22 results about "Reliability theory" patented technology

The invention relates to the technical field of unmanned aerial vehicle design, in particular to an unmanned aerial vehicle propeller definite reliability modeling method and system, a medium and a program product. The method comprises the following steps: firstly, constructing a demand model, a system context, a use case and an activity diagram of an unmanned aerial vehicle propeller based on SysML, and defining a mathematical function relationship of core performance parameters such as thrust, torque and rotating speed; then statistical fitting is carried out in combination with experimental data, a joint performance margin equation is constructed, a definite reliability theory is introduced, and the reliability value of the propeller is calculated through a standard normal cumulative distribution function; and finally, carrying out constraint binding on the constraint equation and the system structure model to realize dynamic response and model linkage under parameter change. According to the method, integration of reliability analysis in the MBSE model is realized, and the automation degree, the evaluation precision and the engineering application efficiency of reliability modeling of the propeller system are remarkably improved.

The invention discloses a wall surface falling risk assessment method, device and equipment and a storage medium, and relates to the technical field of building safety assessment, and the method comprises the steps: calculating a wall surface initial resistance value based on outer wall hyperspectral image data and a regression prediction model; calculating wall surface structure resistance according to the wall surface initial resistance value and a reduction coefficient corresponding to the wall surface initial resistance value, wherein the reduction coefficient is used for representing the inherent defect of the outer wall; simulating a structural load borne by the wall surface structure through a finite element agent model based on machine learning; and based on the structure load and the wall surface structure resistance, the wall surface falling risk probability is calculated through a Monte Carlo numerical simulation method by applying the structure reliability theory. The hyperspectral image can comprehensively capture the defect characteristics of the outer wall, and the initial resistance value is quantified by combining the regression model to supplement the traditional detection blind area. The reduction coefficient is used for associating inherent defects, the finite element agent model dynamically predicts the load to quantify the dynamic environment influence, and the comprehensiveness of wall falling risk identification is improved.

The embodiment of the invention discloses a calculation method and device for the time-varying failure probability of a hydrogen conveying pipeline with corrosion defects, and the method comprises the steps: building a pipeline limit state equation based on a reliability theory through a hydrogen-induced damage factor, and the pipeline limit state equation comprises a pipeline leakage limit state equation and a pipeline burst limit state equation; solving the pipeline limit state equation to obtain a failure probability corresponding to each defect in the pipeline; determining a target equivalent unit normal vector based on the linear limit state function of the pipeline; the linear limit state function is constructed based on the failure probability corresponding to each defect of the pipeline; and determining the time-varying failure probability of the pipeline according to the target equivalent unit normal vector, wherein the time-varying failure probability comprises the leakage failure probability of the pipeline in the set time and the burst failure probability of the pipeline in the set time. According to the technical scheme, rapid and efficient calculation of the time-varying failure probability of the hydrogen-doped natural gas pipeline containing the corrosion defect is achieved, and the method has important significance in guaranteeing pipeline safety.

This invention discloses a random field probability prediction method for long-term settlement of shield tunnels in heterogeneous strata, belonging to the field of underground engineering structural health monitoring and risk assessment. The method first inverts the micromechanical parameters of the strata through shield tunneling parameters, then constructs a three-dimensional anisotropic random field model, generates random field samples through K-L series expansion, and calculates the settlement field using a three-dimensional fluid-structure interaction finite element model and Monte Carlo simulation. Statistical analysis is used to predict the settlement probability, and finally, the probability of settlement exceeding limits is calculated based on reliability theory to complete the risk assessment. This invention breaks through the homogenization assumption, quantifies settlement risk, adapts to complex heterogeneous strata, provides a scientific decision-making basis for the whole life cycle management of tunnels, and has strong engineering applicability.

