26 results about "Shear stiffness" patented technology

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 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 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 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 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 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.

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.

The application relates to the technical field of energy collection, and particularly provides a wide-frequency energy collection device and system of an arch bridge structure. The device comprises a bridge top section, bridge arch sections symmetrically arranged at two ends of the bridge top section, a substrate layer fixedly arranged at one end of the bridge arch section away from the bridge top section, one of the bridge arch sections and the substrate layer is arranged on each side, the device is symmetric about a central axis, the substrate layer comprises, from top to bottom, a fin layer, a shear electrode and a substrate; the arch section comprises, from outside to inside, a first structure layer, a first damping layer and a second structure layer, the first damping layer has a thickness gradient along the length direction of the bridge arch section, the thickness of the first damping layer is large on the side close to the bridge top section and is small on the side close to the substrate layer. The first damping layer bears shearing and improves equivalent loss, reduces a quality factor and widens a single peak; the limited shearing stiffness of the first damping layer introduces interlayer dislocation and weak coupling of a main mode, thereby splitting near neighbors; the thickness is thick on the top and thin on the bottom, forming a soft top and a hard bottom, which strengthens splitting and stably transmits force, so that double peaks are filled and flattened into a platform by the damping, and the frequency band is widened.

The invention belongs to the technical field of aviation equipment calculation and analysis, and discloses an aeronautical plate-fin heat exchanger core structure anisotropic rigidity equivalent calculation method, which comprises the following steps of: determining structural design parameters and material attributes of an aeronautical plate-fin heat exchanger core and fins, segmenting and extracting a minimum array unit of a single-layer core structure, and calculating the anisotropic rigidity of the aeronautical plate-fin heat exchanger core. The method comprises the following steps: establishing a finite element model of a minimum array unit, calculating through three normal minimum array unit finite element models to obtain normal stiffness of the minimum array unit under an orthogonal three-direction stretching working condition, and calculating through six tangential minimum array unit finite element models to obtain shear stiffness of the minimum array unit under an orthogonal three-direction shearing working condition. And determining the shape of the minimum array unit, and calculating the anisotropic rigidity equivalent parameter of the single-layer core body structure. According to the method, the complexity problem of the core body structure is changed into the anisotropic rigidity problem through the equivalent conversion principle, and the dynamic calculation problem of the complex and cross-scale aviation plate-fin type core body structure is solved.

The invention provides a single pile foundation p-y curve construction method considering the influence of a three-dimensional sliding mechanism. The single pile foundation p-y curve construction method comprises the steps that all geometric dimension parameters of a single pile foundation are determined; measuring the distribution parameter of the undrained shear strength of the seabed foundation soil body along with the depth; measuring the roughness of the interface between the single pile foundation and the soil body; taking a foundation soil body to carry out a soil unit single shear test, and measuring the maximum shear stiffness and shear stress-strain curve of the soil body; fitting a stress-strain curve measured by the single shear test by adopting a high-order polynomial to obtain a fitting shape factor; calculating the maximum influence depth of the three-dimensional sliding mechanism; and based on the obtained fitting shape factor and the three-dimensional sliding mechanism influence coefficient, a single pile foundation p-y curve within the maximum depth range of the three-dimensional sliding mechanism influence is calculated. According to the method, the influence of a three-dimensional sliding mechanism caused by the free mud surface on the p-y curve is considered, the technical defects of a traditional method are overcome, and the method has important engineering practical value for design and engineering quantity optimization of a single-pile foundation.

The invention discloses a vertical shear stiffness quantitative identification and safety monitoring evaluation method for a new and old widened bridge joint, and belongs to the field of bridge engineering safety detection and structural performance monitoring. The invention relates to a method for identifying the rigidity of an abutted seam of a widened bridge, which is characterized in that under the excitation of a low-speed vehicle load, the ratio of response time cumulants of quasi-static displacement generated in the midspan of a new bridge and an old bridge and the vertical rigidity of the abutted seam connecting the two have a clear and stable mathematical mapping relationship; and a stable and reliable dimensionless identification index which is directly associated with the abutted seam rigidity is constructed, so that quantitative evaluation of the health state of the abutted seam is realized. The invention discloses a new and old widened bridge joint safety assessment method. The method comprises the following steps: step 1, arranging a new and old widened bridge joint structure performance monitoring system; 2, deploying a signal processing module and a parameter calculation and state evaluation module in a background; and step 3, deploying a display and monitoring early warning module on a client, wherein a manager can see the content of the display and monitoring early warning module.

