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726 results about "Shear stress" patented technology

A shear stress, often denoted by τ (Greek: tau), is the component of stress coplanar with a material cross section. Shear stress arises from the force vector component parallel to the cross section of the material. Normal stress, on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts.

Weak surrounding rock tunnel deformation risk discrimination method based on shear expansion-shear constitutive structure

The invention relates to the field of tunnel engineering geology and support design, and discloses a weak surrounding rock tunnel deformation risk discrimination method based on shear expansion-shear constitutive, which comprises the following steps: constructing a nonlinear coupling model between a shear expansion angle and shear stress, normal stress and joint parameters, and obtaining the shear expansion angle; establishing a volumetric strain rate discrimination formula; inverting an initial crustal stress tensor field; reconstructing an irregular tunnel boundary; constructing a risk level discrimination model, and outputting a risk level; supporting schemes such as supporting rigidity, anchor rod parameters and spraying layer thickness are matched according to the risk grades; establishing a model to predict a risk trend; a support adjustment suggestion is generated; collecting monitoring data to dynamically correct model parameters; and all the modules are integrated in a deployment system. According to the method, the coupling relation between the shear expansion angle and the shear strength is introduced, the coupling type constitutive discrimination model is established, the risk grading system and the support correction strategy associated with the support response are constructed, and active early warning of the high-risk section and dynamic adjustment of the support rigidity are achieved.
Owner:HUAZHONG UNIV OF SCI & TECH

Settlement deformation prediction method and system for reinforced soil slope building structure

The invention relates to the technical field of slope engineering, in particular to a settlement deformation prediction method and system for a reinforced soil slope building structure. The method comprises the following steps: acquiring a soil body infiltration line position parameter of a reinforced soil slope, an interface friction coefficient of a reinforced material and a soil body, a soil body grain grading curve and environment temperature and humidity duration information, and obtaining initial characteristic data of a slope system state; constructing a heat-force-water multi-field coupling monitoring network in the soil-reinforced material interface area according to the initial characteristic data of the slope system state, and obtaining the interface shear stress, the interface normal strain, the pore water pressure gradient and the temperature gradient of each monitoring point to obtain interface action characteristic data. According to the method, the environment disturbance probability density model based on the temperature fluctuation and the sudden change of the water content is constructed, the influence of a complex environment on the slope stability can be quantitatively described, and the robustness of the model is improved.
Owner:TIANHE COLLEGE GUANGDONG POLYTECHNIC NORMAL UNIV

Bed load particle starting test method and device

The invention discloses a bed load particle starting test method and device, and relates to the technical field of hydromechanics, the method comprises the following steps: laying sediment particles in a wave water tank, and adjusting the water flow rate through flow control until the bed surface shear stress is less than the critical shear stress; tracer particles are excited to emit fluorescence through a laser beam, and a camera array is used for synchronously collecting instantaneous flow velocity of a flow field and displacement data of sediment particles; analyzing spatial and temporal distribution characteristics of turbulence energy dissipation and pressure energy dissipation based on a turbulence burst process, and establishing a sediment particle starting mathematical model; experimental data and computational fluid mechanics numerical simulation are combined, and the mathematical model is verified and optimized. According to the technical scheme, the analysis precision and the experimental convergence speed of the sediment starting criterion under the complex hydrodynamic force condition can be remarkably improved, and full-chain efficient cooperation from micromechanical response to macroscopic engineering application is achieved.
Owner:ZHEJIANG INST OF HYDRAULICS & ESTUARY +1

