A risk determination method and system based on engineering structure failure

Abstract

The present invention discloses a risk determination method and system based on engineering structure failure, which relates to the technical field of engineering risk determination, including using finite element software to establish an engineering geometric model of the engineering structure, providing a reliable basis for the subsequent evaluation of stress concentration factor and failure probability. The fatigue life of the engineering structure is evaluated according to the stress concentration factor, and the fatigue life of the entire engineering structure is generated by integrating information such as the stress concentration factor, the type of hazardous area, and the fatigue life of the hazardous area. The failure probability and failure hazard of each failure mode are evaluated, and an accurate failure probability is obtained by considering the correlation between the failure modes. The risk value of the failure mode of the engineering structure is generated based on the fatigue life, failure probability and failure hazard, and the influence of fatigue life on the risk of the engineering structure is added, thereby improving the accuracy and adaptability of the risk determination of the engineering structure failure, and ensuring the safe and stable operation of the engineering structure.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering risk determination, and in particular to a risk determination method and system based on engineering structure failure. Background Art

[0002] As the scale and complexity of engineering construction continue to expand, the risks faced by engineering structures in the design, construction and use process are also increasing. The failure of engineering structures may lead to serious casualties and property losses. Therefore, it is particularly important to accurately assess the risk of engineering structure failure. Traditional risk assessment methods often rely on experience and intuitive judgment, which lacks scientificity and accuracy. In order to more accurately assess the risk of engineering structure failure, it is necessary to introduce advanced mathematical models and assessment methods.

[0003] In the existing technology, the probability of failure of engineering structures is often only vaguely evaluated, and the specific failure mode and failure situation cannot be given, resulting in poor accuracy and adaptability in determining the failure risk of engineering structures, and it is impossible to accurately carry out targeted prevention and maintenance of engineering structures.

[0004] Therefore, how to analyze the specific failure conditions of engineering structures to improve the accuracy and adaptability of determining the failure risks of engineering structures is a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the prior art cannot analyze the specific failure conditions of engineering structures, resulting in poor accuracy and adaptability in determining the failure risk of engineering structures, and proposes a risk determination method based on engineering structure failure, which includes:

[0006] Collect multiple information of engineering structures and use finite element software to establish engineering geometry models of engineering structures;

[0007] Use engineering geometry models to screen out dangerous areas in engineering structures, calculate stress concentration factors in dangerous areas, and evaluate the fatigue life of engineering structures based on stress concentration factors;

[0008] Determine all failure modes of the engineering structure, analyze the correlation between the failure modes of the engineering structure, and evaluate the failure probability and failure severity of each failure mode;

[0009] The risk value of the failure mode of the engineering structure is generated based on fatigue life, failure probability and failure severity to describe the detailed information of the failure of the engineering structure.

[0010] In some embodiments of the present application, the engineering geometry model of the engineering structure is established using finite element software, including:

[0011] The multiple information of the engineering structure includes structural information and load information, and the initial engineering geometric model of the engineering structure is established according to the structural information;

[0012] Construct a load curve showing the load information changing with time, identify and mark the mutation points on the load curve, and record the curve segments between the mutation points as the curve segments to be analyzed;

[0013] The curve segments to be analyzed are classified according to their time lengths, and the standard deviation of each curve segment to be analyzed is calculated, thereby obtaining the standard deviation of each type of curve segment to be analyzed;

[0014] A plurality of points are evenly set on the curve segment to be analyzed to split the curve segment to be analyzed into a plurality of small curve segments, the average value of the slope change on each small curve segment is calculated, and the average value of the slope change of the complete curve segment to be analyzed is obtained after integrating the average values ​​of the slope change of all small curve segments, thereby obtaining the average value of the slope change of each type of curve segment to be analyzed;

[0015] The degree of change of each type of curve segment to be analyzed is generated by combining the standard deviation and the average value of the slope change of each type of curve segment to be analyzed, and the time scale of the load change is determined. In this way, the load time series is determined, the load spectrum parameters are configured, and the load spectrum is compiled;

[0016] The load spectrum is input into the initial engineering geometry model to form a dynamic engineering geometry model of the engineering structure.

[0017] In some embodiments of the present application, the load spectrum is input into the initial engineering geometry model, including:

[0018] The multiple information of engineering structures also includes the load information and response information of the structure;

[0019] Determine the load position and direction according to the load force information of the structure, determine the load action time according to the time of the load spectrum, and specify the load spectrum as the dynamic load in the initial engineering geometry model based on the load action position, direction and action time;

[0020] The first time step range and the second time step range are determined according to the variation of the load spectrum and the response information of the structure, respectively, and the intersection range of the first time step range and the second time step range is used as the time step of the initial engineering geometry model, so that the initial engineering geometry model can capture the changes in load and response.

