47 results about "Infinite element" patented technology

A creep-damage lifetime forecast method of a material under a multi-axial stress state belongs to the field of material lifetime forecast. The method of the material under the multi-axial stress state is characterized by comprising the following steps of (1) building a creep-damage constitutive model which can represent different temperatures under the multi-axial stress state; (2) building a creep constitutive equation describing different temperatures under the multi-axial stress state; (3) building a damage equation of the material during the creep process; (4) embedding the creep-damage equations in the steps (2) and (3) into a finite element for lifetime analysis; and (5) forecasting creep lifetime of the material under the multi-axial stress state according to an analysis result of the infinite element. By the method of the material under the multi-axial stress state, the lifetime forecast of the material under a high-temperature condition can be achieved better, the forecast process is simple, and a result is accurate.

The invention discloses a numerical simulation analysis method for the deformation of a soft soil deep foundation pit. The numerical simulation analysis method comprises the following steps: firstly taking soft soil to carry out a triaxial compression creep experiment in a laboratory before the excavation of the foundation pit, obtaining time hardening model creep parameters of the soft soil through STATISTIC software fitting, in the design stage of the foundation pit, applying large finite element software ABAQUS to build a finite element model, building the influence at the simulation infinity of an infinite element on the excavation of the foundation pit around the model, and obtaining the earth excavation manner and the excavation time of the foundation pit as well as the influence rule of a construction gap for stress and deformation of the foundation pit through analog computation. In the design stage, the construction parameters of the foundation pit, particularly the three important parameters such as earth excavation manner, earth excavation time and construction gap, can be optimally designed. Through the optimization of the three parameters, the deformation and support shaft force of the foundation pit can be effectively reduced, and then the safety coefficient of the foundation pit is increased.

The present invention discloses an ultra-deep foundation pit pumping based ground subsidence intelligent early-warning method and monitoring system. The ground subsidence intelligent early-warning method comprises: S1. in combination with on-site reality, laying a wireless sensor at a monitoring point, so as to obtain an on-site measurement database; S2. based on on-site pumping experimental data of an ultra-deep foundation pit, performing inversion analysis on a hydrologic geological parameter by adopting groundwater flow software, and performing inversion analysis on each earth-layer project geological parameter by adopting finite element software, and establishing an ultra-deep foundation pit infinite element three-dimensional numerical model that is closest to the on-site reality, so as to obtain a ground subsidence threshold; S3. constructing a gray prediction model to perform dynamic prediction; and S4. according to an intelligent prediction and determination result, enabling an early-warning system to predict a risk, so as to implement intelligent and automated monitoring and early-warning. The method and system are capable of effectively monitoring ground subsidence invited by ultra-deep foundation pit piestic water extraction, and achieve intelligent, precise and automated ground subsidence monitoring and early-warning.

The invention discloses a quadrangle segmentation method applied to finite element analysis. Division of quadrangle grids is achieved in all kinds of mainstream software. The method comprises steps of firstly changing multiple connected polygons into single connection; then, reducing the number of boundary fixed points and extracting geometrical characteristics of boundaries in a boundary simplifying process; decomposing original polygons into relatively simple geometrical shapes, thereby facilitating topology generation and mapped polygons; carrying out topology generation, and using a fixed topology mode to match different sub polygons so as to finish construction of a topology structure; and finally, using an ultralimit interpolation mapping method to obtain a finally grid. According to the invention, a high quality quadrangle grid segmentation method is provided; the generated quadrangle grids have few singular points, good smoothness, uniformity and orthogonality, and can be directly applied to infinite element analysis, simulation and solving.

Disclosed is a solar sail structure finite element modeling and post-processing method. The solar sail structure finite element modeling and post-processing method includes: 1), setting a solar sail configuration mode and a connecting format of a support arm and a sail surface and reserving an area for the support arm; 2), establishing a solar-sail geometric model with the preserved area; 3), setting a support arm model and generating a support-arm geometric model in the reserved area; 4), establishing finite element models of the solar sail surface and the support arm; 5), subjecting the solar sail surface and the support arm to finite element mode assembly according to the generated infinite element models of the solar sail surface and the support arm; 6), setting statics boundary conditions and loading conditions on the finite element models; 7), calculating buckling load of the support arm, simulating reverse acceleration speed released by the inertia, and exerting the reverse acceleration speed on the infinite element models; 8), analyzing statics of a solar sail to acquire maximum deformation and axial pressure of the support arm; 9), calculating buckling safety factors and structuring feasibility of a solar sail structural scheme according to the buckling safety factors.

