32 results about "Tangential stress" patented technology

The present disclosure relates to the technical field of stability control of surrounding rock of tunnelling, and provides an excavation compensation method for tunnelling in deep rock engineering, including: acquiring an engineering geological information of the tunnelling in deep rock engineering; determining an engineering hazard type based on the engineering geological information; determining an excavation compensation support strategy for the surrounding rock of the tunnelling in deep rock engineering based on the engineering hazard type; and performing a supplementary support control on the surrounding rock of the tunnelling in deep rock engineering based on the excavation compensation support strategy. Through the supplementary support strategy, the difference value between a radial stress of the surrounding rock of the tunnelling in deep rock engineering and an initial crustal stress can be reduced to within a preset approximate value range, further effectively preventing a stress concentration phenomenon occurred in a tangential stress.

The invention discloses a research method for a crack evolution law of fractured rock under thermal-mechanical coupling, and belongs to the technical field of rock mechanics. Aiming at the problem that most indoor tests and numerical simulation at present still lack systematic research on crack initiation, polymerization and failure behaviors of cracks in a multi-crack rock mass under the action of high temperature-stress coupling, the method comprises the following steps: defining an interaction coefficient and a thermal damage influence coefficient between the cracks on the basis of a tangential stress distribution theory around the cracks; establishing a tangential stress model sum of the inner and outer surfaces of the crack comprehensively considering the coupling effect of the two to predict a potential crack initiation position; based on a crack mode displacement decomposition method, defining a displacement ratio coefficient gamma, and quantifying a displacement field of rock material cracks; on the basis, the rock sample is subjected to mechanical test and PCF numerical simulation, and the crack evolution law of the rock sample containing the prefabricated crack under thermal-mechanical coupling is researched. Theoretical support and experimental basis can be provided for stability evaluation and safety control of deep high-temperature rock mass engineering.

The invention discloses a pile-soil interface shearing algorithm considering related characteristics of a soil body state. The pile-soil interface shearing algorithm is suitable for calculating pile side friction resistance after a pile foundation is driven in offshore engineering. The method mainly comprises the following steps: (1) transferring stress and strain tensors obtained by calculation of a constitutive model considering that rigidity and strength parameters of a soil body change along with the state of the soil body to a soil and structure interface shear model; (2) assuming that a soil and structure contact interface is in a simple shearing state, and iteratively solving the normal strain of the interface; and (3) calculating the normal stress and the interface tangential stress through the calculated normal strain, and considering the influence of the strength change of the pile-side soil body on the interface shear strength. According to the method, the soil constitutive model related to the state is introduced on the basis of traditional coulomb friction, constitutive responses of the soil in different confining pressure and shear strain states can be reflected, pile-soil interface mechanical behaviors are calculated, and the influence of soil characteristics on the interface behaviors is reflected more reasonably.

The utility model belongs to the technical field of micro-driving equipment, and provides a piezoelectric actuator which comprises a shell structure, a piezoelectric structure, a motion guiding structure and a transmission output structure, the shell structure is internally provided with a containing space with a first opening, and the piezoelectric structure is connected to the bottom of the containing space; the transmission output structure is located at the first opening to output the displacement generated by the piezoelectric structure, and the motion guide structure is located between the transmission output structure and the piezoelectric structure and used for providing motion guide for the piezoelectric structure and separating the piezoelectric structure from the transmission output structure, so that the transmission effect of tangential stress is reduced; and a connecting groove is formed in the motion guide structure, so that the length of a force arm of the piezoelectric structure is reduced, the risk of damage to the piezoelectric structure is further reduced, the deflection angle can be reduced, and the guide effect is improved. Therefore, the piezoelectric actuator has excellent structural stability, working reliability and applicability, and can adapt to various complex application scenes.