The invention discloses a control rod falling reliability analysis method based on random point collocation perturbation, and belongs to the field of reliability analysis. The method comprises the following steps: firstly, based on a control rod falling structure, constructing an uncertainty rod falling dynamic model, and determining random variables, random variable vectors and distribution thereof in a rod falling process; secondly, under the condition of considering a random variable, calculating a statistical characteristic value of rod falling time by adopting a random point collocation perturbation method based on an uncertainty rod falling dynamic model; thirdly, obtaining a probability density function of rod falling time based on a maximum entropy principle through statistical feature values; and finally, based on a reliability theory, calculating a control rod falling time reliability index. Reliability analysis is carried out based on the probability density function of the control rod falling time obtained through solving, and the calculation efficiency can be remarkably improved; the blank of control rod falling reliability analysis and research when random variables exist is filled; compared with a reliability analysis method, the efficiency of calculating the reliability index is higher.

The present invention relates to the field of drone design technology, and in particular to a method, system, medium and program product for modeling the reliability of drone propellers. The method first constructs a requirement model, system context, use case and activity diagram of drone propellers based on SysML, and defines the mathematical function relationship of core performance parameters such as thrust, torque and speed; then statistical fitting is performed in combination with experimental data to construct a joint performance margin equation, and the reliability theory is introduced to calculate the reliability value of the propeller through the standard normal cumulative distribution function; finally, the above constraint equation is constrained and bound to the system structure model to realize dynamic response and model linkage under parameter changes. The present invention realizes the integrated integration of reliability analysis in the MBSE model, significantly improving the automation level, evaluation accuracy and engineering application efficiency of propeller system reliability modeling.

The present invention discloses a safety assessment method for danger removal and reinforcement of concrete gravity dams, which includes constructing a calculation model for non-probabilistic reliability index of gravity dams based on interval variables and considering the influence of reinforcement measures and material aging on the service behavior of concrete gravity dams. First, the interval parameter boundaries of the gravity dam are obtained by using the original data of dam deformation, the results of physical models and calculation models. Secondly, the non-probabilistic reliability theory of time-varying is integrated to calculate the non-probabilistic reliability indexes of elements and systems, and a calculation method for non-probabilistic reliability indexes based on the response surface method is developed. Finally, the prediction of the service behavior of danger removal and reinforcement measures and material aging with the increase of the service life of concrete dams is analyzed from the failure modes of elements and systems. Applying this method overcomes factors such as the highly non-linear function of the traditional reliability analysis method, the strict randomness of uncertain parameters, and the sensitivity of calculation results to parameters.

The invention discloses a component residual bearing capacity evaluation method based on an entropy fuzzy analysis method, and belongs to the field of structural engineering. Existing evaluation methods such as subjectivity of an expert experience method and high cost of a load test method, a reliability theory depends on mass data, and weight of an existing fuzzy evaluation method is too subjective. The method comprises the following steps: simulating different damage rates of a component through a physical test, and establishing a dynamic critical value adjustment formula set; correcting the normalized matrix of the traditional entropy method to obtain dynamic entropy weight sets at different rates; collecting actual measurement damage data to construct a current and pre-judgment fuzzy judgment matrix, and combining the current and pre-judgment fuzzy judgment matrix into a compensation matrix; and a target layer fuzzy evaluation matrix is calculated in combination with the compensation matrix and the dynamic weight, a final reduction coefficient is obtained through correction, and then the residual bearing capacity is calculated. The problem of dynamic weight distribution under multi-damage coupling is solved, subjective dependence is reduced, damage rate changes are adapted, evaluation precision is improved, and the method can be used for structure maintenance decision making and emergency study and judgment after disasters.

The present invention relates to the technical field related to bridges, and discloses a method for evaluating the failure probability of a bridge system based on an improved comprehensive weighting method. For bridge structural systems, the application of traditional system reliability theory to the structure of a bridge system will result in two extreme situations: being conservative and being safe. Since the relative importance of each bridge component in contributing to the normal operation of the system is different, it is difficult for traditional system reliability evaluation methods to obtain accurate and true evaluation results. The entropy weight method is an objective weighting method that uses the concept of entropy to determine the weight of an indicator, and reflects the importance of the indicator according to the degree of deviation between the observed values ​​of the same indicator. However, it still cannot avoid the subjectivity brought by expert scoring. To this end, this patent establishes an objective entropy weight evaluation index system, improves the decision matrix of the traditional expert scoring system, and aims to more accurately and reasonably determine the weights of the total components in the bridge system and calculate the failure probability of the bridge system.

