71 results about "Shear stiffness" patented technology

The invention provides a shield tunnel construction period segment longitudinal dynamic floating prediction method, and relates to the field of shield tunnel segment floating prediction.The method comprises the steps that the static upward floating force and the dynamic upward floating force of a shield tunnel are calculated by considering the timeliness of slurry, and the characteristic of nonlinear change of the rigidity of a circular seam connector is considered; the method comprises the following steps: dividing bending-resistant and shearing-resistant deformation modes of a circular seam joint, further deducing bending rigidity and shearing rigidity of a tenon-type joint in each deformation stage, deducing a shield tail segment longitudinal floating prediction model of the circular seam joint in the shield tunnel construction period, and constructing a nonlinear iterative algorithm of shield tunnel longitudinal deformation according to the theories; and acquiring parameter data of actual engineering, and inputting the parameter data into the duct piece floating prediction model to obtain a duct piece floating value. By means of the method, accurate prediction of floating deformation of the shield tail segment in large shield tunneling can be achieved, an effective scientific basis is provided for large-diameter shield tunneling construction, the problems that parameter decision of shield tunneling machine operators is difficult, and the segment floating control effect is poor are solved, and structural diseases caused by too large floating of the shield tail segment are eliminated.

The invention relates to the technical field of connection structure testing, in particular to a bridge deck slab dry joint connection structure testing method which comprises the following steps: preparing a bridge deck slab test piece containing a steel structure embedded dry joint; building a testing device, and arranging strain, displacement and pressure sensors in a dry joint area; carrying out a graded loading test, including static loading to 1.5 times of the designed bearing capacity and dynamic cyclic loading; an environment simulation test is carried out, and repeated loading is carried out in a temperature and humidity circulation box simulation environment; data are evaluated through a multi-source data fusion optimization algorithm model, and indexes such as flexural rigidity and shear rigidity are calculated; in addition, a construction stage simulation test is added, and the alignment deviation and the filling compactness of the components are monitored. According to the method, the structural performance can be comprehensively evaluated, key indexes can be accurately evaluated, durability degradation can be scientifically predicted, construction simulation is innovated, test conditions are guaranteed to be consistent, visualization and verification are achieved, and the problem of limitation of a traditional test method is effectively solved.

The invention provides a method and a system for analyzing influence of local loading and unloading on deformation of an existing shield tunnel, and relates to the field of influence of foundation pit construction on the existing tunnel. The method comprises the steps that shield tunnel vertical additional stress caused by foundation pit excavation is calculated through a Mindlin stress solution; analyzing the influence of the longitudinal axial force on the flexural rigidity and shear rigidity of the circular seam joint, and dividing a joint deformation mode into three stages according to the relative magnitude of the axial force and the bending moment and the vertical displacement between rings; a tunnel displacement control equation is established based on a Winkler foundation model, loop iteration is conducted through a state space method, and the rigidity of a circular seam joint is dynamically adjusted to be matched with the final deformation mode of the circular seam joint; and finally, constructing a prediction system, and outputting a deformation value of the shield tunnel by inputting the number of iterations and parameters of a foundation pit, bolts, concrete and segments. By means of the method, deformation prediction of the existing shield tunnel can be achieved for foundation pit construction, an effective scientific basis is provided for foundation pit engineering construction, the problem that parameter decision of operators on a construction site is difficult is solved, and foundation pit engineering site construction is truly guided.