The present invention discloses a self-sensing sliding friction characteristic modeling and control optimization method and device for unstructured terrain, including: S1. establishing a normal stress distribution model and a tangential stress distribution model when the wheel contacts the lunar soil; S2. adjusting the normal stress distribution model and the tangential stress distribution model based on the friction characteristics of the lunar soil, and establishing a sliding friction characteristic model based on the physical characteristics of the lunar soil; S3. correcting the traction force and driving torque of the wheel based on the sliding friction characteristic model, and feeding back into the PID control model, dynamically adjusting the control input through the error signal of the wheel speed, so as to accurately control the movement process of the lunar rover in real time; the present invention dynamically introduces the physical characteristics of the lunar soil into the modeling of the friction coefficient, and realizes accurate control of the lunar rover's driving process through the coupling of the dynamic state of the wheel and the dynamic feedback mechanism of the PID control, providing theoretical and technical support for the stable driving of the lunar rover in the complex lunar environment.

To provide a wheel flat estimating device, a wheel performance testing device and a key control device for evaluating a wheel re-adhesion control method for allowing proper wheel sliding having the possibility of damaging a wheel and a rail.SOLUTION: The wheel flat estimation device 10 includes a motion analysis part 20 for calculating various parameters by analyzing the behavior between a wheel and a rail when the wheel is fixed, a frictional heat analysis part 30 for calculating the temperature of the tread of the wheel when the wheel is fixed by frictional heat analysis, and a calculation part 30 for calculating the wheel flat based on the calculated temperature of the tread and reference data. The shape estimation device includes a yield stress calculation unit 40 that calculates a wheel yield stress of a wheel, an area calculation unit 50 that calculates an area of a contact ellipse between the wheel and a rail, a comparison unit 60 that compares a magnitude relationship between a tangential stress calculated from a tangential force and the area of the contact ellipse and the wheel yield stress, and an estimation unit 70 that estimates, as a wheel flat shape, a contact ellipse having a minimum area in which the wheel yield stress is determined to be larger than the tangential stress by the comparison in the comparison unit 60.SELECTED DRAWING: Figure 1

The invention provides a strong tectonic stress rockburst section tunnel arch curve design method, and relates to the technical field of high crustal stress tunnel rockburst prevention and control. The method specifically comprises the steps that the basic building limit requirement of a tunnel is obtained, and the transverse maximum width and the vertical maximum height of a tunnel arch curve are determined according to the basic building limit requirement; determining a horizontal crustal stress, a vertical crustal stress and a surrounding rock grade perpendicular to the axial direction of the tunnel hole through crustal stress measurement, and calculating a lateral pressure coefficient; if the lateral pressure coefficient of the tunnel is not smaller than 1 and the surrounding rock grade is III or above, it shows that strong tectonic stress exists in the tunnel area, and then an arch curve of the tunnel is constructed; and drawing a tunnel cross-section diagram of the tunnel based on the arch curve of the tunnel. According to the method, the tunnel arch profile curve is optimized through the elliptic equation, and the problem that tangential stress concentration is likely to be generated in the design of an arc-shaped arch crown of a conventional tunnel section under strong tectonic stress is solved.

The application relates to a semi-analytical method for analyzing the response of deep-buried tunnel excavation, which comprises the following steps: step 1) establishing a deep-buried circular tunnel excavation mechanical model, and solving the stress at the elastic-plastic boundary in the model by using a numerical method, wherein the stress comprises three components, namely radial stress, tangential stress and axial stress; step 2) dividing the plastic zone into n circular rings based on the finite difference method, and sequentially solving the stress components of each circular ring from the elastic-plastic boundary to the tunnel wall; step 3) solving the radius of each circular ring based on the stress components of the circular rings and the balance equation; step 4) decomposing the strain components, and solving the strain components of each circular ring based on the finite difference method; and step 5) solving the radial displacement based on the strain components. Compared with the prior art, the application has the advantages of improving the calculation efficiency of the three-dimensional semi-analytical method of finite difference.

To provide a friction welding structure that can enhance the strength of welded components after joining.SOLUTION: A first workpiece comprises a workpiece body and a first welded structure, and a second workpiece comprises a second workpiece body and a second welded structure. Both the first welded structure and the second welded structure are positioned between the first workpiece body and the second workpiece body. The first welded structure has a first lateral mating surface, and the second welded structure has a second lateral mating surface. The first lateral mating surface and the second lateral mating surface are in contact with each other and are fusion-bonded by relative motion between the first workpiece and the second workpiece. Since the first lateral mating surface and the second lateral mating surface that perform friction are parallel to a first direction, when the first workpiece and the second workpiece tend to separate from each other, tangential stress is generated between the first lateral mating surface and the second lateral mating surface, whereby the first workpiece and the second workpiece can be joined more firmly.SELECTED DRAWING: Figure 2

