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248 results about "Strength reduction" patented technology

In compiler construction, strength reduction is a compiler optimization where expensive operations are replaced with equivalent but less expensive operations.

Method for calculating slope stability safety coefficient based on strength reduction of humidifying condition

InactiveCN107330182AOvercome the shortcomings of the unclear mechanical concept of the strength reduction methodLow shear strengthDesign optimisation/simulationSpecial data processing applicationsWeight changeUltimate tensile strength
The invention discloses a method for calculating the slope stability safety coefficient based on strength reduction of a humidifying condition. The method comprises the steps of testing the dry density rhod, the natural moisture content omega1, and the percentage of saturated moisture content omega2 of a slope soil body sample, testing the cohesive force c and internal friction angles of samples with different moisture contents, and calculating the volume weight gamma of the samples, wherein the formula of internal friction angles is shown in the description; drawing the relation curves of the cohesive force c and the internal friction angles respectively with the moisture content omega, and obtaining a mathematic formula of a fitting relation curve; adopting a dichotomy approximation method and considering the volume weight change, and calculating the moisture content omegaF when the slope is in critical failure; calculating the slope stability safety coefficient F. According to the method for calculating the slope stability safety coefficient based on the strength reduction of the humidifying condition, anti-shearing strength of the slope soil body is reduced based on the humidifying condition, the method better conforms to the engineering practice that the moisture content of the soil body is increased, and thus the strength is lowered due to rainfall infiltration or irrigation or the like, and the shortcoming that a prior strength reduction method is not clear in mechanical concept is overcome. When strength reduction is conducted, the adverse influence of the increase of the volume weight of the soil body on the slope stability is further considered. Therefore, the method for calculating the slope stability safety coefficient based on the strength reduction of the humidifying condition is more scientific and safer.
Owner:NORTHWEST A & F UNIV

Seafloor instability evaluation method

The invention relates to a seafloor instability evaluation method. The method comprises: firstly, selecting out critical geological factors influencing seafloor slope stability according to geological environment conditions of seafloor slope occurrence and basic conditions of seafloor slope instability; secondly, selecting out critical induction factors influencing seafloor slope stability through a decomposition mode and a decomposition effect of natural gas hydrates, and constructing a seafloor slope stability influence factor index system; thirdly, constructing a seafloor slope geomechanics model by generalizing the seafloor slope stability influence factor index system; and finally, based on a Mohr-Coulomb failure criterion, proposing a mathematic method for evaluating seafloor slope stability, i.e., an improved finite element strength reduction method, and analyzing an evolutional process of seafloor slope stability and seafloor slope instability induced by decomposition of natural gas hydrates. The method is scientific in principle, high in calculation precision and short in calculation time, considers the induction factors of seafloor slope instability caused by decomposition of natural gas hydrates for the first time, gives out a deformation process of slope instability in combination with the geomechanics model and the finite element numerical analysis method, and has important practical application values.
Owner:INST OF OCEANOLOGY - CHINESE ACAD OF SCI

Dynamic change original position observation system for seabed interfacial layer

ActiveCN107328552ARealize synchronous observationObservation lastsHydrodynamic testingMeasuring open water movementOcean bottomSeabed sediment
The invention discloses a dynamic change original position observation system for a seabed interfacial layer. The dynamic change original position observation system comprises a seabed interfacial layer observation platform, an oscillating type detection rod penetrating apparatus and a multiparameter observation detection rod, wherein the seabed interfacial layer observation platform is used for loading various observation apparatuses and the oscillating type detection rod penetrating apparatus and is in riveted connection with the detection rod penetrating apparatus, the probe of an anti-sinking plate and a through hole are designed to form the laying stability and recovery convenience of an entire observation system, and the oscillating type detection rod penetrating apparatus uses a vibration exciter to generate vertical power to allow the observation detection rod to continuously insert in seabed deposit. New design principle and means are employed, partial liquefaction and strength reduction of seabed deposit can be realized through high frequency vibration, so that the observation detection rod can continuously insert in the seabed deposit, and the implementation is more convenient. The multiparameter observation detection rod is connected with the vibration exciter, and integrated with various sensors to realize synchronous observation of three-phase media of sea water body-seabed interface-seabed deposit. A water inlet fine pipe is provided and a water inlet when opened during recovery can eliminate vacuum suction on the bottom of the detection rod to facilitate recovery. The observation system provides essential technology support for researching dynamic evolution of the seabed interfacial layer.
Owner:OCEAN UNIV OF CHINA

