Bolt-based relaxation stress prediction method and device

Abstract

The application provides a bolt-based relaxation stress prediction method and device. The bolt-based relaxation stress prediction method comprises the following steps: obtaining the working time of a bolt; determining a relaxation stress model corresponding to historical relaxation stress data according to the comparison result of the working time and a boundary time; and predicting the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model. The application can provide accurate quantitative guarantee for the safety of the bolt in overage service.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloy service life prediction, and in particular to a method and device for predicting relaxation stress based on bolts. Background Art

[0002] High-temperature bolts are important components of power station units and one of the most important fasteners for maintaining the airtightness of steam turbine units, directly affecting the safety of the units. Stress relaxation is a stress decay phenomenon that is common in various materials during service. It refers to the phenomenon that the total deformation (elastic deformation and plastic deformation) of the component remains unchanged, creep causes the plastic deformation to increase continuously, the elastic deformation to decrease accordingly, and the stress slowly decreases over time. It is one of the main forms of failure of high-temperature fasteners. The typical stress relaxation curve can be divided into two stages: in the first stage, the stress drops rapidly in a relatively short period of time, and the stress relaxation rate is relatively large compared to the second stage. The rate of stress decreases gradually with time. In the second stage, the residual stress decreases very slowly, and the rate of decrease decreases with time, and the residual stress tends to be flat.

[0003] R26 high-temperature alloy bolts are used in 300MW / 600MW steam turbine units, and a significant number are still in operation. R26 high-temperature alloy bolts operate in harsh environments. During operation, they are subjected to the interaction of high temperatures and complex loads, which can cause stress relaxation. When the residual stress is insufficient to maintain the bolts in place, high-temperature, high-pressure steam can leak. This stress relaxation has already caused steam leaks in cylinders at multiple power plants.

[0004] During regular maintenance, power plants typically assess the Brinell hardness of in-service R26 high-temperature bolts. Bolts exceeding the hardness standard are replaced. However, a typical maintenance cycle for R26 high-temperature bolts is 25,000 to 30,000 hours. During this operating cycle, the following problem can arise: some R26 high-temperature bolts exceed the hardness standard before the maintenance period, thus going undetected and unreplaced. Excessive hardness increases the risk of bolt failure, potentially leading to steam leaks and compromising production safety. Summary of the Invention

[0005] The main purpose of the embodiments of the present invention is to provide a method and device for predicting relaxation stress based on bolts, so as to provide accurate quantitative guarantee for the safety of bolts in over-service.

[0006] To achieve the above objectives, an embodiment of the present invention provides a method for predicting relaxation stress based on a bolt, comprising:

[0007] Get the working time of the bolt;

[0008] determine a corresponding relaxation stress model created based on historical relaxation stress data according to the comparison result of the working time and the demarcation time;

[0009] predict the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0010] In one embodiment, the method further comprises:

[0011] constructing a relaxation stress time scatter plot according to the historical relaxation stress data;

[0012] determining the demarcation time according to the relaxation stress time scatter plot.

[0013] In one embodiment, determining the demarcation time according to the relaxation stress time scatter plot comprises:

[0014] determining relaxation stress change rate time data according to the relaxation stress time scatter plot;

[0015] determining the demarcation time according to the relaxation stress change rate time data and the change trend of the relaxation stress time scatter plot.

[0016] In one embodiment, the method further comprises:

[0017] dividing the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time;

[0018] creating a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data;

[0019] creating a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data.

[0020] The embodiments of the present application also provide a bolt relaxation stress prediction device based on the bolt relaxation stress prediction method, which comprises:

[0021] a working time module, configured to acquire the working time of the bolt;

[0022] a relaxation stress model module, configured to determine a corresponding relaxation stress model created based on historical relaxation stress data according to the comparison result of the working time and the demarcation time;

[0023] a relaxation stress prediction module, configured to predict the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0024] In one embodiment, the device further comprises:

[0025] a relaxation stress time scatter plot module, configured to construct a relaxation stress time scatter plot according to the historical relaxation stress data;

[0026] A demarcation time module is configured to determine the demarcation time according to the relaxation stress time scatter diagram.

