270results about How to "In line with engineering practice" patented technology

The invention provides a power supply reliability assessment method of a power distribution network comprising a distributed power supply. Factors of the circumstance that the distributed power supply is connected to the power distribution network, randomness of output power of the distributed power supply, capacity limitation of a link circuit, randomness of load requirements, the correlation among random variables and the like are considered, and on the basis that output power of distributed voltages and randomness of loads are considered, island segmenting is conducted on the power distribution network. The power supply reliability assessment method accords with engineering practice better, and a reliability assessment result is more objective and effective.

The invention discloses an accelerated degradation test prediction method based on fuzzy theory, which comprises the following steps: collecting test data; performing the analysis of regression aimingat performance degradation data under each stress level; extrapolating the performance degradation rate of the product under a normal stress level; estimating a diffusion coefficient sigma in an excursion Brownian motion with drift by adopting a maximum likelihood estimation method; establishing an accelerated degradation test life and reliability predication model based on the fussy theory; andpredicting the life and the reliability of the product by adopting the fussy life and reliability prediction model. The method firstly introduces the fussy concept into an accelerated degradation testto enable the prediction result of the accelerated degradation test to be more reasonable, avoids the condition of rash routine reliability estimation result through considering the fussiness fuzziness of the performance degradation threshold, solves the problem of failed performance degradation in the engineering reality, and is suitable for the accelerated degradation tests of step stress and progressive stress and unaccelerated performance degradation prediction for the problem of the performance degradation failure.

The invention discloses a structural reliability analysis method based on a self-adaptive agent model. The method includes the following steps that firstly, according to distribution form of random variables, a small amount of initial input sample points are generated, and the response value of the system is calculated, and the obtained initial input and output sample points serve as initial training sample points for building a Kriging agent model; secondly, a newly added training sample point selection criterion is created, according to the distribution of random variables, a large amount ofrandom candidate training samples are generated and substitute into a learning function for calculation, candidate sample points with the smallest learning function value serve as newly added training sample points, and loop iteration is conducted until convergence occurs; finally, according to obtained final input and output training sample points, a final agent model is constructed, a Monte Carlo simulation method is adopted, the system failure probability and the reliability sensitivity are calculated, and the problems that an existing method only considers the limitations of the characteristics of sample points in an input space, and the accuracy is low and the calculation amount is large in the reliability analysis are solved.

The invention discloses a high ground stress weak surrounding rock tunnel excavation and support construction method. Excavation and support construction are conducted on a weak surrounding rock tunnel to be constructed in multiple sections from rear to front in the longitudinal extension direction of the tunnel. The method comprises the steps that 1, rock body strength and the maximum ground stress inside surrounding rock are tested; 2, the extrusion-type large-deformation level of the surrounding rock is determined; 3, a primary support scheme is determined, wherein the primary support scheme is determined according to the determined extrusion-type large-deformation level, and the primary support scheme is a profile steel frame support scheme or a grid steel frame and cover arch combined support scheme; 4, tunnel excavation and support construction are conducted; 5, excavation and support construction of the next section are conducted; 6, the fifth step is repeated for many times till the whole excavation and support construction process of the weak surrounding rock tunnel to be constructed is completed. According to the high ground stress weak surrounding rock tunnel excavation and support construction method, the steps are simple, the design is reasonable, construction is convenient, the use effect is good, the tunnel excavation and support construction process of the high ground stress weak rock tunnel can be completed easily, conveniently and rapidly, and the construction process is safe and reliable.

The invention discloses a military aircraft reliability quantitative requirement demonstration method which comprises the following steps of: 1, determining a military aircraft reliability top parameter index; 2, decomposing the military aircraft reliability top parameter index; 3, determining a threshold value of a military aircraft reliability top parameter; 4, converting a military aircraft reliability using index into a contract index; 5, comprehensively balancing the military aircraft reliability top parameter index; and 6, analyzing the technical and economic feasibilities of the military aircraft reliability top parameter index. The military aircraft reliability quantitative requirement demonstration method which is accordant with the state of China and has high operability is provided for the determination of the military aircraft reliability top parameter, so that the military aircraft reliability quantitative requirement demonstration work is guided, the reliability level of a military aircraft is lifted, the demonstration process is standardized and programmed, and the demonstration result is scientific and reasonable.

