77 results about "Finite element program" patented technology

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.

A method for determining the time-varying reliability of prestressed concrete box girder bridges based on the stochastic finite element method. For prestressed concrete box girders that are widely used in highway bridge systems and have common early-stage diseases, by combining degenerate shell elements, material constitutive relations and The crack model simulates the nonlinear characteristics of the box girder in the cracking stage, and the embedded concrete creep, shrinkage and steel strand stress relaxation model considers the deformation, prestress loss and internal force redistribution of the box girder during its entire life, through the reinforcement The uniform corrosion model and the pitting corrosion model calculate the section loss of steel bars (steel strands) in carbonization environment and chloride ion environment respectively. Finally, through the definition of random variables, sampling, calling finite element program calculation and extracting stress and strain results, the reliability calculation of the box girder bridge is realized and used to guide the subsequent maintenance and reinforcement work.

The invention relates to a comprehensive analysis method for steam explosion of nuclear reactors. The method mainly comprises the following steps of: 1, obtaining initial parameters of the steam explosion; 2, calculating the change of melt in the steam explosion process; 3, calculating the energy exchange on a phase interface; 4, calculating the mass transfer on the phase interface; 5, calculatingthe momentum exchange on the phase interface; 6, semi-implicitly solving energy and momentum equations; 7, full-implicitly solving a mass conservation equation and outputting distribution of pressurewaves; 8, carrying out geometric modeling on main components by using a finite element program ABAQUS; 9, creating material physical properties and analyzing and inputting by taking the pressure wavedistribution in the step 7 as a load; 10, carrying out grid dividing on the main components established in the step 8; and 11, submitting analysis and outputting the stress change of the main components. The comprehensive analysis method disclosed by the invention has the advantages that the distribution situation of the pressure waves and the impact effect of the pressure waves on the main components under steam explosion accidents of the nuclear reactors can be comprehensively analyzed, so that bases are provided for more comprehensively and effectively evaluating the safety of the reactors.

The invention, a testing method for mode I crack dynamic fracture overall process parameters under blast loading, discloses the testing method for the dynamic crack initiation toughness, dynamic expansion toughness and dynamic crack arrest toughness of mode I crack under blast loading, and belongs to the technical field of geotechnical engineering. The configuration of an internal single crack disc specimen with a large size is an autonomous design; testing results cannot be influenced by reflected extension waves and transmission waves; and the method is suitable for researching the crack growth rate and growth behavior of the whole process. Blast loading adopts an 8# detonator; numeral calculation adopts a finite element difference software AUTODYN; and a result basically accords with atest. A load stress time history curve can be input into a finite element program ABAQUS; the time history curve of a dynamic stress intensity factor can be obtained; and the dynamic fracture toughness of a material can be determined through the fracture time of a crack. The specimen is simple in configuration and easy in processing; the test is concise and clear in process and convenient in operation; and researches on crack dynamic growth behavior and tests on the dynamic fracture toughness can be realized.

The invention relates to an energy dissipation and shock absorption optimization design method which is a joint optimization design method developed based on an MATLAB (matrix laboratory) genetic algorithm toolbox and an SAP2000 finite element program platform. The method includes a preprocessing part, a cycle call optimization part and a post-processing part; the cycle call optimization part is genetic algorithm optimization and anti-seismic checking calculation, and the preprocessing part is used for determining related parameters and codes and establishing an original model and initialized populations for the cycle call optimization part; the cycle call optimization part is realized through the genetic algorithm toolbox GATBX and SAP2000API function compilation, optimum individual are selected, and the post-processing part is used for extracting and processing optimization results to generate a corresponding calculation sheet. The characteristics of the genetic algorithm used in multi-objective problem optimization and a finite element program used in structural energy dissipation and shock absorption reinforcement analysis are integrated, and the method has bigger advantages than a conventional energy dissipation and shock absorption design method.

The invention relates to a multi-block slide calculation method for a giant landslide, and belongs to the field of geological disaster engineering. The method is used for landslide disaster stability evaluation and engineering prevention and control. The method comprises the steps of: (1) finding out a landslide region range, deformation features and hydrogeology and engineering geology conditions; (2) based on a finite element program, establishing a finite element numerical model of a side slope; (3) inputting formation mechanical parameters of the side slope; (4) inputting reduction parameters and physical and mechanical characters of landslide massif for performing finite element calculation; (5) determining a side slope failure region; (6) continuously reducing failure strength parameters until slide surfaces are communicated; (7) determining a tension failure zone of each stage of slide surface; (8) setting the tension failure zone as a null unit in the model; and (9) re-calculating a new numerical model and searching out multiple stages of slide surfaces. According to the multi-block slide calculation method for the giant landslide, provided by the invention, the multiple stages of slide surfaces of the giant landslide can be accurately searched out and an important basis is provided for giant multi-stage landslide stability evaluation and engineering prevention and control.

