191 results about "Contact model" patented technology

The invention relates to a contact predication based large-scale mobile delay tolerant network cluster-based routing method and a system thereof. The method includes: analyzing a truthful data set of a large-scale urban taxi network to disclose the intrinsic contact and clustering characteristics; designing a contact model among nodes and determining a probability distribution expressing form of contact time interval among the nodes; designing and implementing a contact predication based distributed cluster-based routing algorithm, and dividing nodes with high mutual contact probability into a same cluster under the large-scale dynamic environment; and designing and implementing a direct delivery based in-cluster routing algorithm and a flooding based inter-cluster routing algorithm to guarantee effectiveness and expandability in routing transmission on the basis of clustering. The contact predication based large-scale mobile delay tolerant network cluster-based routing method and the system thereof can be widely applied to message communication of large-scale urban transportation networks such as dynamic navigation systems, automatic vehicle driving systems and vehicular entertainment systems.

Merger and duplicate resolution for contact information across platforms is managed employing contact objects and aggregating the contact objects into contact models. Contact data from internal and/or external data stores may be retrieved and contact objects created for each contact from each contact store. A contact model for each contact entity may be created by aggregating contact data from contact objects across the contact stores. The aggregation may include duplicate resolution through weighting of communication system types, ranking of contact information type, and similar approaches. The contact models may be dynamically updated based on changes to the contact objects.

The invention relates to a joint simulation method for a vehicle-road coupled vibration system. The method comprises the following steps of S1, building a vehicle dynamics model according to a dynamics equation; S2, building a pavement dynamics model according to a structural mechanics finite element equation; and S3, loading the vehicle dynamics model in the pavement dynamics model to generate a tire-pavement contact model, and finishing dynamics analysis of the vehicle-road coupled vibration system. According to the method, joint modeling of the vehicle-road coupled vibration system is realized by adopting efficient engineering software Matlab and Ansys; and by taking Matlab as control software and performing secondary development on Ansys, joint simulation of Matlab and Ansys is realized, and dynamics analysis of the vehicle-road coupled vibration system under complex road and vehicle conditions is finished.

The invention relates to an amended gear pair meshing characteristic analysis method taking drum modification into consideration. In order to acquire basic parameters of a gear pair and drum modification parameters, gear teeth of the gear pair are divided into N independent even web gears in the direction of tooth width; the time-variant meshing stiffness of each web gear pair is calculated by adopting the gear pair meshing characteristic analysis method taking prolonging the meshing influence into consideration on the basis of the error of a gear profile of a drum modification gear pair; a meshing gear pair three-dimensional model comprising drum modification is established through three-dimensional drawing simulation software, the three-dimensional model is guided into an ANSYS software to create a three-dimensional finite element contact model, and time-variant meshing stiffness data in the whole meshing process of the gear are solved. The analysis method is simple in modelling process and low in calculated quantity, the requirement on a computer is low, and the calculation result is accurate and true.

The invention provides a method for predicting milling surface errors based on a dynamic workpiece clamping system. The technical problem that a weak-rigidity part is difficult to machine is solved. The method includes the following steps of firstly, establishing a coordinate system of a workpiece and positioning element system; secondly, establishing a workpiece and positioning element contact model according to the coordinate system of the workpiece and positioning element system, wherein when a positioning element is a round head element, the contact rigidity between the positioning element and a workpiece nonlinearly changes while the normal contact force changes; thirdly, establishing a workpiece and positioning element system model through the combination of the workpiece and positioning element contact model; fourthly, judging the stability of the workpiece and positioning element system according to the workpiece and positioning element system model; fifthly, predicting and calculating machining errors on the premise that the workpiece and positioning element system is stable.

The invention provides a force deformation error calculation method for a pin roller linear guide rail pair under vertical loads, and belongs to the precision design field of linear guide rail pairs. The method aims at obtaining deformation of the linear guide rail pair under the load action and improving calculation efficiency. A force deformation error of the pin roller linear guide rail pair is calculated in consideration of the action of the outer loads. Three-dimensional CAD software is used for parametric modeling, the stress condition of the pin roller linear guide rail pair is analyzed, and a mechanical analysis model of the guide rail pair is established under the action of the outer loads. A linear guide rail pair contact model is then researched, and an improved Palmgren formula is applied to analyzing the relation between elastic deformation and the corresponding load when a single pin roller makes contact with a groove. Loads borne by rolling bodies are solved according to the outer loads, elastic deformation quantities of the rolling bodies are worked out, and the displacement quantity of a sliding block is deduced and serves as the force deformation error of the whole linear guide rail pair. Finally, Matlab programming parametric modeling is applied, and the conclusion provides a theoretical basis for movement precision and service life calculation of rolling linear guide rails.