The invention relates to a multi-axial fatigue prediction method and medium based on non-linear coupling of normal and shear strain energy, and the method comprises the steps: calculating the normal strain and tangential strain of each group of experimental results at each angle under a loaded condition by using the fatigue experimental results of a to-be-predicted material, finding out the plane where the maximum shear strain amplitude of the maximum normal strain is located, and calculating the maximum shear strain amplitude of the maximum normal strain; taking as a critical surface; calculating each stress-strain component on the critical surface; acquiring material and shear performance parameters of a to-be-predicted material, and predicting by adopting the fatigue prediction model in combination with each stress-strain component; the model building process comprises the following steps: performing nonlinear coupling on normal strain energy and shear strain energy, obtaining a fatigue damage parameter by combining an average normal stress correction coefficient and an average tangential stress sensitivity coefficient, and obtaining a fatigue prediction model by combining the fatigue damage parameter with a fatigue damage equation in a shear form. Compared with the prior art, the method has the advantages of being high in fatigue life prediction precision, suitable for proportional and non-proportional loading, high in safety and the like.

The invention discloses a stress and rigidity analysis method under a multi-waveform diaphragm disc angular load, which comprises the steps of defining geometric and working condition parameters, constructing a segmented deflection model, establishing a non-axisymmetric stress analysis model and deducing an angular rigidity analysis formula. Deducing a deflection expression of the maximum deformation section by segmenting the corrugated molded line and setting continuous conditions of displacement, slope and curvature; establishing a bending-torsion coupling model through a cylindrical coordinate system, and obtaining radial, circumferential and tangential stress analytic expressions in combination with Hooke's law; and the total bending moment is solved by performing circumferential integration on the infinitesimal bending moment and the shearing force, and the angular stiffness is calculated, so that integrated analytic solution of the deflection, the stress and the stiffness is realized. According to the method, high-precision prediction of the angular mechanical behavior of the complex corrugated diaphragm disc is achieved, the calculation efficiency is high, the result is stable and consistent, a large amount of finite element iteration can be effectively replaced, and a reliable tool is provided for structural optimization and engineering design of the diaphragm disc coupler.

A method of producing a centrifugal compressor impeller is provided. The impeller includes a hub with a rotational axis, a forward surface, and an aft surface. The aft surface extends between an outer radial surface of the impeller and a bore centered on the rotational axis. The method includes: analyzing the impeller to determine a stress field having tangential stress data values and radial stress data values as a function of radial position within the impeller hub and as a function of axial position within the impeller hub; contouring the aft surface so that the impeller hub has radial stress data values less than tangential stress data values for any radial position of the hub during operation of the impeller; and producing the impeller with the contoured aft surface.

The present invention discloses a method and system for obtaining the failure probability of TRISO-type fuel particles, relating to the technical field of nuclear reactor accident safety analysis. The method comprises the following steps: obtaining the temperature, internal pressure generated by the amount of fission gas released, and external pressure at any location in a TRISO-type fuel particle model; obtaining multiple strain types of the material behavior of the pyrolytic carbon layer in the TRISO-type fuel particle model under irradiation conditions, constructing a strain model, and obtaining radial and tangential stresses at any location based on the strain model; determining the tensile stress of the pyrolytic carbon layer on the SiC layer using the radial or tangential stress at any location, and obtaining the failure probability based on the tensile stress. The present invention considers the effect of creep and swelling of the pyrolytic carbon material caused by irradiation on the tangential tensile stress of the SiC layer, performs a comprehensive mechanical assessment of the fuel structure, and significantly improves the accuracy of predicting the failure probability of TRISO-type fuel particles.

The application provides a method for determining the supporting time of underground caverns, which is based on the crack closure degree to determine the supporting time of rock mass at each part of surrounding rock in the time-dependent deformation process. For the cavern surrounding rock in the low confining pressure compression state, the crack closure degree C3 in the radial stress direction is taken as the time-dependent supporting basis of the surrounding rock. The crack closure degree C3 changes with time in three cases. By setting anchor cables and anchor rods, additional radial compressive stress can be provided to compensate for the radial stress released by the surrounding rock, thereby reducing the difference between the tangential stress and the radial stress, maintaining the crack closure degree in a non-destructive stage, and ensuring the safety and smooth progress of the underground cavern construction. Such measures help to maintain the stability of the surrounding rock and can optimize the supporting design, improve the engineering efficiency and safety.