The invention discloses a whole-space radiation noise prediction method of a rail transit bridge and a steel rail. The method comprises the following concrete steps: firstly, respectively establishing three-dimensional fine finite element models of a vehicle, a steel rail and a bridge, and acquiring the dynamic response of the bridge and the steel rail by means of time domain vehicle-rail-bridge coupling vibration analysis; secondly, obtaining modal acoustic vectors of the bridge and the steel rail by means of acoustic space Fourier transform, and calculating the radiation noise of the bridge and the steel rail at a near field point near a track center line by combining the dynamic response of the bridge and the steel rail; after that, respectively establishing a two-dimensional steel rail vibration acoustic coupling propagation model and a two-dimensional bridge vibration acoustic coupling propagation model, and solving the attenuation distribution laws of noise of the steel rail and the bridge at a far field point under the action of a steady-state excitation load by using an acoustic infinite element method; finally, selecting a certain near field point as a strong source point, and predicting the whole-space noise level of the bridge and the steel rail according to near field calculation results of the three-dimensional models and far field attenuation rates of the two-dimensional models.

The present invention discloses a method for calculating hoop stress of a fuselage rib under an airtight load, and belongs to the technical field of aircraft structure mechanics. The method comprises: firstly, allocating a cross-sectional area of a long girder at a fuselage rib onto a fuselage skin, to obtain a combined thickness tx; further, carry out calculation to obtain a radial distribution force T per unit circumference of the rib according to the combined thickness tx; next, calculating an axial stress sigma of the fuselage rib under the action of a pressurization load according to the radial distribution force T; then, by combining a distance e between a cross-sectional centroid after combination of the fuselage rib with the fuselage skin and a neural surface of the fuselage skin, calculating a bending moment M after the combination of the fuselage rib with the fuselage skin under the action of the pressurization load; and finally, calculating a bending stress of inner and outer edges of the fuselage rib under the action of the bending moment M. According to the method, the axial stress of the common frame under the pressurization load of the cabin can be rapidly and accurately obtained, the conventional method of obtaining the stress of the common frame by infinite element modeling and analysis is changed, and the working efficiency is increased.

The invention provides a method of analyzing and evaluating stress of a high-pressure gas dual-wall tube and elastic support thermal expansion displacement. Technological parameters of a dual-wall tube are determined according to actual working conditions, so as to design a direction of the high-pressure gas dual-wall tube, an L-shaped pipeline or a Z-shaped pipeline is designed at where the stress is concentrated, so as to compensate and calculate a finite element stress to ensure reasonable deployment of high-pressure gas supply pipelines, whether the stress of the dual-wall tube under the designed working condition and elastic support thermal expansion displacement meet standards and requirements are checked, a high-pressure gas dual-wall tube online stress response test system tests the stress and thermal expansion displacement of a host in startup, running and shutdown and compares the stress and the thermal expansion displacement with a calculated infinite element value, so as tomake the high-pressure gas supply pipeline deployed more reasonably.

The invention belongs to the technical field of natural electric field numerical simulation methods, and particularly relates to a natural electric field three-dimensional multidirectional mapping coupling numerical simulation method. The method comprises the following steps: S1, establishing a natural electric field electric model, wherein the regional subdivision of the model comprises a finiteelement and an infinite element; S2, constructing an edge value problem of the model; S3, constructing a functional for the edge value problem and solving variations of the functional; S4, starting from the variation problem, performing unit analysis on the finite element and the infinite element respectively, and solving to obtain a finite element stiffness matrix and an infinite element stiffness matrix; S5, assembling the finite element stiffness matrix and the infinite element stiffness matrix to obtain a total stiffness matrix; and S6, obtaining the potential value of each node in the natural electric field electric model through the total stiffness matrix. According to the method, the numerical calculation precision is improved while unit subdivision is reduced, the number of calculation times of the total stiffness matrix is reduced to improve the calculation efficiency of numerical simulation, and accurate and effective numerical simulation of the multi-source dynamic natural electric field is achieved.

The invention discloses an ABAQUS three-dimensional infinite element boundary rapid modeling method based on an INP file and belongs to the field of infinite element boundary modeling. According to an infinite unit defined theory, a method defined by a node and a unit in an ABAQUS input file.inp is utilized and an infinite unit defined data row is output with the help of a Python programming technology; and an input file is generated according to a syntax rule of the INP file and is introduced into ABAQUS/CAE, so that automatic generation of an ABAQUS infinite element boundary is realized. The ABAQUS infinite element boundary rapid modeling method is simple to operate and an ABAQUS infinite element boundary model can be generated within short time; and the ABAQUS modeling speed is extremely improved.

