476 results about "Finite element analyse" patented technology

Methods of modeling anatomical structures, along with pathology including the vasculature, spine and internal organs, for visualization and manipulation in simulation systems. A representation of on the human vascular network is built up from medical images and a geometrical model produced therefrom by extracting topological and geometrical information. The model is constructed using topological and geometrical information. The model is constructed using segments containing topology structure information, flow domain information contour domain information and skeletal domain information. A realistic surface is then applied to the geometric model, by generating a trajectory along a central axis of the geometric model, conducting moving trihedron modeling along the generated trajectory and then creating a sweeping surface along the trajectory. A novel joint reconstruction approach is also proposed whereby a part surface sweeping operation is performed across branches of the joint and then a surface created over the resultatn holes therebetween. A 3-D mesh may also be generated, based upon this model, for finite element analysis and pathology creation.

Methods of selecting a configuration of fixation and compression screws for a bone plate to be installed on a bone of a patient. A computer or website allows a user to load images of a fractured bone and specify a particular configuration of fixation and compression screws with a plate on the loaded bone. The computer replicates stresses imposed on the bone by regular activities using finite element analysis and provide information about the suitability of the selected configuration.

A finite element pre processing method for reconstructing a three-dimensional entity model comprises the steps that first, a material object is scanned so that point cloud data can be acquired; second, the point cloud data are imported to 3-matic software, and the position of the model is adjusted; third, the point cloud data are de-noised and sampled; fourth, three-dimensional reconstructing of the point cloud data is performed through a computer, wherein the point cloud data are packaged so that a surface mesh model can be generated; fifth, thin wall characteristic analysis is performed on the model so that a basic model structure can be known; sixth, three-dimensional repair is performed on model meshes, so that the edges of the model are matched with the defect contour of the material object; seventh, the model is redesigned as required, and thus the structure of the model can be more reasonable and meet the design requirement; eighth, the meshes of the redesigned model are partitioned again; ninth, a volume mesh is generated, material attributes are added, and the new model is saved in the format through which finite elements can be directly analyzed; tenth, finite elements are analyzed. Through the method, the scanned data processing time is shortened and FEA / CFD pre processing time are shortened, and optimal design of the model can be conveniently performed.

The invention provides a method for constructing a vertebral three-dimensional geometry and finite element mixture model, which belongs to the technical field of processing of medical images. The method comprises the following construction processes of: inputting a vertebral computer tomography (CT) image; performing three-dimensional reconstruction and three-dimensional cutting on the CT image to acquire a vertebral three-dimensional image set; establishing a three-dimensional geometric statistical model, namely defining and manually calibrating vertebral characteristic points, aligning and registering vertebral images, and training a sample set to acquire the statistical model; and generating a finite element model, importing the statistical model, generating a surface mesh model, and generating a volume mesh model, wherein the model can be directly imported into finite element analysis software for biomechanics analysis. By the method, a vertebral geometrical shape can be precisely described, the accuracy of finite element analysis results can be ensured, and the precision of vertebral models can be improved. The method is convenient to use, facilitates the scientific measurement of the shapes and the stress of vertebras and can be used for researches related to vertebral columns and the vertebras in the field of surgical medicine.

The temperature distribution associated with a design of an integrated circuit is calculated by convoluting a surface power usage represented by a power matrix with a heat spreading function. The heat spreading function may be calculated from a simulation of a point source on the integrated circuit using a finite element analysis model of the integrated circuit or other techniques. To account for spatial variations on the chip, the heat spreading function may be made dependent on position using a position scaling function. Steady-state or transient temperature distributions may be computed by using a steady-state or transient heat spreading function. A single heat spreading function may be convolved with various alternative power maps to efficiently calculate temperature distributions for different designs. In an inverse problem, one can calculate the power map from an empirically measured temperature distribution and a heat spreading function using various de-convolution techniques. While the forward problem is analogous to image blurring, the inverse problem is analogous to image restoration.

