4593 results about "Stress concentration" patented technology

The invention relates to the technical field of welding processing, and discloses a dissimilar metal welding joint temperature field optimization control method and system. Real-time temperature field scanning is conducted on the dissimilar metal welded joint, image segmentation processing is conducted on a temperature field image obtained through scanning, temperature data of a weld joint area, a heat affected area and a base metal area are extracted, and whether the temperature gradient exceeds a preset threshold value or not is judged; aiming at an area with non-uniform distribution of heat input quantity, analyzing the performance of the welding joint under the combined action of thermal stress and mechanical stress, obtaining the difference between residual stress distribution and plastic deformation capacity, and analyzing a stress concentration area by combining with the yield strength of the material; and a mapping relation between the welding process parameters and temperature field distribution is established, and a welding process parameter adjustment prediction model is obtained through historical welding process parameters and corresponding temperature field data training in combination with heat flux density distribution. The problems of uneven heat input, stress concentration and the like in dissimilar metal welding are effectively solved, and the welding quality and efficiency are improved.

The invention provides a surface flaw analysis method combined with metal material fatigue life prediction, which comprises the following steps: carrying out grid optimization and refinement processing on an initial three-dimensional model, and carrying out refinement reconstruction on a local area to obtain a three-dimensional geometric model of the surface of a metal material, the three-dimensional geometric model comprising micro-scale surface flaw information; carrying out region division on the three-dimensional geometric model, identifying and extracting a surface defect region, carrying out edge detection on the surface defect region, and determining an accurate geometric contour and spatial position information of a defect; using finite element analysis software to import the three-dimensional geometric model and the flaw mathematical description model of the metal material, setting material attributes, boundary conditions and load conditions, and establishing a finite element analysis model containing microscopic flaws; and carrying out stress-strain analysis on the finite element analysis model of the microscopic flaws, calculating stress distribution and stress concentration coefficients around the flaws, and evaluating the influence of the flaws on fatigue crack initiation and expansion by adopting a fracture mechanics theory.

The invention discloses a wind turbine generator hoisting construction tower drum operation system and a construction method thereof, and relates to the technical field of intelligent control. The problems that in the prior art, a static tension balance mechanism cannot restrain bending moment abrupt change, steel-concrete interface stress concentration causes microcrack propagation, the wave dynamic load compensation capacity is insufficient, and dynamic rigidity attenuation early warning is lacked are solved. Comprising a dynamic load prediction module, a multi-mode vibration suppression module, an offset compensation module and a digital twinborn decision module, a hoisting load is solved in real time through a multi-physics field coupling model and an improved time sequence deep learning algorithm, and interface crack propagation is suppressed in combination with traveling wave offset control and sweep frequency vibration. An improved Morison equation is adopted to drive a two-stage hydraulic servo to compensate a wave dynamic load, and a digital twin closed-loop correction mechanism is constructed based on a 5G URLLC protocol; the tower drum hoisting precision, the structural safety and the operation reliability under the complex working condition are remarkably improved.

The invention provides a defect detection method for a metal code disc without coating, and relates to the technical field of information, and the method comprises the following steps: fusing an external geometric model of the metal code disc obtained by three-dimensional scanning with internal defect information of the metal code disc obtained by X-ray flaw detection, and constructing a three-dimensional model of the metal code disc containing internal defects; if a stress concentration phenomenon exists around the defect, carrying out stability analysis on the defect in the metal coded disc by utilizing a fracture mechanics theory, calculating a stress intensity factor at the tip of the defect, evaluating the risk of crack propagation of the defect under the action of external force, and determining the critical dimension and the safety margin of the defect; and obtaining a metal code disc defect distribution rule according to the internal defect information of the metal code disc, and carrying out optimization design on the structural layout and key dimension parameters of the metal code disc in combination with the metal code disc defect distribution rule and a safety evaluation criterion. The failure risk caused by internal defects of the code disc is reduced, and the use reliability and safety of the code disc are improved.