Monitoring and early warning system for geotechnical engineering

The invention discloses a monitoring and early warning system for geotechnical engineering, and relates to the technical field of geological disaster early warning. A monitoring and early warning system for geotechnical engineering comprises a data acquisition module, a data processing module, a model construction module and a disaster early warning module. According to the method, the displacement and the shear stress of the rock-soil body are predicted through the displacement-hydrological-geological coupling prediction model, so that the comprehensive influence of the mechanical state of the rock-soil body and environmental factors on geotechnical engineering disasters can be more comprehensively reflected, and the coupling effect of various monitoring data can be comprehensively considered; therefore, prediction errors and uncertainty caused by data missing or model singleness can be effectively reduced, hydrological data are processed through causal convolution, the long-term dependency relationship among the hydrological data can be effectively captured, the relevance and hysteresis among the water level, the rainfall and the pore water pressure can be reflected, and the prediction accuracy of the hydrological data is improved. Therefore, the accuracy of model prediction can be remarkably improved, and the early warning accuracy of the monitoring and early warning system is also improved.
Owner:FUJIAN RONGQI CONSTR ENG CO LTD

Rock soil stability prediction method and system based on machine learning

The invention relates to the technical field of machine learning, in particular to a rock and soil stability prediction method and system based on machine learning, and the method comprises the following steps: extracting shear stress, displacement and energy dissipation rate time series data, calculating the stress change rate of adjacent time steps, screening the stress increment sudden change period, and calculating the shear deformation gradient change rate. Mutation points in the strain direction are screened, and a key variable interval is obtained. According to the method, traditional analysis limitation is broken through by combining displacement-stress second derivative and energy dissipation rate cross validation, a hardening-softening conversion area is dynamically identified, multi-stage strain gradient differences are compared to establish a space-time correlation parameter system, and static and dynamic parameter conversion is realized by using a strain increment space gradient tracking technology; and quantitative mechanical interaction and energy dissipation collaborative analysis is carried out to describe a stress diffusion path, stress release characteristics and deformation gradient distribution are fused to construct a fracture principal direction multi-dimensional verification mechanism, and a microscopic fracture and macroscopic instability correlation model is established.
Owner:SHAANXI AGRICULTURE & FORESTRY VOCATIONAL & TECHNICAL UNIVERSITY

Method for simulating and deducing torsion cycles

The invention relates to the field of mechanical fatigue simulation, and discloses a method for simulating and deducing the number of torsion cycles. Comprising the steps that a component three-dimensional parameterized model is constructed, and material fatigue characteristics are defined; applying a periodic torsion load spectrum containing a harmonic component; adopting a stress influence coefficient matrix method to execute quasi-static finite element analysis, and extracting a multi-axis stress state; calculating the maximum alternating shear stress and the average shear stress based on a critical plane recognition technology; converting into a single-axis equivalent stress amplitude through a gradient enhanced multi-axis correction rule; calculating node fatigue damage by combining an S-N curve and a damage accumulation theory; and when the damage reaches a threshold value, outputting a failure cycle number and a position. The innovation points are as follows: the prediction error is controlled within 10% by a critical plane and multi-axis correction technology; a stress matrix method realizes ten thousand times of cycle-level efficient simulation, and the efficiency is improved by 10 times; the risk early warning accuracy rate is improved to 96% by integrating a process correlation defect model; and the research and development period is shortened by 40% through a life cloud picture and an automatic optimization closed loop. The method is suitable for transmission shaft system reliability design.
Owner:NANJING ZHENGCHENG JIAMING INTELLIGENT TECHNOLOGY CO LTD

Rolling contact fatigue pitting corrosion prediction method considering crystal plasticity, corresponding computer readable storage medium and electronic equipment

The invention belongs to the field of prediction of fatigue failure caused by surface defects under rolling contact loads, and particularly relates to a rolling contact fatigue pitting corrosion prediction method considering crystal plasticity, a corresponding computer readable storage medium and electronic equipment. The method comprises the following steps: S1, constructing a crystal plastic constitutive model of a coupling damage accumulation theory; s2, developing the model in the step 1 into a UMAT subprogram by using Fortran, and embedding ABAQUS into the UMAT subprogram; s3, establishing a representative volume element crystal plastic finite element model; s4, applying a periodic boundary condition and a shear load, obtaining a shear stress-strain curve, carrying out a torsional fatigue test, obtaining fatigue damage parameters of the material, and determining constitutive model parameters of the material; s5, establishing a crystal plastic finite element model of the roller and raceway contact pair; s6, applying boundary conditions in two steps; and S7, observing a damage evolution path to the surface, and obtaining the rolling contact fatigue pitting corrosion life. The method can fill the blank of rolling contact fatigue pitting corrosion prediction methods at present.
Owner:HARBIN INST OF TECH ZHENGZHOU RES INST +1