The invention discloses an intelligent regulation and control method and system for water transportation, distribution and back supplement in a mining area. The method comprises the steps that pipe network operation data of a transportation and distribution pipe network and current multi-source geological and hydrological data are obtained; determining an optimal state estimation value of the pipe network by using a real-time hydraulic model and an ensemble Kalman filtering algorithm, and calculating a pressure residual error of each monitoring node; when the residual represents an abnormal working condition, determining a leakage result by using a leakage positioning algorithm; generating an emergency regulation and control decision by using an optimization scheduler based on the leakage result; when the residual represents a normal working condition, a scheduler is used for executing multi-time-scale predictive control through a real-time hydraulic model based on pipe network operation data to generate a transmission and distribution scheduling decision, and the pipe network is regulated and controlled to realize back-replenishing water transmission and distribution; performing multi-physics field coupling real-time simulation on the whole diffusion and migration process of the back-replenishing water by using the geologic structure digital twinborn model to obtain a back-replenishing prediction result; and evaluating the risk of the candidate supplementation scheme based on a reliability theory, and solving by using a multi-objective optimization algorithm to obtain a target supplementation scheme.

The invention provides a method for predicting and evaluating the service life of a reinforced concrete structure considering sulfate corrosion. The method is suitable for a concrete structure in a chlorine salt-sulfate composite medium corrosion environment. According to the method, a coupling model for diffusion of chloride ions and sulfate ions is constructed, diffusion parameters are corrected to consider interaction of the two ions, and the failure probability of steel bar corrosion and protective layer cracking is evaluated in combination with a reliability theory, so that the service life of a concrete structure is predicted. The coupling effect of chloride ion diffusion and sulfate ion diffusion is creatively integrated, the accuracy of the model is verified through experiments, a systematic life prediction method is provided, and a scientific basis can be provided for long-term performance evaluation and maintenance of infrastructures such as bridges and ports.

A reliability analysis method for control rod drop based on random collocation perturbation is disclosed, belonging to the field of reliability analysis. First, based on the control rod drop structure, an uncertain drop dynamics model is constructed, and the random variables, random variable vectors, and their distributions during the drop process are determined. Second, considering the random variables, the statistical characteristic values ​​of the drop time are calculated using the random collocation perturbation method based on the uncertain drop dynamics model. Third, using the statistical characteristic values, the probability density function of the drop time is obtained based on the maximum entropy principle. Finally, based on reliability theory, the reliability index of the control rod drop time is calculated. This invention performs reliability analysis based on the calculated probability density function of the control rod drop time, which significantly improves computational efficiency; it fills the gap in the research on reliability analysis of control rod drop when random variables are present; and compared with other reliability analysis methods, it is more efficient in calculating reliability indices.

The present invention discloses a method for calculating load and resistance partial factors, a storage medium, and a device, belonging to the field of ballastless tracks. By establishing a structural limit state function, simplifying it, and introducing an equivalent resistance attenuation coefficient g*, an empirical calculation formula for g* can be obtained through the derivation and simplification of the equivalent resistance attenuation coefficient. On this basis, by introducing the third-moment reliability theory, μ R0 , σ G0 , α 3G0 , β 2T0 , μ RT , σ G , α 3G , β 2T and other parameters can be obtained, and the calculation formula for load and resistance partial factors considering the degradation of structural resistance performance in the whole life cycle can be accurately constructed, and the acquisition of load and resistance analysis coefficients can be quickly realized. The method in the present invention is simple in method and convenient in operation, can fully consider the attenuation of the structural resistance performance of the design object, avoid the iterative calculation process in the existing design process, simplify the calculation process of reliability design, shorten the design cycle, improve the design efficiency, and has good practical value and practical significance.