The invention relates to the technical field of shield tunnel vibration control, in particular to a shield tunnel under-rail vibration isolation structure and a construction method thereof.The shield tunnel under-rail vibration isolation structure comprises a prefabricated rail foundation arranged in the longitudinal direction of a tunnel and prefabricated buttresses arranged in the longitudinal direction of the tunnel at intervals; the bottom of the prefabricated track foundation is provided with receding spaces for receding the prefabricated buttresses, the prefabricated buttresses are arranged in the receding spaces, the bottoms of the prefabricated buttresses are connected with the tunnel lining, and vertical vibration isolation supports are arranged between the tops of the prefabricated buttresses and the top of the prefabricated track foundation. The side faces of the prefabricated buttresses are connected with the prefabricated track foundation through compression-shear rigidity decoupling limiters. The prefabricated track foundation provides an inertia reference, the compression-shear rigidity decoupling limiter restrains horizontal displacement and allows vertical vibration at the same time, the vertical vibration isolation support regulates and controls the vertical vibration, through the synergistic effect of all the assemblies, a three-dimensional vibration isolation system is formed, efficient attenuation of vibration energy of the high-speed rail at the specific frequency band of 20-80 Hz is achieved, and the high-speed rail vibration energy attenuation effect is improved. The vibration damping performance of 15-20 dB is guaranteed, meanwhile, the dynamic displacement of the track is within the standard limit value range of the high-speed railway track, the balance of vibration control and track smoothness is achieved, and the requirement for running of the high-speed railway at 350 km / h is comprehensively met.

The present invention relates to an evaluation method for steel structure splicing nodes, comprising the following steps: (a) obtaining defect information of the steel structure splicing nodes after the steel structure splicing nodes are disassembled; (b) obtaining a correction factor of the rotational stiffness of the steel structure splicing nodes based on the defect information; (c) obtaining the theoretical shear stiffness and theoretical bending stiffness of the steel structure splicing nodes; (d) obtaining the actual rotational stiffness of the steel structure splicing nodes based on the correction factor, the theoretical shear stiffness and the theoretical bending stiffness; (e) obtaining the actual geometric shape of the steel structure splicing nodes after all steel structure splicing nodes are installed; (f) obtaining the actual bearing capacity of the steel structure splicing nodes based on the actual geometric shape and the actual rotational stiffness; (g) obtaining the design bearing capacity of the steel structure splicing nodes; and (h) evaluating the reusability of the steel structure splicing nodes based on the actual bearing capacity and the design bearing capacity of the steel structure splicing nodes.

The invention relates to a balance base for a rowing machine. The base is used as a stand for the rowing machine, and the rowing machine can be positioned thereon in a fixed manner. At least one spring element is provided, wherein the at least one spring element is arranged between an upper frame and a lower frame, and the at least one spring element comprises an elastic or viscoelastic material, the tilting rigidity of which is both lower than the tensile-compressive rigidity of the spring and lower than the shear stiffness of the spring. Additionally, a form-fitting or force-fitting fixture of the upper frame to the rowing machine is provided.

This invention discloses a method for constraining corner elements in a rocking wall structure system. Based on the structural parameters of the rocking wall and the frame structure, the shear stiffness of the frame structure is obtained. A first lateral displacement expression and a second lateral displacement expression are constructed using the shear stiffness and the first and second equilibrium equations. An inter-story drift angle expression is then constructed using these expressions to solve for the stiffness of the rotating combined disc springs. The bending moment of the rotating combined disc springs is obtained from the stiffness of the rotating combined disc springs. The number of single disc springs stacked in the same direction and the number of combined disc springs are determined by the deformation requirement and the bearing capacity requirement of the combined disc springs obtained from the bending moment. This yields the combined height of the disc springs. The combined height of the disc springs is then used to constrain the length of the core rod and the support height in the corner element, achieving rapid constraint of the core rod length and support height in the corner element based on statics.

The present disclosure provides a Timoshenko beam model equivalent method and system of a corrugated steel plate support structure, and relates to the technical field of stress analysis of a corrugated steel plate support structure, comprising: solving the stiffness coefficients of the corrugated steel plate in a local coordinate system, including tensile stiffness, bending stiffness and shear stiffness; solving the equivalent stiffness coefficients of the orthotropic corrugated steel plate in a global coordinate system, including equivalent tensile stiffness, equivalent bending stiffness and equivalent shear stiffness; solving the equivalent section bending stiffness of the corrugated steel support structure; solving the equivalent section shear stiffness of the corrugated steel support structure; and equivalent the corrugated steel support structure to a Timoshenko beam model. The present disclosure can realize the rapid equivalent of the corrugated steel plate support structure to a Timoshenko beam model.