The invention provides an intelligent real-time detection method and system for PCCP welding quality, and relates to the technical field of online detection and intelligent evaluation of pipeline welding quality through machine learning. Light energy data and multi-light-source images of a spiral weld pool are collected, exposure parameters are dynamically adjusted through the energy difference of visible light near-infrared bands, and the real-time detection of the PCCP welding quality is achieved. Inhibiting strong light interference and generating a weld surface image; a stress concentration area is positioned by scanning a welding seam thermal deformation area and combining speckle pattern change, sound frequency change and the elastic characteristic of the thin-wall steel cylinder; inputting the surface image and the deformation data into a space-time convolutional neural network, fusing light energy change, image details and spatial features to construct a weld joint space structure diagram, and adaptively correcting the position of a sensor; and comparing the sinking depth of the three-dimensional point cloud reconstruction, analyzing the correlation between the sinking degree and the stress, and generating a probability thermodynamic diagram to output the pressure-bearing failure risk level, so that the probabilistic early warning of the pressure-bearing failure risk can be realized.

The invention relates to a grid steel structure node failure diffusion prediction method, which comprises the following steps of: forming a failure inducement and evolution path model according to a connection form of a bolt-sphere node and a welding node, a stress transfer path, node local yield and fatigue accumulation factors; a diffusion logic of node failure-force flow redistribution-adjacent node stress concentration-chain reaction is constructed; nodes are regarded as middle points of the graph, rod pieces are regarded as edges, and propagation weights between the nodes are defined; the weight parameters are dynamically assigned based on material attributes, node connection types, spatial geometric positions and historical stress states; multi-source monitoring sensors including strain gauges, displacement meters, thermometers and accelerometers are arranged at key nodes of the grid structure, so that node states are sensed; in combination with real-time monitoring data, extracting strain rate change, vibration characteristics, frequency drift and residual deformation key characteristics of each node; a node health state feature vector set is constructed by using time sequence analysis, and the gradual degradation trend of nodes is reflected.

The invention relates to the technical field of intelligent control, in particular to a composite material forming process intelligent control system which comprises a micro-scale deformation detection module, a stress offset correction module, a temperature gradient regulation and control module, an interlayer curing balance module and a forming intelligent control execution module. According to the method, a deformation rate sudden change area is accurately positioned through micro-scale detection, and stress concentration is found in advance, so that stress adjustment is more targeted, the local stress overload influence is reduced, real-time pressure feedback is combined with target pressure offset analysis to optimize a loading mode, uniform stress in the curing process is ensured, and the defect risk is reduced; high-precision temperature gradient monitoring and thermal diffusion rate analysis improve temperature control precision and improve interlayer temperature equilibrium, curing rate change rate calculation and heat conduction path optimization dynamically adjust a heat dissipation channel and promote uniform curing, stress-temperature distribution equilibrium degree analysis is combined with a deformation trend to optimize heating and pressure parameters, and uniform curing is achieved. And the forming stability and the quality consistency are improved.

The invention relates to the technical field of material performance detection, in particular to an industrial ceramic product performance detection method and system, and the method comprises the following steps: S1, applying a composite dynamic load to the surface of an industrial ceramic product; s2, three-dimensional vibration response signals, surface thermal field distribution data and electromagnetic eddy current response parameters are collected; s3, extracting a crack propagation characteristic frequency; s4, constructing a heat-force coupling field three-dimensional model; s5, constructing a material performance degradation gradient matrix; and S6, determining a critical failure area of the industrial ceramic product, and outputting a performance detection report. According to the method, through collaborative fusion of multi-source data synchronous acquisition, thermal-mechanical coupling field modeling and electromagnetic impedance analysis, precise monitoring and quantitative evaluation of crack propagation, thermal stress concentration and microdefect degradation of the industrial ceramic product under the composite dynamic load are realized, so that the defect identification precision is improved, and a critical failure area is effectively judged.

The invention provides a civil construction monitoring intelligent sensor information detection method and system under signal mismatch, and the method comprises the steps: carrying out the time-frequency analysis of temperature and strain fundamental frequency components, selecting a wavelet basis function adaptive to the concrete setting and strength increasing process, carrying out the self-adaptive threshold processing of a wavelet coefficient, removing high-frequency noise, and carrying out the detection of the temperature and strain fundamental frequency components. Low-frequency signal characteristics reflecting concrete strength increase are reserved; performing feature extraction on the denoised temperature and strain signals by adopting a singular value decomposition algorithm, detecting internal defects of the concrete through abrupt change of a singular value spectrum, and if crack and hole defects exist, causing strain signal abrupt change by stress concentration; if it is detected that defects exist in the concrete, that is, spatial heterogeneity of temperature and stress distribution exists, temperature and strain monitoring data of multi-point arrangement and a defect detection result serve as boundary conditions and constraints, and a temperature field and a stress field in the whole concrete structure are obtained through numerical simulation.