The invention relates to the technical field of geological stability evaluation, in particular to an engineering rock mass stability dynamic evaluation method based on critical dynamic stiffness, which comprises the following steps: determining an evaluation area; dividing the evaluation area into a plurality of friction control units, and performing sample collection on each friction control unit; obtaining a shear force displacement curve and sliding speed data of each sample; determining the critical dynamic stiffness of each sample; determining the conservative critical dynamic stiffness of each friction control unit; determining the field equivalent shear stiffness of each friction control unit; according to the difference distribution of the conservative critical dynamic stiffness and the field equivalent shear stiffness of each friction control unit, generating an evaluation result of the stability of the engineering rock mass; according to the method, stability judgment can be directly carried out on the basis of measurable stiffness under different geological conditions, the subjectivity of dependence on experience safety coefficients in traditional evaluation is avoided, and the physical rationality and repeatability of evaluation results are improved.

The embodiment of the application discloses a method for predicting the dynamic response of a long bridge under a ship collision, comprising: obtaining a time-varying curve of a ship collision force to be evaluated and a bridge unit to be predicted; dividing a pier into a plurality of pier units of a set length along the vertical direction, and determining a stiffness matrix and a mass matrix of each pier unit according to the length of each pier unit; in each time step of the time-varying curve: determining a first shear stiffness between the pier and the pile cap and a second shear stiffness between the pile cap and the pile in the current time step; determining a global stiffness matrix and a global mass matrix of the bridge unit in the current time step; solving the lateral displacement state of the bridge unit in the current time step; and jointly forming the dynamic response of the bridge unit under the time-varying curve of the ship collision force from the lateral displacement state of each time step. The embodiment can determine the dynamic response of the flexible bridge section to the ship collision, and improve the resistance to the ship collision.

The invention relates to a caulking groove type interface strengthening analysis method for a fiber metal laminate. The method comprises the following steps: acquiring a geometric configuration and a material attribute of a caulking groove type joint of the fiber metal laminate; based on a classic laminated plate theory, obtaining the equivalent tensile stiffness of the laminated plate by adopting a performance homogenization method; on the basis of comprehensively considering the tensile rigidity of a metal layer, the tensile rigidity of a composite material, the extrusion rigidity of the composite material in a caulking groove area and the tensile and shear rigidity of an interface layer, a series of rigidity parameters are introduced to quantitatively characterize the internal deformation relation of the caulking groove type joint; establishing a spring-mass point mechanical model of the fiber metal laminate caulking groove type joint; quantitatively analyzing an enhancement mechanism of a mechanical interlocking effect generated by the caulking groove structure on the interface strength; the macroscopic tensile rigidity of the fiber metal laminate subjected to caulking groove type interface strengthening is obtained; and under a given tensile load condition, predicting the deformation response of any position of the fiber metal laminate.

The invention relates to a flexible helical gear time-varying meshing stiffness calculation method considering a center distance, and belongs to the technical field of mechanical dynamics. The method comprises the steps that a bevel gear is sliced in the axial direction, and a sliced gear is equivalent to a straight gear; acquiring a time-varying pressure angle of a pitch circle under the condition that the meshing contact line of the straight gear changes along with the center distance; based on the time-varying pressure angle, a time-varying meshing contact line of the single tooth of the helical gear in one period is obtained, so that five sub-rigidities of the time-varying meshing rigidity of the single tooth of the helical gear are obtained, and the five sub-rigidities comprise bending rigidity, radial compression rigidity, shearing rigidity, matrix rigidity and gear Hertz contact rigidity; and accumulating and summing the meshing stiffness of each meshing point on the contact line to obtain the single-tooth time-varying meshing stiffness of the bevel gear in one meshing period, and superposing the single-tooth time-varying meshing stiffness of the bevel gear in the meshing plane direction of the bevel gear to obtain the total time-varying meshing stiffness of the bevel gear. The method aims at improving the calculation precision of the time-varying meshing stiffness of the bevel gear and reducing the calculation time cost.