The invention provides a digital prototyping design integrated development method which comprises the steps of: establishing a digital prototyping parameterization design model and a digital prototyping finite-element analysis optimization model in a database; synchronously sharing same parameters between the models; calling the digital prototyping parameterization design model in the database for carrying out parameterization design; changing parameters of the digital prototyping parameterization design model according to object characteristics and synchronously changing same parameters in the digital prototyping finite-element analysis optimization model; calling the digital prototyping finite-element analysis optimization model in the database for carrying out finite-element analysis optimization design; and extracting parameters of the digital prototyping finite-element analysis optimization model from the database, automatically forming a finite-element analysis command stream, generating a structure geometrical model, establishing a finite-element model, carrying out structure analysis optimization, and correcting corresponding parameters after analysis optimization. The invention provides a digital prototyping design integrated development method and system which are used for reducing workload of product design.

The invention discloses a method for dynamic modeling on an entire numerical control machine tool based on kinetic parameters of a joint part and analyzing and optimizing dynamic performance and an implementation scheme. The method disclosed by the invention takes a certain type of a vertical machining center as an example, dynamic model building and parameter identification are carried out on a bolt joint part, a guide rail sliding block joint part, a ball screw joint part and a bearing joint part, the dynamic performance of the entire numerical control machine tool is analyzed by combining finite element analysis software, an optimization object is established on the basis, a multi-objective optimization model is constructed, and the best optimization configuration is solved, so that the dynamic performance of the entire numerical control machine tool is optimized. Achievements of the method disclosed by the invention can be used for solving problems finite element analysis and optimization on the dynamic performance of the entire numerical control machine tool, and technical support is provided for improving processability of the numerical control machine tool.

The invention relates to a probabilistic finite element method (PFEM)-based steel-bride fatigue reliability evaluation method, in particular to a fatigue reliability evaluation method by combining dynamic weighing data (WIM) of a car and the analysis of the PFEM, which aims at solving the problems that the bridge structure health monitoring cost is higher and the stress measuring point distribution is limited, and utilizes the real WIM data to statistically analyze car load and establishes a probabilistic distribution model of a car type, road distribution, axle weight and wheel-base. Finite element method analysis software is used for establishing a numeric model of a bridge. A probabilistic finite element program is compiled, stress amplitude and stress cyclic quantity of a key part under the random car load effect are extracted through the sampling, loading and finite element analysis to be statistically counted. The fatigue reliability calculation is performed according to the statistical result, and the reliability attenuation trend of the evaluated part in the subsequent application process is predicted. By adopting the method, a feasible analysis tool is provided for the fine fatigue evaluation of complicated steel-bridge details.

The invention relates to a finite element analysis-based variable-element permanent magnet synchronous motor modeling method which comprises the following steps of constructing a three-dimensional finite element electromagnetic field simulation model of a permanent magnet synchronous motor, and performing transient field road coupling analysis on the three-dimensional finite element electromagnetic field simulation model to obtain a large quantity of characteristic parameters; creating an improved permanent magnet synchronous motor voltage equation and a torque equation; constructing a simulation model of the permanent magnet synchronous motor according to an improved permanent magnet synchronous motor math model; leading all the obtained characteristic parameters into corresponding ports of the simulation model to construct a finite element analysis-based variable-element permanent magnet synchronous motor dynamic simulation model. The permanent magnet synchronous motor model modeled by the method disclosed by the invention comprehensively considers the magnetic field saturation effect, the d-q axis cross coupling effect, the eddy current effect, the hysteresis effect and the like; the instantaneity is considered, and the accuracy of the permanent magnet synchronous motor model is improved; the permanent magnet synchronous motor model is particularly suitable for the research on the dynamic processes such as power failure-bepelt and three-phase sudden short circuit of the permanent magnet synchronous motor.