Construction method of ultra-deep underground diaphragm wall in water-rich soft-soil area

The invention relates to the technical field of civil engineering construction, in particular to a construction method of an ultra-deep underground diaphragm wall in a water-rich soft-soil area. The construction method comprises the following steps: making an analysis and research on the stability of trench walls of the underground diaphragm wall and doing relevant preparations, preparing wall protecting slurry, building a guide wall, performing trenching construction, wall cleaning and sediment removal, manufacturing and hoisting reinforcing cages, backfilling joints between trench sections, and pouring wall concrete. According to the construction method, through a stability analysis method that introduces strength reduction, the security coefficients of stability of the trench walls are calculated based on a finite difference method; through parameter-reduction circular calculations, not only the limit stress and large deformation state of the trench walls but also the stability coefficients of the trench walls are obtained, which has practice guiding significance in construction; and the results are simple and practical and conform to the habits in the engineering field, and the stability requirements of the trench walls are effectively guaranteed, so that the engineering construction can be completed safely and fast with high quality.
Owner:CHINA RAILWAY NO 2 ENG GRP CO LTD +1

Drilling power tool, drilling tool and drilling method for forming boreholes

The invention discloses a drilling power tool, a drilling tool and a drilling method for forming boreholes. The drilling power tool comprises an energy conversion mechanism and a valve shaft system. The energy conversion mechanism is a rotary generator. The valve shaft system comprises a stator, a rotor, a movable valve sheet assembly, a fixed valve sheet assembly and a shaft assembly, wherein the rotor makes a reciprocating motion right and left and drives the movable valve sheet assembly directly connected with the rotor. The energy conversion mechanism is a screw rod or a turbine or an impeller. According to the invention, when a drilling bit is rotated, the drilling pressure at the drilling bit and the drilling pressure at the bottom of a drilling well are similar to the continuous gentle change of the sine law, which is favorable for the strength reduction of surrounding rocks and the development of fractures, so that the rock breaking efficiency can be improved obviously. In addition, because the pressure at the drilling bit and at the bottom of the drilling well is changed periodically, the negative-pressure injection and the high-pressure injection are generated alternately; and when the pressure becomes lower, the well drilling in an underbalance manner or by using the gas drilling fluid is carried out, so that the surrounding rock environment is changed, and the mechanical drilling rate is improved obviously.
Owner:SINOPEC OILFIELD EQUIP CORP +1

Crease-resistant finishing method for point-like crosslinked fabric based on spraying method

The invention relates to a crease-resistant finishing method for point-like crosslinked fabric based on a spraying method. Precisely-controllable spraying equipment is utilized to uniformly spray a crease-resistant finishing agent on the fabric at a certain dimension and at a certain interval, uniform dense uncontinuous crosslinked points are formed in the fabric after thermal processing and/or electron-beam irradiation are/is performed, so that the point-like crosslinking structure is formed. The crosslinking points fix molecular chains, prevent large slippage of the molecular chains and provide crease resistance for the fabric. Certain relative movable capability is provided between the molecular chain segments among crosslinking points and fiber, so that the fabric is endowed with softness and high tensile-strength retention rate, and the tensile-strength reduction phenomenon easily caused by routine fabric crease-resistant finishing method is prevented. The provided method has the advantages of being simple in operation, high in processing efficiency, green and environment-friendly, and high in economic benefit. The prepared product is good in crease resistance, soft in handfeeling, free of obvious reduction on tensile strength and good in tensile-strength retention rate, and is applicable to clothes, bedding articles and the like.
Owner:JIHUA 3509 TEXTILE +1

Design method of embedded type anti-slide piles

The invention discloses a design method of embedded type anti-slide piles and relates to the field of landslide control. The design method comprises the steps as follows: firstly, acquiring landslide system parameters; then, setting I groups of embedded type anti-slide piles with different pile parameters, and establishing a landslide system finite element model according to a Mohr-coulomb matching D-P criterion under a plane strain condition; finally, solving strength reduction safety coefficient Si of each group of anti-slide piles, and selecting pile parameters of the anti-slide piles closest the safety coefficient threshold STH as pile parameter solution values. Landslide systems with different pile parameters are established, the strength reduction safety coefficients of the landslide system with pile parameters are solved by the aid of landslide system finite element model, and the anti-slide piles closest to the safety coefficients are selected. With the adoption of the design method, the pile-soil combined action is fully considered, failure modes and safety coefficients after setting of the anti-slide piles are obtained through strength reduction calculation, the advantages of the embedded type anti-slide piles are truly played, the design method is safe, and the overtopping phenomenon is avoided.
Owner:LOGISTICAL ENGINEERING UNIVERSITY OF PLA