[0021] In some embodiments of the present application, the dangerous areas in the engineering structure are screened out by the engineering geometry model, and the stress concentration factor of the dangerous areas is calculated, including:

[0022] The root mean square value of the dynamic load is taken as the static load, and static simulation and dynamic simulation are performed on the engineering geometric model through the static load and dynamic load, respectively, to obtain the stress cloud map and deformation map;

[0023] Analyze the stress cloud map and deformation map to identify areas with higher stress levels or stress change levels as dangerous areas in the engineering structure, and calculate the stress concentration factor based on the peak stress and nominal stress in the dangerous area.

[0024] In some embodiments of the present application, the fatigue life of an engineering structure is evaluated according to the stress concentration factor, including:

[0025] The dangerous area is divided into high-cycle fatigue area and low-cycle fatigue area according to the stress level, material yield strength and cycle number of the dangerous area;

[0026] For high cycle fatigue areas, the fatigue life of the area is estimated by combining the stress concentration factor and the nominal stress method;

[0027] For low cycle fatigue area, the fatigue life of the area is estimated by combining stress concentration factor and local stress method;

[0028] By using the engineering geometry model, multiple interacting hazardous areas are analyzed, and the interacting hazardous areas are recorded as associated area combinations, and the degree of influence of the interaction of the associated area combinations on the engineering structure is quantified;

[0029] The fatigue life of the engineering structure is evaluated by comprehensively considering the fatigue life of the high-cycle fatigue area, the fatigue life of the low-cycle fatigue area and the influence of the combination of related areas on the engineering structure; ;

[0030] in, is the fatigue life of the engineering structure, are the combined weights of the high cycle fatigue region and the low cycle fatigue region, are the numbers of high cycle fatigue region and low cycle fatigue region respectively, Respectively The high cycle fatigue region and The influence weight of each low cycle fatigue area on the engineering structure is Respectively The high cycle fatigue region and The fatigue life in the low cycle fatigue region is is the number of associated region combinations, For the The influence weight of the associated area combination on the engineering structure, For the The degree of influence of the combination of associated regions on the engineering structure. is a preset constant.

[0031] In some embodiments of the present application, analyzing the correlation between failure modes of engineering structures includes:

[0032] Two tree diagrams, FTA and ETA, of the failure modes of engineering structures are established respectively, and the correlation between the failure modes of engineering structures is found out by comparing the two tree diagrams.

[0033] In some embodiments of the present application, the failure probability and failure severity of each failure mode are evaluated, including:

[0034] Based on the data of the engineering geometry model, the original failure probability of each failure mode of the engineering structure is calculated by a preset probability algorithm;

[0035] The original failure probability is adjusted through the correlation between failure modes to obtain the failure probability of each failure mode, and then the failure hazard of each failure mode is analyzed.

[0036] In some embodiments of the present application, the risk value of the failure mode of the engineering structure is generated based on the fatigue life, failure probability and failure severity, including:

[0037] Set the baseline fatigue life of each failure mode of the engineering structure, and generate the risk value of the failure mode of the engineering structure based on the baseline fatigue life, fatigue life, failure probability and failure hazard; ;

[0038] in, For engineering structure The risk value of each failure mode, For engineering structure The failure probability of a failure mode, For engineering structure The failure severity of each failure mode, For the The baseline fatigue life of each failure mode is For the The current fatigue life of each failure mode, For the An adjustment function of the ratio of the baseline fatigue life to the current fatigue life of a failure mode.

[0039] Correspondingly, the present application also provides a risk determination system based on engineering structure failure, comprising:

[0040] The first module is used to collect multiple information of the engineering structure and establish the engineering geometry model of the engineering structure using finite element software;

[0041] The second module is used to screen out dangerous areas in engineering structures through engineering geometric models, calculate the stress concentration factor of dangerous areas, and evaluate the fatigue life of engineering structures based on the stress concentration factor;

[0042] The third module is used to determine all failure modes of the engineering structure, analyze the correlation between the failure modes of the engineering structure, and evaluate the failure probability and failure severity of each failure mode;

[0043] The fourth module is used to generate risk values ​​of engineering structure failure modes based on fatigue life, failure probability and failure severity, so as to describe detailed information of engineering structure failure.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. Use finite element software to establish the engineering geometry model of the engineering structure, accurately consider the influence of the load on the engineering structure, and provide a reliable basis for the subsequent evaluation of stress concentration factor and failure probability.