The invention relates to the technical field of bridge engineering, in particular to a technical condition evaluation method for two service stages of a bridge pull sling, and aims at solving the problems that an existing evaluation method does not distinguish the service stages and the evaluation applicability of the long-term service pull sling is insufficient. The method comprises the following steps: according to the designed service life of the cable, dividing the service period of the cable into two stages, i.e., a stage within the designed service life and a stage outside the designed service life; constructing an evaluation index multi-level model by adopting an analytic hierarchy process aiming at a design age limit inner pulling sling, and calculating a technical condition score through weight distribution, grade evaluation and a score deduction criterion; the method comprises the following steps: selecting a representative cable body to perform a dissection test aiming at a designed age limit external pulling sling, obtaining indexes such as a steel wire section loss rate, tensile strength and residual fatigue life, calculating time-varying bearing capacity reliability and time-varying fatigue reliability based on a reliability theory in combination with a corrosion rate model and a fatigue degradation model, and predicting the residual service life. Through staged dynamic evaluation, the accuracy of technical condition evaluation in the whole life cycle of the sling is remarkably improved, and a quantitative basis can be provided for safety maintenance decisions of the over-age service sling.

The invention provides a method and device for determining the curvature radius of a hot bent pipe based on a reliability theory. The method comprises the steps that S1, design parameters of the hot bent pipe are obtained; s2, determining an initial curvature radius according to the design parameters; s3, determining an expression through a preset limit state, and calculating a limit state value of the initial curvature radius in combination with the design parameters; s4, determining an expression through a preset reliability, and calculating the reliability of the initial curvature radius in combination with the limit state value; step S5, determining a target curvature radius according to the magnitude relationship between the reliability and the target reliability in the design parameters; the target curvature radius is a production parameter of the hot-bending elbow. The curvature radius of the hot bent pipe is accurately and reasonably designed, and meanwhile it is guaranteed that the structural strength of the bent pipe meets the design requirement of the hot bent pipe all the time.

This invention relates to the field of reliability engineering technology, specifically to a method and system for allocating certainty reliability indicators for an electrically driven turnout tamping machine based on a material-energy-information network. The method first performs functional decomposition and performance analysis of the entire machine, extracting key performance parameters of each subsystem and constructing performance margins. Based on certainty reliability theory, it determines the material-related reliability. Secondly, it establishes energy and information networks through the electric traction power supply relationship and the telemetry and control link, respectively, calculating the energy-related reliability and information-related reliability of each subsystem, and combining these three to obtain the subsystem functional reliability. Based on this, the system reliability is expressed as the minimum value of the subsystem functional reliability. System reliability interval constraints and performance margin mean and variance constraints are introduced to construct an optimization model with causal importance-weighted subsystem functional reliability as the objective function. An intelligent optimization algorithm is used to solve for the reliability indicators and margin allocation of each subsystem. This method can achieve refined and quantitative allocation of reliability indicators for each subsystem of an electrically driven turnout tamping machine under small sample and uncertain conditions, improving the reliability and safety of the entire machine under complex operating conditions.

This invention relates to the field of ship design technology and discloses a rudder system optimization design method based on nonprobabilistic reliability theory, comprising the following steps: S1: Determine the mechanical performance design values ​​of key components of the rudder system based on nonprobabilistic reliability indices, conduct parameter sensitivity analysis to determine the sensitive variables affecting the rudder stock torque, construct a parameterized model library, and generate a sample space through automated simulation scripts; S2: Call the parameterized model library to generate a three-dimensional model, perform finite element calculations of the rudder-propeller combination, simulate the hydrodynamic performance of the rudder system under different rudder angle conditions, and compare and analyze the results with reference data and standard calculations. By integrating nonprobabilistic reliability theory and comparing nonprobabilistic reliability indices and convex set models, parameter uncertainties are effectively handled, the reliability of the rudder system design is improved, and the optimization ideas of portal frame structures are used to reduce design constraints and improve efficiency.