[0027] In one embodiment, the demarcation time module comprises:

[0028] A relaxation stress change rate time data unit is configured to determine the relaxation stress change rate time data according to the relaxation stress time scatter diagram.

[0029] A demarcation time unit is configured to determine the demarcation time according to the relaxation stress change rate time data and the change trend of the relaxation stress time scatter diagram.

[0030] In one embodiment, the method further comprises:

[0031] A relaxation stress time data division module is configured to divide the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time.

[0032] A first relaxation stress model module is configured to create a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data.

[0033] A second relaxation stress model module is configured to create a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data.

[0034] The embodiments of the present application also provide an electronic device, which comprises a memory, a processor and a computer program stored in the memory and running on the processor, and the processor implements the steps of the bolt-based relaxation stress prediction method when executing the computer program.

[0035] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the bolt-based relaxation stress prediction method when executed by a processor.

[0036] The embodiments of the present application also provide a computer program product, which comprises computer programs / instructions, and the computer programs / instructions implement the steps of the bolt-based relaxation stress prediction method when executed by a processor.

[0037] The bolt-based relaxation stress prediction method and device provided by the embodiments of the present application can determine the corresponding relaxation stress model according to the comparison result of the working time and the demarcation time, and then predict the relaxation stress according to the working time relaxation stress model of the bolt, so as to provide accurate quantitative guarantee for the safety of the bolt serving for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0038] 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 needed in the description of the embodiments. Obviously, the drawings described below are only some of the embodiments of the present application, and for those of ordinary skill in the art, other drawings can be obtained from these drawings without creative labor.

[0039] Figure 1 is a flowchart of the bolt-based relaxation stress prediction method in the embodiments of the present application;

[0040] Figure 2 is a flowchart of determining the demarcation time in the embodiments of the present application;

[0041] Figure 3 is a flowchart of S202 in the embodiments of the present application;

[0042] Figure 4 is a flowchart of creating a relaxation stress model in the embodiments of the present application;

[0043] Figure 5 is a relaxation stress time scatter plot of R26 high-temperature alloy bolts at 372 MPa and 560℃ in the embodiments of the present application;

[0044] Figure 6 is a relaxation stress change rate time curve of R26 high-temperature alloy bolts at 372 MPa and 560℃ in the embodiments of the present application;

[0045] Figure 7 is a fitting curve schematic diagram of R26 high-temperature alloy bolts at 372 MPa and 560℃ in the embodiments of the present application;

[0046] Figure 8 is a relaxation stress prediction curve of R26 high-temperature alloy bolts at 372 MPa and 560℃ in the embodiments of the present application;

[0047] Figure 9 is a structural block diagram of the bolt-based relaxation stress prediction device in the embodiments of the present application;

[0048] Figure 10 is a schematic block diagram of the system constitution of the electronic device 9600 of the embodiments of the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0050] Those skilled in the art appreciate that embodiments of the present application can be implemented as a system, apparatus, device, method or computer program product. Therefore, the present disclosure can be embodied in the form of a complete hardware, complete software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0051] In view of the possibility of steam leakage in the prior art, affecting the safety of production, the embodiment of the present application proposes a bolt-based relaxation stress prediction method and device, which provides accurate quantitative guarantee for the safety of over-service hard bolts. The present application will be described in detail below with reference to the accompanying drawings.

[0052] The present application is aimed at R26 high-temperature alloy bolts with service hardness exceeding the standard at 560 DEG C, and the covered Brinell hardness range is (331 HB, 375 HB]; the initial stress coverage range is [372 MPa, 432 MPa]. A large number of tests show that when the in-service R26 high-temperature alloy bolts in the above Brinell hardness range are served in the above initial stress range, the high-temperature stress relaxation life prediction is applicable to the method described in the present application.

[0053] Figure 1 is a flowchart of the bolt-based relaxation stress prediction method in the embodiment of the present application. As shown in Figure 1 , the bolt-based relaxation stress prediction method comprises:

[0054] S101: Obtain the working time of the bolt.