A method for determining tunnel limit displacement

The invention discloses a method for determining tunnel limit displacement. The method comprises the steps of establishing a finite element numerical model; determining main mechanical parameters of the surrounding rock; wherein the tunnel site region ground stress adopts a self-weight ground stress field; determining a key monitoring point; simulating an excavation and support process; checking model rationality; dividing the surrounding rock strength by the reduction coefficient, and simulating an excavation and support process; if the calculation does not meet the stop condition, returningto the previous step and increasing the reduction coefficient until the stop condition is met; extracting the key point displacement of the previous reduction step reaching the stop condition; and theobtained key point displacement is multiplied by a measurable coefficient to serve as tunnel limit displacement for monitoring, measuring and early warning. The limit state and the limit displacementof the tunnel surrounding rock are obtained through surrounding rock strength reduction, operation is easy, reliability is achieved, cost is low, the influence of factors such as the tunnel section type, the buried depth, the construction procedure and the supporting structure on the tunnel limit displacement can be considered, and necessary technical support is provided for researching the tunnel limit displacement and establishing a monitoring and measuring early warning standard.
Owner:HEBEI PROVINCIAL COMM PLANNING & DESIGN INST

Method for calculating stability safety factor of concrete gravity dam under multi-dam-section combined skid resistance condition

The invention relates to a method for calculating the stability safety factor of a concrete gravity dam under a multi-dam-section combined skid resistance condition and belongs to the field of gravity dam stability analysis. According to the method, a three-dimensional stability analysis calculation model is established on the basis of a three-dimensional rigid body limit balance analysis and strength reduction method by aiming at a situation that key slots are formed or grouting is performed between dam sections of the concrete gravity dam so as to combine slide resistance; by introducing a plurality of reasonable assumption and unbalanced force transfer concepts, the statically indeterminate problem of combined anti-sliding stability of multiple dam sections along a dam foundation surface is converted into a statically determinate problem; on the basis of solving out the independent anti-sliding safety factor of the dam sections, the transfer of unbalanced forces of adjacent dam sections on a river valley side is considered, circulation calculation is performed, and the overall stability safety factor of combined slide resistance of multiple dam sections, the sequence of sequentially achieving limit balance by each dam section and the local stability safety factor of the dam sections are solved out. The method has the characteristics of easiness for realization of programming, reasonable calculation result and the like, and is convenient in popularization and application in practical engineering.
Owner:HOHAI UNIV

Finite element stability calculation method for filling slope of composite foundation

The invention discloses a finite element stability calculation method for a filling slope of a composite foundation. The method comprises the following steps that firstly, rock-soil physical and mechanical parameters of all materials are determined through a field test or an indoor test; 2, determining the arrangement form, the arrangement interval and the pile body diameter of the pile body; and3, calculating the cohesion Cc of the composite foundation, the internal friction angle phic of the composite foundation, the elasticity modulus Ec of the composite foundation and the volume weight gammac of the composite foundation within the pile body arrangement range according to the following formula; 4, establishing a filling slope finite element model with a composite foundation, calculating soil parameters of a composite foundation area through the calculation result in the step 3, and calculating the slope stability safety factor FOS through a strength reduction method. Compared withthe prior art, the method has the advantages that compared with a finite element model for establishing a complete pile body, the calculation precision of the method does not exceed 3%; 2, the calculation time of the method only needs to establish 1 / 10-1 / 8 of the finite element model calculation time of the complete pile body;
Owner:ZHENGYE ENG & INVESTMENT INC

