153 results about "Contact model" patented technology

The invention relates to a rigid-flexible trans-mass self-adaptive robot force position and rigidity collaborative optimization method and system, and relates to the technical field of robot control, and the method comprises the steps: firstly, carrying out the linearization processing of a robot dynamic model through a semi-implicit integral method, and obtaining a robot dynamic model; and in combination with an extended Kalman filter, stiffness parameters in the contact operation process are estimated in real time, a dynamic stiffness sensing model is constructed, and the system response capability is effectively improved. Then, a rigidity parameter is embedded into a Hertz contact model, the dependence of a traditional model on prior information of a contact surface is broken through, a dynamic interaction model between the robot and an operation object is established, and high-precision real-time sensing of normal force and friction force is achieved. And finally, under a nonlinear model predictive control framework, multi-dimensional physical constraints are constructed based on the contact force, the position and the contact rigidity, an optimal control model is obtained, control input is dynamically and adaptively updated through rolling optimization, and the stability and the control precision of the robot in rigid-flexible heterogeneous contact operation are improved.

The invention discloses a three-dimensional fluid-solid coupling simulation method and device for a rod falling behavior of a control rod drive line, and relates to the technical field of simulation of the rod falling behavior of the control rod drive line. Fluid boundary updating in the rod falling process of the control rod is processed through a structural grid and dynamic grid layer laying technology on the basis of computational fluid dynamics and multi-body dynamics theories; a modal synthesis method and a Hertz contact model are adopted to solve the problems of flexibility and contact friction of a large-length-diameter-ratio moving part, key factors including fluid resistance and mechanical friction resistance influencing rod falling simulation accuracy are calculated, fluid-solid coupling is achieved through one-way data transmission, three-dimensional fluid-solid coupling of the rod falling behavior of the control rod drive wire is achieved, and the control rod drive wire rod falling simulation accuracy is improved. The accuracy of a simulation result is improved, the degree of dependence on a prototype test is reduced, and a technical basis is provided for researching the rod falling behavior of the reactor control rod drive wire.

The invention discloses an aggregate random distribution concrete PFC (Power Factor Correction) simulation method, which comprises the following steps: a model selection step: determining a parallel bonding model as a mechanical model for concrete material simulation; a cement mortar matrix generation step of generating a cement mortar matrix by using particles in a set size range in a set space range based on the model, and setting pore density, particle density and contact model parameters; a coarse aggregate random distribution simulation step: randomly covering and grouping original particles in the matrix in a grouping and range mode; a concrete numerical model construction step: determining particle classification so as to distinguish cement mortar and coarse aggregate; and a model reliability verification step: comparing indoor test results through a uniaxial compression test. According to the method, the simulation accuracy is improved, the randomness of aggregate is reduced, the model reliability is ensured, the matrix simulation refinement degree is improved, and a method is provided for concrete modeling and performance research.

The invention relates to a dynamic characteristic modeling method and system for an alternating impact disassembling operation robot, and relates to the technical field of robot control, and the method comprises the steps: firstly, comprehensively considering the dynamic characteristics of a robot joint side and a motor side, building a torque-driven flexible joint dynamic model, and determining the influence of joint flexibility on impact response; secondly, estimating normal impact force and tangential friction force by adopting an exponential inelastic continuous contact model, constructing an alternating impact dynamic model, and quantifying momentum change and a nonlinear dynamic effect in the impact process; and finally, a multi-space dynamic characteristic coupling model is established, the interaction mechanism of the joint space, the impact contact space and the task space is systematically analyzed, the accurate speed after impact is output, an impact force control strategy is generated, the dynamic response precision of the robot under the alternating impact operation is improved, the active utilization of the robot on the impact effect is achieved, and the reliability of the robot is improved. And the stability, the accuracy and the high efficiency of the disassembling operation are ensured.