The invention relates to a post-crack shear stiffness identification method for a reinforced concrete beam. The method comprises the following steps: S1, acquiring inclined crack distribution, inclined crack width, inclined crack length and development angle data after the concrete beam is cracked; s2, dividing a cracking part of the concrete beam into a plurality of continuous sections according to a construction section, and completing inclined crack grading scale evaluation according to an evaluation standard to obtain a cracking grade gcr, i of each section; s3, calculating a shear stiffness degradation factor lambda i; s4, calculating the shear stiffness Kv, cr of each section after degradation according to gcr, i and lambda i; and S5, correcting the Poisson's ratio of the concrete according to the lambda i, the Kv and the cr so as to correct the shear stiffness of the section of the concrete beam for post-cracking performance evaluation of the concrete structure. The technical problem that the real working state of the concrete beam bridge cannot be obtained due to the fact that traditional concrete beam bridge bearing capacity evaluation is greatly influenced by subjective factors is solved, and the method can be conveniently applied to performance evaluation of the concrete structure after cracking.

The present invention relates to the technical field of shield tunnels and discloses a rigid-flexible socket-type shield tunnel joint structure, comprising a socket-type structure, a rotor assembly, a screw, an embedded part one and an embedded part two; the embedded part one and the embedded part two of the present invention are respectively embedded in adjacent pipe segments, and the embedded parts can fully exert the functions of bolts and steel bars, thereby improving the overall bearing capacity of the bolts; one end of the screw is inserted, and the joint is introduced into the rotor assembly, thereby reducing the sensitivity of the inter-ring joint to structural manufacturing and assembly errors; the screw can be tightened to ensure the shear stiffness of the joint; through optimized design, the screw can be loosened after the shear force of the joint reaches a certain value, thereby reducing the stiffness of the joint, realizing the "rigid-flexible" state change under more extreme conditions during operation, and improving the adaptability of the joint structure to extreme conditions; by re-tightening the bolt rod at a later time, the stiffness of the joint structure can be restored, and the repairability of the joint can be achieved.

The invention discloses a clothing modeling-oriented fabric shearing property intelligent prediction method and device. The fabric shearing property intelligent prediction device collects an image corresponding to a detected fabric; the image is preprocessed through an intelligent fabric shearing prediction method and then input into a target segmentation model for target segmentation, a threshold value is dynamically adjusted according to the local brightness of the image in the target segmentation model for binaryzation, and the accuracy of target segmentation of the target segmentation model is improved; meanwhile, a feature embedding model is used for extracting embedded features from the segmentation result; carrying out dimensionality reduction on the embedded features by adopting principal component analysis, and fusing the embedded features after dimensionality reduction with the collected three-dimensional features; inputting the fusion result into an error correction model to obtain an error correction value; according to the error correction value and a shear stiffness theoretical value obtained through the shear stiffness mechanism model, a final shear stiffness prediction value is obtained, it is guaranteed that the physical significance of a prediction result can be explained, and the prediction precision of the shear stiffness can be improved.

The application relates to a stress deformation prediction method for a confined space foundation pit retaining structure, which comprises the following steps: S1: inputting soil body parameters and foundation pit design parameters to generate a stiffness matrix; S2: determining initial soil pressure parameters and calculating lateral deformation of the retaining structure; S3: according to the confined space of the foundation soil, updating the stiffness matrix; based on the updated stiffness matrix, performing second calculation; S4: judging whether an error Delta u reaches a precision requirement, if yes, turning to S5, and if not, repeating S3, and iteratively calculating until the error Delta u meets the precision requirement; S5: after the stiffness matrix is determined, calculating soil body shear stress, and further calculating shear strain and soil body shear stiffness; S6: calculating a soil spring elastic modulus k, and updating the stiffness matrix; step S7: recording u T ; then returning to S1 to enter next excavation stage calculation; S8: after the calculation to a design excavation depth, outputting the stiffness matrix, the shear strain and a bending moment M, so as to evaluate stress deformation conditions of the foundation pit retaining structure. The method is favorable for improving the precision of stress deformation prediction of the confined space foundation pit retaining structure.

