71 results about "Critical load" patented technology

The invention provides a reinforced concrete structure performance degradation intelligent prediction and durability limit state evaluation method. The method comprises the following steps: establishing a random variable probability model of environment and structure parameters; a convolutional neural network is fused to construct a chloride ion diffusion intelligent prediction model, and Monte Carlo sampling is adopted to analyze probability distribution of the initial corrosion time of the steel bar, so that prediction of the steel bar de-blunt time is realized; establishing a steel bar time-varying corrosion model to obtain the change condition of the steel bar corrosion loss rate along with time; further, an incremental static analysis method is adopted, and a multi-scale finite element model of the reinforced concrete structure under different corrosion rate conditions is established through random sampling; obtaining a critical load value in a limit state, and obtaining a failure probability curve under different corrosion degrees; finally, the bearing capacity failure time of the reinforced concrete structure is obtained by defining a bearing capacity reduction coefficient, and evaluation of the durability limit state of the reinforced concrete structure in the corrosion state is achieved.

The invention discloses a method for dynamically evaluating the ultimate bearing capacity of a layered damage composite material cylindrical pressure-resistant shell in the field of deep sea equipment structure health monitoring, which comprises the following steps of: establishing a nonlinear relationship between a critical buckling load of an unlayered composite material cylindrical shell and a critical buckling load of a layered composite material cylindrical shell, and calculating an attenuation coefficient of each group of samples; measuring inner and outer layer strain values of the to-be-evaluated composite cylindrical shell, detecting extreme value statistics and cumulative sum based on change points of the inner and outer strain values, judging that the position of the point is layered, constructing a layering point set, calculating five layering characteristic parameters of the to-be-evaluated composite cylindrical shell based on the layering point set, and substituting the five layering characteristic parameters into an attenuation coefficient formula, obtaining a critical load of the to-be-evaluated composite cylindrical shell; according to the method, through combination of dual-surface strain cooperative monitoring and a regression model, prediction of critical buckling loads in a service state is realized, environments such as shell thickness fluctuation, salt spray corrosion, interface fracture parameter measurement errors and impact loads are compatible, strain gauge monitoring and limit load online evaluation are fused, and a dual evaluation system is formed.

The invention discloses a power system cascading failure chain modeling and blocking method, device and system considering source-load double-end uncertainty, and a medium. The method comprises the steps of constructing source-load uncertainty input distribution (wind power introduces Weibull distribution based on a wind speed segmented power model, photovoltaic introduces Beta distribution based on an irradiance output model, and a load side introduces a normal distribution fluctuation model); an MSFF method is adopted to construct a unified source-load stochastic power flow model, and a multi-scene power flow state set is obtained; introducing a power flow out-of-limit criterion and a hidden fault probability function, building a cascading fault propagation model fusing wind-solar load uncertainty, and dynamically simulating fault chain evolution; and formulating a staged collaborative blocking strategy (cutting off non-critical load emergency control, quickly responding a battery energy storage system and dynamically adjusting a critical line protection constant value) to realize real-time fault suppression. Simulation shows that the method is suitable for power system security defense in a high-proportion new energy penetration scene, and has good engineering adaptability and dynamic control performance.

The invention relates to the technical field of electric power engineering structure failure assessment, and discloses a reinforced concrete pole icing failure assessment method, system, device and medium, and the method comprises the steps: collecting the initial data of a pole, and assessing the stress distribution and potential crack position of the pole under a specific load based on the data. According to the stress distribution and the crack position, the expansion condition of the concrete crack is determined, and the stress state of the steel bar is analyzed. And based on the stress state, executing preliminary judgment. And establishing a relation model of the critical fracture value and the critical load of the steel bar in combination with the preliminary judgment result, and calculating the probability of overall failure of the electric pole. By analyzing the stress distribution and potential cracks of the electric pole under different loads, the actual stress state of the electric pole can be accurately predicted. Through fitting the joint distribution of the preset loads, the interaction between the loads is considered, and the evaluation precision is improved. The established relation model provides a basis for electric pole failure probability evaluation based on a preliminary judgment result.