The invention belongs to the technical field of crossing of artificial intelligence and computational mechanics, and particularly relates to an artificial intelligence-based MPM simulation method and system for a mold bag sand cofferdam, a three-dimensional simulation system of the mold bag sand cofferdam is constructed in combination with an MPM method, and the penetration state of sand and geotechnical cloth is detected in an accelerated manner by utilizing a penetration tracking algorithm and spatial Hash. An artificial intelligence algorithm is introduced, a reward function is designed with minimum penetration depth and penetration times as targets, penetration prediction of MPM particles is driven, the speed and stress of the MPM particles are further dynamically regulated and controlled on the basis of a predicted contact model and the artificial intelligence algorithm, penetration is prevented, numerical stability is ensured, and the prediction accuracy of the MPM particles is improved. The calculation precision is improved by adopting implicit integration and gradient descent methods; and bidirectional coupling of the sand and the geotechnical cloth is realized through a visualization module. The problems that in a traditional method, coupling simulation of sandy soil and a flexible structure is low in efficiency, easy to penetrate, unstable in numerical value and the like are solved, and the accuracy and reliability of simulation analysis of the mold bag sand cofferdam structure under the complex working condition are remarkably improved.

Provided are a method and apparatus for calibrating contact parameters of electrode materials, and a computer storage medium. The method includes the following operations. A discrete element simulation test is performed on an electrode material based on a calibration model and calibration ranges of contact parameters of the electrode material when an axial force-displacement curve of a target pellet of the electrode material meets an adaption condition of the contact model; then a simulated axial pressure-axial strain relationship of the electrode material is acquired based on a target discrete element simulation parameter of the electrode material; whether the contact parameters are calibrated successfully is judged based on this relationship; and when the contact parameters are calibrated successfully, calibration results of the contact parameters are determined.

The invention provides a root-soil mixture impact penetration sounding dynamic response prediction method. The method comprises the following steps: firstly, constructing a discrete element model of a root-soil mixture, and constructing a root system structure with high simulation characteristics in the discrete element model; and fine simulation of interaction of the root system and the soil particles under the impact penetration power load is realized in combination with a contact model for simulating mechanical properties of the root-soil mixture, so that impact penetration penetration prediction of the root-soil mixture is finally realized. According to the method, various behaviors such as contact, friction, stripping and tearing between root-soil particles can be dynamically simulated on a microcosmic level, the behaviors are coupled into an integral model of impact penetration sounding, and the penetration resistance mechanism of a root-soil mixed medium can be accurately captured through the method, so that the penetration resistance of the root-soil mixed medium is accurately determined. And a reference is provided for abnormal identification and correction of the penetration signal.

The invention discloses a gas turbine pull rod rotor wheel disc vibration analysis method, system and device, and relates to the technical field of gas turbines.The method comprises the steps that a three-dimensional finite element kinetic equation of a rotating part is constructed; the contact stiffness of adjacent contact units is deduced by considering the rough contact characteristic of the contact interface and combining a microscopic contact mechanical model of the contact interface and a rough consolidation interface contact mechanical model based on the statistical theory; a stress strengthening effect is considered, and a stress stiffness matrix and a contact stiffness matrix are iteratively calculated; a central pull rod end face tooth structure considering local contact nonlinearity is constructed, and an end face tooth contact model considering collision separation is constructed; carrying out vibration response solution on the three-dimensional finite element kinetic equation by adopting a degree-of-freedom reduction method; according to the method, the vibration analysis model is established, the pull rod rotor does not need to be simplified, and geometric features, contact surface features and load effects of an original model can be reserved to a great extent.

The invention belongs to the field of geologic disaster prevention and control of geotechnical engineering, and provides a multi-scale numerical simulation method for a slope instability mechanism of a ductile shear zone, which comprises the following steps: acquiring physical and mechanical parameters of a rock-soil body material, and establishing a numerical model based on a particle flow discrete element method; a Johnson-Kendall-Robert contact model is adopted as a contact model between particles, the contact force between the particles is calculated, and meanwhile, a pressure interference parameter is defined to control the limit value of normal contact rigidity; performing dynamic modeling of the discrete element particle system based on a particle generator; static modeling of a discrete element particle system is carried out based on a Lagrange body continuous unit component; the acting force of discrete element particles is converted into equivalent grid node force through an equivalent node force conversion method, and surface attributes of all unit sets possibly involved in contact are defined in a solver.