The present application relates to the field of civil engineering technology, and in particular to a buckling-resistant support structure and a design method for a buckling-resistant support structure, which are used to support a main structure. The buckling-resistant support structure includes a core unit, a constraint unit and a connection portion, wherein the core unit extends along a first direction, the constraint unit is sleeved on the outside of the core unit, the connection portion is provided at both ends of the core unit in the first direction, the core unit is connected to the constraint unit via the connection portion, and the shear stiffness of the connection portion is equal to a predetermined stiffness. According to the buckling-resistant support structure and the design method for the buckling-resistant support structure provided in the present application, the strength required for the core unit is effectively reduced, so that the core unit can be made of steel with greater elastic-plasticity, and the vibration energy absorption effect of the buckling-resistant support structure is effectively improved.

The utility model relates to a shearing force connecting structure of a corrugated steel web box girder, and belongs to the technical field of bridge engineering. The angle steel is vertically embedded into the concrete slab and is welded with the corrugated steel web; the embedded part of the angle steel is respectively provided with three open holes which are respectively convenient for the perforated steel bars to pass through; the first perforated reinforcements are parallel to the length direction of the corrugated steel web, and the second perforated reinforcements are perpendicular to the first perforated reinforcements. The multiple pieces of angle steel are sequentially arranged in the length direction of the corrugated steel web and sequentially arranged at the bottom of each groove of the corrugated steel web according to the alternating rule, and the same first perforated steel bar penetrates through the multiple first open holes. The connecting structure has interface shear resistance and web root bending resistance and torsion resistance, and the rigidity and strength of the roots of the corrugated steel webs under the action of distortion and torsion are improved while shear resistance connection is achieved; and on the premise of ensuring the shear stiffness, the deformation of the steel-concrete junction of the cross section of the box girder under the action of eccentric load and the like can be better adapted.

This invention discloses a hopper support beam and its manufacturing method, belonging to the field of large silos and hoppers, and is mainly used for the installation of large hoppers. The technical problem to be solved by this invention is to provide a hopper support beam and its manufacturing method, comprising a first transverse steel plate, a second transverse steel plate, a first vertical steel plate, and a second vertical steel plate; the first vertical steel plate is positioned between the first and second transverse steel plates, forming an "I" shape; two second vertical steel plates are respectively positioned at the left and right ends of the second transverse steel plate, forming an "H" shape; second stirrups are positioned between the first transverse steel plate and the second vertical steel plate; the first transverse steel plate, the first stirrup, the second vertical steel plate, and the second stirrup enclose a frame structure; the frame structure is filled with concrete. The hopper support beam provided by this invention can improve the load-bearing capacity and stability of the hopper support beam, and enhance its bending, torsional, and shear stiffness.

The invention discloses a longitudinal loading device and method for a shield tunnel longitudinal deformation test, and the method comprises the steps: driving a first support and a second support to drive a first axial loading part and a second axial loading part to move relatively through an axial load loading mechanism, so as to apply an axial load to a segment sample group at two axial ends; and meanwhile, the bending moment loading mechanism drives the first axial loading piece and the second axial loading piece to rotate so as to apply bending moment to the segment sample group at the two axial ends, so that the segment sample group can be subjected to an equivalent bending rigidity test under the action of the applied axial load and bending moment. In addition, a vertical load loading mechanism capable of applying a vertical load to the segment sample is also arranged, so that the segment sample group can be subjected to an equivalent shear stiffness test under the action of the applied axial load and vertical load. Therefore, the method has good universality, so that the test efficiency can be improved, and the cost can be remarkably reduced.

The invention provides a calculation optimization method for an arch and cross beam combined section of a separated steel truss girder arch bridge, and belongs to the technical field of civil engineering, and the method comprises the following steps: determining a shear-resistant section according to the arch and cross beam combined section structure and a force transmission path, and determining main shear-resistant plates and welding seams; setting constraint conditions, and calculating to obtain vertical and horizontal shear forces of the shear-resistant section; solving the shear stiffness of a shear resistant plate and a welding seam by utilizing a shear stiffness calculation formula of a connecting plate of the arch and the cross beam and the welding seam after correction, and distributing shear force to calculate the force transmission of the plate and the welding seam; calculating the average shear stress of the force transmission plate and the weld joint, constructing a shear stress function, and calculating the maximum shear stress; introducing a strength check coefficient to judge a shear stress result, and optimizing the thickness of a combined section plate and the number of partition plates to obtain a structure optimization scheme; the method solves the problems that an existing arch and cross beam combined section optimization calculation method is huge in workload, complex in process and long in structure checking calculation time.

