolated stress-strain curve. A prediction module, configured to use the optimized extrapolated stress-strain curve as the material constitutive relationship of the metal structure to be predicted, perform finite element simulation on the pressure-bearing process of the metal structure to be predicted, and determine the ultimate bursting load of the metal structure to be predicted.

8. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the metal structure ultimate bursting load prediction method according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the metal structure ultimate bursting load prediction method according to any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the metal structure ultimate bursting load prediction method according to any one of claims 1-6.

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