[0055] S102: Determine the corresponding relaxation stress model created based on the historical relaxation stress data according to the comparison result of the working time and the boundary time.

[0056] Wherein, when the working time is less than the boundary time, the corresponding relaxation stress model is the first relaxation stress model; when the working time is greater than or equal to the boundary time, the corresponding relaxation stress model is the second relaxation stress model.

[0057] Figure 2 is a flowchart of determining the boundary time in the embodiment of the present application. As shown in Figure 2 , the bolt-based relaxation stress prediction method further comprises:

[0058] S201: Construct a relaxation stress time scatter plot according to the historical relaxation stress data.

[0059] S202: Determine the boundary time according to the relaxation stress time scatter plot.

[0060] Figure 3 is a flowchart of S202 in the embodiment of the present application. As shown in Figure 3 , S202 comprises:

[0061] S301: Determine the relaxation stress rate time data according to the relaxation stress time scatter diagram.

[0062] Figure 5 is a relaxation stress time scatter diagram of the R26 high-temperature alloy bolt at 372 MPa and 560 DEG C in the embodiment of the present application. Figure 6 is a relaxation stress rate time curve of the R26 high-temperature alloy bolt at 372 MPa and 560 DEG C in the embodiment of the present application. As shown in Figures 5-6 , Figure 6 is the relaxation stress rate time data after differentiation Figure 5 .

[0063] S302: Determine the demarcation time according to the relaxation stress rate time data and the change trend of the relaxation stress time scatter diagram.

[0064] The demarcation time of the first stage and the second stage of the relaxation stress is the time when the relaxation stress rate dσ / dt = 0. In addition, according to the downward trend of the relaxation stress time scatter diagram, it can be determined that the relaxation stress rate time data is less than 200 h, that is, the demarcation time is less than 200 h and close to 200 h, so that the demarcation time is t i = 190.6 h.

[0065] Figure 4 is a flowchart for creating a relaxation stress model in the embodiment of the present application. Figure 7 is a fitting curve diagram of the R26 high-temperature alloy bolt at 372 MPa and 560 DEG C in the embodiment of the present application. As shown in Figure 4 and Figure 7 , the bolt relaxation stress prediction method further comprises:

[0066] S401: Divide the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time.

[0067] The first relaxation stress time data is the historical relaxation stress data less than the demarcation time, and the second relaxation stress time data is the historical relaxation stress data greater than or equal to the demarcation time.

[0068] S402: Create a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data.

[0069] In an embodiment, the first stress initial model is as follows:

[0070]

[0071] wherein σ is the relaxation stress, the unit is MPa; t is the time, the unit is h; t iis the dividing time (the dividing point time between the first and second stages of stress relaxation), in h; B is the relaxation stress at the end of the first stage, in MPa. Figure 7 As shown in the figure, the relaxation stress at the beginning of the second stage (end of the first stage) is 334 MPa; b1 is the first constant, b2 is the second constant, c1 is the third constant, and c2 is the fourth constant. Based on the first relaxation stress time data, b1, b2, c1, and c2 can be fitted to obtain the first relaxation stress model.

[0072] S403: Creating a second relaxation stress model according to the preset second stress initial model and the second relaxation stress time data.

[0073] In one embodiment, the second stress initial model is as follows:

[0074] σ=at w (t≥t i );

[0075] Where, σ is the relaxation stress, in MPa; t is the time, in h; t i is the dividing time (the dividing point time between the first and second stages of stress relaxation), in h; a is the fifth constant, used to control the vertical height of the fitting curve in the second stage; w is the sixth constant, used to control the horizontal inclination of the fitting curve in the second stage.

[0076] According to the second relaxation stress time data, a and w can be fitted, and then the second relaxation stress model can be obtained. Figure 7 As shown, Figure 7 The horizontal axis in is nonlinear, and the fitting curves of the two stages are naturally connected.