The present application relates to the field of railway operation and maintenance technology, in particular to a simply supported beam bridge section TQI prediction method based on Gaussian random process, which comprises the following steps: step one, data collection and preprocessing of simply supported beam bridge; step two, construction of composite kernel function model suitable for bridge characteristics; step three, adaptive training and optimization of model parameters; step four, probability prediction and uncertainty quantification; step five, calculation of over-limit probability based on reliability theory; step six, residual life prediction and maintenance window generation; the present application can preferably predict the TQI of simply supported beam bridge section.

The embodiment of the present disclosure discloses a method and device for calculating time-varying failure probability of hydrogen-containing pipeline with corrosion defects, comprising: based on reliability theory, using hydrogen-induced damage factor to construct pipeline limit state equation, the pipeline limit state equation includes pipeline leakage limit state equation and pipeline burst limit state equation; solving the pipeline limit state equation to obtain the failure probability corresponding to each defect in the pipeline; determining the target equivalent unit normal vector based on the linear limit state function of the pipeline; the linear limit state function is constructed based on the failure probability corresponding to each defect of the pipeline; determining the time-varying failure probability of the pipeline according to the target equivalent unit normal vector, the time-varying failure probability includes the leakage failure probability of the pipeline within a set time and the burst failure probability of the pipeline within a set time. The technical scheme realizes fast and efficient calculation of the time-varying failure probability of the hydrogen-containing natural gas pipeline with corrosion defects, which is of great significance to the safety of the pipeline.

The invention provides a thin-layer weakly-cemented expansive rock tunnel safety risk grading method and a supporting structure, and relates to the technical field of tunnel surrounding rock engineering. Carrying out stratification feature recognition and index quantification on the expansive rock geological parameters, and constructing an index comprehensive judgment model; inputting the index comprehensive judgment model into a fuzzy neural network algorithm for coupling processing, and establishing a nonlinear risk evaluation model; according to a reliability theory and Monte Carlo simulation, determining a quantitative relation between a risk index and a surrounding rock instability probability in the nonlinear risk evaluation model, and constructing a dynamic risk threshold value; and performing grade division on tunnel construction risks based on the dynamic risk threshold, and performing dynamic feedback and parameter updating on a preset risk evaluation model in combination with real-time monitoring data to obtain a tunnel safety risk grading scheme. According to the invention, the prominent problem of unbalanced engineering safety risk and cost control is solved.

This application provides a reliability-based durability analysis method and apparatus for subsea immersed tunnels. The method includes: acquiring marine environmental parameters and tunnel damage parameters of the target subsea immersed tunnel; the marine environmental parameters include seawater chloride concentration, and the tunnel damage parameters include crack length, crack width, number of cracks, and crack initiation time; establishing a target steel reinforcement surface chloride concentration calculation model for the target subsea immersed tunnel based on a pre-defined calculation model related to seawater chloride concentration, crack length, crack width, number of cracks, and crack initiation time; and calculating the durability failure probability and reliability index of the target subsea immersed tunnel based on reliability theory and the target steel reinforcement surface chloride concentration calculation model. This application can obtain comprehensive and accurate durability analysis results for subsea immersed tunnels.

The invention discloses a mechanical property analysis-based icing distribution line breakage probability calculation method, relates to the technical field of distribution lines, and solves the problem that in the prior art, due to the fact that the model, erection mode and the like of a distribution line are obviously different from those of a power transmission line, defects still exist in the aspect of icing and breakage risk assessment of the distribution line. According to the method, the stress state of the distribution line under the action of icing and wind load is analyzed by establishing a tension model, the horizontal tension and the vertical tension are calculated respectively, and a resultant tension formula is deduced. Thirdly, on the basis of the reliability theory, a broken line probability model is constructed, and influences of random variables such as the icing thickness, the wind speed and the line resistance are considered; and finally, the line breakage probability under the conditions of different icing thicknesses and height differences is evaluated, and an effective risk early warning basis is provided for an electric power department.