22 results about "Equivalent stiffness" patented technology

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 present invention discloses a method for identifying nonlinear parameters of structural clearances. First, a mathematical model of the structural clearance nonlinear system is established; then, the frequency response function of the system under sinusoidal sweep excitation is obtained through the input-output response of the system; in the frequency response function, a pair of symmetric displacement points exist at any displacement response amplitude to define the same displacement frequency response function. By defining the real and imaginary parts of the displacement frequency response function through the symmetric displacement FRF points at each given displacement response amplitude, the natural frequency of the system related to the displacement response amplitude can be obtained; then, the expression of the nonlinear equivalent stiffness of the system is extracted through the simulation analysis of the model, and the equivalent stiffness curve of the system is further obtained through the model simulation data; finally, based on the particle swarm algorithm, the clearance characteristic parameters are obtained by curve fitting according to the equivalent stiffness expression obtained by integration and the equivalent stiffness curve obtained by model simulation; the present invention can identify the clearance nonlinear parameters more quickly and accurately globally.

The application discloses a kind of water turbine rotor dry mode model updating method and related device, comprising: forming numerical modal family;Equivalent boundary parameter and key connecting surface equivalent stiffness are set;Under the predetermined rotating speed set, calculate centrifugal prestress;On the basis of the centrifugal prestress, consider gyroscopic effect, sequentially solve each rotating speed condition, obtain the natural frequency and vibration mode branch varying with rotating speed;Identify test frequency, damping and vibration mode;With adjacent sector vibration mode phase difference consistency and vibration mode energy distribution as criterion, carry out node radial number determination to test vibration mode, and with the numerical modal family is matched one by one;With the deviation of test frequency and mode assurance criterion as comprehensive target, the equivalent boundary parameter and key connecting surface equivalent stiffness are carried out inversion updating, until meeting preset convergence criterion, complete the updating of water turbine rotor dry mode model, the method and related device can reduce model scale and improve solving convergence.

The present application relates to the field of textile machinery and equipment damping, specifically warp knitting machine bed damping device and method thereof; containing damping base, negative Poisson's ratio lattice metal bearing framework, corrugated air chamber, venturi micro flow channel, composite fluid and electromagnetic coil and controller and other modules; The system fills the shear thickening and magnetorheological mixed composite fluid in the bearing cavity, cooperates with the bearing framework with three-dimensional interconnected pores, and occurs local shear thickening under high frequency impact; The core is that the controller extracts the high frequency vibration characteristics of the main shaft motor, combines the air chamber pressure pulse to solve the dynamic kinetic energy and total stiffness demand, and actively adjusts the electromagnetic coil current and duty cycle; The present application effectively avoids the dynamic hardening defect of traditional hydraulic damping, and realizes the active adjustment type energy consumption and self-adaptive compensation of equivalent stiffness for high frequency periodic impact.

The application discloses a preliminary design rapid estimation method and system for tower deviation of a multi-tower cable hoisting system, and relates to the field of tower deviation estimation in bridge construction technology.The estimation method comprises the following steps: calculating the single-span horizontal elastic stiffness of each span compression tower cable based on an equivalent elastic modulus method; calculating the total equivalent stiffness of each tower according to a series stiffness model, specifically comprising the following steps: first, calculating the corresponding left series stiffness and right series stiffness, and then adding the left series stiffness and the right series stiffness to the self equivalent stiffness of the tower to obtain the corresponding total equivalent stiffness; when a single tower is subjected to an external force, calculating the self deviation and the collaborative deviation of the adjacent tower based on a deviation influence coefficient; and when multiple towers are simultaneously subjected to force, calculating the total deviation of any tower by using a superposition principle.The application is suitable for rapid scheme comparison and selection in the preliminary design of a multi-tower cable hoisting system with any number of spans and towers, and has the advantages of strong universality, reliable precision, easy implementation and the like.