The invention belongs to the technical field of building structure design and particularly relates to a checking calculation method for the stability of a building foundation under the earthquake action. According to the method, at first, a general finite element program ANSYS is selected for setting up a three-dimensional space finite element model of a building, loading, calculating and deriving are carried out according to the mechanics principle to obtain a concentrated mass bar unit model with the identical dynamic characteristics, the obtained concentrated mass bar model is guided into an ACS SASSI program, a foundation model is supplemented and set up in the ACS SASSI program according to the factory site foundation condition, the ground motion time history is input, and a calculation kernel of the ACS SASSI program is utilized for achieving calculation functions such as soil-structure interaction (SSI) and foundation nonlinearity. By the adoption of the method, an analysis model can conform to actuality better, the calculation result is more accurate and reliable, and the method is simple, applicable, easy to operate, and convenient to realize in actual engineering.

The invention provides a two-stage partitioned two-time polycondensation parallel computing system development method and a corresponding parallel computing system. The two-stage partitioned two-time polycondensation parallel computing system development method comprises the steps of 1 producing all program source codes required by finite element analysis parallel computing through a finite element program automatic generation system according to a mathematical equation expression for solving problems, 2 removing solution linear equation systems in the program source codes and conducting parallelized modification on remaining modules by means of a solution linear equation, 3 developing parallel solution linear equation systems based on two-stage partitioning and two-time polycondensation strategies and conducting seamless integration on the parallel solution linear equation systems and the modules subjected to parallelized modification, and 4 compiling and debugging the integrated system and generating a finite element analysis parallel computing executable program. By means of the two-stage partitioned two-time polycondensation parallel computing system development method and the corresponding parallel computing system, solutions can be provided for the finite element analysis problems in all disciplines and fields, and the quality and efficiency of finite element analysis parallel computing software development can be improved.

The invention discloses a finite element prediction method, under the action of force-electricity-heat multi-field coupling, of electrode-containing ferroelectric single crystal based on phase-field method analysis. The method comprises the following steps of establishing a new phase-field model with the multi-field coupling based on a Landau theory and an expansion interface model; obtaining the model establishment and the grid division of the electrode-containing ferroelectric single crystal by using ANSYS finite element software, and extracting node information and unit information; importing the obtained node information, the obtained unit information and considered different boundary condition information, and realizing a solution to the force-electricity-heat nonlinear coupling problem of the electrode-containing ferroelectric single crystal by using an FEAP fast solver; importing field variables which are obtained through FEAP finite element solution into a postprocessing program which is written by Fortran, and obtaining visual field variable results by using TECPLOT software. According to the method provided by the invention, not only is the process simple, but also the adaptability and the stability are good; a commercial finite element program can be developed to flexibly adapt to problem changes.

The invention discloses an overground-underground bidirectional ultra-long concrete seamless design method and belongs to the field of constructional engineering. The method is characterized in that home and abroad large finite element programs, such as ANSYS, ABAQUS, SAP2000 and PMSAP, are used for calculation and analysis, and indoor and outdoor temperature data actually measured in practical projects is applied in the calculation so as to actually measure the regional average temperature; the maximum temperature difference of concrete shrinkage is calculated; and the division of a post-pouring strip or an expansion reinforcing strip and the restrained expansion rate of the used crack resistant waterproofing agent and expanding agent are provided in the design according to the conditions of individual buildings. By utilizing the method, the problem of difficulty in overground-underground bidirectional ultra-long concrete seamless design is solved successfully, requirements on entire use functions of the buildings are satisfied, the usable area is increased, and simultaneously, the construction speed is accelerated; problems in aspects of durability, fire resistance, water tightness, maintenance and the like and building defects caused by arrangement of a deformation joint are solved; and the arrangement of equipment pipelines can be facilitated.

The invention relates to a method for calculating a continuous wall with supporting legs under the action of horizontal loads. According to the specific constructing mode of the underground continuous wall with the supporting legs, firstly, a finite element program of a common elastic foundation beam method is modified and improved, a finite element program of a variable stiffness elastic foundation beam method is made, an engineering calculation method of internal force and horizontal displacement under the action of the horizontal loads is formed in combination of a depth judgment method on the interface of the supporting legs, and therefore when the continuous wall is used as a basement exterior wall and a foundation pit support structure, the lateral pressure of a soil body can be borne. The method can make engineer design personnel fast and effectively design and calculate the underground continuous wall with the supporting legs.

The invention discloses a high-precision numerical value method for solving an interval heat convection diffusion problem. The high-precision numerical value method comprises the following steps: establishing a heat transfer control equation of the heat convection diffusion problem; introducing an interval variable to represent the uncertainty of an input parameter in a heat transfer model, and establishing an interval control equation of the heat convection diffusion problem; utilizing a Legendre polynomial expansion to carry out approximate representation on temperature response in the interval control equation; according to tensor product operation, determining a collocation point set in a high-dimension space; utilizing a finite element program to calculate the temperature response of all collocation points, establishing a linear equation set in regard to an expansion coefficient in a temperature response approximate expression, and adopting a least square method to solve; and on the basis of the smoothness of a polynomial function, determining an extreme point of the temperature response approximate expression, and obtaining the upper bound and the lower bound of interval temperature response. The high-precision numerical value method can systematically solve the heat convection diffusion problem with interval uncertainty parameters and effectively improves the calculation precision of the interval numerical value method.