[0046] 2. Evaluate the fatigue life of the engineering structure according to the stress concentration factor, and generate the fatigue life of the entire engineering structure by integrating information such as the stress concentration factor, the type of hazardous area, and the fatigue life of the hazardous area, thereby improving the stability of fatigue life analysis. Analyze the correlation between the failure modes of the engineering structure, evaluate the failure probability and failure hazard of each failure mode, and consider the correlation between the failure modes to obtain an accurate failure probability. Generate the risk value of the failure mode of the engineering structure based on fatigue life, failure probability, and failure hazard, and add the impact of fatigue life on the risk of the engineering structure, thereby improving the accuracy and adaptability of the risk determination of the engineering structure failure and ensuring the safe and stable operation of the engineering structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a process of a risk determination method based on engineering structure failure proposed by the present invention;

[0048] Figure 2 A schematic diagram of the structure of a risk determination system based on engineering structure failure proposed by the present invention;

[0049] Figure 3 This is an experimental data diagram of the relationship between the stress concentration factor and fatigue life at a certain position under the engineering structure in a risk determination method based on engineering structure failure proposed by the present invention;

[0050] Figure 4 This is an experimental data diagram of the relationship between stress concentration factors of different dangerous areas of an engineering structure in a risk determination method based on engineering structure failure proposed by the present invention;

[0051] Figure 5 This is an experimental data diagram of the relationship between failure probability and risk value in failure mode 1 in a risk determination method based on engineering structure failure proposed by the present invention;

[0052] Figure 6 This is an experimental data diagram of the relationship between failure probability and risk value in failure mode 2 in a risk determination method based on engineering structure failure proposed by the present invention;

[0053] Figure 7 This is an experimental data diagram of the relationship between failure probability and risk value under failure mode 3 in a risk determination method based on engineering structure failure proposed by the present invention. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0055] Reference Figure 1 , a risk determination method based on engineering structure failure, comprising the following steps,

[0056] Step S101, collecting multiple information of the engineering structure, and establishing an engineering geometric model of the engineering structure using finite element software.

[0057] In this embodiment, the multiple information includes geometric dimensions, material properties, connection methods, loads and other related information. Sensors and monitoring systems are used to collect real-time load data of the engineering structure during use, such as the flow of people and vehicles on the bridge, wind loads on buildings, etc.

[0058] In this embodiment, a detailed geometric model is constructed in the finite element software based on the collected engineering structure information. Ensure that the geometric dimensions, material properties, connection methods, etc. of the model are consistent with the actual engineering structure to improve the accuracy of the analysis results. Meshing, meshing the geometric model, and selecting appropriate unit types and sizes to ensure the accuracy of the analysis results and computational efficiency. In dangerous areas and stress concentration areas, finer grids are used for division to more accurately capture stress distribution and deformation. Boundary conditions and load application, set reasonable boundary conditions and loads according to the actual use of the engineering structure. The collected dynamic load data (such as pedestrian and vehicle traffic loads) are applied to the finite element model in the form of a time series to simulate the dynamic response of the engineering structure during actual use.

[0059] It should be noted that the use of finite element software to establish an engineering geometric model of an engineering structure is mainly to consider the load conditions that affect the engineering structure. Because the load is always in a state of dynamic change, it is necessary to consider the load changes to simulate the response of the engineering structure to it.

[0060] In some embodiments of the present application, the engineering geometry model of the engineering structure is established using finite element software, including:

[0061] The multiple information of the engineering structure includes structural information and load information, and the initial engineering geometric model of the engineering structure is established according to the structural information;

[0062] Construct a load curve showing the load information changing with time, identify and mark the mutation points on the load curve, and record the curve segments between the mutation points as the curve segments to be analyzed;

[0063] The curve segments to be analyzed are classified according to their time lengths, and the standard deviation of each curve segment to be analyzed is calculated, thereby obtaining the standard deviation of each type of curve segment to be analyzed;

[0064] A plurality of points are evenly set on the curve segment to be analyzed to split the curve segment to be analyzed into a plurality of small curve segments, the average value of the slope change on each small curve segment is calculated, and the average value of the slope change of the complete curve segment to be analyzed is obtained after integrating the average values ​​of the slope change of all small curve segments, thereby obtaining the average value of the slope change of each type of curve segment to be analyzed;

[0065] The degree of change of each type of curve segment to be analyzed is generated by combining the standard deviation and the average value of the slope change of each type of curve segment to be analyzed, and the time scale of the load change is determined. In this way, the load time series is determined, the load spectrum parameters are configured, and the load spectrum is compiled;

[0066] The load spectrum is input into the initial engineering geometry model to form a dynamic engineering geometry model of the engineering structure.

[0067] In this embodiment, the time scale can be selected according to the load changes under different time lengths to simulate the dynamic load. This selection process should comprehensively consider the need for the significance of the load change. Selecting a time scale with small changes (relatively stable time size) can reflect the long-term cumulative effect of the load, which is of great significance for evaluating the long-term performance and service life of the bridge.