Numerical test method considering direct shear-seepage of rock joint under different boundary conditions

The invention belongs to the technical field of direct shear-seepage tests of rock joints, and discloses a numerical test method for direct shear-seepage of rock joints under different boundary conditions, which comprises the following steps of: establishing a joint surface numerical model by using finite element software, and performing tests for simulating joint shear mechanical behaviors by applying different boundary conditions. And the contact state and the opening distribution of the joint surface under different shear displacements are obtained, so that the shear stress evolution mechanism of the joint surface is better revealed, and the mechanical behavior of the rough joint surface in the shear process is accurately expressed. According to the method, the evolution law of mechanical properties in the joint shearing process can be reflected, the influence of shearing deformation on the joint seepage characteristics can be reflected, joint opening data distribution is imported into programming software to be processed, a joint seepage numerical model is constructed, then multi-physics field simulation analysis software is imported, and the joint seepage performance is improved. The flow velocity, the osmotic pressure and the streamline distribution characteristics in the flowing process are calculated, so that the joint permeability characteristics are analyzed.
Owner:SHANDONG UNIV OF SCI & TECH

Estimation method for boundary shear stress of salt rock single crystal slippage surface

The invention discloses a method for estimating the boundary shear stress of a salt rock single crystal sliding face, belongs to the technical field of geotechnical engineering mechanics and material mechanics, and establishes a frame capable of directly estimating the boundary shear stress of the salt rock single crystal sliding face based on the Hall-Pearch theory. The mapping from the measurable macromechanical parameters to the boundary shear stress of the microcosmic single crystal slippage surface is realized. The method only needs conventional cold pressing preparation, EBSD grain size data and uniaxial compression test results, and does not need to depend on high-cost FIB microcolumn compression or in-situ nanoindentation tests. The method can provide more accurate material mechanical parameters for salt cavern design, creep stability analysis and underground engineering safety evaluation, and has good engineering applicability and wide engineering application prospects.
Owner:XI'AN UNIVERSITY OF ARCHITECTURE AND TECHNOLOGY +1

Method for determining critical anchoring length of anchor rod based on numerical simulation

The invention relates to the technical field of anchoring structure design, in particular to a method for determining the critical anchoring length of an anchor rod based on numerical simulation. Firstly, the critical anchoring length is determined, a short anchor rod pull-out test is conducted on site, a pull-out force and displacement curve of the anchor rod is obtained through the field test, the pull-out displacement curve is converted into the relation between shear stress and shear displacement through a formula, then numerical simulation is conducted, FLAC3D is selected for numerical simulation of the pull-out test, and the tensile strength of the anchor rod is improved. By increasing the nodes of the pile structure units and continuously increasing the drawing length of the anchor rod, a large number of tests do not need to be carried out on site, the influence of site environment and human factors on the determination of the anchoring length of the anchor rod does not need to be considered, manpower and material resources are saved, and the mechanical property of site surrounding rock is not destructed; and engineering can be well adapted.
Owner:ANHUI UNIV OF SCI & TECH

Method and system for characterizing rheological characteristics of submarine landslide mass

A method for characterizing thixotropic characteristics of submarine landslide mass material, including: performing steady shear on landslide mass material, and determining solid-fluid transition boundary according to variation of yield stress value in yield stress test; performing conversions between shear speed and shear rate and between shear torque and shear stress according to variations of apparent viscosity-shear speed and shear torque-shear speed of landslide mass material at different shear times in apparent viscosity test to obtain variations of the apparent viscosity and the shear stress at different shear rates to construct conventional rheological model; constructing thixotropy characterization equation according to variations of the shear stress and the apparent viscosity with the shear time in the thixotropy test; and constructing rheological model for characterizing the thixotropic characteristics of the submarine landslide mass material according to the solid-fluid transition boundary, the conventional rheological model, and the thixotropy characterization equation.
Owner:SHANDONG UNIV