The invention relates to a correction method for preventing excessive stress concentration of teeth roots and jaws in the process of orthodontic treatment, belonging to the technical field of orthodontics of teeth. The correction method comprises the following steps of: establishing an automatic-matching 3D (three dimensional) integrated tooth-jaw model; carrying out stepwise virtual correction on the 3D integrated tooth-jaw model; applying 3D finite-element analysis to determine the dynamic change of stress distribution of the teeth roots and the jaws in the whole process of the virtual correction and guarantee that the stress of the teeth roots and the jaws in correction is in the safety range; and manufacturing a clinical correction device by a fast laser forming technology. By the individualized correction device designed and manufactured by a computer in an auxiliary manner, the positions and the routes of movement of the teeth roots can be controlled. By expression and verification, the correction method can duplicate the condition of virtual correction in actual treatment, realizes good position relation among the teeth roots, the teeth and the jaws in the correction process, and is beneficial to reducing and eliminating absorption of the teeth roots and the alveolar bones due to excessive stress concentration in the process of orthodontic treatment and reducing and avoiding recurrence after correction.

In hydroforming of hollow metal articles in a die, such as pressure-ram-forming procedures, a method of decreasing cycle time of the forming process, while ensuring acceptable product properties and avoiding failures, by modeling the process using finite element analysis to establish a pressure-time history that optimizes the forming operation and applies failure limits to selected variables such as minimum wall thickness or maximum strain rate, and transferring this pressure-time history to a computer controlling the forming process. Thermocouple and / or continuity sensors are incorporated into the die wall and connected to the computer so as to provide active feedback from the die to the control of the process.

The invention discloses an optimized design method of overall static rigidity of a machine. The method includes the steps of establishing a simple machine model by Pro / E software; importing the simple machine model into SAMCEF software to establish a machine finite element model; parameterizing rigidity features of large structures of the machine to determine design parameters and a design space; selecting test sample points for finite element analysis by a central composite experiment design method; subjecting the test sample points to finite element analysis to obtain machine static rigidity response values of the test sample points; establishing a response surface model for large structure rigidity feature parameters and machine static rigidity; analyzing sensitivities of large structure rigidities to the machine static rigidity so as to determine a static rigidity weak link, and performing optimized design. The optimized design method of overall static rigidity of the machine has the advantages that the sensitivities of the structures of the machine to the machine static rigidity are effectively determined, the weak link restricting the improvement of the machine static rigidity is effectively found, and accordingly important basis for the optimized design of machine structure is provided to guide designers to optimally design the weak large structures of the machine.

The invention relates to a method for quantitatively analyzing material interface properties by combining non-destructive testing and definite element modelling. In the method, by loading a composite material, a non-destructive testing system records a loading variable; and at the same time, a finite element method correspondingly simulates the whole loading process of a test piece according to intrinsic properties, modulus, tensile strength, Poisson ratio and the like of the material so as to find a simulation state corresponding to the non-destructive testing variable and further obtain comprehensive analysis results, including various physical quantities reflecting the material interface properties such as friction coefficient between fibers and a matrix, stress, straining, counterforce and the like, in the simulation state. The non-destructive testing high-precision method verifies partial parameters of finite element analysis, and the finite element analysis provides more comprehensive analysis results. The method has the advantages of high sensitivity, credible quantitative values and no need of damaging an adhesive layer.

The invention discloses a three-point support optimization design method of a machine tool bed based on a response surface model. The method comprises the steps that a simplified model of a bed structure is established in CAD (Computer-Aided Design) software; three-point support limiting positions are found; a variable design space and an optimization objective are determined; test sample points for statics analysis are selected from the design space, and subjected to the statics analysis by finite element analysis software; a response value is calculated and extracted; a second-order response surface model, reflecting an input-output relation of structural design, of deformation at guide rails of the bed is established according to the response value; an optimal solution of the response surface model is acquired by a genetic algorithm; based on the established second-order response surface model, three-point support positions when the deformation of the guide rails is minimum are found; a practical model of the bed is subjected to the statics analysis; and the reliability of three-point support optimization design is verified. With the adoption of the method, the deformation of a machine tool is reduced; the machining precision of the machine tool is improved; the three-point support optimization efficiency and the optimization precision are improved; and the problems that the calculation amount is large, the efficiency is low, and an optimal result cannot be ensured easily in the existing optimization technique are solved.

