17 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.

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 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.

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 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 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 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 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 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 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.

This invention relates to the fields of geotechnical engineering and rock fracture mechanics, and particularly to a method for predicting the crack initiation angle in locked rock slopes or rock masses containing locked sections. The steps are as follows: Obtain the parameters of the locked rock slope or rock mass sample; decompose the axial stress into normal and tangential stresses acting on the crack surface of the creep section; calculate the Type I and Type II stress intensity factors at the crack tip of the creep section; establish a correction coefficient k(L) related to the trailing edge tensile fracture length L to correct the stress intensity factor at the crack tip; substitute the corrected stress intensity factor into the crack initiation angle calculation formula to obtain the crack initiation angle of the creep section. θ 0. The crack initiation angle prediction method for locked rock slopes or rock masses containing locked sections provided by this invention uses the length of the trailing edge tensile crack as a correction parameter and introduces it into the crack initiation angle calculation process to solve the problem of insufficient prediction accuracy of the existing maximum circumferential stress criterion under locked rock slope conditions.