The invention discloses a heavy haul railway turnout static and dynamic design model construction method. The heavy haul railway turnout static and dynamic design model construction method is characterized in that the method comprises the steps of performing quasi-static analysis on a heavy haul railway turnout based on a finite-element theory, and simulating rail, rail fastening, sleeper, ballast and limiter structures and filler structures to construct a heavy haul railway seamless space coupling entity analysis model; constructing a dynamic analysis model to perform dynamic simulation calculation on car-heavy haul turnout coupling, wherein the dynamic analysis model comprises a freight train model, a heavy haul railway turnout model and a wheel-rail contact model. By adopting the technical scheme, the constructed heavy haul railway seamless space coupling entity analysis model and the constructed dynamic analysis model can provide higher-simulation-degree models for heavy haul railway turnout design and analysis; by using the models constructed by adopting the scheme provided by the invention, heavy haul railway turnouts which can fully meet use requirements can be designed.

The invention provides an analysis method for predicting crack propagation of a dam body of a concrete dam. The method comprises the following steps of building a first finite element model of the dam body, wherein the dam body contains an existing crack; simulating crack end concrete of the dam body by adopting a damage model to obtain a fracture prediction path of the crack end concrete of the dam body; adjusting a grid of the first finite element model to form a second finite element model, simulating a preset crack by adopting a first contact model, and performing calculation to obtain a slip quantity and an opening degree of the preset crack, wherein the preset crack is a crack generated according to the fracture prediction path, and the first contact model relates to the tensile strength and the shear strength of the concrete. According to the method, the advantages of the damage model and the contact model are coupled; the finite element analysis method for predicting the crack propagation by two stages is proposed; the limitation of a numerical analysis method in the present stage is overcome; and the method can be applied to the prediction of the crack propagation of the dam body of the concrete dam.

Provided is a method of utilizing finite element modeling to judge whether a turntable bearing meets requirements. A turntable bearing model is established in ANSYS according to a structure parameter of the turntable bearing. Total freedom constraints are imposed on a lower end face of an outer ring of the turntable bearing model, and a radial load, an axial load and an overturning moment load are imposed on an inner ring. Load data of a rolling body is solved and obtained. The security coefficient of the bearing is calculated by utilizing the maximum rolling body load data, and whether the security coefficient meets the requirements. According to the method of utilizing the finite element modeling to judge whether the turntable bearing meets the requirements, the ANSYS is utilized to establish a 'rod-entity' hybrid finite element model of the turntable bearing, and a contact model between an entity rolling body and an entity rolling path is dispensed. The finite element model obviously lowers requirements to computer resources, and the calculation time is greatly shortened.

The invention discloses a bridge crossing train overturning risk assessment method based on a mode superposition method. The method comprises the following steps that: establishing a train system equation of motion, establishing a bridge system equation of motion on the basis of the mode superposition method, establishing a simplified wheeltrack contact model, and establishing a train-bridge system integral equation of motion. On the basis of the simplified wheeltrack contact model, the mutual acting force of the wheeltrack can prevent from being iteratively solved, and a basis is provided forthe equation of motion of a combined train system and bridge system; the train-bridge system integral equation of motion can prevent from separating the iterative solving of the equation of motion ofthe combined train system and bridge system, the synchronous solving of a train and bridge response is realized, and train-bridge system response calculation efficiency is improved. By use of the method, the calculation amount of train-bridge system response analysis under an axial wind function is effectively reduced, and a bridge crossing train overturning risk can be quickly evaluated.

The invention discloses a contact characteristic analysis method based on three-dimensional microscopic surface morphology, and is suitable for researching the contact rigidity and the contact dampingof the combined surface based on the multi-scale theory. According to the method, the surface morphology of the combined surface is obtained through a three-dimensional morphology measuring instrument, and multi-scale decomposition reconstruction is carried out through wavelet transformation, and a three-dimensional entity model for the data of separated different frequency bands. Due to the factthat the established contact model is based on real surface data and influences of different scales are considered, the accuracy of the contact model is improved to a great extent, and the research of the contact characteristic of the combined surface is closer to the actual situation. The real surface morphology height matrix is subjected to multi-scale separation by wavelet transformation, andthe three-dimensional entity model for the data of the separated different frequency bands. Due to the fact that the established contact model is based on real surface data and influences of differentscales are considered, the accuracy of the contact model is improved to a great extent.