The application relates to the technical field of mechanical dynamics, in particular to a fault gear time-varying meshing stiffness calculation method considering crack positions, which comprises the following steps: establishing a gear fault calculation model; determining corresponding crack category information, and pre-storing crack gear section division rules corresponding to the crack category information; detecting a crack position on the gear that has occurred a fault, adopting the crack gear section division rule to divide the crack position into sections to obtain a plurality of crack sub-sections; obtaining the bending stiffness and the shear stiffness of each crack sub-section for each crack sub-section; and summing the bending stiffness and the shear stiffness of each crack sub-section to obtain the bending stiffness and the shear stiffness of the fault gear. The bending stiffness and the shear stiffness of the fault gear can be obtained by inputting the parameters of the crack, and the calculation efficiency is higher.

The invention relates to the technical field of virtual fitting, in particular to a virtual fitting fit evaluation method based on dynamic postures, which comprises the following steps: acquiring dynamic posture data when a user executes a preset action sequence, and constructing a digital fabric physical model containing physical parameters of tensile rigidity, bending rigidity and shearing rigidity, the stretching, wrinkling and fitting changes of the clothes are calculated under the driving of the dynamic posture data, and dynamic deformation data are generated; then, initial gap distribution and initial pressure mapping between the clothes and the body are calculated based on the dynamic deformation data, and stable gap distribution and accurate pressure mapping are obtained through space-time consistency analysis; and finally, generating a fitness evaluation index including a dynamic fitness index, a local compression coefficient and an overall fitness score, and outputting a fitness report through visual rendering. According to the method, the fitting state of the clothes under dynamic movement can be truly reflected, and the fine evaluation capability of virtual fitting is improved.

The invention relates to the technical field of fabricated buildings, in particular to a prestressed integrated support-free large-span laminated slab which comprises a concrete bottom slab and further comprises prestressed steel bars embedded in the concrete bottom slab, the prestressed steel bars are arranged in the length direction of the slab, and anchoring structures are arranged at the ends of the prestressed steel bars; the steel framework assembly and the concrete bottom plate are integrally formed in a pouring mode, and the steel framework assembly is composed of a rectangular steel pipe on the lower portion and C-shaped channel steel on the upper portion. Through cooperative stress of the steel skeleton assembly and the prestressed steel bars, optimization of a stress path is achieved, the prestress effectively counteracts pull-down stress caused by self weight and loads, and the steel skeleton assembly provides extremely high bending resistance and shear stiffness, so that large-span support-free and secondary beam canceling can be achieved, and the space utilization rate is effectively increased; one-time integral pouring is adopted between the steel skeleton assembly and the concrete bottom plate, and the problem of weak new and old concrete interface caused by a traditional process is solved.

The invention relates to the technical field of centrifugal machines, in particular to a centrifugal machine dynamic unbalance force measuring device and calculation method.The centrifugal machine dynamic unbalance force measuring device comprises a base, a mounting plate, a shearing elastic piece and a nested force sensor, and the mounting plate is used for bearing a rotating part of a centrifugal machine; the shearing elastic piece is arranged between the base and the mounting plate, and the nested force sensor is horizontally arranged between the base and the mounting plate and used for measuring acting force generated by the mounting plate in the horizontal direction due to dynamic unbalanced force; the shearing elastic piece with high compressive rigidity and low shearing rigidity is adopted to replace a traditional rolling guide rail, it is guaranteed that the rotating arm support can effectively support the rotating arm, and meanwhile the problems of static friction force existing in traditional rolling guide rail connection and friction coefficient change caused by abrasion of the rolling guide rail are avoided; the rotating arm can generate relative displacement with the rotating arm support under the action of small unbalanced force and act on the force sensor, so that the measuring sensitivity of the unbalanced force is improved.