The invention discloses an additive manufacturing-based product lightweight design method. The method comprises the following steps: 1, establishing a parametric porous structure database, and establishing corresponding relationships between various parametric structures and mechanical property; 2, carrying out finite element analysis on an original product model structure; 3, adjusting a parametric unit structure to satisfy difference demands, for the mechanical property, of different mesh regions in the product; 4, carrying out filling replacement on the regions with excess performance in the products by using a lightweight unit structure; 5, carrying out mechanical property check on a lightweight product structure through finite element analysis. According to the method disclosed in the invention, the finite element analysis and the gradient distribution design of a parametric porous structure are combined, and different lightweight strategies are adopted in allusion to the performance demands of different parts of function parts under the premise of satisfying the mechanical property, so that the reasonable and efficient lightweight design is realized, and lightweight products can be prepared by using an additive manufacturing method.

The invention relates to a finite element analysis method for crack propagation, in particular to a numerical value analysis method using wavelet extension as a new finite analysis unit. The method comprises the following steps that: based on a computer-aided drawing software, a gear meshing model containing any crack failure is built; the module is imported into a finite element analysis software ABAQUS, and geometric data of a finite element mesh is obtained by combination of ABAQUS meshing and data output functions; according to the obtained data, a mathematics-assisted calculation software is applied to a program to calculate the element stiffness matrix of a wavelet extension unit, and then according to the mesh of the analyzed structure, the overall stiffness matrix of an integratedstructure is arranged; and after boundary constraint conditions and loads are introduced, a finite element equation is solved to obtain the numerical value solution of crack propagation. In the invention, the growth conditions of cracks can be tracked, and the difficulty brought by highly concentrated stress is also solved; and the method has higher computational accuracy and higher computationalefficiency, and facilitates the study of fault diagnosis of mechanical equipment.

Certain embodiments of the present invention provide a system and method for improved distortion measurement and compensation. Certain embodiments include selecting a set of sources on a surface of a volume, determining mutual inductances from the set of sources on the surface, and calculating distortion from the volume using the mutual inductances from the set of sources on the surface. In an embodiment, distortion is calculated using an integral method and / or a finite element analysis. The volume may be modeled as a simplified construct, such as a ring model, a coil array with straight line segments model, a polygon model, and / or dipole array model. The model may be adjusted based on the distortion calculated from the volume. Magnetic fields may also be used to calculate distortion. In an embodiment, an object may be tracked using a distortion mapping.

Systems and methods of simulating an explosion in time-marching finite element analysis are disclosed in the present invention. According to one aspect, a method is configured for increasing user (e.g., engineer or scientist) productivity by reducing computation time of simulating fluid-structure interaction due to an explosion. The method comprises a creation of a finite element analysis model that includes structure, surrounding fluid, a blast source of the explosion and a single layer of ambient elements each having a segment representing a boundary of the fluid facing the blast source. Each ambient element is associated with a particular finite element representing the fluid at the boundary. The ambient elements are configured to be situated between the blast source and the structure such that the simulation can be carried on a set of boundary conditions specified thereon. The boundary conditions comprise a set of nodal velocities that are determined from the empirical formula (e.g., Friedlander equation).