The invention provides an on-line monitoring method and system for crack propagation of silicon-based new material equipment in a high-temperature environment, and relates to the technical field of crack detection, and the method comprises the steps: collecting stress distribution data through arranging a stress sensor, and generating a stress field distribution diagram by using an attention mechanism deep neural network model; identifying a stress concentration region based on a region growing algorithm, when a stress value exceeds a preset threshold value, acquiring temperature distribution data, extracting temperature distribution characteristics through a deep mixed probability model, performing multi-modal data fusion in combination with a stress field distribution diagram, and establishing a crack propagation prediction model by using a graph structure neural network. The crack propagation rate and direction are solved through a swarm intelligence optimization algorithm, when the crack propagation rate exceeds a preset threshold value, a control system adjusts equipment operation parameters, the sampling frequency of a sensor is adjusted according to the crack propagation direction, and model parameters are updated through an incremental learning method to achieve real-time monitoring.

The invention relates to a settlement data analysis and early warning method based on a cloud platform, and the method comprises the steps: collecting settlement data of a basic part of a main transformer in real time through a high-precision electronic settlement observation device array, obtaining deformation stress data through data preprocessing and coordinate calculation, and uploading the deformation stress data to the cloud platform; transmitting an ultrasonic pulse signal to the stress concentration position of the local area through ultrasonic detection equipment, receiving reflected wave data, and identifying the depth and range of the crack initiation position according to the reflected wave data; a sensor array is arranged on the basic surface of a crack initiation position, sound wave signals released in the crack propagation process are captured, and a time sequence of the crack propagation direction and speed is determined; and detecting crack depth data of the repair priority region through ultrasonic waves, calculating an adjusted basic health state value, comparing the adjusted basic health state value with a preset safety threshold, and generating a corresponding safety early warning signal.

The invention relates to the technical field of mine safety monitoring, and discloses a roadway surrounding rock stability evaluation method, which comprises the following steps: step 1, collecting roadway surrounding rock geological data, step 2, constructing a three-dimensional geomechanical model, step 3, inverting mechanical parameters, step 4, calculating a stability coefficient, and step 5, outputting an evaluation result. According to the method, rock mass types, structural plane occurrence, crustal stress vectors and permeability parameters are integrally collected through geological radar scanning, drilling coring and crustal stress measuring devices, the problem of model distortion caused by single data in a traditional method is solved, deformation of a stress concentration area is accurately captured by adopting a non-uniform grid division strategy, inversion mechanical parameters are combined, and the method is suitable for large-scale popularization and application. The network is trained by using in-situ direct shear and triaxial test data, the inversion efficiency is improved compared with manual trial and error, the whole surrounding rock fracture process is simulated based on a finite element-discrete element coupling algorithm, plastic zone distribution and a comprehensive index S are output, and automatic judgment of the stability level is realized.

The invention relates to a thermal insulation evaluation method for a light recycled building block based on thermal coupling simulation, which comprises the following steps: modeling the recycled building block into a heterogeneous multiphase complex, and introducing a three-layer structure field of micro pores, mesoscopic aggregates and macroscopic blocks; a partition coupling strategy is adopted, a microstructure variability-heat flux density disturbance-stress field reconstruction causal chain is constructed, and macroscopic thermal insulation performance fluctuation caused by thermal deformation is captured; tracking a thermal stress concentration area caused by temperature difference change through thermal and force coupling simulation; analyzing the influence of a thermal stress migration path on local structure integrity, pore change and crack evolution; constructing a thermal stress and structure disturbance factor framework, and evaluating the influence degree of the structure local deformation on the thermal resistance; extracting high-dimensional feature data; establishing a heat and force characteristic space; constructing a response surface equation, and mapping a change track of the thermal insulation performance in a heat and force coupling response space; a time and structure response composite scoring system is formed, real coupling of multiple physical fields is achieved, and limitation of traditional evaluation is broken through.