The invention relates to the technical field of structural engineering safety monitoring, in particular to a fire resistance real-time evaluation system and method based on a steel structure, and the method comprises the steps: collecting the surface radiation energy of the steel structure through a distributed thermal infrared imager array, and constructing a millimeter-level precision three-dimensional temperature field distribution diagram in combination with an environment temperature compensation algorithm; inputting the temperature field into the phase change correction model, and dynamically calculating a yield strength attenuation coefficient and an elastic modulus reduction coefficient; constructing a thermal-mechanical coupling nonlinear finite element model based on the degradation parameters, iteratively solving the displacement and stress response of the structure under the fire load action by adopting an arc length method, and extracting a buckling critical load spectrum; and according to the ratio of the real-time fire load to the critical load, a fire-resistant safety level signal is generated, and a graded early warning instruction is triggered. According to the invention, thermal-force response whole-process monitoring and intelligent early warning of the steel structure in a fire disaster can be realized, and the system has high spatial resolution, high physical coupling and multi-level response capability.

The present invention relates to a technical solution of unloading pressure and shocking preventing, achieved by 3D stratified buffer and energy absorbing belt in thick coal seam. It is a technology for Prevention and Control of the Impact of Ground Pressure in Coal Mines that with Thick Coal Seam Bottom Roadway. Firstly, determine the distribution length L of the supporting stress curve along the advancing direction of the working face, divide the independent impact prevention unit by L, and sequentially determine the length L1 of the stress elevation zone, the length L2 of the stress critical load zone, the length L3 of the stress decline zone, and the length L4 of the stress static load zone, and also determine the different parameters of the spacing of the cutter drilling holes within the different stress zones; In the vertical direction of the working face, determine the height of the coal body stress stabilization zone H1, the height of the stress increase zone H2 and the height of the stress superposition zone H3 in turn, and determine the parameters of the cut slits and the location of the blocking grooves in different zones within the different stress zones. The appropriate jet parameters are adopted in different stress areas, and barrier slots are formed by continuous cutting at the junction of different partitions, which can both perform the function of coal unloading and block the stress transfer, solving the problems of insufficient and uneven unloading of coal seams.

The invention discloses a power distribution network toughness evaluation method based on dynamic disturbance evaluation, and relates to the technical field of power systems and automation, and the method comprises the following steps: constructing a disturbance model to simulate the response process of a power distribution network when the power distribution network encounters an extreme disaster or fault, the disturbance model comprises various disturbance scenes such as natural disasters, power equipment faults and network attacks. By introducing the distributed power supply evaluation method based on the dynamic response model, the accuracy of power distribution network toughness evaluation is improved, the response characteristics of photovoltaic power generation and energy storage equipment in an extreme environment can be simulated in real time, and it is ensured that the evaluation result is more accurate. Through a flexible resource scheduling and recovery strategy optimization technology and based on a multi-objective particle swarm optimization algorithm, a post-disaster recovery process is optimized, key loads are scheduled preferentially, recovery time is reduced, power grid recovery efficiency is improved, and emergency response capability and recovery capability of a power distribution network in the face of extreme disasters are enhanced.

The invention discloses a low-temperature-impact-resistant high-strength bolt for a high-cold railway and a heat treatment method of the low-temperature-impact-resistant high-strength bolt. The bolt is of a special three-layer structure of a base body, a bionic nanometer laminated layer and a high-entropy alloy nitriding layer, wherein the grain size of the base body reaches the ASTM8 level or above; the bionic nano laminated layer is formed by alternately depositing TiN and VC, and the thickness of a single layer is less than 50nm; the high-entropy alloy nitriding layer is made of AlCoCrFeNiTi, the thickness is larger than 50 microns, the heat treatment method comprises the steps of grain refinement pretreatment, lamination preparation through magnetron sputtering, high-entropy alloy laser cladding, electromagnetic field assisted nitriding, oil quenching, cryogenic oscillation, tempering and the like, and intelligent quality control means such as a machine learning model, sound pressure feedback and image recognition are integrated. According to the scheme, the impact energy of the bolt at the temperature of minus 60 DEG C is higher than 55 J, the tensile strength is larger than 1200 MPa, the surface hardness is not lower than 1200 HV, the interface bonding critical load is higher than 80 N, and the problems of low-temperature brittle fracture, obdurability contradiction and quality consistency of the high and cold bolt are solved.