The present application relates to the technical field of tunnel and underground engineering construction and safety monitoring, and particularly relates to a method and a terminal for determining the boundary of a tunnel surrounding rock pressure arch, comprising: theoretical prediction, field measurement and comparative verification; the present application constructs a comprehensive determination system of the boundary of the tunnel surrounding rock pressure arch by fusing theoretical calculation and field measurement, at the theoretical level, the theoretical boundary of the pressure arch is defined by quantifying the specific proportional position of the radius of the plastic zone and the peak value of the tangential stress of the elastic zone; at the measurement level, the propagation characteristics of the transient Rayleigh surface wave in the non-uniform medium are used to identify the surface of property mutation of the rock mass by capturing the inflection point of the wave velocity changing with depth in the dispersion curve; finally, the theoretical prediction result is compared with the field measurement result for checking, so as to determine the final boundary of the pressure arch.

The application provides a wire toughness evaluation method and device, and relates to the technical field of material analysis. The method comprises the following steps: when a target wire is symmetrically bent with a vertical line of a to-be-measured point tangential direction as a symmetric axis, the curvatures K of the to-be-measured point under different bending degrees are obtained; initial curvature K0, end curvature K2 and at least one transition curvature K1 between K0 and K2 are determined from the plurality of K, and K0 and K2 are measured before and after plastic deformation of the symmetric bending of the target wire respectively; the stress of the to-be-measured point of the target wire under K0, K1 and K2 is determined by adopting an X-ray diffraction method, and the stress at least includes a tangential stress; and the toughness characteristics of the target wire are determined according to at least one of the tangential stress of the to-be-measured point corresponding to K0, the tangential stress of the to-be-measured point corresponding to K1 and the tangential stress of the to-be-measured point corresponding to K2. The toughness characteristics of the wire can also be accurately characterized for the wire with a relatively thin diameter, so that the quality of the wire can be more comprehensively and accurately evaluated.

The invention provides a quantitative evaluation method for shear mechanical parameters of a natural hard structural plane of a dangerous rock, which comprises the following steps of: acquiring a natural rock structural plane sample, and drilling and coring upper and lower wall rock masses of the structural plane to obtain a cylindrical rock sample; adopting a three-dimensional scanning method to obtain apparent morphology data of the rock mass structural plane samples, grouping the apparent morphology data, and respectively determining the joint roughness of each group; respectively placing the three groups of rock mass structural plane samples in molds, pouring concrete on the structural plane, and manufacturing three groups of concrete-rock mass structural plane shearing samples with different roughness; performing a uniaxial compression test on the cylindrical rock sample to obtain the structural surface rock strength; respectively carrying out direct shear test on the three groups of concrete-rock mass structural surface shear samples to obtain tangential stress data under different roughness and different normal stress; fitting the test data of the three groups of samples, and calculating the shear strength under any roughness condition by adopting a coefficient obtained by fitting.

The invention relates to the technical field of tunnel and underground engineering construction and safety monitoring, in particular to a method and terminal for determining the boundary of a tunnel surrounding rock pressure arch, and the method comprises the steps of theoretical prediction, field actual measurement and comparison verification. According to the method, a tunnel surrounding rock pressure arch boundary comprehensive determination system fusing theoretical calculation and field actual measurement is constructed, and on the theoretical level, the theoretical boundary of a pressure arch is defined by quantifying the radius of a plastic zone and the specific proportional position of a tangential stress peak value of an elastic zone; on an actual measurement level, the propagation characteristics of transient Rayleigh surface waves in a non-uniform medium are utilized, and a rock mass property mutation surface is identified by capturing an inflection point of the wave velocity changing along with the depth in a frequency dispersion curve; and finally, comparing and checking a theoretical prediction result with a field actual measurement result to determine a final pressure arch boundary.