The invention relates to the technical field of alloy die-casting, and particularly discloses an alloy die-casting temperature field control method and system capable of reducing hot cracks, temperature gradients of different areas of a die are adjusted in real time according to flowing and solidification characteristics of alloy liquid, so that the surface temperature distribution of the die is matched with the solidification rate of the alloy liquid, and the alloy die-casting temperature field is controlled. Utilizing a machine learning algorithm to predict a risk area where hot cracks are generated on the basis of historical data and real-time monitoring data, and dynamically adjusting the flow velocity of a cooling system, the heating power of a die or die-casting process parameters according to a prediction result; through dynamic temperature gradient control, intelligent prediction and feedback control, a cooling strategy, a stress release mechanism and a real-time monitoring and optimizing process, thermal stress concentration can be effectively reduced, the possibility of generation of thermal cracks is reduced, the yield of castings is improved, the cooling time of the castings can be shortened through the cooling strategy, and therefore the production efficiency is improved, and the production cost is reduced. And reworking and scrapping of castings are reduced.

The embodiment of the invention discloses a numerical optimization method and device considering bearing capacity of a steel frame and a concrete precast slab, equipment and a medium. The method comprises the following steps: acquiring geometric parameters, material attributes and connection parameters between the steel frame and the concrete precast slab corresponding to the steel frame and the concrete precast slab respectively, constructing a geometric model based on the geometric parameters, performing finite element mesh division, assigning the material attributes and the connection parameters to generate a finite element model, and performing finite element mesh division on the finite element model; static load analysis and dynamic load analysis are conducted on the finite element model to obtain bearing capacity response, continuous optimization is conducted by changing set parameters, material attributes and connection parameters, the influence of different parameters on the bearing capacity is analyzed, an optimal parameter combination is found, the bearing capacity is maximized, and the bearing capacity is improved. Marking stress concentration and weak areas based on the optimal parameter combination; according to the technical scheme, the accuracy of the steel frame-concrete prefabricated slab model can be improved, and the effectiveness and efficiency of parameter optimization on stress concentration and weak areas are improved.

The invention discloses an injection molding process for a plastic part of an air purifier, and relates to the technical field of injection molding processes. Multi-area dynamic mold temperature adjustment is performed, a plurality of temperature control areas are divided according to the thin wall and curved surface structure characteristics of the plastic part, the temperature is adjusted in real time, stress concentration and deformation are remarkably reduced, and the service life of the plastic part is prolonged. The problem of shrinkage stress of a thin-wall area is solved in a targeted mode, cooling of a thick area is accelerated, meanwhile, real-time temperature control and deformation compensation are controlled in a linkage mode, the temperature and the cooling rate are dynamically adjusted according to deformation data monitored in real time, and the deformation trend is predicted, so that pre-deformation compensation is provided, warping of the thin-wall area and the curved surface area is controlled, and deformation of the thin-wall area and the curved surface area is controlled. The stability of the plastic part in the forming process is kept, and the product precision is improved; in addition, simulation prediction and mold parameter adjustment are carried out, cooling requirements of different areas are adjusted, the temperature difference between the thin wall and the curved surface area is reduced, and the whole cooling process is more efficient.

The invention relates to the technical field of low-temperature storage tank installation, in particular to a low-temperature storage tank heat insulation module installation construction method which comprises the steps that expansion bolts are implanted into preset point positions of the inner wall of a low-temperature storage tank, inner wall morphology data are obtained through three-dimensional laser scanning, and a point cloud model is generated. A BIM system is used for constructing a three-dimensional model of the installation datum plane, the theoretical leveling height of each expansion bolt point position is calculated, and a leveling parameter instruction set is generated. And a servo motor of the bolt tightening equipment is driven to rotate the ball nut, so that the leveling gasket moves to the target height. And a press-fitting path is generated, a press-fitting mechanical arm is controlled to align the preformed hole of the heat insulation module to the screw part of the expansion bolt and press-fit, and the surface of the heat insulation module is fully attached to the surface of the leveling gasket. And a fastening nut is installed on the screw part of the expansion bolt, three-dimensional deviation analysis is carried out, and iterative correction is carried out. Compared with the prior art, the effects of shortening the construction period, improving the leveling precision, reducing stress concentration, ensuring long-term stability and the like are achieved.