The invention discloses a pneumatic/structure/static aeroelasticity coupling optimizing method for a high-aspect-ratio wing. The pneumatic/structure/static aeroelasticity coupling optimizing method is based on the system decomposition strategy in multidisciplinary optimization for system-level decomposition and subsystem-level decomposition. In pneumatic subsystem-level decomposition, the pneumatic performance under the cruising appearance serves as an optimal object, and the rigidity-appearance pneumatic performance in traditional pneumatic optimization is replaced; after pneumatic subsystem-level decomposition is completed, and pneumatic loads, pneumatic appearance design parameters and structural configuration parameters serve as the input conditions for structure subsystem-level optimization; after pneumatic subsystem-level decomposition and structure subsystem-level decomposition are completed, the target quantity of system-level decomposition is output, system-level decomposition is returned, and therefore the pneumatic/structure/static aeroelasticity multidisciplinary comprehensive optimization design process is achieved through iterative optimization of the pneumatic appearance parameters and the structure parameters.

The invention discloses a structural reliability analysis method based on an agent model under the condition of hybrid uncertainty. The structural reliability analysis method comprises the steps that random uncertainty is modeled by adopting random variables, and epistemic uncertainty is modeled by adopting interval variables; uniform samples generated by the random variables in an approximate value section and all the interval variables within upper bounds and lower bounds of respective intervals and a system response value are used as training sample points for establishing a Kriging agent model, and according to the obtained Kriging agent model, the maximum values and the minimum values of the reliability sensitivity, the failure probability and the system failure probability under any interval variable value are calculated by adopting a Monte Carlo simulation method. By the adoption of the structural reliability analysis method, the problems that a traditional agent model under the condition of the hybrid uncertainty has a certain precision locally, and the traditional reliability analysis calculated quantity is larger are solved, and the structural reliability analysis method better accords with engineering practice.

The invention discloses a device and a method for testing porosity and adsorption parameters of gas-bearing shale, belonging to the fields of shale engineering and unconventional gas engineering. The device for testing the porosity and adsorption parameters of the gas-bearing shale comprises a constant-temperature triaxial cell, an axial pressure loading system, a confining pressure loading system, an upper end adsorbing system, a lower end adsorbing system, a vacuuming system, a constant temperature system and a data acquisition control system. The method for testing the porosity and adsorption parameters of the gas-bearing shale is used for simultaneously testing the porosity and adsorption parameters of the shale at different temperatures and under different bias environments and calculating the real adsorption quantity and is applicable to the environment with deep high ground stress and high temperature, the axial pressure is as high as 300MPa, the confining pressure is as high as 100MPa, the pressure of filled gas is as high as 70MPa, the highest temperature is up to 100 DEG C, a sample is a virgin rock core of which the size is as large as Phi 50mm*100mm, the test time is saved by nearly 75%, and the test efficiency is improved greatly.

The invention discloses a warship reliability quantitative requirement demonstration method. The method comprises the following steps of: 1, determining a warship reliability top layer parameter index; 2, decomposing the warship reliability top layer parameter index; 3, determining a warship reliability parameter limit value; 4, balancing the warship reliability parameter index and expense; and 5, analyzing the technical and economic practicability of the warship reliability parameter index. By adopting the method, a warship reliability quantitative requirement demonstration method which is consistent with the condition of China and has high operability is provided for the determination of a warship reliability parameter, warship reliability quantitative requirement demonstration work is guided, and reliability level of a warship is raised.

The invention discloses a water-rich weak surrounding rock long-and-big tunnel construction method. The method includes that a tunnel inclined shaft is arranged on one side of a main tunnel of a tunnel to be constructed, the main tunnel is divided into a tunnel entry section, a tunnel exit section and a middle connecting section connected between the tunnel entry section and the tunnel exit section, the middle connecting section is divided into an inclined shaft assisting construction entry section and an inclined shaft assisting construction exit section, and each of the tunnel entry section, the tunnel exit section, the inclined shaft assisting construction entry section and the inclined shaft assisting construction exit section is divided into multiple sections for construction. A construction method of each section includes: step 1, performing geological forecasting in advance, and when a debris flow formation exists ahead, entering a step 2, or else, entering a step 3; step 2, performing stability control construction; step 3, determining a primary supporting scheme; step 4, excavating the tunnel, and performing primary supporting construction; step 5, performing secondary lining construction on the tunnel. The water-rich weak surrounding rock long-big tunnel construction method is simple in step, reasonable in design, simple and convenient to construct, good in using effect, capable of meeting construction requirements of water-rich weak surrounding rock long-and-big tunnels, short in construction period and safe in construction process.

The invention belongs to the field of a reliable engineering technology and discloses a statistical analysis technique for an accelerated life test related to ineffectiveness in competition. The statistical analysis technique comprises the steps of acquiring relevant information and test data of the accelerated life test of a product; selecting an acceleration model and a copula model; building an MLE (Maximum Likelihood Estimation) model; estimating failure mode acceleration model parameters and copula function parameters of the product; and obtaining the distribution rule of the product life. According to the statistical analysis technique, based on a copula theory and a copula method, the product life and reliability level are estimated by a copula function as a tool connected with a correlationship between failure mode edge distribution of ineffectiveness in competition and joint distribution of product ineffectiveness in competition. The statistical analysis technique for accelerated life test related to ineffectiveness in competition and parameter estimation models are systematically built based on the copula theory at first time, so that the blank of the relative research field is filled, the product service life is prolonged, and the accuracy of reliability evaluation can be improved.