The invention discloses an automatic data conversion method between a three-dimensional modeling software and a finite element analysis software, which comprises the following steps of starting the finite element analysis software, loading the model and performing finite element analysis; starting the three-dimensional modeling software in the finite element analysis software; reading files and performing finite element analysis in the finite element analysis software; saving the result in format of data file by utilizing a data post-processing module and the read and write function of the finite element analysis software; and circularly running the above processes by utilizing the process control command of the finite element analysis software. The automatic data conversion method achieves seamless integration of the powerful modeling function of the three-dimensional modeling software and the finite element function of the finite element analysis software and provides a scientific, high-efficiency and reliable solution for design and analysis of a complicated mechanical system, thereby increasing the product design accuracy and design efficiency.

The invention discloses a method for assessing the detail fatigue crack propagation of a steel bridge. Aiming at a steel bridge which is widely used in a road bridge system and is severe in fatigue crack dangers, the method comprises the steps: firstly building a bridge model and a local zone crack submodel through finite elements, obtaining an existing bridge load according to the definition and sampling of a vehicle and other random variables, and obtaining the boundary conditions of the submodel based on the whole bridge finite element analysis and the submodel technology; secondly updating the submodel through employing local remeshing, and carrying out the crack propagation finite element analysis; thirdly extracting a stress intensity factor amplitude, calculating a mean crack propagation rate, a mean crack propagation angle, the circulating number of times of each crack propagation step, the mean number of the stress intensity factor amplitude caused by a single vehicle, and the fatigue life; finally achieving the simulation of the fatigue crack of the steel bridge and the assessment of the fatigue life, so as to guide the subsequent maintenance and reinforcing operation.

The invention provides an electronic product vibration DLP method based on cross-power spectrum function mode parameter identification. The method comprises the following steps of arranging acceleration sensors on a circuit board; uniformly arranging the acceleration sensors on a single-surface testing circuit board; selecting an online monitoring device, and performing connecting mounting on the online monitoring device; determining a cross-power spectrum function algorithm on a random vibration condition, and generating a cross-power spectrum density function; performing derivation of a mode parameter identification algorithm, and obtaining a first-order frequency and a damping ratio; and performing residual service life estimation by means of a Steinberg model. According to the electronic product vibration DLP method, finite-element analysis software such as vibration analysis software and simulation software are not required for simulating a vibration response mode. A vibration response data collecting operation can be finished just through the acceleration sensors and data collecting equipment. The electronic product vibration DLP method overcomes a defect that partial parameters of existing service life prediction software are empirical parameters which cannot be accurately calculated. Furthermore the first-order frequency and the damping ratio can be calculated through applying a mode identification method.

The invention discloses a fatigue life evaluation method of a component based on a nonlinear fatigue damage accumulation theory, which comprises the following steps of: adopting a finite element analysis model to carry out stress analysis on the component under at least one working condition, and selecting a region with a stress value greater than a set stress as a hazard analysis region under theworking condition; obtaining the maximum and minimum of stress and strain in the hazard analysis area by simulating the load on the finite element analysis model of the component in one mission. According to the maximum and minimum value of stress in the hazard analysis area, the equivalent stress of each working condition is calculated. According to the maximum and minimum value of strain in thehazard analysis area, the fatigue life prediction value of the component under each working condition is predicted. According to the equivalent stress and fatigue life predicted under each working condition, the fatigue cumulative damage of the member under stress spectrum is calculated. According to the accumulated fatigue damage, the fatigue life of the component is calculated.

Systems and methods of limiting contact penetration in numerical simulation of non-linear structure response using implicit finite element analysis are described. According to one aspect, a finite element analysis (FEA) model of a structure is defined as a number of nodes and elements based on geometry and material properties of the structure. A time-marching analysis of the FEA model is then performed. The time-marching analysis results contain a number of solutions of non-linear structure response at respective time steps. Solution at each time step requires at least one iteration to compute. Non-linear structure response is determined in the following manner: 1) determining a search direction; 2) calculating a contact penetration parameter in the search direction; and 3) finding a minimum energy imbalance location along the search direction as a solution which is further restricted by the CPP such that contact penetration of the structure is substantially limited.