The invention relates to a stamping die service life dynamic evaluation system and method based on multi-mode sensing. According to the system, a feature extraction module obtains stress distribution data and crack position information and inputs the data into a trained three-dimensional stress field model to obtain dynamic feature parameters of a stress concentration area under high-frequency cyclic loads; the crack prediction module judges the dynamic characteristic parameters based on a preset threshold value, and once the dynamic characteristic parameters exceed the preset threshold value, analysis is carried out according to the mapping relation between the stress level and the crack rate and the microstructure evolution rule at the same time, and a crack propagation prediction value is generated. And the service life evaluation module inputs the crack propagation prediction value into the trained health state evaluation model, and finally the service life evaluation value of the stamping die is obtained. The service life evaluation value of the stamping die under the existing working condition and the operation condition is accurately estimated, the production efficiency is effectively improved, the production cost is reduced, the potential crack risk of the die is perceived in advance, and accurate and dynamic die service life evaluation is achieved.

Methods and apparatus are disclosed for assessment of microstructural defects in a large structure. Third order elastic constants engender nonlinear excitation of acoustic modes particularly at points of local stiffness changes or stress concentration such as ends of microcracks. A broadband multimode acoustic signal is transmitted through an interrogation region from a first transducer, whereby a second transducer receives an acoustic signal containing linear and nonlinear components. Linear terms are canceled, and a magnitude of the nonlinear acoustic response is measured using time-resolved spectral analysis, to determine a coefficient for acoustic nonlinearity of the interrogation region that serves as a qualitative or quantitative representation of microcrack damage. Broadband signals avoid mode-specific effects such as shadowing or phase mismatch. Damage location can be identified by region or time-of-flight. Portable or dedicated embodiments can be deployed on a wide range of structures of arbitrary shape.

The invention relates to the technical field of mining safety, and discloses a rock stability analysis device and method in a mining process, and the device comprises a real-time monitoring module which is used for arranging equipment to monitor the stress and displacement state of a rock body; the data acquisition module is used for storing and processing sensor data in real time; the stress-strain analysis module is used for calculating stress and strain to generate a stress-strain relation curve and analyzing elastic modulus and yield strength; the risk assessment module is used for calculating a stress concentration ratio and an instability probability and carrying out risk grade division on the monitoring area; and the threshold value early warning module is used for setting a safety threshold value of the monitoring index and giving an alarm when the safety threshold value is exceeded. According to the device, fine changes of the rock mass in a dynamic stress state can be rapidly captured through the real-time monitoring module, and the device can timely obtain dynamic behavior data of the rock mass through continuous monitoring of strain, pressure and displacement, so that the device can automatically adapt to continuously changing geological conditions in the mining process.

The cover plate assembly comprises a cover plate, a pole and a connecting piece, the pole is mounted on the cover plate, the connecting piece comprises a pole connecting part and a tab connecting part, the pole connecting part is connected with the pole, a first insulating part is arranged between the pole connecting part and the cover plate, the first insulating part is provided with a hook part, and the hook part is connected with the pole connecting part. The pole connecting part is clamped with the clamping hook part, and an anti-cracking notch is formed in the position, close to the tab connecting part, of the pole connecting part. According to the utility model, the pole connecting part can be clamped through the clamping hook part so as to limit the connecting sheet to droop and fall off under the action of external force, and the stress at the joint of the pole connecting part and the tab connecting part is released through the anti-cracking notch so as to avoid stress concentration, so that the tab connecting part is not easy to break; therefore, the shock resistance and the vibration resistance of the connecting piece are improved, the battery is not easy to lose efficacy, and the use performance is good.

A method for virtual fatigue testing includes reading a coarse-grid finite-element-model of a component from one or more libraries with a computer, and identifying static stress locations neighboring at least one of fasteners and non-fastener stress concentration regions in the component by a static analysis of a component intermediate-grid finite-element-model of the component, identifying hot spot locations in the component intermediate-grid finite-element-model by performing a fatigue screening on the component, generating details for the component intermediate-grid finite-element-model based on the hot spot locations, and predicting crack results by a deterministic durability-and-damage-tolerance analysis of the details for a component fine-grid finite-element-model of the component, calculating a crack margins for the component fine-grid finite-element-model by a probabilistic durability-and-damage-tolerance analysis of the crack results, and generating an output file that contains the final crack initiation margin and the final crack growth margin.