This invention relates to a full-frequency vibration reduction design method for metamaterial pipelines based on multiple band gaps, comprising: establishing an equivalent mechanical model of the target pipeline; periodically arranging elastic supports on the target pipeline to induce the formation of a zero-frequency band gap and a Bragg band gap, coupling the equivalent support stiffness of the elastic supports with the equivalent mechanical model of the pipeline to construct a first band gap calculation model; periodically arranging local resonant vibration absorbers on the target pipeline to form a local resonant band gap, coupling the equivalent stiffness and equivalent mass of the local resonant vibration absorbers into the first band gap calculation model to obtain a second band gap calculation model; constructing a system finite structure dynamic vibration calculation model with a second assembly as the analysis object; constructing a vibration transmissibility index, and using the system finite structure dynamic vibration calculation model as a fitness evaluation tool for a genetic algorithm to perform non-periodic optimization of the elastic support positions, solving for the optimal arrangement position of the elastic supports with the largest bandwidth of the zero-frequency band gap.

The application relates to the technical field of performance analysis of viscoelastic materials, and discloses a performance analysis method and device of viscoelastic materials, wherein the method comprises the following steps: obtaining elastic operators of a specific viscoelastic material at multiple time points, and dividing the material into coarse element domains and fine element domains by using a multi-scale finite element method. A multi-scale base function is constructed for each coarse element domain, and an equivalent stiffness matrix set is calculated, and then a scale reduction calculation is performed to extract a micro information set. Based on the functional relationship of the micro information, viscoelastic analysis of the specified viscoelastic material is finally realized, and a basis is provided for performance evaluation of the material. The application has the advantages of high calculation efficiency, resource saving and large problem scale expansion compared with the prior art, reduces the historical data storage demand, significantly reduces the degree of freedom of the macro equation, is widely applicable to non-periodic structures, and has the potential to be extended to nonlinear viscoelastic problems.

This invention discloses a design method for blade wall replacement in deep foundation pits based on stiffness matching and deformation control. The method involves obtaining the equivalent stiffness of the original support and deformation control indices of the retaining structure; establishing a shear-bending coupled stiffness model within the blade wall surface; setting a stiffness matching coefficient, constructing a stiffness matching equation, and solving for the recommended combination of section parameters; establishing a deformation control equation for the retaining structure based on the principle of elastic foundation beams, back-calculating the maximum allowable spacing, and outputting the standardized spacing; establishing a dual-control reinforcement model, introducing a temporary structure importance reduction coefficient, calculating the area of ​​edge longitudinal reinforcement and the reinforcement ratio of horizontally distributed reinforcement, and outputting complete design parameters. This invention achieves rapid design of blade walls based on stiffness matching and deformation control for the first time, improving efficiency by more than 80% compared to traditional finite element trial calculation methods, ensuring continuous deformation of the support system before and after replacement, and controllable failure modes.

This invention belongs to the technical field of structural health monitoring, and relates to a node connection system for a steel-concrete composite beam bridge based on equivalent stiffness matching. The system includes: a data acquisition module for generating a four-dimensional dynamic strain tensor; a manifold mapping module for constructing a dynamic strain manifold; a risk identification module for outputting precursory stress concentration areas and their topological locations; a command generation module for generating spatially addressed active driving commands; an execution management module for switching from an energy harvesting state to an active stiffness modulation state; a stress intervention module for generating local active reverse strain; and a closed-loop verification module for completing the entire closed-loop control process. This invention solves the problem that many monitoring systems remain at the level of data acquisition and threshold alarms, making it difficult to identify implicit precursors of stress concentration evolution and their topological locations from massive amounts of sensor data.

This invention discloses a method for calculating the local equivalent stiffness of a beam structure based on frequency equivalence. The steps are as follows: Based on the length d of the damaged region of the beam structure, set an appropriate length ε of the locally damaged beam segment; calculate the equivalent stiffness coefficient c. eq Calculate the equivalent stiffness of the locally damaged beam segment, where equivalent stiffness = c. eq × Bending stiffness of the undamaged beam section; c for locally damaged beam segments, excluding those near the zero point of the modal curvature curve. eq It can be calculated using an approximate method; for each location of the beam structure, c eq Based on the modal curvature curves of the beam structure before damage, strain energy methods can be used to calculate the curvature for simply supported beams, cantilever beams, and statically indeterminate beams. For single-span beams with uniform cross-sections, theoretical modal curvature curves are used. For other structures, the modal curvature curves are obtained through finite element model calculations or actual measurements, and the curvature is calculated using the central difference method. This invention proposes a concise method for calculating the equivalent stiffness between local damage measurement points, providing a theoretical basis for calculating the actual damage degree when conducting quantitative damage tests based on dynamic indicators.