Solid wood furniture material detection method and system

The invention relates to the technical field of material detection, in particular to a solid wood furniture material detection method and system.The method comprises the following steps that form data of a furniture bearing component under the shearing-bending loading condition is obtained, wood connection node imaging is collected, crack displacement is calculated according to a loading sequence, and a fiber bonding point load value is extracted; and calculating the furniture crack growth rate. According to the method, form data is collected through shear-bending loading, crack displacement and fiber bonding point load calculation is achieved, the crack propagation rate is more accurate, the pixel displacement gradient and the maximum shear stress gradient area are combined, the stress concentration point recognition precision is improved, the crack path is tracked based on the local shear stress gradient, and the interlayer energy consumption rate is calculated. Extracting a critical state, identifying a crack instability point, improving damage evolution prediction precision, and improving bending resistance and shearing resistance evaluation comprehensiveness and quality detection reliability in combination with multi-layer stress change and gradient calculation.
Owner:GANZHOU XIANMU LIVING FURNITURE CO LTD

Three-dimensional rough fractured rock mass seepage heat transfer numerical simulation method and device

The invention discloses a numerical simulation method and device for seepage heat transfer of a three-dimensional rough fractured rock mass, and relates to the technical field of rock mechanics engineering.The dynamic opening degree of the fractured rock mass is obtained by combining the initial opening degree and the equivalent opening degree of the fractured rock mass, and in the process of obtaining the dynamic opening degree of the fractured rock mass, the dynamic opening degree of the fractured rock mass is obtained. According to the method, based on the initial opening and the equivalent opening, the coupling influence of the shear expansion effect and roughness degradation on the fracture opening under the action of shear stress is quantified, and then based on the dynamic opening of the fractured rock mass, the point cloud data of the upper and lower fracture surfaces of the fractured rock mass after shearing is updated; the dynamic updating of the three-dimensional geometrical morphology of the real fracture in the shearing process is realized, and the bidirectional coupling simulation of the seepage field and the temperature field is realized based on the three-dimensional geometrical morphology data of the real fracture, so that the precision of the seepage heat transfer numerical simulation of the fractured rock mass is improved.
Owner:INNER MONGOLIA UNIV OF TECH

Fault stability evaluation method considering pressure-stress coupling effect

The invention relates to a fault stability evaluation method considering a pressure-stress coupling effect. The method comprises the following steps: calculating a pressure-stress coupling ratio according to target layer rock mechanical parameters or field actual measurement pressure and ground stress data; fault three-dimensional structure modeling is carried out based on the seismic interpretation result, and fault occurrence distribution is simulated and calculated; analyzing and calculating the initial stress of the section and the stress after the coupling action by combining the three-way principal stress, wherein the stress comprises shear stress and effective normal stress; a quadratic equation of unary about fault instability critical pressure is constructed, and fault instability risk types are judged in combination with the actual pressure limit of oil field production; and calculating the critical pressure of fault instability under different risk types. According to the method, the influence of the pressure-stress coupling effect on the fault stability can be considered, so that the fault stability evaluation result is more practical.
Owner:NORTHEAST GASOLINEEUM UNIV

Structural surface ring shear creep test method under real-time water pressure rise and fall and dry-wet cycle action

The invention discloses a structural plane ring shear creep test method under real-time water pressure rise and fall and dry-wet cycle action, which comprises the following steps: S1, applying shear stress step by step to a preset peak strength ratio by adopting a constant normal stress and shear stress graded loading mode; s2, under the working condition of loading each stage of shear stress, performing dry-wet cycle and / or water pressure rising and falling cycle operation synchronously; s3, based on test data, analyzing creep deformation characteristics, long-term strength and failure rules of the structural plane; the device synchronously simulates reservoir water level rising and falling and dry-wet circulation in a ring shear creep test, and can be applied to long-term stability prediction and control measure optimization design of reservoir bank rock slopes and other rock shear tests needing to simulate water pressure change and dry-wet circulation conditions.
Owner:CHANGJIANG INST OF TECH +1