The application discloses a kind of based on deep learning's shield underpass existing tunnel structure deformation calculation method, belong to tunnel engineering pile foundation underpinning technical field.The method includes the following steps: establishing deep learning prediction model, obtains the ground subsidence caused by newly-built shield tunnel;Through Loganathan-Poulos ground subsidence analytic formula inversion, ground loss rate is obtained;Calculate the soil displacement at the depth of existing tunnel;Calculate the additional load of existing tunnel structure in longitudinal direction;Calculate the equivalent bending stiffness and equivalent shear stiffness of existing tunnel structure in longitudinal direction;Calculate the vertical displacement under the action of additional load on the axis of existing tunnel structure, and the longitudinal deformation of tunnel structure under additional load is calculated.The application can effectively solve the problem that ground loss rate is difficult to determine due to stratum difference, and quickly and accurately obtain the ground subsidence value caused by shield construction and the soil displacement at the depth of existing tunnel.

The invention relates to a corrugated pipe expansion joint large-displacement working condition shear rigidity testing tool and system, and the tool comprises a fixed end, a movable end which is disposed at one side of the fixed end, and is spaced from the fixed end, so as to form a testing space for installing a to-be-tested model machine; the movable end comprises a shearing loading plate and guide grooves, the guide grooves are formed in the two sides of the shearing loading plate, the extending direction of the guide grooves is perpendicular to the axis of the to-be-tested sample machine, and the shearing loading plate is connected with the guide grooves in a sliding mode. Through the constraint effect of the guide groove, the bending moment is borne by the guide groove, it is ensured that the moving end only generates translational displacement, rotation deformation is avoided, meanwhile, the stress level of key components is reduced, and the accuracy and reliability of a test result are improved.

The invention relates to a data-driven column sheet shear stiffness artificial cognition method. The method comprises the following steps: data acquisition: acquiring data through a column sheet shear performance experiment; establishing a data set: selecting a column piece structure parameter as the input of the data set, taking experimental acquisition data as the output to establish the data set, and dividing a training set and a test set; data arrangement: standardizing the data in the data set; establishing a prediction algorithm: performing parameter tuning on the XGBoost model by using a grid search method, and establishing a prediction model; model explanation: using an SHAP value method, and cognizing main factors influencing the shear stiffness and an action mechanism thereof through a visualization means. The method solves the problem that effective technical measures are difficult to provide to improve the anti-seismic performance of the column piece structure due to insufficient cognition on the shearing behavior of the column piece in the anti-seismic design of the high-rise industrial goods shelf, enhances cognition on internal factors of the shearing rigidity of the column piece and an interaction mechanism of the internal factors, and can accurately and quickly obtain the shearing rigidity value of the column piece.

The invention provides a longitudinal non-uniform deformation calculation method and system for a corrugated steel plate supporting structure, and belongs to the technical field of traffic infrastructure structural design. Comprising the steps that an orthotropic equivalent stiffness model of a corrugated steel plate is constructed, a corrugated steel plate supporting structure is equivalent to a Timoshenko beam, and equivalent section bending stiffness and equivalent section shear stiffness are calculated; the method comprises the following steps: by constructing a calculation model of longitudinal non-uniform deformation, determining longitudinal differential load distribution according to an actual soil covering condition and a soil arching effect above a corrugated steel plate supporting structure; and calculating the longitudinal difference load distribution based on the longitudinal non-uniform deformation calculation model to obtain the longitudinal non-uniform deformation of the corrugated steel plate supporting structure. According to the method, the longitudinal non-uniform deformation of the shallow-buried corrugated steel plate supporting structure can be effectively and rapidly evaluated.

The application discloses an assembled corrugated steel web composite beam bridge deck structure and a construction method, the bridge deck structure comprising a box girder body; an open steel plate welded on the flange plate of the box girder body, the open steel plate being provided with multiple U-shaped notches at equal intervals; a bridge deck assembly comprising a first bridge deck and two second bridge decks, a cast-in-place groove being left between the first bridge deck and the second bridge decks, the cast-in-place groove being arranged on the top of the flange plate, transverse steel bars penetrating through the U-shaped notches and connecting the first bridge deck and the second bridge decks; and a concrete layer cast in the cast-in-place groove for consolidation. The open steel plate welded on the flange plate bears the shearing force, and has higher shearing stiffness and ductility compared with a traditional shearing key. When the bridge deck is hoisted for installation, the transverse steel bars can correspond to the U-shaped notches on the open steel plate, and compared with a traditional hole shaft connection, the assembly is simpler and easier to align, and the installation efficiency is improved.