The invention discloses a method for estimating the stability of an anti-inclined slope, which belongs to the technical field of rock and soil engineering and is characterized by comprising the following steps: on the basis of slope geometric dynamic boundary conditions, determining the potential destruction mode of the anti-inclined slope; establishing a uniform expression formula of slope rock block physical quantities, such as equivalent inclination weight, transfer coefficients and the like, which only depend on slope rock block number, and sequentially establishing an inclination destruction stability analysis model of the anti-inclined slope to enable the slope inclination stability analysis to be formulized and programmed. The method is applicable for the condition of oblique crossing of two groups of structural surfaces and expands the applied range of slope inclination stability analysis; and meanwhile, the method is easy for compiling a stability analysis program on the basis of Excel which is widely familiar to engineering technical personnel, and realizes the rapid programmed analysis of the stability of the anti-inclined slope. The invention is applicable for the stability estimation work of the anti-inclined slope in the fields of mines, water conservancy and hydropower, roads and bridges and the like and has good engineering practical value.

The invention relates to a system maintenance time distribution method based on operation decomposition, which comprises the following steps: 1. analyzing tasks, the step of analyzing the tasks comprises distribution request analysis, distribution object analysis, maintenance activity and influence factor analysis, wherein the distribution object analysis is mainly used for determining distributive system levels, functions and structural levels of all components of a device, and a product decomposed into the needed level by the system, namely, a replaceable unit, and mapping systemic functions and structural level diagrams; and the number of the levels is determined by complexity level of the device; 2. obtaining data, obtaining existing data of a distribution object required to be analyzed, namely, data of a similar product, fault frequency data, reachability data, testability data and the like; 3. selecting a distribution method, selecting high-level distribution or low-level distribution according to the stage of product design and the product level; 4. distributing indexes, distributing maintainability indexes of the given product to product units at all levels according to the selected method; 5. analyzing a result, judging whether a distribution result is in line with requirements and is feasible.

The invention discloses a reliability assessment method for a power grid multi-link system. According to the method, influences of a power transmission network on the reliability of a power distribution network are quantified through the equivalence of the reliability of a load and the reliability of a power supply, the limitation of the assumption that traditionally the reliability of a traditional power distribution network is that the power supply is completely reliable is broken, and a calculation result accords with engineering practice of the power grid; in the method, a loop is used as the basic unit of a reliability assessment of the power transmission network, and a preconceived accident set is further formed, so that the system condition number in the preconceived accident set is substantially reduced, and the statistic analysis of engineering data of the reliability is facilitated. The reliability assessment method can be used for analysis of the sensitivity of reliability indexes to reliability parameters and enhancement measures relevant to the power transmission network or the power distribution network, and consequently planning, operation and maintenance of a power supply enterprise can be guided.

The invention relates to a system and method for tunnel water-bursting test under high crustal stress-osmotic pressure. The system comprises a main box used for simulating excavation of a tunnel model, the main box is of integrated structure and placed on a base, two opposite sides of the base are fixed on two slide rails, and an n-shaped counter-force frame is arranged between the two slide rails. The bottom ends of two support legs of the counter-force frame are fixed detachably on the slide rails. The top beam of the counter-force frame is fixedly connected with the top end of a loading system. An information monitoring element is arranged in the main box, the loading system and the information monitoring element are connected with a monitoring and controlling system. The monitoring and controlling system controls the loading system to apply crustal stress and osmotic pressure to the model material in the main box.Research on tunnel water bursting under the condition of high crustal stress-osmotic pressure engineering excavation turbulence is realized, and actual needs of the engineering are met.Further, fully automatic control of operation is realized and experiment operation is greatly facilitated.

The invention discloses a flight control method for large civil aircrafts on the basis of direct adaptive control reconfiguration, and relates to the field of control technology for aircrafts. The flight control method has the advantages that a direct adaptive process and a model following process are combined with each other and are applied to B747-200 aircrafts, control reconfiguration flight simulation for the large civil aircrafts in an actuator failure mode is implemented, reference is provided for control reconfiguration for the large civil aircrafts in the actuator failure mode, and accordingly the flight control method has an important significance in improving the safety of the aircrafts, reducing the accident rate of the aircrafts and improving the survival ability of the aircrafts under failure conditions.