The invention discloses a drill rod for construction of an integrated stirring forming type cemented soil stiff anchor rod, the drill rod comprises a drill bit part and a hollow drill rod, the drill bit part comprises a shell, an anchor disc fixed in the shell and a spiral blade welded on the shell, and the hollow drill rod is inserted into the shell; the sheath steel pipe is inserted into the hollow drill rod and fixed to the shell, the grouting pipe is inserted into the sheath steel pipe, one end of the rod body is fixed to the anchor disc, and the other end of the rod body extends out of the sheath steel pipe. A first grouting hole is formed in the shell, and a second grouting hole is formed in the sheath steel pipe. The invention further discloses a construction method of the integrated stirring forming type cemented soil stiff anchor rod. When the method is used, the processes of hole forming, anchoring, grouting and the like are integrally formed, the process is simple, the speed is high, and the quality is easy to control; the formed cement-soil pile body is uniform in internal structure and reliable in strength; tension of the anchor rod is uniformly distributed, so that stress concentration can be reduced; and the formed cement soil pile body is high in end strength and good in safety.

The invention discloses a three-dimensional finite element simulation method for a complex slope excavation unloading process, which comprises the following steps of: 1) constructing a three-dimensional model of a complex slope, and establishing a finite element grid; 2) inputting boundary conditions of the model and material parameter information of each stratum; 3) calculating and simulating an initial stress field of the slope before excavation; (4) according to the initial stress field, the unloading load of the slope excavation part is calculated; (5) finite element calculation is conducted on stress deformation of the excavated slope; according to the method, the high-precision three-dimensional finite element model is established, various material parameters and actual boundary conditions are combined, the stress change and the unloading effect of the slope in the excavation process are simulated, the stress redistribution in the unloading process is accurately reproduced, the prediction precision of local instability and stress concentration areas is improved, and the prediction accuracy of the slope is improved. Therefore, a scientific basis is provided for safety assessment of slope excavation.

The invention discloses automatic welding equipment for a circular seam of an oil cylinder of a hydraulic turnover mechanism, and relates to the technical field of welding. Through joint cooperation of the burr removing assembly and the multiple profiling lifting assemblies, simulation profiling can be conducted on the outline of the oil cylinder barrel section before the oil cylinder barrel section is supported, so that the top of the burr removing assembly and the top of part of the profiling lifting assemblies jointly form the outline shape matched with the oil cylinder barrel section; according to the lifting device, the lifting assembly can annularly wrap a part of the area below the oil cylinder barrel section, a stable lifting and supporting effect is achieved, when the lifting assembly supports the bottom of the oil cylinder barrel section, the lifting assembly can be matched with the multiple profiling lifting assemblies on the two sides to jointly form simulated supporting on the oil cylinder barrel section, and the lifting effect is greatly improved while the oil cylinder barrel section is lifted and supported. And the welded circular seam position can be polished by using the grinding wheel rotating at a high speed, metal burrs and welding slag generated by welding are removed, tip stress concentration is avoided, and the connection strength of the welding seam position is ensured.

The invention relates to the technical field of laser welding, and discloses a laser machining device and method for a nuclear reactor shell, and the method comprises the steps that a shell plate welding area to be welded is subjected to surface modification pretreatment; the laser processing device is used for carrying out initial welding on the pretreated shell plate, in the initial welding process, the temperature sensing assembly is used for monitoring temperature distribution of the welding area in real time, and temperature information of the welding area is obtained; the temperature information is input into a preset temperature-deformation prediction model for prediction of a variable trend and a stress distribution condition so as to obtain a first prediction result; based on the obtained first prediction result, the welding parameters of the laser processing device are dynamically adjusted for the first time; welding deformation and stress concentration are effectively coped with, the welding quality and structural strength of the nuclear reactor shell after laser welding are improved, and the reliability and safety of the nuclear reactor shell during use are effectively improved.