[0068] In this embodiment, classifying the curve segments to be analyzed according to the time length of the curve segments to be analyzed means that the curve segments with similar or close time lengths are divided into the same type of curve segments to be analyzed. On the load change curve graph, the mutation point indicates that the load changes significantly in a short period of time. Analyze the time period between the mutation points and filter out the time scale with smaller changes, which can be used as a time scale. The mutation point can be identified by a differential method or a change point detection method. The degree of change is described by the stability of two types of changes, the standard deviation of each type of curve segment to be analyzed and the average value of the slope change, and the time length of the curve segment to be analyzed with the smallest degree of change is used as the time scale. Construct a load time series to reflect the change law of the load over time under a stable state. The load spectrum should include key parameters such as the amplitude, frequency, and duration of the load, and compile the load spectrum based on the load time series. The load spectrum should include key parameters such as the amplitude, frequency, and duration of the load. Use statistical methods or empirical formulas to determine the parameters of the load spectrum to ensure its accuracy and applicability.

[0069] In some embodiments of the present application, the load spectrum is input into the initial engineering geometry model, including:

[0070] The multiple information of engineering structures also includes the load information and response information of the structure;

[0071] Determine the load position and direction according to the load force information of the structure, determine the load action time according to the time of the load spectrum, and specify the load spectrum as the dynamic load in the initial engineering geometry model based on the load action position, direction and action time;

[0072] The first time step range and the second time step range are determined according to the variation of the load spectrum and the response information of the structure, respectively, and the intersection range of the first time step range and the second time step range is used as the time step of the initial engineering geometry model, so that the initial engineering geometry model can capture the changes in load and response.

[0073] In this embodiment, the load force information of the structure is the force of the load on the engineering structure, and the response information of the structure is the response characteristics of the structure, such as natural frequency and damping ratio. When the load is input into the model of the finite element software, the action position: determine the positions where the load should be applied based on the actual force conditions of the bridge or structure. Direction: The direction of the load should be consistent with the actual situation, for example, the vertical load generated by vehicle driving, the horizontal direction of wind load, etc. Action time: Each load in the load spectrum has its specific action time, ensure that these time parameters are accurately set in the model. Dynamic loads are usually defined by load spectra. The load spectrum is a sequence that describes the load size, direction, and action position that changes with time. In the finite element software, import the compiled load spectrum and specify it as the dynamic load in the model.

[0074] In this embodiment, the time step should be set according to the load conditions to capture the rapid changes in load and response, which is crucial to ensure the accuracy of the simulation. A time step that is too small will excessively increase computing time and resources, and a time step that is too large will make it difficult to accurately capture the rapid changes in load and response, so it is important to choose a suitable time step. The first time step range and the second time step range are determined according to the degree of change of the load spectrum and the response information of the structure, respectively, which means that the load changes: if the load changes very quickly, a smaller time step needs to be selected. Response characteristics: Consider the response characteristics of the structure, such as natural frequency and damping ratio, to ensure that the time step can accurately capture these characteristics. The time step that satisfies both is used as the time step of the model.

[0075] It is understood that the time step is a parameter used to control the time progression of the solution process in finite element analysis. It determines the actual length of time represented by each calculation step in the simulation. In dynamic analysis, the choice of time step is crucial because it directly affects whether the simulation can accurately capture the rapid changes in structural response and the stability of the numerical solution.

[0076] Step S102, screening out dangerous areas in the engineering structure through the engineering geometry model, calculating the stress concentration factor of the dangerous area, and evaluating the fatigue life of the engineering structure according to the stress concentration factor.

[0077] In this embodiment, static analysis and dynamic analysis are performed on the finite element model to calculate the stress distribution and deformation of the engineering structure under different loads. Through the analysis results, areas with high stress levels or high changes in stress levels are screened out as dangerous areas. These areas are usually weak links in the structure, such as welding points, connection points, and hole edges. The stress concentration factor is the ratio of the peak stress (σmax) to the nominal stress (or average stress, σnom). According to the calculated stress concentration factor K, the stress concentration level in the dangerous area is evaluated. Generally, the larger the K value, the higher the stress concentration level, and the greater the risk of failure of the structure in this area.

[0078] In some embodiments of the present application, the dangerous areas in the engineering structure are screened out by the engineering geometry model, and the stress concentration factor of the dangerous areas is calculated, including:

[0079] The root mean square value of the dynamic load is taken as the static load, and static simulation and dynamic simulation are performed on the engineering geometric model through the static load and dynamic load, respectively, to obtain the stress cloud map and deformation map;

[0080] Analyze the stress cloud map and deformation map to identify areas with higher stress levels or stress change levels as dangerous areas in the engineering structure, and calculate the stress concentration factor based on the peak stress and nominal stress in the dangerous area.

[0081] In this embodiment, the dynamic load is known, and the static load is set by considering the equivalent static effect of the dynamic load, and its peak value or root mean square value can be used as the equivalent static load. Static load refers to a force whose size, direction and point of action do not change over time on the structure. When selecting a static load, it is necessary to consider various constant loads that the structure may bear in actual use, such as gravity, pressure, tension, etc. According to the purpose and design specifications of the structure, the size, direction and point of action of the static load are determined. Static analysis is performed using finite element analysis software. The stress distribution and deformation of the structure under the action of static load are calculated. Results such as stress cloud maps and deformation maps are obtained for subsequent analysis. Dynamic load refers to a force whose size, direction or point of action changes over time on the structure. Dynamic analysis is performed using finite element analysis software. The stress distribution and deformation of the structure under the action of dynamic load are calculated over time. Results such as stress time history curves and deformation time history curves are obtained for subsequent analysis.