The invention discloses an involute helical gear forming grinding force prediction method, which comprises the following steps: firstly, based on a helical gear forming grinding space motion relationship, establishing a helical tooth surface model comprising an involute surface and a tooth root transition curved surface, and constructing a geometric contact model of a grinding wheel and a gear; then, tooth surface deformation data obtained after heat treatment are obtained through a three-coordinate measuring machine, coordinate mapping is carried out, and the grinding depth and contact parameters are corrected; on the basis, a grinding force integral model considering the heat treatment influence is established by combining a plane grinding mechanism, and integral calculation is carried out on tangential and normal grinding force of a tooth surface involute section, a transition arc section and a tooth bottom section; finally, actual measurement data are obtained through a grinding experiment, and model parameter calibration is completed. According to the method, dynamic and accurate prediction of tangential and normal grinding force in the bevel gear forming and grinding process can be achieved, and a reliable basis is provided for mechanical behavior analysis and process optimization in the gear machining process.

The invention discloses an efficient identification method for connection rigidity of a steel pipe pole of a power transmission line, which relates to the field of structural health monitoring, and comprises the following steps: constructing a multi-scale finite element model of the steel pipe pole, acquiring displacement and frequency response of the structure to carry out parameter sensitivity analysis, and screening key correction parameters; constructing a key parameter-structure response sample data set, and training and optimizing an FEA-Net neural network model; and constructing a Bayesian correction framework, solving posterior probability distribution by adopting a TMCMC algorithm, and realizing the probabilistic identification of the connection stiffness and the systematic correction of the finite element model. By constructing a local refined contact model, a bolt pretightening force-connection rigidity corresponding relation is established, and an effective means is provided for verifying whether the rigidity of the corrected model is matched with the rigidity of an actual structure or not. The structure rigidity damage position can be accurately recognized, the rigidity degradation degree can be quantified, and a high-credibility model basis is provided for safety evaluation, digital twinborn construction and operation and maintenance decision making of engineering structures such as electric transmission line steel pipe poles and the like.

The invention relates to the technical field of optical machining, in particular to a polishing surface roughness prediction method based on a robot flexible ball head tool, which comprises the following steps: firstly, establishing a microscopic contact model of the flexible ball head tool and a workpiece, and determining first pressure distribution of a contact area between the flexible ball head tool and the workpiece; vibration of the flexible ball head tool is converted into pressure fluctuation of the flexible ball head tool, total pressure distribution during machining is obtained, and then second pressure distribution is formed; in combination with the second pressure distribution and the relative speed model during machining of the flexible ball head tool, a material removal rate model during machining of the flexible ball head tool is obtained; performing path integration on the material removal rate model to obtain the surface height change of the workpiece in the machining process; and the surface roughness of the machined workpiece is obtained by combining the original surface height and the surface height change of the workpiece. According to the method, the quantitative relation between the vibration parameters and the surface roughness is disclosed, and a theoretical basis is provided for optimizing polishing process parameters and controlling the surface quality.

The application discloses a short-fiber reinforced ablative material bulk ablation simulation method, and belongs to the technical field of multifunctional composite materials and structure numerical simulation.The application comprises the following steps: constructing a discrete system composed of a series of spherical particle units by using a discrete element method; calculating the contact area, contact force and connecting force of the particle units by using a Hertz-Mindlin contact model and a parallel-bond model at each calculation time step; calculating the temperature of the particle units by using an energy conservation principle and a Fourier heat conduction law; calculating the displacement and angular displacement of the particle units by continuously integrating the momentum conservation equation twice; updating the velocity, displacement and diameter of each particle unit, and updating the porosity and pore pressure of the discrete system; iteratively solving and visualizing until a specific condition is met, and ending the simulation.The application characterizes the internal structure features of the short-fiber reinforced ablative material by using the discrete element method, so that the numerical simulation accuracy of the ablation process is improved, and the possibility of capturing the micro ablation mechanism is provided.