The invention discloses a design method of an electromagnetic ultrasonic body wave transducer, relating to a design method of an electromagnetic ultrasonic body wave transducer, solving the problems of the weak excited body wave signal of the existing electromagnetic ultrasonic body wave transducer and more wave modes in the excited body wave signal. The design method comprises the main steps of: defining parameters required by modeling; establishing a geometric model of each part; setting material attributes; dividing a physical field solving region; modeling an emitting process; modeling a receiving process; partitioning a net of a finite element and solving the finite element; and finding out key parameters influencing induction voltage signal strength and sound wave mode purity in an electromagnetic ultrasonic body wave transducer coil 2, calculating a transducer parameter when the signal of the electromagnetic ultrasonic body wave transducer is strongest and the sound wave mode is optimal, and designing the electromagnetic ultrasonic body wave transducer. The design method has the characteristics that the simplicity is achieved in operation and the influence of the parameters of the electromagnetic ultrasonic body wave transducer to the induction voltage signal is easily analyzed. The design method can be widely applied to the design of the infinite element of any electromagnetic ultrasonic body wave transducer.

The method discloses a method for calculating a specification of an eight-anchor-bolt rigid tower base plate for a power transmission tower. The method comprises: firstly, calculating a down force applied to the rigid tower base plate and an uplifting force applied to each anchor bolt so as to obtain the diameter of each anchor bolt, then calculating the minimum width of the rigid tower base plate, and calculating the minimum thickness required by pressure application and a minimum thickness required by pulling force application. According to the method, by using infinite element analysis and by means of infinite element analysis software, data is fitted; a concept of equivalent force arm computation is introduced, the influence of a base plate on a geometric force arm is considered, and subtraction is performed on the geometric force arm, so that the bearing capability of the tower base plate is reflected truely; the extreme bearing capability, calculated by the method, of the rigid tower base plates with the same specification is greater than a calculation numerical value in the (technical specification) and is smaller than an experimental value; and while the method overcomes the defects of the (technical specification), the calculation result is more reasonable and more reliable.

The invention discloses a damping-optimization design method of a panoramic observation mirror equipment structure. The method comprises the following steps: 1) obtaining material parameters and working condition parameters of observation mirror equipment, and analyzing and calculating the maximum relative deviation angle allowed by two end points of an optical axis of an observation mirror; 2) establishing a panoramic observation mirror three-dimensional model by using three-dimensional modeling software, and guiding finite element emulation analysis software to generate a geometric model; 3) establishing an finite element emulation analysis model; 4) reading the stress value and coordinate of a stress maximum value part and the displacement values and coordinates of the two end points of the optical axis of the observation mirror; 5) in allusion to the infinite element analysis model, setting different damping coefficients on boundary conditions of an equipment mounting surface, and repeating the step 4; and 6) repeating the steps 3-5, and when the deviation angle of the optical axis does not exceed an allowable value, taking the damping coefficient when the stress maximum value is nearest to the material yield strength and a body structure model of the observation mirror equipment as the optimum damping design schemes of the panoramic observation mirror equipment.

The invention relates to the technical field of natural potential numerical simulation methods, in particular to a three-dimensional multi-source natural potential numerical simulation method based onnatural unit-infinite element. The method comprises the following steps: S1, constructing a three-dimensional multi-source natural potential geoelectric model; S2, constructing a differential equation and an integral equation of the model; S3, based on Laplace interpolation, constructing a basic equation of a three-dimensional natural unit interpolation function and a derivative thereof; S4, constructing a basic equation of a three-dimensional one-way mapping infinite element interpolation function and a derivative thereof; S5, based on the step S2-S4, carrying out global integration on the model to obtain a rigidity matrix of each integral unit; S6, accumulating the stiffness matrixes of the integral units according to node numbers to obtain a total stiffness matrix; S7, constructing a source vector; and S8, based on the total stiffness matrix and the source vector, solving a large sparse equation set to obtain natural potential distribution. The technical problems that complex anomalous bodies in a multi-source complex model are difficult to subdivide, and truncation boundary problem processing is tedious are solved.

The invention discloses a testing device for achieving a plane strain state in a large-deformation range. The testing device comprises a motor, a support, a pressing plate, a screw rod, a first baffle, a check block, a first laser ranging sensor, a worktable, a second baffle, a second laser ranging sensor, a first pressure sensor, a second pressure sensor and a tested board. The motor is installed on the support and connected with the pressing plate and the screw rod. The pressing plate is provided with the second laser ranging sensor and the first pressure sensor. The baffles are arranged on the two sides of the worktable and are connected with the check block and the worktable through screws. The first laser ranging sensor is arranged in the middle of the check block, and the second pressure sensor is arranged in the middle of the first baffle. The tested board is arranged on the worktable defined by the first baffle, the second baffle and a third baffle. The support is connected to the worktable. A data processing method of the testing device for achieving the plane strain state in the large-deformation range comprises four steps. According to the testing device and the data processing method, experimental bases are provided for some forming technologies, theoretical calculation and infinite element modeling in engineering practice production.