CFD (Computational Fluid Dynamics) method for near-continuous hypersonic thermochemical non-equilibrium flow

The invention relates to a CFD (Computational Fluid Dynamics) method for nearly continuous hypersonic high-temperature thermochemical unbalanced flow numerical simulation, which comprises the following steps of: 1, introducing a Park double-temperature model into an NS equation to describe a thermochemical unbalanced effect at high temperature, and closing a shear stress tensor, a heat flow vector and a mass diffusion flux by adopting an equivalent constitutive model to obtain a closed shear stress model; capturing speed slippage and temperature jump phenomena on the wall surface by adopting corresponding slippage boundary conditions to obtain a macroscopic control equation and boundary conditions suitable for near-continuous hypersonic high-temperature thermochemical non-equilibrium flow; 2, discretely solving the macroscopic control equation and the boundary conditions given in the step 1 by adopting a finite volume method; and step 3, performing post-processing on a solution result obtained in the step 2 to obtain a streaming flow field, a wall surface aerodynamic force and a wall surface heat flow of the calculated appearance.
Owner:TIANJIN UNIV

Process control optimization method and system based on metal composite material

The invention relates to the technical field of intelligent manufacturing, in particular to a process control optimization method and system based on a metal composite material, and the method comprises the following steps: extracting a crystal grain deviation section based on a path crossing section, judging shear response delay, recognizing a rhythm difference region, dividing a shear strain trend mutation section, and building a boundary layer partition map; and sorting shear stress responses, constructing a slippage thermal orientation chain, and adjusting a loading sequence to obtain a path section structure table. According to the method, the change trend of the included angle between the grain arrangement and the path is analyzed, the grain section deviating from the main direction of the path is extracted, the time difference between the shear response moment and the loading rhythm is combined, the response differentiation area is identified, and the deformation direction turning section is divided according to the trend divergence of the shear strain direction between layers; and constructing a response sequence by utilizing the consistency of grain boundary slippage and heat flow direction, comparing a path loading sequence with a response offset relationship, matching a path direction with a structure rhythm, and enhancing the coherence of a loading action and a grain slippage trend.
Owner:XINRIXIN METAL MATERIALS (SHENZHEN CO LTD

Saturated porous medium metasurface Portrait wave frequency dispersion relation calculation method and system

The invention relates to the technical field of physical acoustics, in particular to a saturated porous medium metasurface Portrait wave frequency dispersion relation calculation method and system, and the method comprises the following steps: obtaining expressions of solid skeleton displacement, fluid relative displacement, total stress, solid shear stress and pore pressure under the action of Portrait waves; obtaining an expression of a fluid displacement component and a fluid normal stress; obtaining an expression about the relative motion of the resonator; according to all the expressions, stress and displacement continuity boundary conditions are applied to the interface of the saturated porous medium and the fluid layer, a characteristic equation of frequency dispersion characteristics is obtained and solved, and a frequency dispersion curve is obtained. According to the method, the explicit frequency dispersion relation of the saturated porous medium metasurface portrait waves is provided, the calculation efficiency and prediction precision of complex interface wave propagation are improved, the optimal design of the metasurface resonator array can be guided, and a key theoretical tool and technical support are provided for design of high-performance acoustic functional devices and structures.
Owner:EAST CHINA JIAOTONG UNIVERSITY