Aerodynamic design method of subsonic adsorption type axial compressor

ActiveCN103244459AIncrease axial speedReduce the diffusion factorPump componentsPumpsAxial compressorEngineering
The invention belongs to the technical field of axial compressors, and relates to an aerodynamic design method of a subsonic adsorption type axial compressor, in order to solve the problems of increasing of blade rotating angles of a subsonic axial compressor and boundary layer separated in a moving blade during stage load increasing as well as the problems of suction pipeline layout difficulty, blade strength reduction and the like caused by boundary layer suction in the moving blade. On the premise of unchanging an inlet velocity triangle, with design stage load coefficient increasing gradually and exceeding a conventional design value, outlet axial velocity of the moving blade is increased greatly so as to reduce diffusion factors in the moving blade, so that efficient flow of the moving blade is guaranteed; and boundary layer suction is utilized for achieving internal flow of a fixed blade. As boundary layer suction is performed in the moving blade as well as the fixed blade, problems of poor blade strength of a rotatable part and difficulty in suction structure design are solved effectively; and as compared with a tandem cascade technique, the aerodynamic design method has the advantages that blades can be decreased, and accordingly size and weight of an engine are reduced. The method can be applied to aerodynamic design of aero-engines with high thrust-weight ratio.
Owner:HARBIN INST OF TECH

Forming and fabrication method of ultra-high strength steel seamless high pressure gas cylinder

The invention belongs to the technical field of the processing of seamless steel tubes and provides a forming and fabrication method of an ultra-high strength steel seamless high pressure gas cylinder. The forming and fabrication method of the ultra-high strength steel seamless high pressure gas cylinder specifically comprises the following steps of 1) heating the nosing sections of a seamless steel tube for processing the large-volume steel seamless high pressure gas cylinder to a temperature of 1000-1200 DEG C; performing hemispheric nosing and spinning on the nosing sections of the seamless steel tube for 8-10 times to obtain hemispheric cylinder shoulders; 3) obtaining the cylinder lip by performing cylinder lip spinning forming on the seamless steel tube for 3-4 times; 4) finishing and spinning the surface. According to the forming and fabrication method of the ultra-high strength steel seamless high pressure gas cylinder, ultra-high strength steel with the yield strength larger than 980 MPa can be used for fabricating the seamless high pressure air cylinder of 40 MPa level; shortcomings such as incontinuity, strength reduction, brittle fracture and tensile stress concentration and the like due to welding seams of a welded air cylinder produced through a traditional method can be prevented, and the gas tightness and pressure-resistant performance of the air cylinder can be greatly improved.
Owner:LUOYANG SUNRUI SPECIAL EQUIP

Landslide deformation prediction computing method

The invention discloses a landslide deformation prediction computing method. The method comprises the steps that 1 a full strain stress test and a creep test are carried out, and the equal deformationafter a rock and soil body exceeds a peak point is used as a reference to establish relation between a full stress strain test curve and a creep test curve to acquire the curve of mechanical parameters of the rock and soil body, wherein the curve changes with time; 2 the tested mechanical parameters of the rock and soil body are used to acquire the curve of the landslide deformation of differentrock and soil body mechanical parameters through a finite element strength reduction method, wherein the curve changes with time; and 3 a slope finite element computing model in a stress state predicts the landslide deformation value at the parameter according to the soil body mechanical parameter at the time of landslide. The method provided by the invention has the advantages that the rock and soil full stress strain test, the creep test and the finite element strength reduction method are combined to compute and analyze the landslide deformation; the computing is accurate; only full stressstrain and creep tests are needed; establishing a new constitutive model is not needed; and the method has the characteristics of clear mechanism, small spending cycle and good economic effect.
Owner:BC P INC CHINA NAT PETROLEUM CORP +2

Excavated soil body stability analysis method using deformation quantity as instability criterion

The invention discloses an excavated soil body stability analysis method using deformation quantity as an instability criterion. The excavated soil body stability analysis method comprises the following steps that 1, a soil body elastoplastic constitutive model capable of reflecting a stress deformation law of an excavation slope soil body is established, the relation between position displacement deformation amounts of typical characteristic points of an excavation slope and the internal stability of the excavation slope is determined through calculation and analysis of finite elements; 2, the reliability is verified by adopting a traditional limit equilibrium method; 3, normalization processing is conducted on the position displacement deformation amounts of the typical characteristic points of the excavation slope to obtain normalized deformation parameters, and the relation between the normalized deformation parameters and the internal stability of the excavation slope is established; 4, field monitoring of the actual deformation amount of the excavation slope is performed, and the internal stability of the excavation slope is determined and monitored according to the relation. Stress deformation analysis is conducted on the slope by adopting a finite element shear strength reduction method, and the deformation amount of the slope is related with the stability of the slope after being subjected to normalization processing.
Owner:HOHAI UNIV
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