This invention discloses a method and system for collaborative power supply restoration of a distribution network using multiple emergency resources under disaster scenarios. The method includes: constructing a probabilistic fault model of the distribution network under disaster scenarios and pre-deploying multiple emergency resources, and performing active power supply islanding; initially locating faulty lines based on real-time data of the distribution network and verifying the location results in conjunction with the probabilistic fault model to form a final set of faulty lines; dividing faulty areas and performing fault isolation and temporary power supply topology reconstruction of non-faulty areas based on the active power supply islanding scheme; constructing multiple recovery subtree networks (RSNs) in the non-faulty areas and collaboratively optimizing the multi-emergency resource scheduling scheme; comprehensively evaluating the restoration effect, and if the evaluation is not up to standard, dynamically adjusting the RSN construction and resource scheduling scheme to form a closed-loop optimization. This invention, by constructing a full-process collaborative framework, integrates multiple emergency resources to achieve rapid and reliable restoration of critical loads, improving the resilience and power supply stability of the distribution network under extreme weather conditions.

The invention relates to the technical field of suspension bridge cable clamp detection, and particularly discloses a cable clamp anti-sliding performance detection method based on multi-point stress-strain monitoring, and the method comprises the steps: simulating a main cable through a full-scale sample, installing a test cable clamp and a brake cable clamp, and applying an axial thrust through a jack. A strain gauge, an axial force meter and a displacement meter are arranged on a cable clamp and a bolt, graded loading is carried out to obtain a bolt pre-tightening force attenuation curve and a slippage critical load, and therefore the friction coefficient mu is calculated. And establishing a main cable-cable clamp three-dimensional contact finite element model, and inputting mu and pre-tightening force attenuation data measured by the test to carry out simulation calibration, so that a simulation result is consistent with that of the test. And finally, a bolt is fastened to a design value in the calibrated model, and vertical sling force is applied to the sling clamp lug plate until the sling clamp lug plate slides, so that the maximum anti-sliding force of the sling clamp is obtained. The objective of the invention is to solve the problems that an existing cable clamp anti-sliding performance testing method excessively depends on a finished bridge main cable, the cost is high, the period is long, and matching verification cannot be carried out in the early stage of a project.

The invention provides a prediction method for dynamic buckling characteristics of a reinforced cylindrical shell with initial defects under an underwater explosion load based on artificial intelligence. The method specifically comprises the following steps: establishing a dynamic response characteristic three-dimensional numerical calculation model of initial defects of the reinforced cylindrical shell structure under an underwater explosion load; obtaining a rib and skin rigidity matching factor; calculating dynamic response characteristics of the reinforced cylindrical shell under different explosive equivalents, different explosion distances and different laying water depths; determining a dynamic buckling critical load and a buckling mode of the reinforced cylindrical shell under the underwater explosion load by combining a dynamic buckling criterion and annular and axial typical response characteristic space distribution characteristics; and establishing an artificial intelligence proxy model of the dynamic buckling characteristics of the reinforced cylindrical shell under the underwater explosion load. According to the method, different defect amplitudes and rib and skin rigidities under the underwater explosion shock wave and bubble pulsation coupling load can be rapidly given based on the proxy model, the dynamic buckling critical load and modality of the reinforced cylindrical shell under the water depth are laid, and the method has high practicability and engineering significance.

This invention discloses a structural strength optimization method based on a triangular fractal algorithm, relating to the field of structural optimization design in civil engineering. The method includes the following steps: Ⅰ. Setting the geometric and material parameters of initial members and calculating their buckling critical load and specific strength; Ⅱ. Setting the geometric and material parameters of the reinforced members in the first iteration and calculating their buckling critical load and specific strength after iteration; Ⅲ. In each iteration, changing the radius of the added members, calculating the maximum specific strength of the triangular fractal structure in each iteration, and recording the corresponding member radius. The fractal structure generated after multiple iterations of this invention can withstand greater loads and has higher strength. It maintains increased strength even with further increases in the number of iterations, making the structure less prone to failure. The fractal structure generated after multiple iterations can withstand greater loads and has higher strength, which is helpful for optimizing engineering solutions.