The application provides a well-side fracture shear stiffness evaluation method based on dipole shear wave far detection logging, and belongs to the technical field of oil and gas exploration and development. The method comprises the following steps: step 1, extracting the shear wave velocity and shear wave attenuation of a target formation from the direct wave information of the dipole shear wave far detection logging data; step 2, performing migration imaging on the reflection wave information in the dipole shear wave far detection logging data, and picking up the dip angle and distance from the well of the fracture from the imaging result; step 3, calculating the shear wave reflection coefficient at the reflection point on the fracture surface; step 4, inverting the shear stiffness of the fracture through the obtained shear wave reflection coefficient; and step 5, circulating step 3 and step 4, obtaining the shear wave reflection coefficient on the fracture surface corresponding to each depth point and inverting the shear stiffness of the fracture at each depth point. The method has important significance for the quantitative characterization of the well-side fracture parameters of the dipole shear wave far detection logging, and fills the blank of the quantitative evaluation of the well-side large-scale fracture.

This invention proposes a method and system for calculating longitudinal uneven deformation of corrugated steel plate support structures, belonging to the field of transportation infrastructure structural design technology. The method includes: constructing an orthotropic equivalent stiffness model of the corrugated steel plate, treating the corrugated steel plate support structure as an equivalent Timoshenko beam, and calculating the equivalent section bending stiffness and equivalent section shear stiffness; constructing a calculation model for longitudinal uneven deformation, determining the longitudinal differential load distribution based on the actual soil cover conditions and soil arching effect above the corrugated steel plate support structure; and calculating the longitudinal differential load distribution based on the longitudinal uneven deformation calculation model to obtain the longitudinal uneven deformation of the corrugated steel plate support structure. This invention enables effective and rapid assessment of the longitudinal uneven deformation of shallow-buried corrugated steel plate support structures.

The application discloses a tensile-bending stiffness decoupling method in fiber preform die forming simulation, and relates to the technical field of simulation learning, and comprises the following steps: a macro finite element model composed of triangular shell elements is established; a biorthogonal fiber coordinate system aligned with the yarn direction is established in each element. Tensile, shear and bending stiffness changing with deformation state are obtained and a constitutive equation is constructed. In the element, an in-plane model controlled by tensile and shear stiffness and an out-of-plane model independently controlled by bending stiffness are respectively established to realize stiffness decoupling. In each increment step, the biorthogonal coordinate system is updated according to the deformation gradient, and after stress is calculated in the biorthogonal coordinate system based on the constitutive equation, the stress is converted to the global coordinate system. Finally, boundary conditions are applied for numerical solution to obtain deformation field, stress and strain distribution and fiber orientation evolution results. The application decouples tensile stiffness and bending stiffness, and eliminates false stiffness in a traditional model.

The invention discloses a novel bolt flange structure analytical model and a verification method thereof, and belongs to the technical field of numerical analysis and computational mechanics. The method comprises the following steps: discretizing and modeling a bolt flange structure; deriving a unit stiffness matrix, a unit mass matrix and a unit inertia matrix for the rotor system; calculating the equivalent stiffness of a bolt for connecting the upper flange plate and the lower flange plate, wherein the equivalent stiffness comprises the axial stiffness and the shearing stiffness of the bolt and the stiffness of the joint surface of the connected flange plates; establishing a complete system kinetic equation of the bolt flange structure; and verifying the model. The problem that an existing method excessively depends on a simplified model or numerical simulation or experience statistics is solved, and a theoretical basis is provided for forward design and performance optimization of a connection structure.

The application belongs to the field of underground space engineering, and provides a Timoshenko beam shear stiffness correction method based on tunnel joint misalignment calculation, which comprises the following steps: establishing a Timoshenko beam high-order differential equation considering shear stiffness correction, establishing a boundary differential equation based on foundation stiffness difference, establishing a Timoshenko beam joint shear stiffness correction model, assembling an overall stiffness matrix and solving, and realizing the calculation of the tunnel joint misalignment amount; the application establishes a Timoshenko beam model based on joint shear stiffness correction, realizes the prediction calculation of the tunnel joint, and can establish a basis for the related work of design units and construction units; in the model, the bending stiffness and shear stiffness can be adjusted, and the accuracy of the model calculation is improved.