The application discloses a wheel fatigue life prediction method based on a rolling contact fatigue simulation technology, and comprises the following steps: establishing a finite element model of a wheel-axle-rail, performing grid encryption on a wheel-rail contact area, and performing static strength checking to obtain an initial finite element model meeting static force requirements; establishing a wheel-rail rolling contact model based on the initial finite element model, describing rolling motion of the wheel by using a hybrid Lagrangian / Eulerian description or a co-rotating coordinate system, and applying a wheel non-circularity excitation spectrum in explicit dynamics analysis to calculate a dynamic contact stress field under different axle loads and friction coefficients; and based on the dynamic contact stress field, a multi-axle fatigue damage model is used in combination with a linear cumulative damage criterion to calculate fatigue life, and an abrasion correction coefficient and a residual stress correction coefficient are introduced to correct the calculation results. The application significantly improves the prediction accuracy of fatigue defects such as wheel peeling, cracking and polygonization.

A method for constructing a dynamic model of a coupled system of high-speed railway train-track-substructure includes: experimentally obtaining key technical parameters with nonlinear and frequency-varying characteristics in the high-speed railway infrastructure system; constructing a novel wheel-rail contact model suitable for higher speed levels and integrating it into the vehicle-track coupled dynamic model; constructing a train vehicle model and track structure model based on the principles of multi-rigid-body dynamics and the finite element method; and using a self-developed program to realize the dynamic modeling of the train-track system; taking the ballastless track structure, subgrade, bridge, and tunnel structures of high-speed railways as research objects, and applying a finite element simulation platform to realize the construction of a refined finite element model of the track-substructure structure; this invention achieves a breakthrough in the theoretical modeling of the vehicle-track-substructure system of higher speed railways, providing a research method and platform for deepening the understanding of the coupled dynamic mechanism of complex systems of high-speed railway infrastructure with speeds of 400 km / h and above.

The application discloses a kind of discrete element modeling methods of multi-layer interpenetrating shear mixing drill and soil body, comprising: S1, the design parameter of multi-layer interpenetrating shear mixing drill is obtained, design parameter includes the pitch of blade, inclination, shape, size and quantity;Multi-layer interpenetrating shear mixing drill includes inner drill rod, multiple pairs of inner blades and outer frame arranged on inner drill rod;The outer frame includes multiple pairs of outer blades, two side plates and a collar arranged at intervals, and each pair of outer blades and each pair of inner blades are arranged at intervals;S2, the modeling of multi-layer interpenetrating shear mixing drill is carried out to obtain drill model;S3, establish soil model, import drill model, distribute contact model, and construct the coupling discrete element model between multi-layer interpenetrating shear mixing drill and soil particles;S4, simulation is carried out using coupling discrete element model, and quantitative analysis is carried out on mixing effect according to simulation result.The coupling discrete element model constructed by the above method has reliability and engineering applicability, and provides quantifiable basis for drill structure optimization.

The invention discloses a flexible wiping method and system of a flexible joint space robot based on dynamic adaptive impedance control, and the method comprises the steps: firstly, building a contact model between the flexible joint space robot and a wiped target; then, self-adaptive impedance control for dynamically updating impedance parameters is designed; and finally, performing comparison simulation on classical constant impedance, fixed update rate adaptive impedance control and dynamic update rate adaptive impedance control, and verifying the effectiveness of the method combining the dynamic update rate adaptive impedance control and singular perturbation control on friction force compliance control in the wiping process of the flexible joint space manipulator by a simulation result. The method is used for the field of on-orbit wiping of the flexible joint space robot, and accurate compliance force control can be conducted on the flexible joint space robot rapidly, efficiently and accurately; when the flexible joint space robot executes a task, necessary guarantee can be provided for the flexible joint space robot, and it is ensured that the space robot and a wiping target are not damaged, and meanwhile a good cleaning effect is obtained.