[0077] S103: Predicting relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0078] Figure 8 : This is a relaxation stress prediction curve of R26 high temperature alloy bolts at 372MPa and 560℃ in the embodiment of the present invention. Figure 8 As shown in the figure, the prediction curve can accurately characterize the relaxation stress of R26 bolts with in-service hardness exceeding the standard.

[0079] Figure 1 The execution subject of the bolt-based relaxation stress prediction method shown can be a computer. Figure 1 As can be seen from the process shown, the bolt-based relaxation stress prediction method of the embodiment of the present invention first determines the corresponding relaxation stress model based on the comparison result of the working time and the demarcation time, and then predicts the relaxation stress based on the bolt's working time relaxation stress model, which can provide accurate quantitative guarantee for the safety of the bolt's extended service.

[0080] The specific flow of the embodiment of the present application is as follows:

[0081] 1. Constructing a relaxation stress time scatter diagram according to the historical relaxation stress data.

[0082] 2. Determining relaxation stress change rate time data according to the relaxation stress time scatter diagram.

[0083] 3. Determining the demarcation time according to the relaxation stress change rate time data and the change trend of the relaxation stress time scatter diagram.

[0084] 4. Dividing the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time.

[0085] 5. Creating a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data.

[0086] 6. Creating a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data.

[0087] 7. Obtaining the working time of the bolt, and determining the corresponding relaxation stress model according to the comparison result of the working time and the demarcation time.

[0088] 8. Predicting the relaxation stress according to the working time of the bolt and the relaxation stress model.

[0089] In summary, the relaxation stress prediction method based on a bolt according to the embodiment of the present application first determines the corresponding relaxation stress model according to the comparison result of the working time and the demarcation time, and then predicts the relaxation stress according to the working time of the bolt and the relaxation stress model, which can provide accurate quantitative guarantee for the safety of the bolt serving beyond the period.

[0090] Based on the same inventive concept, the embodiment of the present application also provides a relaxation stress prediction device based on a bolt. Since the principle of the device for solving the problem is similar to the relaxation stress prediction method based on a bolt, the implementation of the device can be referred to the implementation of the method, and the repeated parts will not be described here.

[0091] Figure 9 is the structural block diagram of the relaxation stress prediction device based on a bolt in the embodiment of the present application. As shown in Figure 9 , the relaxation stress prediction device based on a bolt comprises:

[0092] a working time module, configured to obtain the working time of the bolt;

[0093] a relaxation stress model module, configured to determine the corresponding relaxation stress model created based on the historical relaxation stress data according to the comparison result of the working time and the demarcation time;

[0094] The relaxation stress prediction module is configured to predict the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0095] In one embodiment, the method further comprises:

[0096] The relaxation stress time scatter plot module is configured to construct a relaxation stress time scatter plot according to historical relaxation stress data.

[0097] The demarcation time module is configured to determine the demarcation time according to the relaxation stress time scatter plot.

[0098] In one embodiment, the demarcation time module comprises:

[0099] The relaxation stress change rate time data unit is configured to determine relaxation stress change rate time data according to the relaxation stress time scatter plot.

[0100] The demarcation time unit is configured to determine the demarcation time according to the relaxation stress change rate time data and the change trend of the relaxation stress time scatter plot.

[0101] In one embodiment, the method further comprises:

[0102] The relaxation stress time data division module is configured to divide the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time.

[0103] The first relaxation stress model module is configured to create a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data.

[0104] The second relaxation stress model module is configured to create a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data.

[0105] In summary, the bolt-based relaxation stress prediction device according to the embodiments of the present application first determines the corresponding relaxation stress model according to the comparison result of the working time and the demarcation time, and then predicts the relaxation stress according to the working time of the bolt and the relaxation stress model, which can provide accurate quantitative guarantee for the safety of the over-service bolt.