The invention discloses a simulation and forecast evaluation method for delaying water inrush by a mine fracture structure, comprising the follow steps: (1) putting forward an analysis method that mechanism for delaying water inrush, inoculation process and fracture structure hydraulic properties change with the time going because of the action of mining engineering under the condition of hydrogeological parameter variation due to stress strain redistribution; according to the water-rock interaction theory, analyzing circulation process of mutual action and mutual influence among stress, strain and permeance performance of the substances in fracture zone, and the genesis mechanism for hydraulic property conversion under the disturbance of the mining engineering; (2) according to the coupling rule of the mechanics parameters and the hydraulics parameter of the rock body, putting forward a rheology-seepage coupling simulation evaluation method under the variable parameter condition. The rheology-seepage coupling simulation evaluation method under the variable parameter condition builds the variable parameter rheology stress field and the seepage field coupling model by virtue of complying with the coupling rule of the mechanics parameters and the hydraulics parameter of the rock body, considering the substances in the fracture zone as rheopectic material, and basing on the rheological model of the rock body under the variable parameter condition.

The invention discloses a reliability design method of a force applying component of a high-speed press considering multiple types of uncertainties. The method includes the following steps: considering the random, interval and fuzzy uncertainties of high-speed press force components, choosing the minimum reliability value under the influence of three uncertainties as reliability index, establishing the stochastic model of high-speed press force components, and establishing the stochastic model of high-speed press force components; interval-Fuzzy mixed reliability design model; according to theconservation principle of entropy and '3 sigma criterion', a simplified stochastic-interval reliability design model; adopting Latin hypercube sampling and cooperative simulation technology, the Kriging model of function and objective function is constructed. The simplified reliability design model is decoupled from the reliability analysis to form a two-loop optimization solution. The inner loopuses adaptive step-size iterative method for reliability analysis, and the minimum value of reliability index is obtained. The outer loop uses genetic algorithm to optimize the design vector, and judges the feasibility of the design vector according to the reliability analysis results. When the maximum evolutionary algebra or convergence threshold is reached, the optimal solution is output.

The invention discloses a method for determining the first weighting supporting resistance of shallow thin bedrock coal seam mining, and relates to the technical field of coal seam mining. The method comprises the steps that the sliding instability supporting force of a non-symmetric three-hinged arch structure with an upper roof not picked and the length of a rock are determined; the sliding instability supporting force of a monocline rock structure is determined after the upper roof is picked; the non-symmetric three-hinged arch structure with the upper roof not picked is analyzed, and a first weighting support-surrounding rock relation model of shallow thin bedrock coal seam mining is established; a load transfer coefficient is determined; the load of the rock on the upper roof during first weighting is determined; the pressure transferred through sliding instability of the upper roof structure is determined; the weight of an immediate roof rock column is determined, and the first weighting supporting resistance of shallow thin bedrock coal seam upper roof is determined. According to the method, a top plate structure for first weighting of a shallow thin bedrock coal seam is fully considered, a mechanical model is established for resolving, the reasonable supporting resistance of a support in the first weighting period is obtained, and the method has important theoretical significance and practical value in achieving safe and efficient production of a mine.

The invention discloses a transformer maintenance decision method for optimizing reliability and economy. The transformer maintenance decision method comprises the following steps: (1) establishing a failure rate function and a reliability function considering preventive maintenance; (2) determining the maximum maintenance period of a transformer so that the transformer meets certain reliability; (3) performing regular preventive maintenance on the transformer in the maximum maintenance period, and performing optimization solution on the optimal preventive maintenance period by using maintenance cost minimality as a target function; and (4) determining the maintenance priority of transformer components through quantitative analysis of failure mode of internal parts of the transformers so that the maintenance schedule is more definite. The transformer maintenance decision method can solve the disadvantage that the decision of the preventive maintenance period of the transformer has no regard for the reliability change of the transformer and the influence on the system, and the maintenance of the transformer is optimized in the two aspects of reliability and economy.

The invention discloses a multi-parameter related degraded product reliability evaluation method considering multi-source uncertainty, and belongs to the technical field of product performance degradation modeling and reliability evaluation. The method comprises the following steps: analyzing a mission profile and a failure mechanism of a product, designing an accelerated degradation test, and measuring multi-element performance parameters of the product; aiming at degradation data of a single performance parameter, establishing an edge degradation model which considers multi-source uncertainty and degradation process nonlinearity at the same time, and deducing an approximate analysis form of a failure probability density function and a failure distribution function under the condition that a failure threshold value is given; establishing a joint failure distribution function of each performance parameter by using a Copula function; and obtaining each edge degradation model and an unknown parameter set in the Copula function by using maximum likelihood estimation to realize product reliability evaluation. According to the method, the problem that the reliability evaluation result lacks rationality due to the fact that influences of multi-source uncertainty and degradation process nonlinearity are not considered at the same time in an existing multi-parameter related degradation model is solved.