[0082] The stress cloud diagram and deformation diagram here include the stress time history curve and deformation time history curve of the dynamic load results.

[0083] In some embodiments of the present application, the fatigue life of an engineering structure is evaluated according to the stress concentration factor, including:

[0084] The dangerous area is divided into high-cycle fatigue area and low-cycle fatigue area according to the stress level, material yield strength and cycle number of the dangerous area;

[0085] For high cycle fatigue areas, the fatigue life of the area is estimated by combining the stress concentration factor and the nominal stress method;

[0086] For low cycle fatigue area, the fatigue life of the area is estimated by combining stress concentration factor and local stress method;

[0087] By using the engineering geometry model, multiple interacting hazardous areas are analyzed, and the interacting hazardous areas are recorded as associated area combinations, and the degree of influence of the interaction of the associated area combinations on the engineering structure is quantified;

[0088] The fatigue life of the engineering structure is evaluated by comprehensively considering the fatigue life of the high-cycle fatigue area, the fatigue life of the low-cycle fatigue area and the influence of the combination of related areas on the engineering structure; ;

[0089] in, is the fatigue life of the engineering structure, are the combined weights of the high cycle fatigue region and the low cycle fatigue region, are the numbers of high cycle fatigue region and low cycle fatigue region respectively, Respectively The high cycle fatigue region and The influence weight of each low cycle fatigue area on the engineering structure is Respectively The high cycle fatigue region and The fatigue life in the low cycle fatigue region is is the number of associated region combinations, For the The influence weight of the associated area combination on the engineering structure, For the The degree of influence of the combination of associated regions on the engineering structure. is a preset constant.

[0090] In this embodiment, the dangerous area is divided into a high-cycle fatigue area and a low-cycle fatigue area by the stress level, material yield strength and number of cycles in the dangerous area. High-cycle fatigue (HCF) refers to fatigue damage that occurs when a material undergoes a large number of cycles (usually more than 105 cycles) at a stress level lower than its yield strength. The stress level is low, usually lower than the yield strength of the material. The number of cycles is large, and the material is subjected to cyclic loads for a long time. The failure form is mostly brittle fracture, and features such as fatigue stripes often appear on the fracture. Low-cycle fatigue (LCF) refers to fatigue damage that occurs when a material undergoes fewer cycles (usually between 104 cycles) at a stress level close to or exceeding its yield strength. The stress level is high, close to or exceeding the yield strength of the material. The number of cycles is small, and the material is subjected to a large cyclic load in a short time. The failure form is mostly plastic deformation and fracture, and obvious plastic deformation features often appear on the fracture.

[0091] The nominal stress method is applicable to high cycle fatigue and is based on the SN curve (stress-life curve) of the material or part. It assumes that the structure works under a uniform stress state, but in fact there are often stress concentration areas (dangerous areas) in the structure. The nominal stress is multiplied by the stress concentration factor K to obtain the actual stress. The corrected actual stress is used in combination with the SN curve of the material to estimate the fatigue life of the structure.

[0092] The local stress-strain method is suitable for low-cycle fatigue. It is based on the ε-N curve (strain-life curve) of the material and focuses on the local stress and strain state of the structure in the stress concentration area. Through finite element analysis, the nominal stress distribution of the structure under a specific load is obtained. Then, the stress concentration factor K in the stress concentration area is calculated. Using the stress concentration factor K, the nominal stress is converted into local stress. Combined with the ε-N curve of the material and the local stress-strain history, the fatigue life of the structure is estimated.

[0093] In this embodiment, when integrating the fatigue life of high-cycle fatigue areas and low-cycle fatigue areas, it is necessary to consider the interaction between them and their contribution to the overall fatigue life of the structure. This interaction may be manifested as fatigue damage in one area triggering a chain reaction in other areas, or mutual influence between various areas when subjected to loads. Through finite element analysis of the relative position relationship of each dangerous area in the structure, possible interaction paths are identified. Consider how fatigue damage in one area affects the stress distribution and stress state of adjacent areas or the entire structure. Evaluate the impact of this interaction on the overall fatigue life of the structure. Quantify the specific impact of the interaction on the overall fatigue life of the structure. It is possible to consider using methods such as multi-axis fatigue analysis and fatigue crack propagation analysis to more accurately evaluate the fatigue life of the structure under complex stress states.

[0094] Understandably, The correction of the relative average of the fatigue life in the high-cycle fatigue region and the fatigue life in the low-cycle fatigue region by multiple interacting hazard regions, Represents a constant used to balance the size of this correction value.