The invention discloses a gear pair meshing stiffness calculation method considering a thermoelastic coupling effect, which relates to the field of gear transmission, and comprises the following steps: establishing a gear temperature field model and a contact model by utilizing a finite element method, obtaining a gear heat conduction matrix and a structural stiffness matrix, and calculating to obtain gear meshing stiffness and tooth surface load distribution based on an actual tooth surface equation. Calculating tooth surface heat flux density based on tooth surface load distribution, tooth surface friction coefficient and relative sliding speed of each meshing position to obtain a gear thermal load matrix, calculating to obtain an equivalent node load matrix according to a gear heat conduction matrix and the thermal load matrix, and calculating to obtain tooth surface thermal deformation by combining the equivalent node load matrix with a gear structure stiffness matrix. And repeating the steps to obtain the meshing rigidity of the gear pair under the thermoelastic coupling effect. According to the method, the gear contact state iterative solution model based on the potential energy method, the matrix polycondensation method and the slicing thought is established, the requirement for computing equipment is lowered, and the solution efficiency is improved.

The invention relates to a concrete structure fault movement damage simulation method based on damage contact constitutive, which belongs to the technical field of geotechnical engineering numerical simulation, and has the technical key points that the method is based on a plastic damage constitutive theory proposed by A.D.Jefferson and is combined with a discrete element method to simulate the fault movement damage of a concrete structure. A contact model suitable for cracking evolution of the concrete lining structure under the fault shearing condition is constructed; the method comprises the following steps: establishing a contact surface force-displacement increment relationship and a failure criterion by introducing parameters such as normal rigidity, tangential rigidity, tensile strength, cohesive force, a friction angle and fracture energy, carrying out secondary development coding based on a 3DEC development port by utilizing a C + + language, and generating a constructed DLL module file; by constructing a typical engineering numerical model, the development process of concrete cracks under fault movement is simulated, and sensitivity analysis is carried out. The method can accurately capture a structural damage path and a stress concentration part, and is suitable for engineering application scenes such as tunnel crossing fault and high-stress area support optimization.

The invention provides a method and system for improving the wheel-rail relation of a fixed frog based on rim groove depth design, and relates to the technical field of fixed frogs. The method comprises the steps that profile design data and wheel tread parameters of a wing rail-point rail of the fixed frog are obtained; according to the profile design data and the wheel tread parameters, wheel-rail contact traces are fitted, the wheel pair side roll angle is calculated through a minimum distance method, and contact geometric parameters are obtained; determining an initial optimization interval according to the contact geometric parameters and the limit value of the wheel-rail contact geometric relationship design index; processing the initial optimization interval based on a preset wheel set-frog rolling contact model to obtain a calculation result; and evaluating according to a calculation result to obtain a rim groove design scheme and a depth value. According to the method, the wheel-rail relation of the fixed frog area is systematically improved through collaborative design of the depth of the rim groove and the frog profile in combination with contact geometric analysis and multi-target dynamics optimization.

An apparatus and method for planning a contact interaction trajectory are provided. The apparatus is a robot that accepts a contact interaction between the robot and an environment. The robot stores a dynamics model representing geometric properties, dynamic properties, and friction properties of the robot and the environment and a relaxed contact model representing a dynamic interaction between the robot and an object via virtual forces. The robot also iteratively determines, by performing an optimization, an associated control command, a trajectory, and a virtual stiffness value for controlling the robot until a termination condition is satisfied, the optimization reducing a stiffness of the virtual forces and minimizing a difference between a target pose of the object and a final pose of the object moved from an initial pose. Further, an actuator moves a robot arm of the robot in accordance with the trajectory and the associated control command.