The invention provides a Timoshenko beam model equivalent method and system of a corrugated steel plate supporting structure, and relates to the technical field of corrugated steel plate supporting structure stress analysis, and the method comprises the steps: solving rigidity coefficients of a corrugated steel plate under a local coordinate system, including tensile rigidity, bending rigidity and shearing rigidity; solving equivalent stiffness coefficients of the orthotropic corrugated steel plate under the global coordinate system, wherein the equivalent stiffness coefficients comprise equivalent tensile stiffness, equivalent bending stiffness and equivalent shearing stiffness; the equivalent section flexural rigidity of the corrugated steel supporting structure is solved; the equivalent section shear stiffness of the corrugated steel supporting structure is solved; and enabling the corrugated steel supporting structure to be equivalent to a Timoshenko beam model. According to the method, the corrugated steel plate supporting structure can be quickly equivalent to the Timoshenko beam model.

The invention relates to a bridge early warning method and system based on a support state. The method comprises the following steps: S1, establishing a detection signal database; s2, training the enhanced YOLO-v5s model based on the detection signal database to establish a support state detection model; s3, collecting a detection signal of the target bridge support through an active sensing experiment, preprocessing the detection signal of the target bridge support, and converting the detection signal into a wavelet spectrum through continuous wavelet transform; s4, inputting the wavelet spectrum corresponding to the target bridge support detection signal into the support state detection model to obtain the state of the target bridge support; and S5, obtaining a shear stiffness change rate, a compression stiffness change rate and a support axial pressure index according to the state of the target bridge support, judging an early warning level of the target bridge, performing early warning, and outputting damage information of the support and the bridge. According to the invention, high-precision detection of the support state and early warning of the bridge state can be realized.

The application provides a shield tunnel longitudinal stress calculation method and system considering inter-ring joint nonlinearity, and relates to the technical field of underground engineering. The method comprises the following steps: obtaining parameter information of a shield tunnel, wherein the parameter information comprises structural design parameters, material parameters and stratum parameters; establishing a finite element model of the shield tunnel according to the initial stiffness of the inter-ring joint and the parameter information, and solving the finite element model based on a preset load to obtain first information, wherein the first information comprises the bending moment, shear force and longitudinal axial force of each inter-ring joint of the shield tunnel; constructing a stiffness three-dimensional surface of the inter-ring joint, calculating the stiffness information of the inter-ring joint according to the stiffness three-dimensional surface and the first information; updating the finite element model according to the stiffness information, and obtaining the longitudinal structural stress result of the shield tunnel through the updated finite element model. The application solves the problem that the existing beam-spring model ignores the changes of the bending stiffness and shear stiffness with the load when simulating the nonlinear behavior of the inter-ring joint.

This invention relates to the field of structural strength analysis technology, specifically a method, equipment, medium, and product for strength assessment of hybrid fiber sandwich structures. The method assesses the microscopic heterogeneity of the glass fiber outer layer, functionalized core layer, and carbon fiber inner layer, and assigns differentiated representative volumetric element modeling strategies based on the heterogeneity level. It establishes two-phase representative volumetric elements for the fiber layers and three-phase representative volumetric elements for the functionalized core layer, extracting the equivalent stiffness tensor of each layer through homogenization calculations. Representative volumetric elements are established for the conductive adhesive layer, and the interlaminar equivalent shear stiffness is extracted. The equivalent stiffness of each layer and the interlaminar shear stiffness are assigned to the corresponding ply and interface elements of the macroscopic finite element model to solve for the ply stress under structural service loads. Strength and stability criteria are applied to the glass fiber outer layer, carbon fiber inner layer, and functionalized core layer for strength assessment, obtaining the safety margin and failure location of each ply. This improves the accuracy and reliability of multi-scale mechanical analysis of hybrid fiber sandwich structures.