[0106] Figure 10 This is a schematic block diagram of the system configuration of the electronic device 9600 according to the embodiments of the present application. As shown in the figure, the electronic device 9600 can include a central processor 9100 and a memory 9140; the memory 9140 is coupled to the central processor 9100. It is worth noting that the structure shown in the figure is exemplary; other types of structures can also be used to supplement or replace the structure to realize telecommunication functions or other functions. Figure 10 Figure 10

[0107] ​​In one embodiment, the function of the bolt-based relaxation stress prediction method can be integrated into the central processing unit 9100. The central processing unit 9100 can be configured to perform the following control:

[0108] Get the working time of the bolt;

[0109] Determine the corresponding relaxation stress model created based on historical relaxation stress data according to the comparison result between the working time and the demarcation time;

[0110] The relaxation stress is predicted based on the working time of the bolt and the corresponding relaxation stress model.

[0111] From the above description, it can be seen that the bolt-based relaxation stress prediction method provided in this application first determines the corresponding relaxation stress model based on the comparison results of the working time and the demarcation time, and then predicts the relaxation stress based on the bolt's working time relaxation stress model, which can provide accurate quantitative guarantee for the safety of the bolt's extended service.

[0112] In another embodiment, the bolt-based relaxation stress prediction device can be configured separately from the central processing unit 9100. For example, the bolt-based relaxation stress prediction device can be configured as a chip connected to the central processing unit 9100, and the function of the bolt-based relaxation stress prediction method can be realized through the control of the central processing unit.

[0113] like Figure 10 As shown, the electronic device 9600 may further include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Figure 10 In addition, the electronic device 9600 may also include all components shown in Figure 10 For components not shown, reference may be made to the prior art.

[0114] like Figure 10 As shown, the central processing unit 9100 is sometimes also referred to as a controller or operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0115] Memory 9140 can be, for example, one or more of a cache, flash memory, hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It can store the aforementioned failure-related information and also store programs that execute the relevant information. The CPU 9100 can execute the programs stored in memory 9140 to implement information storage or processing.

[0116] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is for supplying power to the electronic device 9600. The display 9160 is for displaying display objects such as images and characters. The display is, for example, an LCD display, but is not limited thereto.

[0117] The memory 9140 can be a solid-state memory such as a read only memory (ROM), a random access memory (RAM), a SIM card, and the like. It can also be a memory that retains information even when power is off, can be selectively erased, and is provided with more data, an example of which is sometimes referred to as an EPROM or the like. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 can include an application / function storage section 9142 for storing application programs and function programs or a flow for executing the operation of the electronic device 9600 by the central processing unit 9100.

[0118] The memory 9140 can also include a data storage section 9143 for storing data such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. A driver storage section 9144 of the memory 9140 can include various drivers of the electronic device for a communication function and / or for executing other functions of the electronic device such as a messaging application, an address book application, and the like.

[0119] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via an antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in the case of a conventional mobile communication terminal.

[0120] Based on different communication technologies, a plurality of communication modules 9110 can be provided in the same electronic device, such as a cellular network module, a Bluetooth module, and / or a wireless local area network module, and the like. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide audio output via the speaker 9131 and receive audio input from the microphone 9132, thereby implementing a conventional telecommunication function. The audio processor 9130 can include any suitable buffer, decoder, amplifier, and the like. In addition, the audio processor 9130 is also coupled to the central processing unit 9100, thereby enabling recording on the local device through the microphone 9132 and enabling playing of a sound stored on the local device through the speaker 9131.

[0121] The embodiment of the present application further provides a computer readable storage medium capable of realizing all steps of the bolt-based relaxation stress prediction method with the execution subject being the server or the client in the above embodiment, and the computer program is stored on the computer readable storage medium, and the computer program is executed by the processor to realize all steps of the bolt-based relaxation stress prediction method in the above embodiment, for example, the processor executes the computer program to realize the following steps:

[0122] obtaining the working time of the bolt;

[0123] determining the corresponding relaxation stress model created based on the historical relaxation stress data according to the comparison result of the working time and the boundary time;

[0124] predicting the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0125] In summary, the computer readable storage medium of the embodiment of the present application first determines the corresponding relaxation stress model according to the comparison result of the working time and the boundary time, and then predicts the relaxation stress according to the working time of the bolt and the relaxation stress model, which can provide accurate quantitative guarantee for the safety of the bolt serving beyond the period.