The invention relates to a rail rigidity homogenization technology, and discloses a high-speed turnout zone rigidity homogenization method which comprises the following steps: modeling a rigid vehicle and a flexible turnout rail piece, and analyzing a contact relation between the vehicle and the turnout rail piece to obtain a vehicle-turnout coupling dynamic model; the vehicle-turnout coupling dynamic model comprises a vehicle model, a turnout rail piece model and a wheel-rail contact model; simulating calculation is carried out by changing the rigidity value of the before-forking elastic base plate in the turnout rail piece model, the change of the wheel-rail dynamic effect is calculated, the influence of the before-forking rigidity change on the wheel-rail dynamic effect is obtained, the before-forking rigidity value when the wheel-rail impact effect is minimum is determined to serve as the target rigidity value, and therefore rigidity homogenization of the high-speed turnout area is completed. By simulating the actual state of each part in the turnout when the turnout is in contact with a vehicle, the risk of structural fatigue failure of a certain part in the turnout caused by the long-term train load effect is reduced.

The invention relates to a heavy-load forming robot dynamic modeling method considering spherical pair gaps and connecting rod deformation. The heavy-load forming robot dynamic modeling method comprises the following steps that S1, the basic structure of a heavy-load forming robot is determined; s2, the movement position relation of the heavy-load forming robot component is determined; s3, constructing a ball pair clearance contact model of the heavy-load forming robot; s4, a kinetic equation of the heavy-load forming robot sliding block is determined; s5, a kinetic equation of a heavy-load forming robot connecting rod is established; s6, a kinetic equation of the heavy-load forming robot moving platform is determined; and S7, determining a total kinetic equation of the heavy-load forming robot. According to the heavy-load forming robot dynamic modeling method considering the spherical pair gap and the connecting rod deformation, more accurate prediction of the real-time pose of the robot can be achieved. According to the method, the dynamic model considering the spherical pair gap and the connecting rod deformation is established, the dynamic model is verified through a loading experiment, and the accuracy of the error of the moving platform can reach 70%.

The invention relates to an anti-deformation leveling algorithm based on a foot-ground contact model and a platform rigidity model. The anti-deformation leveling algorithm comprises the steps that a foot-ground interaction load-settlement model, a platform load-deformation rigidity model and a leveling algorithm with feed-forward compensation are established; a foot-ground interaction load-settlement model is adopted to describe foot-ground contact settlement behaviors, and the landing leg settlement amount is predicted by identifying ground rigidity parameters; secondly, establishing a platform structure stiffness matrix, quantifying a platform load-deformation relationship, performing simulation calculation on a platform system under a typical leveling pose by using a finite element method, and obtaining stiffness coefficient matrixes corresponding to different poses; and finally, designing a leveling algorithm with feed-forward compensation, and superposing the total compensation amount to leveling control output by predicting the landing leg settlement amount and the landing leg structure deformation amount so as to realize feed-forward control. According to the method, the foot-ground contact model and the platform load-deformation rigidity model are constructed, and rapid and stable leveling is realized through a dual-mode control algorithm.

This application discloses a simulation and optimization design method for a snow plow for EMUs based on multi-physics field coupling. Efficient snow plow design is achieved through three stages: physical modeling, experimental verification, and parameter optimization. The method collects environmental parameters for line snowfall and snow density, establishes a soft-ball dynamics model for snow particles based on the Hertz-Mindlin with JK R Cohesion contact model, and simulates the wall-covering snow process using a discrete phase model. The simulation accuracy is verified through snow removal experiments. A parameterized snow plow model is constructed, and shape parameters are introduced to modify the driving resistance coefficient, evaluate snow removal performance, and select the optimal geometric parameter combination. The vehicle model is constructed by integrating the front end, modifying the snow removal resistance formula under multi-body coupling, and generating snow plow selection recommendations. Simulating different snow depth and speed conditions, a correlation model is established, and the maximum safe vehicle speed threshold that meets operational constraints is output. Through multi-physics field coupling simulation and parameter optimization, the limitations of traditional design relying on experience are overcome, achieving coordinated optimization of snow removal efficiency, driving safety, and structural strength.

Systems and methods related to generating video sequences containing physiologically realistic avatars are provided. In an example, an albedo for an avatar is received, a subsurface skin color associated with the albedo is modified based on physiological data associated with a physiological characteristic, and the avatar is rendered based on the albedo and the modified subsurface skin color. The rendered avatar can then be composited in frames of a video. In some examples, the video containing the composited avatar can be used to train a machine learning model to detect the physiological characteristic. The machine learning model can receive a plurality of video segments, where one or more of the video segments contain a composited physiologically realistic avatar generated with the physiological characteristic. The machine learning model can be trained using the plurality of video segments. The trained model can be provided to a requesting entity.