The invention relates to the technical field of oil exploration, and provides an analysis method and device for safe tripping-in of a well completion pipe string, and the method comprises the steps: obtaining the actual hook load data and well section information of an open hole section based on a drifting process; constructing a tubular column friction torque calculation model of the drifting drilling tool assembly; on the basis of the tubular column friction resistance torque calculation model, the actual hook load data of the open hole section and the well section information of the well, the well hole open hole section friction resistance coefficient is calibrated; on the basis of well section information and the well hole open hole section friction resistance coefficient, a solving model of the axial force of the well completion pipe string and a critical load value calculation model of well completion pipe string buckling are built; and on the basis of the solving model of the axial force of the well completion pipe string and the calculation model of the critical load value of buckling of the well completion pipe string, whether the well completion pipe string is safely tripped is determined. According to the method, the friction resistance coefficient in the drifting stage is determined, the invisible shaft cleaning state is known, the current friction resistance coefficient is used for evaluating the to-be-tripped well completion pipe string, and therefore operation risks and operation complexity are avoided, and the operation efficiency is improved.

This invention provides a method for improving the reliability of distribution networks during ice storms based on micro-meteorological sensing and multi-resource collaboration, relating to the field of distribution network disaster prevention technology. The method includes: simulating a distribution network fault sequence during the ice storm evolution process using Markov chains based on real-time ice storm data acquired during the ice storm and a pre-defined distribution network recovery plan; determining the expected value of critical load losses based on the distribution network fault sequence; generating a new distribution network recovery plan with the objective function of minimizing power supply loss if the expected value is greater than a preset risk threshold; estimating the transient impact intensity based on the new distribution network recovery plan; selecting target equipment whose regulation performance meets preset regulation performance standards when the transient impact intensity exceeds a preset safety limit, and using the target equipment to reduce the transient impact intensity; and executing the new distribution network recovery plan when the reduced transient impact intensity is less than the preset safety limit. This method reduces expected power outage energy losses and improves the power supply reliability of the distribution network during ice storms.

The present application belongs to the technical field of anti-cracking design of fiber reinforced concrete, and particularly relates to a mesoscale fiber reinforced concrete anti-cracking design method without size effect. A fiber reinforced concrete tensile strength prediction model without size effect is established based on a nonlinear mesoscale fracture theory. The present application innovatively proposes that the average fiber spacing is a dominant factor influencing the critical crack propagation length and the critical load at the macro and mesoscale levels of fiber reinforced concrete, reveals the whole process of cracking failure of fiber reinforced concrete, and further establishes a closed solution mesoscale prediction model of the tensile strength of fiber reinforced concrete without size effect. Compared with the prediction results of traditional models, the present application is more accurate, is applicable to geometrically similar and geometrically dissimilar specimens of different sizes, is simple to operate, can reduce the cracking risk of fiber reinforced concrete structures in combination with numerical simulation, and is conducive to engineering promotion and application.

The invention discloses a bridge two-dimensional over-limit partition monitoring and early warning and safety risk control method, device, equipment, medium and product, and relates to the field of bridge safety risk control, and the method comprises the steps: carrying out the bi-two-dimensional safety evaluation according to a finite element simulation value of a to-be-evaluated bridge structure state and a real bridge monitoring value, determining the technical condition and the evaluation grade of the to-be-evaluated bridge; determining a plurality of over-limit vehicle load grades based on bridge technical conditions and evaluation grades thereof; determining a load range corresponding to each over-limit vehicle load grade according to the vehicle critical load in the normal use limit state and the bearing capacity limit state; based on this, determining a load upper limit corresponding to the current structure state; and according to the determined load upper limit, determining a current over-limit vehicle load grade from the plurality of over-limit vehicle load grades so as to determine a current early warning grade and a current safety risk control measure, and carrying out early warning and safety risk control on the to-be-evaluated bridge. According to the invention, quantitative evaluation of the bridge safety risk is realized.