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 present application relates to the technical field of structural engineering and fan foundation design, and specifically relates to a load distribution calculation method for a foundation pile column node, which comprises defining an input load vector of a main control point and a corresponding spatial six-degree-of-freedom generalized displacement; decoupling the foundation pile column node into two parallel subsystems in terms of physics and stiffness, deriving a single-pile spatial stiffness matrix based on the m method of the Winkler foundation model; constructing a first equivalent stiffness matrix and a second equivalent stiffness matrix; superimposing the matrices of the first equivalent stiffness matrix and the second equivalent stiffness matrix to obtain a global spatial stiffness matrix of the foundation composite system; and calculating a dynamic load distribution ratio of the parallel subsystems. The present application is used to accurately describe the nonlinear interaction between the pile foundation and the foundation, to provide more accurate pile foundation stiffness calculation and load distribution results, and to improve the accuracy and reliability of the load distribution calculation.

The application discloses a sealing performance analysis method, device, equipment and medium of a tubing thread joint, relates to the technical field of gas well tubing safety evaluation, and comprises the following steps: dividing a connection structure composed of a preset thread joint and unconventional oil and gas well tubing at both ends of the thread joint into two parts of continuity and discontinuity, so as to construct a nonlinear discrete equivalent model of the connection structure; the preset thread joint is a thread joint provided with an independent sealing structure; a vibration modal experiment is conducted on the preset thread joint, and inherent frequency experimental data of the connection structure under different sealing contact states is obtained; based on the inherent frequency experimental data, the nonlinear discrete equivalent model and a Markov chain Monte Carlo algorithm, equivalent stiffness coefficients and target inherent frequencies of the preset thread joint under different sealing contact states are determined; and based on the equivalent stiffness coefficients and the target inherent frequencies, sealing performance analysis results of the preset thread joint are determined. The application improves the efficiency, accuracy and interpretability of sealing performance analysis.

The application discloses a kind of based on normal stress electromagnetic stiffness adjustable quick tool servo device and method, including base, shell component;Shell component is provided with plane stiffness adjusting brake assembly and normal stiffness adjusting brake assembly in, and plane stiffness adjusting brake assembly and normal stiffness adjusting brake assembly are configured as the structure that consistent structure is arranged mutually orthogonal;Plane stiffness adjusting brake assembly is used to drive output shaft to generate micro-displacement along X direction and adjust the equivalent stiffness of Z direction of output shaft;Normal stiffness adjusting brake assembly is used to drive output shaft to generate micro-displacement along Z direction and adjust the equivalent stiffness of X direction of output shaft.The device of the application can realize two-dimensional high-frequency micro-displacement output under different machining conditions, and the equivalent stiffness of system can be quickly, continuously and in situ adjusted, so as to improve machining stability and machining precision and expand application range.

The present application relates to the technical field of performance monitoring, in particular to a coupled beam damper hysteresis performance prediction method and system, comprising the following steps: obtaining monitoring data to generate a prediction input sequence, discretizing and fitting an equivalent stiffness prediction primitive based on a multi-cycle extreme value range to generate a path, using cross-cycle comparison and residual displacement evolution calculation to generate stable prediction data, screening stable cycle sections and combining evolution direction to establish a performance prediction constraint set, combining the to-be-predicted path and the constraint set to calculate force increment and correct the state to generate hysteresis performance prediction results. In the present application, the cycle recognition is used to cut the displacement and force time history data, the prediction input sequence is generated, the displacement extreme value proportion is discretized, the interval force displacement ratio is calculated, the cross-cycle comparison and residual displacement smoothing judgment are used to realize the stable prediction of hysteresis performance, improve the performance evaluation accuracy and reliability, and maintain the consistency of the prediction results.

The application discloses a kind of composite material frame layering mechanical property rapid simulation verification method, it is related to composite material structure mechanics simulation technical field.The method includes: S1 imports geometry model and layering design data, is marked key joint with conventional layering area by region analysis, constructs global partition parameter dataset;S2 is generated equivalent stiffness matrix based on classic laminated plate theory conventional layering area;S3 key joint area is dispersed into subdomain, and its equivalent stiffness matrix is inverted by augmented lagrange iteration coordination calculation;S4 assembles frame overall stiffness matrix, obtains overall displacement response using sparse matrix solution algorithm;S5 calculates overall mechanical performance index, combines key joint area stress distribution, generates simulation verification result according to composite material failure criterion.The method greatly improves the calculation efficiency while ensuring the simulation accuracy, provides reliable technical support for the rapid verification and optimization of composite material frame layering design.