[0095] Step S103, determining all failure modes of the engineering structure, analyzing the correlation between the failure modes of the engineering structure, and evaluating the failure probability and failure criticality of each failure mode.

[0096] In this embodiment, all possible failure modes of the engineering structure are identified through literature review, experimental testing, and expert consultation. Failure modes may include various types such as material fatigue, fracture, corrosion, wear, and deformation. Fault tree analysis (FTA), event tree analysis (ETA) and other methods are used to analyze the correlation between failure modes of engineering structures. Determine which failure modes are independent of each other, which are interrelated, and the causal relationship and transmission path between them.

[0097] In some embodiments of the present application, analyzing the correlation between failure modes of engineering structures includes:

[0098] Two tree diagrams, FTA and ETA, of the failure modes of engineering structures are established respectively, and the correlation between the failure modes of engineering structures is found out by comparing the two tree diagrams.

[0099] In this embodiment, a fault tree is constructed, and the top event is set as the overall failure of the engineering structure. Decompose layer by layer to find out all the basic events (i.e., failure modes) that lead to the top event. Analyze the logical relationships between basic events, such as "and" and "or" relationships. Output a fault tree diagram to clearly show the causal relationship and transmission path between failure modes. Starting from the initial event (such as the occurrence of a certain failure mode), build an event tree, analyze the subsequent events that may be triggered by the initial event and their probabilities, and evaluate the severity and possibility of different consequences. Output an event tree diagram to show the possible evolution paths and consequences after the failure mode occurs. Compare the outputs of FTA and ETA, find out the failure modes that are interrelated or causally related, and analyze the transmission paths and mutual influences between these failure modes. The correlation matrix or chart clearly shows which failure modes are independent of each other and which are interrelated.

[0100] In some embodiments of the present application, the failure probability and failure severity of each failure mode are evaluated, including:

[0101] Based on the data of the engineering geometry model, the original failure probability of each failure mode of the engineering structure is calculated by a preset probability algorithm;

[0102] The original failure probability is adjusted through the correlation between failure modes to obtain the failure probability of each failure mode, and then the failure hazard of each failure mode is analyzed.

[0103] In this embodiment, although the finite element model itself does not directly calculate the failure probability, it can provide key data for the calculation of the failure probability. For example, through finite element analysis, the stress, strain and other responses of the structure under different working conditions can be obtained, and then the reliability of the structure can be evaluated in combination with the performance data of the material (such as strength, toughness, etc.). On this basis, the failure probability can be further calculated by combining statistical methods and reliability theory (such as Monte Carlo simulation, first-order second moment method, etc.). The adjustment method may include multiplication adjustment (such as multiplying the original failure probability by an associated factor), addition adjustment (such as adding an associated increment to the original failure probability), etc. For each failure mode, according to its associated relationship and other influencing factors, the original failure probability is adjusted by a determined adjustment method.

[0104] Step S104: generating a risk value of the engineering structure failure mode based on the fatigue life, failure probability and failure criticality, so as to describe detailed information of the engineering structure failure.

[0105] In some embodiments of the present application, the risk value of the failure mode of the engineering structure is generated based on the fatigue life, failure probability and failure severity, including:

[0106] Set the baseline fatigue life of each failure mode of the engineering structure, and generate the risk value of the failure mode of the engineering structure based on the baseline fatigue life, fatigue life, failure probability and failure hazard; ;

[0107] in, For engineering structure The risk value of each failure mode, For engineering structure The failure probability of a failure mode, For engineering structure The failure severity of each failure mode, For the The baseline fatigue life of each failure mode is For the The current fatigue life of each failure mode, For the An adjustment function of the ratio of the baseline fatigue life to the current fatigue life of a failure mode.

[0108] In this embodiment, the fatigue life of the engineering structure will affect the risk. The risk value of each failure mode is obtained by considering the fatigue life. represents the original risk value, Indicates the relative situation of fatigue life to correct the original risk value, The larger the value, The value of the output adjustment function (the larger the adjustment factor), is proportional, and vice versa.

[0109] The experimental data proves the following:

[0110] Tables and graphs of data simulation experiments are given on the relationship between the stress concentration factor and fatigue life at a certain position of the engineering structure, the relationship between the stress concentration factors in different dangerous areas of the engineering structure, and the relationship between the failure probability and the risk value.