This invention discloses an optimization method for restoring power supply to critical loads in active distribution networks based on user outage loss assessment. The method includes the following steps: collecting user outage time, duration, and economic and social loss information; establishing a quantitative model of outage loss; using the results of the outage loss model, combined with the grid topology and restoration difficulty, comprehensively evaluating and prioritizing loads to generate a critical load sequence; constructing a power restoration optimization model with the goal of minimizing outage loss; applying the optimization strategy to actual distribution network operation; collecting restoration effect data; dynamically adjusting; and forming an iterative optimization. This invention not only achieves critical load identification and prioritization based on user outage loss, enabling priority restoration of loads with the greatest economic and social impact under limited resources, but also significantly improves the restoration efficiency and scientific nature of power supply decisions in active distribution networks after sudden power outages, balancing power supply security, economy, and social benefits.

This invention proposes an intelligent prediction method for performance degradation and durability limit state assessment of reinforced concrete structures, comprising: establishing a probabilistic model of random variables for environmental and structural parameters; constructing an intelligent prediction model for chloride ion diffusion by fusing convolutional neural networks, and using Monte Carlo sampling analysis to analyze the probability distribution of the initial corrosion time of the reinforcing bars to predict the depassivation time of the reinforcing bars; establishing a time-varying corrosion model of the reinforcing bars to obtain the change of the corrosion loss rate of the reinforcing bars over time; further, using an incremental static analysis method, establishing a multi-scale finite element model of the reinforced concrete structure under different corrosion rate conditions through random sampling; obtaining the critical load value under the limit state to obtain the failure probability curve under different corrosion degrees; and finally, by defining a bearing capacity reduction coefficient, obtaining the bearing capacity failure time of the reinforced concrete structure to achieve the durability limit state assessment of the reinforced concrete structure under corrosion.

The invention belongs to the technical field of ships, and discloses a testing method for a PCTC ship stern ramp load monitoring system, the theoretical maximum load capacity of a stern ramp in the non-starting state of the stern ramp load monitoring system is Wmax1, the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2, and the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2. Comprising the following steps that a starting button of a stern ramp load monitoring system is pressed down, a stern ramp is opened, and the included angle between the stern ramp and the wharf ground is smaller than or equal to 6 degrees; a weight-free load test is carried out; carrying out load testing within Wmax1; a load test of a Wmax1 critical value is carried out; a load test of a Wmax2 critical value is carried out; compared with the mode that a crane is used for hoisting the weights one by one and the module vehicle loads and moves the weights, crane resources are saved, the testing efficiency is greatly improved, the influence of testing on the wharf production period is reduced, the influence of water level changes caused by tide rising and tide falling on testing is reduced, and the reliability of testing results is improved.

The invention belongs to the technical field of fiber concrete anti-cracking design, and particularly relates to a micro-scale fiber reinforced concrete size-effect-free anti-cracking design method. And establishing a size-effect-free tensile strength prediction model of the fiber reinforced concrete based on a nonlinear microscopic fracture theory. According to the method disclosed by the invention, the average fiber spacing is innovatively proposed as a leading factor of macro and micro-scale layers of the fiber concrete for influencing the critical crack extension length and the critical load, and the whole process of cracking and failure of the fiber concrete is disclosed, so that a closed solution micro-scale prediction model for the size-effect-free tensile strength of the fiber reinforced concrete is established; compared with a traditional model, the prediction result is more accurate, the method is suitable for geometrically similar and geometrically dissimilar test pieces of different sizes, the test operation is simple, the cracking risk of the fiber concrete structure can be reduced by combining with numerical simulation, and engineering popularization and application are facilitated.

The invention provides a lateral buckling detection device for a steel belt of a flexible connecting piece and a detection method of the lateral buckling detection device, and relates to the technical field of lateral buckling detection of steel belts. The steel belt is wound on the outer wall of the inner cylinder and limited in the annular space between the inner cylinder and the outer cylinder, the first end of the steel belt is fixed to the bottom plate, the second end of the steel belt is fixed to the driving assembly, and the driving assembly enables the steel belt to bend laterally; the monitoring assembly is used for acquiring first image information, second image information, first data information and second data information of the steel belt in real time, and the calculation unit is used for determining the buckling form of the steel belt according to the first image information and the second image information and determining the buckling critical load of the steel belt according to the first data information and the second data information. According to the technical scheme, the lateral buckling behavior of the steel belt can be accurately reproduced, miniaturization and precision of the detection device are achieved, and a visual whole-process dynamic monitoring means is provided for revealing the lateral buckling evolution mechanism of the steel belt in the limited space.