The invention discloses a tunnel fractured rock mass hydraulic coupling fracture FDEM simulation method and system, and relates to the technical field of rock mechanics and rock engineering. The method comprises the following steps: acquiring fracture information of a target area in a target tunnel and mechanical property parameters of a surrounding rock sample; according to the fracture occurrence and connectivity, the fracture type is determined; constructing an excavation numerical model of the target tunnel by utilizing an FDEM simulation program according to the mechanical property parameters and the fracture types; hydraulic coupling fracture simulation is executed based on the excavation numerical model; in the simulation process, normal stress and tangential stress generated by water flow on adjacent triangular units on the two sides of each target unit are calculated according to the fracture type; the target unit is a quadrilateral unit with a fracture path; the normal stress and the tangential stress are converted into corresponding nodal forces; and the node force is applied to the corresponding target unit, and the fracture opening degree is updated. According to the invention, the instability mechanism of the deep tunnel surrounding rock under the combined action of water pressure and ground stress can be accurately simulated.

A method of producing a centrifugal compressor impeller is provided. The impeller includes a hub with a rotational axis, and forward and aft surfaces. The aft surface extends between an outer radial surface of the impeller and a bore centered on the rotational axis. The method includes: analyzing the impeller to determine a stress field having tangential stress data values and radial stress data values as a function of radial position within the impeller hub and as a function of axial position within the impeller hub; determining biaxiality ratio (BR) data using the determined tangential stress data values and the determined radial stress data values; determining a peak von Mises creep strain location on the impeller; contouring the aft surface at the peak von Mises creep strain location using the radial stress data values and the BR data; and producing the impeller with the contoured aft surface.

The application provides a tunnel double-layer initial support construction timing calculation method, device, equipment and medium, and relates to the technical field of civil engineering. A first layer initial support provided support force expression is obtained based on an initial ground stress and a preset displacement expression occurring after support structure construction; a construction timing function is obtained by optimizing construction according to a tangential stress expression at the boundary of a tunnel plastic zone, the first layer initial support provided support force expression and tunnel wall peripheral displacement; a target loss function is obtained by construction according to the construction timing function and a preset physical constraint condition; a transcendental neural network model is obtained by construction based on the target loss function and a preset transcendental equation method, the transcendental neural network model is solved, and the second layer initial optimal support timing is obtained. The application solves the problem that the tunnel double-layer initial optimal support timing cannot be quickly and accurately obtained in the prior art, and ensures the construction safety of the tunnel.

The invention discloses a method for predicting the pressure bearing capacity of a deep crack-plugging layer system, and relates to the technical field of drilling fluid leakage control. The method comprises the following steps: solving a strain coordination equation according to a stress component expression expressed by a stress function under a two-dimensional plane polar coordinate and the strain coordination equation to obtain a tangential stress component expressed by the stress function; then establishing a crack-induced shaft tangential stress model by combining a plane dislocation theory; solving a dislocation density function and fracture-induced shaft tangential stress; finally, the fracture extension pressure and the fracture restart pressure are solved, and the minimum value of the fracture extension pressure and the fracture restart pressure is the pressure bearing capacity of the fracture-plugging layer system. According to the method, the influence of solid-phase particles generated during fluid convergence in the reservoir on the damage degree of the reservoir is considered, the finally obtained result better conforms to the actual situation, and corresponding data support can be provided for actual production.

The application discloses a kind of calculation method of slope stability analysis associated with displacement, comprising the following steps: for any one strip block, establish horizontal and vertical static equilibrium equation and the moment equilibrium equation in the plane of the strip block;From the motion compatibility between each strip block, start from the first strip block, establish the displacement coordination relationship between each strip block in turn, determine the displacement expression of any one strip block;For the bottom surface of any one strip block, the relationship between its tangential stress and shear displacement is characterized by strain softening model;According to the condition that the inter-block force transmitted by the first strip block is zero, form the calculation control equation set;For the displacement of each strip block, start from zero, and form a series of displacement values with certain displacement increment;Under each displacement value of each strip block, the average value of the local stability coefficient of all strip blocks is used as the overall stability coefficient of the slope body, i.e. the relationship between the overall stability coefficient of the slope body and the potential sliding body displacement is obtained.