This invention relates to the field of vibration control technology, and more particularly to a cable multimodal control device and method based on a passive adjustable stiffness-damper. The device includes a mechanical damper and an adjustable equivalent stiffness device. The adjustable equivalent stiffness device comprises a preloaded spring-type negative stiffness mechanism, a lever-type positive stiffness mechanism, and a power mechanism. The lever-type positive stiffness mechanism changes the equivalent stiffness generated by the series connection of the preloaded spring-type negative stiffness mechanism and the lever-type positive stiffness mechanism by changing the lever ratio. The power mechanism is installed between the cable and the ground to sense the cable's vibration, generate relative motion with it, and drive the lever-type positive stiffness mechanism, thereby changing the lever ratio of the lever-type positive stiffness mechanism. Through a purely mechanical structure, this invention provides a novel solution for multimodal control of cables targeting nodal modes, with a wide range of applications. Compared to existing active / semi-active methods that change the dynamic parameters of the damper, it eliminates the need for external power supply.

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.

This application provides a method and system for evaluating the sealing performance of a thermal isostatic pressure ultra-high pressure vessel. The method includes: acquiring isostatic pressure parameters, temperature parameters, and structural response parameters from a set of operating state parameters; in the sealing load-bearing area of ​​the end cap assembly, acquiring structural response characteristics related to the sealing contact state based on the structural response parameters from the set of operating state parameters; constructing an equivalent stiffness characteristic quantity of the sealing interface based on the correspondence between the isostatic pressure parameters and the structural response characteristics; generating a thermo-mechanical coupling characteristic index of the sealing interface based on the coupling relationship between temperature parameters and structural response characteristics at different operating stages; during pressure loading or unloading, generating a pressure change rate based on the isostatic pressure parameters and acquiring the theoretical displacement of the self-pressurizing structure or pre-tightening structure of the sealing assembly; and outputting the sealing performance evaluation results through the equivalent stiffness characteristic quantity, thermo-mechanical coupling characteristic index, and theoretical displacement. This application realizes real-time measurement of the sealing state under high temperature and high pressure conditions, improving the safety and reliability of the device operation.

This invention relates to a method, system, device, and storage medium for modeling dynamic geometric errors of a mold clamping mechanism. The modeling method disclosed in this invention includes the following steps: identifying key geometric and stiffness features of the mold clamping mechanism; solving for the initial static error of the moving template based on the key geometric features; using a parametric virtual prototype, taking the initial static error as the initial geometric pose of the moving template, and introducing a nonlinear contact force model and an equivalent stiffness model to construct a parametric multibody dynamics model; calculating and extracting dynamic error and mold clamping force data based on the parametric multibody dynamics model, and constructing a collaborative explicit function model of dynamic error and mold clamping force. Compared with existing technologies, the advantages of this invention are: it can evaluate the impact of nonlinear dynamic effects induced by the clearance of the kinematic pairs on error analysis, and perform collaborative analysis of motion accuracy and mechanical performance, quantifying the geometric error of the mold clamping mechanism under high-speed operation and mold-locking conditions.

The application discloses a solid material plastic deformation prediction method and device, equipment and medium, and relates to the technical field of solid mechanics, and comprises the following steps: acquiring first configuration data corresponding to a solid material to be analyzed, and performing energy minimization processing on the first configuration data to obtain corresponding second configuration data; constructing a preset dynamic matrix corresponding to each atom in the second configuration data, and determining a target equivalent stiffness parameter of each atom based on the preset dynamic matrix; performing coarse-grained processing on the target equivalent stiffness parameter of each atom to construct a corresponding target equivalent stiffness field; the target equivalent stiffness field is used for characterizing the relative stiffness distribution of each spatial position inside the solid material; and based on the target equivalent stiffness field, a target defect area in the solid material is identified, and plastic deformation prediction is performed based on the target defect area. As can be seen from the above, the application can realize general, efficient and accurate solid material plastic deformation prediction of multi-structure materials.