This invention discloses a method and system for optimizing burnout air at full load in a coal-fired boiler. The method includes: acquiring the real-time load of the coal-fired boiler; determining the burnout air operation status based on a comparison of the real-time load with the first critical load, second critical load, and third critical load of the coal-fired boiler; in the first burnout air operation status, opening all burnout air layer regulating dampers, with the opening degree of each damper determined according to the optimal burnout air coefficient; in the second burnout air operation status, gradually closing the burnout air layer regulating dampers until the optimal two burnout air layer regulating dampers remain open; in the third burnout air operation status, leaving the optimal two burnout air layer regulating dampers open, and using hot primary air instead of hot secondary air as the burnout air source. This invention ensures full-load burnout air penetration while avoiding a significant increase in auxiliary equipment power consumption and reducing the risk of stalling of the primary air fan at low load.

The invention provides a method and system for determining the thickness of an intrinsic crack, computer equipment and a medium, and belongs to the field of crack-containing structure fracture performance evaluation.The method comprises the steps that a real stress-strain curve and a tensile strength value of a sample material are obtained; the method comprises the following steps: processing a material into a sample containing a crack structure, applying a slowly increasing I-type load, and collecting a real critical load value at the moment of fracture; constructing a crack geometric model matched with the crack structure sample, presetting an initial intrinsic crack thickness and importing material performance data; applying the same I-type load to the model, and calculating the maximum principal stress of the crack tip in real time; the intrinsic crack thickness value is circularly adjusted, and when the error between the tip stress and the tensile strength and the error between the simulated fracture load and the real critical load meet the preset standard, the optimized intrinsic crack thickness is the intrinsic crack thickness of the characterization material; according to the method, the fracture performance of the crack-containing structure can be accurately evaluated by establishing a method for measuring the thickness of the intrinsic crack in an actual material.

The application discloses a buckling-restrained design analysis method for a steel lining anchoring system, which comprises the following steps: obtaining a node force balance equation based on a steel lining plate constitutive relation and a bolt constitutive relation; obtaining node displacement data based on the node force balance equation, and obtaining strain value data based on the node displacement data; obtaining actual node force of the steel lining plate based on the strain value data and the steel lining plate constitutive relation, and obtaining actual node force of the bolt based on the node displacement data and the bolt constitutive relation; obtaining node force residual based on the node displacement data, the strain value data, the actual node force of the steel lining plate and the actual node force of the bolt; if the node force residual is greater than a threshold value, updating the node displacement data and the strain value data, and continuing to calculate the node force residual until the node force residual is less than the threshold value. The method realizes accurate calculation of a buckling critical load of the steel lining, and provides theoretical support for a containment structure design of a nuclear power plant.

The present application discloses a method, device, equipment and medium for identifying and controlling the load of the entire machine, which relates to the field of wind power technology. The method includes: measuring the root bending moment of the three blades of the wind turbine in real time, and determining the pitch mechanism bending moment based on the root bending moment and the real-time pitch angle; determining the hub center bending moment in different hub coordinate systems based on the blade cone angle, the rotor azimuth angle and the pitch mechanism bending moment; determining the cabin bending moment in the tower top coordinate system based on the cabin center of gravity, the cabin weight and the hub center bending moment of the wind turbine; determining the rotor thrust of the wind turbine using the root bending moment, and determining the tower bottom pitching moment in the tower bottom coordinate system based on the rotor thrust and the cabin bending moment; when it is detected that the measured target critical load triggers a pre-set load control strategy, the entire wind turbine is controlled to enter the adjustment link to control the target critical load. The technical solution of the present application is conducive to ensuring the safety of the wind turbine tower structure and improving the maintenance level.