The application discloses a tunneling method under soft surrounding rock conditions, comprising the following steps: S1, performing advanced support construction outside a tunnel excavation contour; S2, dividing a working face into a center soil part, an arc part, a left wall part, a right wall part and an arch restraining part with an arch waist as a center line; S3, excavating the arc part and performing arc initial support construction; S4, excavating the center soil part and pouring temporary inverted arches corresponding to the arc initial support; S5, excavating the left wall part and then performing left wall initial support construction corresponding to the left wall part; S6, excavating the right wall part and then performing right wall initial support construction corresponding to the right wall part; S7, excavating the arch restraining part and then performing arch restraining part construction and concrete backfilling; S8, removing the temporary arch and performing secondary lining; and S9, circular tunneling to an end point. The application has the beneficial effects of controlling the deformation degree of surrounding rock, improving the self-stability of the surrounding rock, reducing the tangential stress of the surrounding rock, the stress of initial support, and the relaxation load borne by the initial support and the secondary lining.

The invention relates to a computer-implemented method of designing a gas tank comprising a thin metal liner defining a plenum for gas and surrounded by a composite housing. The gas tank is represented by a computer model, and for selected diameters, thicknesses and materials of the liner, design routines calculate composite material thicknesses and / or materials to achieve target fatigue requirements of the metal liner. The design routine includes the steps of: (a) calculating a tangential stress on the liner for the pressure cycle based on predetermined geometric characteristics and material characteristics of the gas tank; and (b) increasing the thickness and / or Young's modulus of the composite shell if the tangential stress on the liner is greater than the stress target of the liner material from the fatigue profile of the liner material, or if the tangential stress on the liner is below the opposite value of the yield stress of the liner material. Steps a) and b) are repeated until the tangential stress is less than or equal to the stress target of the liner material, or if the tangential stress is greater than or equal to the opposite value of the yield stress of the liner material, then the thickness and / or Young's modulus from the final repeating step is stored.

The application provides a rear support of an open TBM and the open TBM and belongs to the field of tunnel boring equipment. The rear support of the open TBM comprises an adjusting frame, a connecting seat and a vertical adjusting device connected between the adjusting frame and the connecting seat, further comprises an auxiliary seat, and a first adjusting structure is arranged between the connecting seat and the adjusting frame and a second adjusting structure is arranged between the auxiliary seat and the adjusting frame. The open TBM comprises the rear support or a main beam or an inner keel. The application adjusts the pitch angle of the adjusting frame when the excavation slope is changed, so that the force of the vertical adjusting device on the main beam or the inner keel is perpendicular to the main beam or the inner keel, and the tangential stress at the connecting position of the connecting seat and the main beam or the inner keel is reduced.

The present invention discloses a method, system, terminal, and medium for analyzing the internal shear zone of a composite sliding slope, relating to the technical field of rock mechanics analysis. The key points of the technical solution are: decomposing the composite sliding slope into a main sliding block and a blocking sliding block; considering the tangential stress and normal stress of the shear surface within the landslide body, establishing a first mechanical equilibrium model for the main sliding block and a second mechanical equilibrium model for the blocking sliding block based on the rigid body limit equilibrium method; combining the first and second mechanical equilibrium models to calculate the geometric parameter range of the internal shear surface of the composite sliding slope body under the limit equilibrium state; determining the correlation function between the geometric parameters of the internal shear surface and the safety factor of the composite sliding slope body based on the first and second mechanical equilibrium models; and determining the minimum safety factor based on the correlation function and the geometric parameter range. The present invention can determine the geometric parameters of the internal shear surface of the slope, thereby determining the minimum safety factor of the composite sliding slope body.

The application provides a kind of axial extrusion pipe joint groove depth design method based on preventing pull-out, and relates to the technical field of metal conduit connection.The steps of the application are as follows: (1) calculating the tangential stress σ of the conduit when pull-out θ ; (2) calculating the unit pressure q on the surface of the conduit; (3) calculating the pull-out force F on the conduit; (4) calculating the groove depth H of the pipe joint.The groove depth design method is suitable for the design of the minimum groove diameter of the axial extrusion pipe joint, so that the pipe joint can meet the connection strength standard in structure, provides a theoretical basis for the research of such joints in China, and is conducive to promoting the domestic research progress.