The invention discloses an object grabbing method based on oval surface contact. The object grabbing method comprises the following steps that firstly, a 3D depth camera obtains the image information of an object; secondly, a master control computer judges the feasible grabbing area, meeting the force closure condition, in the image information; thirdly, the master control computer screens out the optimal feasible grabbing area in the feasible grabbing area; and fourthly, the master control computer generates a control instruction, and a mechanical arm and a two-finger mechanical hand are controlled to conduct the grabbing action on the object. Through modeling of the mechanical hand and target object contact shape in the real scene, the force closure condition in an oval surface contact model is obtained, and the mechanical hand and target object contact real situation can be further restored; through the convolutional neural network, the optimal feasible grabbing area with the grabbing probability is screened out, the mechanical arm is controlled to achieve stable grabbing, the high one-time grabbing success rate can be achieved in the actual operation process, and the repeated operating and grabbing time cost and energy cost are reduced.

The invention belongs to the technical field of mechanical dynamics, and particularly relates to a meshing characteristic analysis method of stripping bevel gear pair which is corrected by considering substrate rigidity. According to the method, firstly the gear tooth of a bevel gear pair is divided into N independent and uniform thin-sheet straight gears in the tooth width direction, and based on the known stripping size and position parameters, the stripping condition of each straight gear is determined; through a potential energy method, a finite element substrate rigidity correction coefficient is introduced to calculate the time-varying meshing rigidity of each single stripping straight bevel gear; based on ANSYS software parameterized programming, a three-dimensional finite element stripping bevel gear contact model is established, the time-varying meshing rigidity is solved and obtained, and analysis and comparison with an analysis method result are conveniently achieved. Based on an analysis and finite element solution method, the influence of the stripping width ws, the stripping length as, the stripping axial position and the stripping tooth-direction position on the bevel gear time-varying meshing rigidity is analyzed, and the influence of axial multi-stripping and tooth-direction multi-stripping on the bevel gear meshing rigidity is considered at the same time.

The invention discloses a discrete element numerical simulation method for viscous sandy soil hydraulic erosion damage. The method comprises the steps of:establishing an initial calculation space areaand a viscous sandy soil numerical model; initializing a numerical model and balancing stress; compiling a strength degradation criterion linear bonding contact model based on a time effect to simulate a clay phase between aggregate particles in the viscous sandy soil; selecting a contact model as a mesomechanics model of contact between aggregate particles, and valuing mesoscopic parameters of the contact model; calibrating the numerical model through a direct shear strength test; establishing a flow field to simulate the hydraulic erosion damage process of the viscous sandy soil; and obtaining a numerical simulation result of the hydraulic erosion damage test. According to the method, the viscous sand hydraulic erosion damage is simulated through the discrete elements, the thought is simplified, the viscous sand hydraulic erosion damage process can be truly simulated on the mesoscopic level under the conditions that the calculated amount is reduced as much as possible and the calculation efficiency is improved, the migration situation of soil particles is observed and recorded, and the result is accurate.

The invention discloses a finite element modeling system and method for a bolt connection structure. The finite element modeling system comprises a CAD model processing module, a finite element meshing module, a contact model creation module, a bolt element creation module, a rigid element creation module and a pretension element creation module. Compared to the prior art, the system and method provided by the invention have wide application; when key details are reserved, modeling and calculation efficiency is improved; and problems of fussy process and large calculation amount of detailed modeling and a problem of large error of simplified modeling are solved.

The invention belongs to the technical field of mechanical dynamics, and particularly relates to an aviation pipeline modeling and vibration characteristic analysis method considering bolt connection.The method comprises the following steps: establishing an entity contact finite element model constrained by a pipeline clamp, and correcting the elasticity modulus of a pipeline through a free modaltest to obtain a corrected pipeline model; Carrying out simulation calculation on the inherent frequency under the set tightening torque, and verifying the simulation calculation by adopting a modaltest and a basic excitation response test; And analyzing the rule of the influence of the bolt tightening torque, the clamp span and the pipe body length on the inherent frequency of the double-clamppipeline system. According to the method, a finite element contact model is adopted and is combined with a test to carry out comparative study, and the modeling method is accurate in calculation result and conforms to the actual structure.

The invention discloses an implementation method applied to a flexible line higher pair constraint simplification model. The method includes: defining a workpiece with at least one arc face being a contact face as a flexible component A; subjecting a flexible component A and roller mutual contact model to constraint simplification to obtain a flexible line higher pair constraint model; defining aface, acting on a roller, of the flexible component A as an operating face of the flexible component A to construct a dynamic flexible line, and subjecting to further constraint processing; subjectingthe roller and flexible component A simplified model to loading processing; finally calculating a roller driving angle. By adoption of the method, defects of high mechanism contact quantity, poor calculation stability, difficulty in convergence, high simulation result burr quantity, low calculation efficiency and the like in axisymmetric vectoring exhaust nozzle many-body dynamics simulation canbe overcome.