Specifically, the application discloses a multi-stage protection method for an intelligent safety rope for power aerial work, and belongs to the field of intelligent safety, and comprises the following steps: S1. Assembling a main bearing rope body, a companion constraint rope body, an anchor point assembly, a sliding modulation assembly, a segmented locking assembly, a human body connecting assembly and a distributed sensing unit along the rope before work, and establishing an initial stress configuration; S2. Collecting state parameters of the main bearing rope body, the anchor point assembly and the human body connecting assembly during work, and forming a three-level state set; S3. Adjusting a stress path of the main bearing rope body, a state of the companion constraint rope body and a stress center of the human body connecting assembly before a critical load is applied; S4. Sequentially performing segmented locking, sliding energy dissipation, shunt bearing and rigid limiting in an impact stage; and S5. Generating a load history after impact and completing review and retirement. The method has the beneficial effects of improving the protection reliability and impact control capability in power aerial work.

This invention discloses a method for assessing the resilience of distribution networks under hail disasters, belonging to the technical field of AC distribution network resilience assessment. When calculating the component failure rate of a distribution network under hail disasters, this invention filters the importance of *d* physical characteristics affecting the distribution network, identifying the most influential physical characteristics. The component failure rate under hail disasters is then calculated using these selected important physical characteristics, solving the problems of instability and inaccurate calculation results caused by relying on experience to judge physical characteristics in existing technologies. This invention uses two dimensions for assessing distribution network resilience: the critical load loss rate and the mobile energy storage response rate, which more accurately reflect the actual situation. Furthermore, the probability of hail disaster occurrence and the component failure rate of the distribution network under hail disasters are introduced to correct the assessment results, making the assessment method of this invention more accurate.

The invention provides a preparation method of a high-temperature-resistant composite lubricating film in a vacuum environment, and relates to the technical field of functional materials. Through a magnetron sputtering process, a titanium (Ti) transition layer is deposited on the surface of a metal substrate, and silver (Ag) layers and molybdenum disulfide (MoS2) layers are sequentially and alternately deposited on the surface of the transition layer. Through the gradient heterojunction constructed through interface engineering, the bonding strength between the thin film and the metal matrix is remarkably improved, and the scratch critical load is 30 N or above. Under the severe working condition of 300 DEG C in vacuum, the material shows an ultralow friction coefficient (less than 0.15) and a wear-resistant life gt; 5 * 10 < 5 > r. The lubricating oil is particularly suitable for long-life lubrication of a key kinematic pair of a high-temperature transmission mechanism of a spacecraft.

The invention discloses a variable cross-section arc arch rib out-of-plane instability critical load calculation method and system, and the method comprises the steps: building an axial and radial control equation of a variable cross-section arc arch based on an out-of-plane instability analysis model of the variable cross-section arch under the action of a uniformly distributed radial load; solving the axial and radial control equations of the variable cross-section arc arch through a harmonic differential quadrature algorithm to obtain an in-plane dimensionless displacement matrix of the arch under unit load set; based on the out-of-plane instability state of the variable cross-section arc arch, an out-of-plane control equation is constructed and solved, and an out-of-plane instability critical load matrix of the variable cross-section arc arch is obtained; and the out-of-plane instability critical load calculation of the variable cross-section arc arch rib is realized. The method can be suitable for various in-plane and out-of-plane boundary conditions and variable cross-section working conditions, and the calculation precision of the out-of-plane instability critical load of the variable cross-section arc arch rib is improved. The method and the system for calculating the out-of-plane instability critical load of the variable cross-section arc arch rib can be widely applied to the technical field of bridge design.

The invention relates to the technical field of metal fatigue prediction, in particular to a damage and fracture-based additive metal fatigue full-life rapid prediction method, device and equipment and a computer readable storage medium, and the method comprises the following steps: obtaining three-dimensional geometric parameters of internal hole defects; the porosity of the edge of each dangerous defect is calculated, and the critical load of the hole defect is obtained; introducing an equivalent crack surface at the original position of the defect, and calculating an equivalent initial crack length by utilizing the damage constitutive model; and a semi-analytical crack propagation algorithm is adopted, the propagation processes of the surface cracks, the embedded cracks and the corner cracks in the component are calculated, the crack propagation life is obtained, and the shortest crack propagation life is defined as the final structural fatigue full life. The damage constitutive model is utilized to fully consider the damage evolution and load coupling effect of the defect, and the semi-analytical crack propagation calculation method is combined with the acceleration algorithm and the crack conversion mechanism, so that the calculation efficiency is remarkably improved, and the rapid evaluation requirement in engineering practice is met.