[0126] The embodiment of the present application further provides a computer program product capable of realizing all steps of the bolt-based relaxation stress prediction method with the execution subject being the server or the client in the above embodiment, and the computer program product comprises computer program / instruction, and the computer program / instruction is executed by the processor to realize all steps of the bolt-based relaxation stress prediction method in the above embodiment, for example, the processor executes the computer program to realize the following steps:

[0127] obtaining the working time of the bolt;

[0128] determining the corresponding relaxation stress model created based on the historical relaxation stress data according to the comparison result of the working time and the boundary time;

[0129] predicting the relaxation stress according to the working time of the bolt and the corresponding relaxation stress model.

[0130] In summary, the computer program product of the embodiment of the present application first determines the corresponding relaxation stress model according to the comparison result of the working time and the boundary time, and then predicts the relaxation stress according to the working time of the bolt and the relaxation stress model, which can provide accurate quantitative guarantee for the safety of the bolt serving beyond the period.

[0131] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are merely specific embodiments of the present application and are not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0132] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment mainly describes the difference from other embodiments. In particular, for the hardware+program type embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiment.

[0133] The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims can be performed in a different order than those described in the embodiments and still achieve desirable results. In addition, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.

[0134] Although the embodiments of the present application provide the method operation steps as described in the embodiments or flowcharts, more or fewer operation steps can be included based on conventional or non-inventive means. The order of steps listed in the embodiments is only one of the many execution orders of the steps, and does not represent the only execution order. When the device or terminal product is executed in practice, the method order shown in the embodiments or the drawings can be executed in sequence or in parallel (for example, in a parallel processor or a multi-thread processing environment, or even in a distributed data processing environment). The term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, product or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, product or equipment. Without more limitations, it does not exclude the presence of other same or equivalent elements in the process, method, product or equipment including the elements.

[0135] Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present embodiments.

[0136] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor, an application specific integrated circuit (ASIC), a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, but in the alternative, the general purpose processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

[0137] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is tangible. A storage medium can be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present embodiments. The various methods described herein can be implemented on a computer readable medium to provide a computer program product. The various methods described herein can be implemented as a routine embedded in a computer program product. The computer readable medium can include a computer readable storage medium to store or transfer the computer program product and a computer readable communication medium to transfer the computer program product. The computer storage medium can include volatile and non-volatile, removable and non-removable media implemented in a method or technology for storage and / or transfer of information such as computer readable instructions, data structures, program modules or other data. The computer storage medium can include, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store or transfer the computer program product and which can be read by a computer. Also, any connection is properly termed a computer readable medium. For example, if the computer readable medium is a modular, portable memory chip, a computer program embedded on the chip can be computer program product (with the program code) and the chip can be considered a computer readable medium. Alternatively, the computer readable medium can be paper or other suitable medium upon which the computer program is printed, as the ultimate object of computer

[0138] In one or more exemplary designs, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or other wire-based, fiber-based, or wireless technologies, then the coaxial cable, fiber optic cable, twisted pair, DSL, or other wire-based, fiber-based, or wireless technologies are included in the definition of computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, DVD, floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0139] Those skilled in the art will appreciate that embodiments of the present application can be devised for a method, a system, or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer readable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0140] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams box or blocks. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 means for carrying out each of the one or more functions specified in the flowchart illustrations and / or block diagrams.

[0141] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 The functions of a flow or multiple flows and / or a block or multiple blocks in conjunction with the disclosed methods can be implemented on practitioners' computers in computer software, firmware, hardware, or combinations of them. Figure 1

[0142] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow Figure 1 The functions of a flow or multiple flows and / or a block or multiple blocks in conjunction with the disclosed methods can be implemented on practitioners' computers in computer software, firmware, hardware, or combinations of them. Figure 1

[0143] The principles and implementations of the present application are described in the specific embodiments, the above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation and application range will be changed, and the above description should not be understood as the limitation of the present application.​​