The invention discloses a vertical response calculating method of a three-slide-block monorail flexible rocket sled. Bearings of the rocket sled are analyzed, and a rocket body is dispersed into finite element beam models; structural vibration, caused by unsmoothness of a rail, of the rocket sled and the rail is taken into consideration and a Hertz nonlinear contact model is used to calculate collision contact forces born by the rocket body in different time; and the whole-course vertical dynamic response of a three-slide-block monorail rocket sled system within given time is calculated by utilizing a central difference value method. In the calculation process, flexible deformation characteristic of a rocket sled body and a quality reduction effect, caused by fuel ejection, of the rocket sled system are taken into consideration, the nonlinear contact problem caused by that the rail is unsmooth is also considered, and thus, a more reliably dynamic response result can be obtained.

The invention discloses a physical property measurement system and a method for a material based on an AFM (atomic force microscope) probe force curve. According to the method, a high-speed and high-precision digital acquisition card and a digital controller are adopted to realize broad-band and high-resolution measurement during a probe force curve testing process. Therefore, a peak force in the probe force curve can be controlled and measured precisely. On the basis of acquiring the force curve, a Hertz contact model and a Derjaguin-Muller-Toporov (DMT) model are used for acquiring appearance information of the surface of a sample, and a power dissipation and force curve area integral method is used for acquiring a viscous force and dissipated energy information of the sample. According to the system and the method, a large amount of information reflecting physical properties of the surface of the sample is included. The application scope of an AFM is expanded greatly, the development of correlational study fields is promoted, and the system and the method have very important scientific values and good application prospects.

The invention provides an aircraft wheel vibration analysis method based on finite elements. The method is used for analyzing vibration characteristics of an aircraft wheel. The method comprises the following steps: 1, establishing an airplane wheel geometric model, and importing airplane wheel geometric model to software to establish a finite element model; 2, establishing a contact model of each assembly part of the airplane wheel; 3, setting material parameters of each part of the airplane wheel; 4, calculating a wheel static lateral load, an inflation load, a bearing supporting force and a piston applied pressure; 5, carrying out modal analysis on the airplane wheel under prestress; 6, importing the modal analysis result into a harmonic response analysis module; carrying out harmonic response analysis to obtain displacement frequency domain curves, speed frequency domain curves and acceleration frequency domain curves of the airplane wheel and components thereof, analyzing vibration types through the frequency curves, and judging frequencies of three main vibration modes of flutter, howling and vortex motion to obtain vibration characteristics of the airplane wheel, so that anti-vibration design and optimization can be conveniently carried out in the later period.

The invention provides a method for analyzing stress of an asphalt pavement structure in different interlayer bonding states, and belongs to the technical field of asphalt pavements. The problems thatat present, modeling of pavement structures in different interlayer bonding states is inaccurate, and results have errors are solved. The method comprises the following steps: generating an asphalt pavement structure initial model with determined gradation of each layer by adopting discrete element software; secondly, setting corresponding boundary conditions, physical parameters of a material ina pavement structure layer and a contact model among unit particles, and establishing a discrete element mechanical analysis model; and finally, using a servo mechanism for simulating vehicle loads to load the asphalt pavement in different combination states, monitoring tensile stress, shear stress, tensile strain and pavement surface deflection value data at the load positions of all structurallayers of the pavement, drawing a stress data comparison graph, and analyzing the stress conditions of the asphalt pavement structure in different interlayer combination states. The method provided bythe invention is visual, simple and convenient, accurate in calculation data, and suitable for simulating various asphalt pavements in different interlayer states.

The invention discloses a binary-system-based network data transmission method and system. The method comprises: S1, a client establishes a contract model of a transmission field, wherein the contact model includes a plurality of data fields and data types; S2, a client uses an automatic tool to convert the contact model into model languages of different platforms; S3, the client carries out serialization on the contact model to obtain binary data and then the data are sent to a server side; S4, the server side carries out deserialization on the binary data to obtain a contact model; S5, the server side carries out operation and processing on the contract model and carries out serialization on the processing result to obtain binary data, and then the binary data are sent to the client; and S6, the client carries out deserialization on the binary data sent by the server side to obtain a contract model. According to the invention, network data transmission is carried out based on an extensible binary data transmission protocol with good data type support and the data format can be defined by the user. Therefore, the transmission data volume is reduced; and the data extensibility and supportability are enhanced.