[0111] Stress concentration factor (Kt) Fatigue life (number of cycles) 1.0 100200 1.5 80300 2.0 60040 2.5 45060 3.0 35050 3.5 28070 4.0 22080 4.5 18090 5.0 14060 5.5 11060 6.0 8560 6.5 6860 7.0 5270 7.5 4080 8.0 3030

[0112] Area code horizontal Stress concentration factor (Kt) longitudinal 1Welding point A1 2.5 2Welding point A2 3.0 3 welding point A3 2.8 4 welding point A4 3.5 5 welding point A5 2.2 6 welding point A6 3.2 7 welding point A7 2.9 8Connection point B1 3.8 9Connection point B2 2.6 10Connection point B3 3.4 11Connection point B4 2.7 12 Connection point B5 3.6 13 Connection point B6 2.4 14 Hole edge C1 3.3 15 Hole edge C2 3.1

[0113] Failure probability (%) Value at Risk 2 10 5 20 8 35 11 55 14 80 17 110 20 150 23 200 26 260 29 330

[0114] Failure probability Value at Risk 1 10 3 18 5 28 7 39 11 55 13 65 17 80 19 92 23 110 27 130 29 145 31 160 33 175 35 195 37 215

[0115] Failure probability Value at Risk 2 10 6 18 10 28 15 40 20 55 25 72 30 92 35 115 38 138 40 160 41 185 41.5 205 42 230 42.2 250 42.5 275

[0116] Correspondingly, the present application also provides a risk determination system based on engineering structure failure, comprising:

[0117] The first module is used to collect multiple information of the engineering structure and establish the engineering geometry model of the engineering structure using finite element software;

[0118] The second module is used to screen out dangerous areas in engineering structures through engineering geometric models, calculate the stress concentration factor of dangerous areas, and evaluate the fatigue life of engineering structures based on the stress concentration factor;

[0119] The third module is used to determine all failure modes of the engineering structure, analyze the correlation between the failure modes of the engineering structure, and evaluate the failure probability and failure severity of each failure mode;

[0120] The fourth module is used to generate risk values ​​of engineering structure failure modes based on fatigue life, failure probability and failure severity, so as to describe detailed information of engineering structure failure.

[0121] Compared with the prior art, the present invention has the following beneficial effects:

[0122] 1. Use finite element software to establish the engineering geometry model of the engineering structure, accurately consider the influence of the load on the engineering structure, and provide a reliable basis for the subsequent evaluation of stress concentration factor and failure probability.

[0123] 2. Evaluate the fatigue life of the engineering structure according to the stress concentration factor, and generate the fatigue life of the entire engineering structure by integrating information such as the stress concentration factor, the type of hazardous area, and the fatigue life of the hazardous area, thereby improving the stability of fatigue life analysis. Analyze the correlation between the failure modes of the engineering structure, evaluate the failure probability and failure hazard of each failure mode, and consider the correlation between the failure modes to obtain an accurate failure probability. Generate the risk value of the failure mode of the engineering structure based on fatigue life, failure probability, and failure hazard, and add the impact of fatigue life on the risk of the engineering structure, thereby improving the accuracy and adaptability of the risk determination of the engineering structure failure and ensuring the safe and stable operation of the engineering structure.

[0124] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or by software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present invention.

[0125] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present invention.

[0126] Those skilled in the art will appreciate that the modules in the system in the implementation scenario can be distributed in the system of the implementation scenario according to the implementation scenario description, or can be changed accordingly and located in one or more systems different from the implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple sub-modules.

[0127] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A risk determination method based on engineering structure failure, characterized in that: include, Collect multiple information of engineering structures and use finite element software to establish engineering geometry models of engineering structures; Use engineering geometry models to screen out dangerous areas in engineering structures, calculate stress concentration factors in dangerous areas, and evaluate the fatigue life of engineering structures based on stress concentration factors; Determine all failure modes of the engineering structure, analyze the correlation between the failure modes of the engineering structure, and evaluate the failure probability and failure severity of each failure mode; Generate risk values ​​of engineering structure failure modes based on fatigue life, failure probability and failure severity to describe detailed information of engineering structure failure; in, Calculate the stress concentration factor based on the peak stress and nominal stress in the hazardous area; Evaluate the fatigue life of engineering structures based on stress concentration factors, including: The dangerous area is divided into high-cycle fatigue area and low-cycle fatigue area according to the stress level, material yield strength and cycle number of the dangerous area; For high cycle fatigue areas, the fatigue life of the area is estimated by combining the stress concentration factor and the nominal stress method; For low cycle fatigue area, the fatigue life of the area is estimated by combining stress concentration factor and local stress method; By using the engineering geometry model, multiple interacting hazardous areas are analyzed, and the interacting hazardous areas are recorded as associated area combinations, and the degree of influence of the interaction of the associated area combinations on the engineering structure is quantified; The fatigue life of the engineering structure is evaluated by comprehensively considering the fatigue life of the high-cycle fatigue area, the fatigue life of the low-cycle fatigue area and the influence of the combination of related areas on the engineering structure; ； in, is the fatigue life of the engineering structure, are the combined weights of the high cycle fatigue region and the low cycle fatigue region, are the numbers of high cycle fatigue region and low cycle fatigue region respectively, Respectively The high cycle fatigue region and The influence weight of each low cycle fatigue area on the engineering structure is Respectively The high cycle fatigue region and The fatigue life in the low cycle fatigue region is is the number of associated region combinations, For the The influence weight of the associated area combination on the engineering structure, For the The degree of influence of the combination of associated regions on the engineering structure. is a preset constant; Generate risk values ​​for engineering structure failure modes based on fatigue life, failure probability and failure severity, including: Set the baseline fatigue life of each failure mode of the engineering structure, and generate the risk value of the failure mode of the engineering structure based on the baseline fatigue life, fatigue life, failure probability and failure hazard; ; in, For engineering structure The risk value of each failure mode, For engineering structure The failure probability of a failure mode, For engineering structure The failure severity of each failure mode, For the The baseline fatigue life of each failure mode is For the The current fatigue life of each failure mode, For the An adjustment function of the ratio of the baseline fatigue life to the current fatigue life of a failure mode.