The invention belongs to the technical field of rail traffic, and particularly discloses an efficient calculation method for the strain rate of a steel rail material under wheel-rail rolling contact, and the method comprises the steps: building a three-dimensional wheel-rail rolling contact model considering a dynamic stress effect, and precisely solving a wheel-rail contact local solution under dynamic stress fluctuation; an efficient steel rail stress-strain calculation model is established and embedded into dynamics, a steel rail internal stress-strain field is solved in real time, and the limitation that a traditional multi-body dynamics model only considers a contact interface and cannot calculate steel rail dynamic deformation is broken through; the method for determining the grid size and the integral step size in strain rate calculation is provided, high-frequency numerical fluctuation occurring during dynamic calculation is eliminated, calculation efficiency is improved while calculation precision is guaranteed, and the method is suitable for being embedded into vehicle-track coupling dynamics for rapid real-time calculation.

The invention provides a method for analyzing the damage of a hidden part of a track structure after train derailment caused by an earthquake, and relates to the field of dynamic response analysis of track structures. The method comprises the following steps: establishing a track substructure model, sequentially establishing track substructures such as a steel rail, a fastener system, a track plate, a filling layer and a base plate from top to bottom, and introducing cohesion unit simulation between structural layers, according to the earthquake load simulation, earthquake waves are transmitted to the structural non-supporting point freedom degree through the structural supporting point freedom degree, and then the whole vehicle system is influenced. According to the method, the accuracy and the calculation efficiency of dynamic response analysis of a track structure under the earthquake action are remarkably improved by introducing an improved nonlinear elastic theory and a multi-point non-Hertz contact model and combining a modal superposition method and a multi-scale analysis method in consideration of a vehicle-track complex collision contact behavior after derailment.

The invention provides a motion analysis method and system based on image and sole contact modeling, and the method comprises the steps: reconstructing a three-dimensional posture of the motion of a subject according to recognized 2D key points, and generating a personalized skeleton model matched with the subject according to the height data of the subject; the method comprises the following steps: acquiring a pelma image of a subject, automatically generating a plurality of contact balls in a pelma region according to an extracted pelma contour shape to approximately represent each region where the pelma is in contact with the ground, and optimally setting the positions and radiuses of the contact balls according to the foot type of the subject to form a personalized pelma contact model; according to the personalized skeleton model, the joint movement data and the personalized plantar contact model, solving a ground reaction force GRF which enables dynamics to be consistent under a given kinematics condition; determining a moving path of a resultant force acting point of stress along with time according to the stress condition of each contact ball of the two feet, and calculating a track of a plantar pressure center COP. Motion analysis can be carried out based on image and plantar contact modeling.

The present invention proposes a method and system for optimizing a calculation model for the structure and stress of blast furnace particles. The method comprises the following steps: calculating the current diameter of the particles based on the initial diameter of the particles in the blast furnace and the current physical properties of the blast furnace particles; determining the piecewise function relationship between the Young's modulus and the current temperature of the particles; and using a discrete element method particle contact model to simulate and calculate the structure and stress of the particles in the blast furnace at the current temperature based on the current diameter of the particles and the piecewise function relationship. Based on this method, a system for optimizing a calculation model for the structure and stress of blast furnace particles is also proposed. The present invention calculates the current diameter of the particles based on the temperature of the particles in the blast furnace, obtains the key parameters of the material layer structure at the particle scale, and proposes control conditions for the discrete element method particle calculation process. The influence of the softening and melting phenomena of the particles during the temperature increase on the interaction force between the particles in the material layer is fully considered, the contact model of the existing discrete element method is optimized, and the accuracy of the numerical simulation calculation of the soft melting zone area of ​​the blast furnace is improved.