Method and system for analyzing reflooding cooling process

The invention discloses a reflooding cooling process analysis method and system. The method comprises the following steps: step 1, obtaining reflooding process data; 2, according to the re-submerging process data, obtaining a liquid core shear stress relation and a constitutive relation, and obtaining a disturbance wave height; 3, according to local shock cooling in the cooling process, a liquid film dynamic equilibrium relation is constructed, and the average vapor film thickness is obtained; 4, axial distribution of the minimum film state boiling temperature is obtained according to the disturbance wave height and the average steam film thickness; 5, shock cooling moments at different axial heights are obtained according to the axial distribution of the minimum film state boiling temperature, the relationship among the shock cooling speed, the shock cooling moments and the heights is obtained, the shock cooling speed of all the shock cooling moments is solved, and then analysis of the re-submerging cooling process is completed; according to the method, the problem of strong correlation of time-physical behaviors of two-phase evolution in the whole re-submerging process is solved, and accurate prediction of the whole strong transient re-submerging cooling process is realized.
Owner:CHONGQING UNIV

Support installation angle measuring device for photovoltaic power generation

The invention discloses a support installation angle measuring device for photovoltaic power generation, which relates to the technical field of measurement and comprises an installation position structure, a magnetic field control assembly and a measuring assembly. The installation position structure is arranged at the connection position of a stand column and a cross beam of the photovoltaic support, the connection point of an inclined supporting rod and a main frame and the connection area of a base and a foundation, under the cooperation of the magnetorheological fluid cavity assembly and the magnetic field control assembly and the design of a spiral flow guide groove and a cone frustum cavity, the fluid distribution uniformity is improved, and under the action of a magnetic field, the fluid distribution uniformity is improved. The spiral flow guide grooves guide the magnetorheological fluid to form spiral flow and cooperate with a rotating magnetic field, the support fixing effect is remarkably enhanced, and when the support deviates due to external force, the micro stress sensor of the magnetorheological fluid cavity reversely deduces the angle through shear stress changes and feeds the angle back to the magnetic field control assembly for real-time correction. Therefore, stress is released and deformation is corrected under extreme working conditions such as strong wind and earthquakes, and the accuracy and response speed of angle control and measurement of the support are greatly improved.
Owner:DA AN RUN FENG ENERGYDEVELOPMENT CO LTD

Estimation method for fatigue crack propagation rate of laminated structure

The invention discloses a method for estimating the fatigue crack propagation rate of a laminated structure, and belongs to the technical field of laminated structure fatigue crack prediction. The invention aims to solve the problem that the prediction of the existing fatigue crack growth rate cannot be separated from experimental data support. Comprising the following steps: dividing a laminated structure into an upper sub-beam and a lower sub-beam, calculating tangential displacement and normal displacement of a crack interface, and calculating tangential traction force and normal traction force of the layered crack interface by combining the interface fracture toughness of the laminated structure; calculating the total strain energy of the laminated structure by combining the internal stress resultant force, the bending moment and the shear stress resultant force of the upper sub-beam and the lower sub-beam; establishing a laminated structure balance equation and obtaining a control equation set; and solving the control equation set to obtain the theoretically calculated crack length, cycle index, upper sub-beam applied load theoretical value and upper sub-beam displacement theoretical value of the laminated structure under the fatigue load of the laminated structure, calculating to obtain the cycle energy release rate, and further calculating to obtain the crack growth rate. The method is used for estimating the fatigue crack growth rate.
Owner:HARBIN INST OF TECH

Accurate feeding control method, device and system for solid waste-based material 3D printer

The invention relates to an accurate feeding control method, device and system for a solid waste-based material 3D printer, and the method comprises the following steps: S1, collecting the viscosity and shear stress data of a solid waste-based material in real time based on a miniature rheological sensor array at an inlet of a spiral feeder by adopting a wavelet transform signal analysis method, and synchronously obtaining the material temperature through a temperature sensor, and constructing a material rheological characteristic dynamic model, and generating a dynamic rheological characteristic matrix. The method has the advantages that the real-time model is constructed by dynamically sensing the rheological characteristics of the material and fusing temperature data through a wavelet transform signal analysis method, and the capture precision of the heterogeneity of the solid waste material is remarkably improved; multi-source heterogeneous sensor data is subjected to fusion analysis through a graph neural network, the fluidity index and the blockage risk probability are accurately quantified, and the effect of early warning of abnormal working conditions is achieved.
Owner:BEIJING CHONGJIAN ENG +1