The invention belongs to the technical field of nuclear building design, and relates to a floor response spectrum simplified calculation method considering an SSSI effect. The simplified calculation method is combined with two kinds of finite element programs of the general finite element program and the SSI analysis program; on one hand, part of the structure units in a building group are assembled into a unit by means of super-elements in the general finite element program; on the other hand, by means of format conversion of a dynamic characteristic matrix, the SSI analysis program can directly read unit matrix information of the general finite element program, and floor response spectrum simplified calculation considering the SSI effect is conducted by means of a computing kernel of theSSI analysis program. According to the floor response spectrum simplified calculation method considering the SSSI effect, the SSSI effect can be considered in a real, efficient and rapid mode, calculation results conform to reality on the basis of ensuring consistency and accuracy of a model, and the computing cost is low.

The invention provides a generator stator end part winding structure optimization method based on particle swarm algorithm and support vector machine, which comprises the following steps of: (1) carrying out finite element analysis, recording design variables and structural responses of each analysis as input variables and output variables respectively to obtain a sample point required for establishing an approximate model of a support vector machine; (2) using the obtained sample point, taking SVM parameters as design variables and carrying out initialization; (3) carrying out SVM parameter selection to establish a support vector machine approximate model with optimal parameters to predict structural response; (4) carrying out optimization combined with the approximate model of the support vector machine by using PSO as an optimization algorithm to obtain an optimal solution of the approximate model; (5) substituting the obtained optimal design variable values into the support vectormachine approximate model to call a finite element program for calculation, and comparing the calculation result with the finite element accurate calculation result, and judging the optimal solution.According to the invention, an accurate approximate model is established by using the SVM instead of the finite element analysis, and the optimization efficiency is improved.

A specific force capacity thrust bearing and a method for producing such a design for a particular application are disclosed. The magnetic flux density in the stator material is maximized by varying cross-sectional area normal to the flux path. After a set of initial parameters are chosen, the design can be improved upon by changing the design variables and then verifying the force capacity using a finite element program. By linking the finite element program to a model of the geometry and using some basic algorithms, it is possible to automatically iterate until an optimal design is reached. The resulting design has a much higher force capacity than designs typical of the prior art.

The invention discloses a structural parameter sensitivity analysis method based on a complex variable function method. The structural parameter sensitivity analysis method comprises the following steps that (1), a structural parameter pn to be calculated is selected for small perturbation; (2), a structural finite element calculation program is written, the complex variable function method is implanted into the finite element program, and after the virtual step length is added to the structural parameter, an objective function f(pn+ih) of a structure is solved in the complex space; (3), basedon the objective function f(pn+ih), a first order partial derivative which is the sensitivity of the objective function is solved; (4), by parity of reasoning, when n is smaller than m, n is equal tothe sum of n and 1, and a sensitivity value of the (n+1) structural parameter is obtained; when n is equal to m, the m structural parameter variable is set as a complex variable, and throughthe finite element analysis program, the objective function f(pn+ih) of the structure is solved in the complex space; finally, the sensitivity of the m parameter is solved by the first order partial derivative of the objective function in step (3). The method can utilize the complex variable function method to obtain a high-precision sensitivity matrix of the objective function to structural parameters.

The invention provides a suspension type waterproof curtain deep foundation pit dewatering scheme simulation optimization method, and the method comprises the following steps: S1, establishing a deep foundation pit dewatering hydrogeological conceptual model according to geological and hydrogeological characteristics of a research domain and hydraulic connection between aquifers; S2, according to the hydrogeological conceptual model, establishing a three-dimensional unstable seepage mathematical model and a land subsidence mathematical model of the water-bearing layer soil compression amount, coupling the three-dimensional unstable seepage mathematical model and the land subsidence mathematical model, and developing and solving through a finite element program; S3, carrying out parameter inversion through water pumping test data, and obtaining an optimized three-dimensional coupling numerical model of unstable seepage and land subsidence; S4, carrying out deep foundation pit dewatering and ground subsidence simulation calculation of different combination depths of the suspension type waterproof curtain and the dewatering well filter, and obtaining the optimal deep foundation pit efficient dewatering technical scheme. The coupling model constructed by the method meets certain precision and confidence, and the calculation speed and stability of the model are improved.

The invention provides a solid deformation interface calculation method considering liquid surface tension. A displacement-surface force decoupling numerical method is directly considered, discrete points of a fluid-solid boundary surface in a finite element model are fitted by utilizing a cubic spline curve, the curvature of each point is calculated, overall curvature data of a liquid-solid interface is obtained, and the fluid-solid coupling load problem with surface tension is solved. According to the method, boundary curvature calculation and finite element analysis are alternately carriedout, and the functions of preprocessing, postprocessing, nonlinear constitutive relation and the like of an existing finite element program can be fully utilized.