2. The risk determination method based on engineering structure failure according to claim 1 is characterized in that: Use finite element software to build engineering geometry models of engineering structures, including, The multiple information of the engineering structure includes structural information and load information, and the initial engineering geometric model of the engineering structure is established according to the structural information; Construct a load curve showing the load information changing with time, identify and mark the mutation points on the load curve, and record the curve segments between the mutation points as the curve segments to be analyzed; The curve segments to be analyzed are classified according to their time lengths, and the standard deviation of each curve segment to be analyzed is calculated, thereby obtaining the standard deviation of each type of curve segment to be analyzed; A plurality of points are evenly set on the curve segment to be analyzed to split the curve segment to be analyzed into a plurality of small curve segments, the average value of the slope change on each small curve segment is calculated, and the average value of the slope change of the complete curve segment to be analyzed is obtained after integrating the average values ​​of the slope change of all small curve segments, thereby obtaining the average value of the slope change of each type of curve segment to be analyzed; The degree of change of each type of curve segment to be analyzed is generated by combining the standard deviation and the average value of the slope change of each type of curve segment to be analyzed, and the time scale of the load change is determined. In this way, the load time series is determined, the load spectrum parameters are configured, and the load spectrum is compiled; The load spectrum is input into the initial engineering geometry model to form a dynamic engineering geometry model of the engineering structure.

3. The risk determination method based on engineering structure failure according to claim 2 is characterized in that: Input the load spectrum into the initial engineering geometry model, including, The multiple information of engineering structures also includes the load information and response information of the structure; Determine the load position and direction according to the load force information of the structure, determine the load action time according to the time of the load spectrum, and specify the load spectrum as the dynamic load in the initial engineering geometry model based on the load action position, direction and action time; The first time step range and the second time step range are determined according to the variation of the load spectrum and the response information of the structure, respectively, and the intersection range of the first time step range and the second time step range is used as the time step of the initial engineering geometry model, so that the initial engineering geometry model can capture the changes in load and response.

4. The risk determination method based on engineering structure failure according to claim 3 is characterized in that: Through the engineering geometry model, dangerous areas in the engineering structure are screened out and the stress concentration factor of the dangerous area is calculated, including: The root mean square value of the dynamic load is taken as the static load, and static simulation and dynamic simulation are performed on the engineering geometric model through the static load and dynamic load, respectively, to obtain the stress cloud map and deformation map; Analyze stress contours and deformation diagrams to identify areas with higher stress levels or stress variation levels as dangerous areas in engineering structures.

5. The risk determination method based on engineering structure failure according to claim 1 is characterized in that: Analyze the relationship between the failure modes of engineering structures, including: Two tree diagrams, FTA and ETA, of the failure modes of engineering structures are established respectively, and the correlation between the failure modes of engineering structures is found out by comparing the two tree diagrams.

6. The risk determination method based on engineering structure failure according to claim 5 is characterized in that: And evaluate the failure probability and failure severity of each failure mode, including, Based on the data of the engineering geometry model, the original failure probability of each failure mode of the engineering structure is calculated by a preset probability algorithm; The original failure probability is adjusted through the correlation between failure modes to obtain the failure probability of each failure mode, and then the failure hazard of each failure mode is analyzed.

7. A risk determination system based on engineering structure failure, characterized in that: Used to implement the risk determination method based on engineering structure failure as described in any one of claims 1 to 6, the system comprises: The first module is used to collect multiple information of the engineering structure and establish the engineering geometry model of the engineering structure using finite element software; The second module is used to screen out dangerous areas in engineering structures through engineering geometric models, calculate the stress concentration factor of dangerous areas, and evaluate the fatigue life of engineering structures based on the stress concentration factor; The third module is used to determine all failure modes of the engineering structure, analyze the correlation between the failure modes of the engineering structure, and evaluate the failure probability and failure severity of each failure mode; The fourth module is used to generate risk values ​​of engineering structure failure modes based on fatigue life, failure probability and failure severity, so as to describe detailed information of engineering structure failure.

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