Anchoring structure internal force calculation method of internal anchoring type anchor rod

The invention belongs to the technical field of engineering protection and treatment, and discloses an anchoring structure internal force calculation method for an internal anchoring type anchor rod, and the method comprises the steps: building a first shear stress coupling relation between axial displacement and an anchor rod mortar interface according to the stress balance condition, axial stress and axial displacement of the anchor rod; presetting a load transfer mode from an anchor rod to a mortar body to a surrounding rock body in the anchoring structure based on the shear hysteresis model, and constructing a second shear stress coupling relationship between the axial displacement and the shear stress of the anchor rod mortar interface and the shear stress of the mortar surrounding rock interface according to the load transfer mode; based on the first shear stress coupling relation, the second shear stress coupling relation and stress boundary conditions of the anchoring structure, an anchor rod axial force analytical equation and an internal shear stress analytical equation set of the anchoring structure are constructed; and calculating the axial force and the internal shear stress of the anchor rod of the anchoring structure according to the physical parameters and the construction parameters of the anchoring structure. According to the invention, the transmission analysis of the drawing load in the anchoring structure is realized, and the displacement axial force and interface shear stress distribution of the internal anchoring type anchor rod can be calculated.
Owner:NORTHWEST ENGINEERING CORPORATION LIMITED

Gear pair life prediction method based on dynamic stress

The invention discloses a gear pair life prediction method based on dynamic stress, belongs to the technical field of reliability design of mechanical transmission systems, and aims to solve the problem of inaccurate life prediction caused by neglecting a dynamic effect and a real surface topography in an existing gear design method. The method comprises the following steps: firstly, acquiring gear pair interface mechanical property parameters considering shafting vibration, dynamic load and surface roughness, wherein the parameters comprise transient oil film pressure, friction coefficient, oil film thickness and shear stress; solving a three-dimensional subsurface stress field by adopting an algorithm and calculating von Mises equivalent stress distribution; stress volume integration is conducted on different rough surfaces, the honed surface is used as the reference, the relative fatigue life of other surfaces is calculated based on the Zaretsky life prediction theory, and accurate prediction and process optimization of the contact fatigue life are achieved; meanwhile, the dynamic bending stress of the tooth root is calculated based on the dynamic normal load, and the bending fatigue safety coefficient is checked.
Owner:NO 703 RES INST OF CHINA SHIPBUILDING IND CORP +1

Chip packaging structure and chip packaging module

The utility model provides a chip packaging structure and a chip packaging module, the chip packaging structure is provided with a salient point and a welding column between a packaging body and a first substrate, and the welding column is at least partially arranged around the salient point, so that after the packaging body and the first substrate are connected through the salient point and the welding column, the packaging body and the first substrate are connected through the salient point and the welding column; the shear stress caused by thermal mismatch between the packaging body and the first substrate can be released by using the bending (rotational degree of freedom in a first plane) or stretching (stretching degree of freedom in a first direction) deformation of the welding columns, so that the situation that the stress generated by thermal mismatch between the packaging body and the first substrate cannot be released is reduced; therefore, the probability of packaging failure between the packaging body and the first substrate is reduced, and the reliability of the chip packaging structure is improved.
Owner:PHYTIUM TECH CO LTD

Steel shear key-based prefabricated segment beam bridge joint shear capacity calculation method