Systems and methods of predicting sheet metal forming failure using numerical simulations (e.g., finite element analysis) are disclosed. A FEA model is defined for a particular sheet metal forming process. Blank sheet metal is modeled with a plurality of shell elements. Additionally, a deformation path-dependent forming limit diagram (FLD) is converted to a path-independent FLD. A time-marching simulation of the sheet metal forming process is conducted using the FEA model. At each solution cycle, equivalent strain at each integration point of shell element is checked against the corresponding forming limit strain value of the path-independent FLD. The ratio of the equivalent strain and the forming limit strain is defined as formability index. A time history of the formability index of each shell element is saved into a file and displayed to a monitor upon user's instructions. When a particular element's formability index reaches one or higher, a localized necking is predicted.

The invention discloses a finite element theory based direct current magnetic bias suppression method under the condition of multiple direct-current falling points, and belongs to the field of direct current electric fields. According to the method, direct current electric fields are calculated with a finite element analysis method, the resistance in the direction parallel to the axis is obtained by calculating the radial resistance of the assigned specified soil grid, the distribution tendency of voltages and currents in the assigned direction is obtained, the current fields in different current falling points are determined, and the CDEGS software is adopted as a verification means; the current distribution curves corresponding to a plurality of directions are obtained to serve as the technical base for adopting the corresponding direct current magnetic bias suppression scheme in the following steps. Magnetic bias current calculating sub-models oriented to different power transmission systems can be respectively formed, the coverage range of the direct current magnetic bias research and the direct current magnetic bias suppression scheme is widened, and the simulating calculating efficiency is greatly improved. The method can be widely applied to the field of design, running and management of extra-high-voltage direct current power transmission lines.

Methods, systems and computer program products for assessing residual life of an airfoil, which would experience high cycle fatigue failure under at- or near-resonance vibration condition, are provided. The method includes receiving, at a processing system, at least one vibration response parameter associated with the airfoil. The method processes at least one cracked airfoil finite element model. Processing the cracked airfoil finite element model includes accessing the cracked airfoil finite element model, computing a modal stress intensity factor (SIF) of the cracked airfoil finite element model using fracture mechanics based finite element analysis, and computing a vibratory SIF based, at least in part, on the modal SIF and the at least one vibration response parameter. The method then computes a residual life indicator of the airfoil based, at least in part, on the vibratory SIF.

The invention provides a structure optimization design method which comprises the following steps: establishing an optimization design objective function and constraint conditions; establishing structure optimization design regions; initializing an optimization model; carrying out structural finite element analysis on the model, and calculating values of the objective function and the constraint equation according to the analysis result; analyzing the shape sensitivity, and updating the model in an appropriate evolution algorithm according to the analysis result; and carrying out other operations to ultimately obtain the optimal structure model. The invention also provides a software system using the optimization design method. The software system sufficiently implements the optimization algorithm and simultaneously provides a favorable user interface and a data interface. The optimization design method and system provided by the invention can be directly used for computer-aided design, has low grid dependence and is applicable to various common objects.

The invention belongs to the field of power system overhead transmission line tower safety monitoring, and provides a transmission tower online safety monitoring system and method for stress measuring. Firstly, stress sensors are installed on the key parts of a tower, and installation points can be obtained through finite element analysis and load application. Measurement values of the stress sensors are transmitted to a background server through the internet, the background server works out the reliability of each section of main material in real time according to each group of data together with the mean value and the variance of the strength of steel materials, and therefore the overall reliability of the tower can be obtained. The transmission tower online safety monitoring system and method have the following advantages that the problem of real-time tower stress monitoring is solved, and the stress distribution situations of the key parts can be monitored in real time; the safety state of the tower can be estimated in real time and serious accidents such as collapse can be effectively prevented under severe working conditions; research results are wide in application and can be directly applied to various tower shapes.