The invention discloses a three-dimensional physical-structure topological optimization method and system. By adopting three-dimensional CAD software for creating a structural model of a three-dimensional physical structure, the structural model is imported into infinite element analysis software, an infinite element model is created, and an optimization area is determined and stored in an optimization area unit; a functional section decomposition method is utilized to conduct topological optimization dimensional deduction on the three-dimensional physical structure to obtain multiple groups of two-dimensional functional sections; topological optimization is conducted on the two-dimensional functional sections to obtain an optimization result of each functional section; through grouping matching, a corresponding relation of the optimization result of each section is determined, and a sweeping method in the three-dimensional CAD software is adopted for reconstructing a curved surface toobtain a three-dimensional reconstruction model; according to process constraint conditions, dimension optimization is conducted on the three-dimensional reconstruction model to obtain an optimized three-dimension model. By means of the method and system, the topological optimization efficiency of a large-scale and complicated structure can be improved, and the readability of a topological optimization result can be improved.

The invention provides a 2.5-dimensional natural electric field numerical simulation method based on natural unit infinite element coupling, and the method comprises the following specific steps: S1,building a two-dimensional natural electric field electric model, setting a discrete point set in a natural unit region according to model parameters, and expanding an infinite element at the boundaryof the region to serve as a boundary unit; S2, constructing a differential equation satisfied by the 2.5-dimensional natural electricity field electricity model, and deriving a variation form based on natural unit infinite element coupling and an integral form of the variation form; s3, constructing a natural element method based on a Laplace interpolation function, and deriving a basic equationof a 2.5-dimensional natural element shape function and a derivative thereof; s4, constructing a basic equation of a 2.5-dimensional infinite element shape function and a derivative thereof; s5, calculating a total stiffness matrix under each wave number condition; s6, processing power supply information; and S7, solving the large sparse equation set to obtain a wave number domain natural potential profile under each wave number condition, and finally performing inverse Fourier transform on each wave number domain natural potential profile to obtain a natural potential profile under a spatialdomain.

The invention relates to a three-dimensional scanning camera array for preparing a skeletal assisting support and a scanning method. The three-dimensional scanning array and the scanning method are characterized in that human body portion position is acquired by means of camera photographing, software processing and model generating, the photographing process and the three-dimensional processing are relatively independent, and a patient only needs to participate the early photographing process and doesn't need to wait for subsequent data processing. Through software which is arranged well in advance, images acquired during camera photographing can be processed directly, and processed image data are about to generate corresponding three-dimensional models which can be directly used for design and manufacture of a bone fracture fixing outer support. The three-dimensional scanning camera array and the scanning method have the advantages that data acquiring is quicker and more convenient, burden needing the patient to bear is smaller, and learning cost of hospital related personnel is lower, and complete basis and data are provided to subsequent accurate design of the skeletal assisting support, infinite element analysis and 3D printing processing and manufacturing.

The present invention discloses a multi-dimensional analysis method for a focused solar thermal power generation system, and provides a multi-dimensional coupling model. The multi-dimensional coupling model adopts different sub-models for different problems, for example, a Monte Carlo ray tracing method is used for light-focusing and heat collection, a one-dimensional discrete model is adopted for a thermal hydraulic parameter, a two-dimensional finite model is adopted for temperate distribution of a heat collection tube, a three-dimensional finite element model is adopted for a thermal stress problem, and a zero-dimensional model is adopted for thermal cycle calculation. The coupling method can both improve precision and efficiency, and moreover, local detailed information and overall system performance can be obtained, and the model can be utilized very flexibly. The operating system can be adjusted according to the acquired thermal hydraulic parameter, and the method can be used for predicting influence of various infinite elements on performance of a power plant, and can position and monitor a thermal stress strain situation of the heat collection tube in real time. Moreover, the model method is easily applied to solar thermal power generation systems in other light-focusing forms.

The invention relates to a numerical simulation method of a vehicle load based on a finite element-infinite element model. Firstly, according to the basic physical parameters of soil, the finite element method is established based on ABAQUS. Infinite element soil model; Secondly, according to the speed, amplitude and shape of the moving load, the subprogram is written to define the form of the load. With the help of the body force subprogram interface in ABAQUS Explicit, the Vdload subprogram is accessed, and the physical force is used in the subprogram. The thin layer loading method applies moving vertical load and moving horizontal friction load. Finally, the numerical simulation of vertical and horizontal moving loads acting on the foundation soil is carried out. Compared with the priorart, the invention has the advantages of improving the absorbing effect of the boundary stress wave, solving the problem that the Vdload is difficult to apply the horizontal friction load and the like.