The invention discloses a method for calculating the shear capacity of a joint of a prefabricated segmental girder bridge based on a steel shear key, and belongs to the technical field of fabricated prefabricated segmental girder bridges. On the basis of a concrete local pressure bearing theory and a maximum shear stress failure criterion, the concrete local pressure bearing strength is corrected, and a shear bearing capacity calculation formula of a single steel shear key is established; according to the method, a theoretical stress model of the steel shear keys is constructed, a joint shear bearing capacity calculation formula based on the steel shear keys under the construction state of the fabricated prefabricated segmental girder bridge and a joint shear bearing capacity calculation formula under the bridge forming state are provided, and design refinement and design efficiency are improved; assuming that the main compression area of the steel shear key is the front # imgabs0 # / 2 part, so that the shear bearing capacity of the single steel shear key can be calculated more safely; the shear bearing capacity of the fabricated prefabricated segmental girder bridge based on the steel shear keys can be accurately calculated, and through comparison with an experimental value, it is verified that the calculation method is safe and reliable.
Owner:ANHUI TRANSPORT CONSULTING & DESIGN INST

Method for collaborative optimization of section coal pillar width through undercut pressure relief and bottom plate filling

The invention relates to the field of coal mine tunnel design, in particular to a method for cooperatively optimizing the width of a section coal pillar through undercut pressure relief and bottom plate filling. Comprising the steps of determining shear stress distribution in a first mining working face section coal pillar lower bottom plate; determining previous collapse positions of the basic roof; stoping and constructing a bottom cutting drilling hole in a maximum shear stress area in a lower bottom plate of the section coal pillar from the haulage roadway; lagging undercut pressure relief work is conducted, and bottom plate filling drilling is conducted from the track roadway to the position below the undercut pressure relief position at intervals; and grouting is conducted on the bottom plate rock stratum through the filling drill holes. According to the method, the bottom cutting drilling is constructed in the maximum shear stress area, so that the concentration of the shear stress of the bottom plate at the lower part of the section coal pillar is effectively reduced, and the stress of the section coal pillar is reduced. And furthermore, rock blocks at the bottom plate pressure relief position are upwards supported through bottom plate separation layer grouting filling at the lower part of the bottom cutting pressure relief position to prop against a cantilever structure formed by caving of the bottom plate, so that the overlying rock stress borne by the section coal pillar is shared, and the reserved width of the section coal pillar can be reduced.
Owner:CHINA UNIV OF MINING & TECH

Intelligent storage control system for silo

The invention relates to the technical field of material layer automatic control, and discloses a silo intelligent storage control system, which comprises a data acquisition module for acquiring and preprocessing silo data through multiple types of sensors; the data analysis module is used for calculating to obtain a state evaluation parameter set; the intelligent decision-making module determines an early warning level through a double-threshold early warning mechanism, and obtains a control decision-making parameter set based on the state evaluation parameter set and the early warning level; and the execution control module is used for executing the control decision parameter set. According to the method, the silo space is discretized into the three-dimensional voxel grid, accurate three-dimensional description of the material distribution state is achieved, the shear stress of each voxel is calculated on the basis of fused data such as the material level height and the pressure difference, the flow state of each voxel is accurately judged by comparing the shear stress with the yield threshold value, and the flow state of each voxel is accurately judged. Scientific basis is provided for making a discharging strategy, blind operation is avoided, quantitative evaluation of the silo operation risk is achieved, and scientific basis is provided for preventive maintenance.
Owner:HENAN SHIRONG SILO ENG CO LTD

Closed double-layer stirring type photobioreactor

The invention discloses a closed double-layer stirring type photobioreactor, and relates to the technical field of microalgae culture. A double-layer special-shaped paddle combination is formed through the composite design of a four-straight-blade overall open turbine type (SK) and a three-blade left-handed push type spiral stirring paddle (TXL), paddle combination optimization is formed through the cooperative flow field design of the TXL paddle (lower layer) and the SK paddle (upper layer), axial-radial flow coupling is achieved, and the material exchange rate between gas and liquid is increased; according to the combined design of the double-layer special-shaped paddles, the proportion of a high-shear area is reduced to be lower than 12% through a wide-area low-strength shear mode of the TXL paddles, the shear stress is greatly reduced, and the problem that the shear stress is too high is solved; a dynamic rotating speed strategy is convenient to implement, and the mass transfer efficiency and the cell activity are both considered by adjusting the rotating speed in stages.
Owner:CHONGQING UNIV OF TECH