Claims

1. A method for predicting relaxation stress of bolts, characterized in that: include: Get the working time of the bolt; Determining a corresponding relaxation stress model created based on historical relaxation stress data according to a comparison result between the working time and the demarcation time; Predicting relaxation stress according to the working time of the bolt and the corresponding relaxation stress model; The method further includes: constructing a relaxation stress time scatter plot based on the historical relaxation stress data; determining the demarcation time based on the relaxation stress time scatter plot; Determining the demarcation time according to the relaxation stress time scatter diagram includes: determining relaxation stress change rate time data according to the relaxation stress time scatter diagram; determining the demarcation time according to the relaxation stress change rate time data and the change trend of the relaxation stress time scatter diagram; The determining of the corresponding relaxation stress model created based on the historical relaxation stress data according to the comparison result of the working time and the demarcation time includes: when the working time is less than the demarcation time, the corresponding relaxation stress model is the first relaxation stress model; when the working time is greater than or equal to the demarcation time, the corresponding relaxation stress model is the second relaxation stress model; Also includes: dividing the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the demarcation time; Creating a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data; Creating a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data; The initial model of the first stress is as follows: ,t<t i ; in, is the relaxation stress, in MPa; is time, unit is h; is the demarcation time, in h; B is the relaxation stress at the end of the first stage, in MPa; is the first constant, is the second constant, is the third constant, is the fourth constant; The initial model of the second stress is as follows: ,t≥t i ; in, is the relaxation stress, in MPa; is time, unit is h; is the demarcation time, in h; is the fifth constant, used to control the vertical height of the fitting curve in the second stage; is the sixth constant, which is used to control the horizontal inclination of the fitting curve in the second stage.

2. A bolt-based relaxation stress prediction device, characterized in that: include: Working time module, used to obtain the working time of the bolt; A relaxation stress model module, configured to determine a corresponding relaxation stress model created based on historical relaxation stress data according to a comparison result between the working time and the demarcation time; a relaxation stress prediction module, configured to predict the relaxation stress according to the working time of the bolt and a corresponding relaxation stress model; The bolt-based relaxation stress prediction device further includes: a relaxation stress time scatter plot module, configured to construct a relaxation stress time scatter plot based on the historical relaxation stress data; and a demarcation time module, configured to determine the demarcation time based on the relaxation stress time scatter plot; The demarcation time module includes: a relaxation stress change rate time data unit, used to determine the relaxation stress change rate time data according to the relaxation stress time scatter plot; a demarcation time unit, used to determine the demarcation time according to the change trend of the relaxation stress change rate time data and the relaxation stress time scatter plot; The relaxation stress model module is specifically configured to: when the working time is less than the demarcation time, the corresponding relaxation stress model is the first relaxation stress model; when the working time is greater than or equal to the demarcation time, the corresponding relaxation stress model is the second relaxation stress model; Also includes: a relaxation stress time data division module, configured to divide the historical relaxation stress data into first relaxation stress time data and second relaxation stress time data according to the dividing time; A first relaxation stress model module, configured to create a first relaxation stress model according to a preset first stress initial model and the first relaxation stress time data; A second relaxation stress model module, configured to create a second relaxation stress model according to a preset second stress initial model and the second relaxation stress time data; The initial model of the first stress is as follows: ,t<t i ; in, is the relaxation stress, in MPa; is time, unit is h; is the dividing point time between the first and second stages of stress relaxation, in h; B is the relaxation stress at the end of the first stage, in MPa; is the first constant, is the second constant, is the third constant, is the fourth constant; The initial model of the second stress is as follows: ,t≥t i ; in, is the relaxation stress, in MPa; is time, unit is h; The dividing point time between the first and second stages of stress relaxation, in h; is the fifth constant, used to control the vertical height of the fitting curve in the second stage; is the sixth constant, which is used to control the horizontal inclination of the fitting curve in the second stage.

3. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the bolt-based relaxation stress prediction method according to claim 1 are implemented.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the bolt-based relaxation stress prediction method according to claim 1 are implemented.

5. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the bolt-based relaxation stress prediction method according to claim 1 are implemented.

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