The invention provides a finite element-based method for estimating pulling-out ultimate bearing capacity of a grouting screw anchor in gravelly soil, and relates to the technical field of civil structure engineering.A three-dimensional finite element model containing the grouting screw anchor and surrounding gravelly soil is established, model parameters cover the structure and material characteristics of the grouting screw anchor, and the grouting screw anchor and the surrounding gravelly soil are subjected to finite element modeling; a coordinate axis is established with the center of the anchor bottom as an original point for grid division, a stress concentration area is analyzed, principal stress is calculated to serve as critical bearing stress, vertical pull-out loads are applied step by step through a grouting pull-out test, a pull-out stress influence area is determined, soil stress of the area is analyzed, and soil binding power and friction force are calculated. And a grouting coefficient and a rock crack coefficient are generated, soil parameters are corrected, and the ultimate pulling bearing capacity of the grouting screw anchor is comprehensively obtained. According to the method, the pulling ultimate bearing capacity of the grouting screw anchor is accurately evaluated by establishing the three-dimensional finite element model and the graded loading experiment.

The invention relates to the technical field of tungsten alloy, and discloses a tungsten alloy material and a preparation method thereof.The tungsten alloy material comprises, by mass, 90-100 parts of modified tungsten powder, 8-10 parts of nickel powder, 5-7 parts of iron powder, 4-6 parts of cobalt powder and 1-3 parts of modified carbon fibers. The nickel powder, the iron powder and the cobalt powder in the molten state permeate into the tungsten powder through pores evenly distributed in porous carbon on the surface of the modified tungsten powder to form a uniform and compact alloy material, and the situation that due to the large melting point difference between the tungsten powder and the nickel powder, the iron powder and the cobalt powder, the nickel powder, the iron powder and the cobalt powder are distributed unevenly in the tungsten alloy material, and the mechanical strength of the alloy material is reduced is avoided; the pretreated silicon carbide whiskers are adhered to the surface of the carbon fiber loaded with the graphene oxide to form modified carbon fiber, so that interface stress can be absorbed and dispersed, stress concentration is reduced, cracks and debonding phenomena at an interface are prevented, and the mechanical performance of the tungsten alloy material is enhanced.

The invention discloses a risk determination method and system based on engineering structure failure, relates to the technical field of engineering risk determination, and comprises the steps of establishing an engineering geometric model of an engineering structure by utilizing finite element software, and providing a reliable basis for subsequent assessment of stress concentration coefficients and failure probabilities. And evaluating the fatigue life of the engineering structure according to the stress concentration coefficient, and generating the overall fatigue life of the engineering structure by combining information such as the stress concentration coefficient, the dangerous area type and the fatigue life of the dangerous area. And evaluating the failure probability and the failure criticality of each failure mode, and considering the correlation between the failure modes to obtain an accurate failure probability. The risk value of the engineering structure failure mode is generated based on the fatigue life, the failure probability and the failure criticality, the influence of the fatigue life on the risk of the engineering structure is added, the accuracy and adaptability of risk determination of the engineering structure failure are improved, and safe and stable operation of the engineering structure is ensured.

The invention discloses an open caisson construction deviation rectifying device and relates to the technical field of open caisson construction deviation rectifying, the deviation rectifying device is used for rectifying an inclined well wall, the deviation rectifying device comprises a supporting frame, a connecting module, a driving motor, a rope collecting module, a lifting module, a gripper, a mooring rope and a ground anchor, the supporting frame is fixed to the ground, and the top end of the supporting frame is fixedly connected with the connecting module; the connecting module is fixedly connected with the rope collecting module and slidably connected with the lifting module, the driving motor is fixedly connected with the connecting module and fixedly connected with the rope collecting module, the lifting module applies downward pressure to the highest point, the rope collecting module pulls a gripper to apply downward pulling force to the two ends of the highest point, and well wall deformation caused by stress concentration during deviation rectification is prevented. The ground anchor can change the direction of the mooring rope position adjusting force, pressure can be accurately applied, secondary deviation of the open caisson caused by too large pressure is prevented, force can be applied from multiple directions to enable the open caisson to be evenly stressed during deviation rectification, and the deviation rectification stability is improved.