共查询到20条相似文献，搜索用时 31 毫秒
1.
In order to use FEM for engineer to anlysis structures by inputing only the designing parameters, the parametrical finite element software of a framed structure is developed, which has the functions of automatically modeling, adding constraints and loads, showing the results by inputing the changeable parameters. The validity of the software is proved by actual example. 相似文献
2.
We apply the Hermite integrate to nonlinear stochastic finite element method, and establish the theory and algorithm of Stochastic FEM based on the Hermite integrate. An example is put forward, which is solved by choosing different kinds of integrate points and verified with Monte-Carlo stochastic FEM. The result show that the new method own a high efficiency. On the precision, the first and the second order quadrature reach high precision although the integrate points only is 3, however, the high precision of the third and the fourth order quadrature need more integrate points (e.g.11). 相似文献
3.
In order to analyze the seismic behavior of widened beam flange joints, 16 specimens were derived from finite element models base on experiments. The effects of some parameters, such as the increased width and length, on ultimate load and ductility performance of joints were further discussed with ANSYS finite element method. According to specimen failure phenomenon of both experiment and finite element method, the weak link of the joints was found and the cracking possibility was evaluated. A theoretical analysis of the fracture mechanism of widened beam flange connection was conducted. In addition, design method of widened beam flange parameters was introduced, which will offer valuable information and reference for seismic design in steel frame joints. 相似文献
4.
LUO Cheng-gang GONG Xian-shengl Engineering Chongqing University Chongqing Chin 《保鲜与加工》2004,(2):20-23
To solve implant's looseness and subsidence, and to adapt for the requirement of custom-made hip endoprostheses' rapid automatic design and manufacture, a new method is presented for constituting the anisotropic and inhomogeneous model of proximal femur based on CT, CAD technology and finite element analysis during design of custom-made hip endoprostheses, Raw CT image data, 3-D modeling and finite element software is utilized to set up 3-D finite element model of proximal femur. The model is provided with anisotropy and inhomogeneity by self-developed specific software. The near true proximal femur model is structured and good biomechanics condition is provided for optimize design of custom-made hip endoprostheses. For simulating and analysing of proximal femur's structrue and material mechanics property, and determining stress ,strain and response after-operation under the action of physiological load more exactly, and supplying design of custom-made hip endoprostheses with data, the method can provide biomechanics condition for optimize design of custom-made hip prostheses. 相似文献
5.
The whole reliability index of a slope is derived through using the strength reduction method in the finite element analysis, which can make use of the former finite element program and can be used to both linear and nonlinear finite element analysis. The affection of the evaluation of derivative and the selection of reliability analysis methods is discussed, which shows that it is very important to select the type of limit state function of the slope stability. A new iterafive formula, which can consider the correlation of fundamental parameters, is proposed for FORM, and the convergence is very well. 相似文献
6.
Based on the refined three dimensional modeling method, a coupled vibration FEA(finite element analysis) model was established for light railway train and long span two layer cable stayed bridge with the consideration of the material and geometry nonlinearity and over 2.2 million of element and nodes.To overcome the computing difficulty for large number of element, the solution was carried out with the Dawning 4000A supercomputer in Shanghai Supercomputer Center based on Contact Balance Bisection Algorithm for parallel computing.Through the simulation of one way and two way conditions, the key component's stress of cable stayed bridge girders and dynamic response of middle span section was respectively analyzed. 相似文献
7.
Nonlinear thermophysics parameters are considered in ansys finite element software, so it can be used to compute temperature in the quenching. The temperature field in quenching process of 45 steel part is simulated by ansys finite element software, and the relationship between temperature of part and quenching time is obtained. Simulation result is correspondent with real process, this method has quick computing speed, and it can optimize quenching technology and select quenching bath. The most of all,this method can supply the temperature condition in computation of thermal stress and residual stress of quenching process. 相似文献
8.
To effectively analyze the one way coupled thermoelastic problem for composite laminated shells, a simplified thermoelastic shell model based on the variational asymptotic method (VAM) was developed. The 3 D energy functional for composite laminated shell was established according to the Hamilton extended principle. Then the 3 D energy was asymptotic expanded into a series of 2 D approximation energies by taking advantage of the inherent small parameters. Finally, the approximate energy was converted to the form of Reissner Mindlin model, and the 3 D recovery relationships were deduced to accurately predict the 3 D field distribution along the thickness direction. The cylindrical bending example of a four layer composite laminated shells under the sinusoidal surface load and temperature field shows that the modeling speed is fast (equivalent single layer model, which can reduce two or three order calculations compared to the 3 D finite element method), and the nonlinear approximation ability is excellent (convergent to the exact solution). 相似文献
9.
Ou Hengan Gong Jianxia 《保鲜与加工》1988,(1)
This paper presents an improved mixed finite element method of analyzing elastic contact problems, in which a new numerical algorithm is developed to calculate the flexibility matrix of the contact region. With this method the contact problem of two teeth-engaging is initially solved as a three-dimensional elastic finite element analgsis, In comparison with mixed fimte element method, the improved mixed finite element method is much more efficiency in solving contact problems. 相似文献
10.
The numerical simulations of the casting process for making metal matrix composite by infiltrating melting alloys into a fiber preform arestudied. The evaluation of the infiltration flow, the thermal conduction, the stress and strains of the matrix are studied with finite element method, and the corresponding finite element program for axi-symmetry condition is programmed. The influences of the controllable initial and boundary conditions on the casting process, residual stress and residual plastic strains, and selection of optimal technological parameters are researched. The reliability of the numerical simulation is analyzed by comparison between the calculated results andsimilar experimental data.[WT5HZ] 相似文献
11.
Biphasic porous medium model,based on the mixture theory in continuum mechanics frame,is used to depict the distributing disciplinarian of sclerotin's stress field,distortion field and pore pressure when the bone tissue is subjected to various dynamic loadings.The coupling relationship among the distortion,fluid flow and the streaming potential is studied.The penalty finite element formulation for streaming potential is studied.The penalty finite element formulation for streaming potential distributing in bone tissue is obtained by using Galerkin weighted residual method for the biphasic porous medium model with corresponding initial and boundary conditions,in this modeling,the solid phase is assumed to be isotropic elastic medium,and the fluid phase is ideal fluid.The computational results show that because of the distortion of bone tissue the marrow's flow is raised,then the electriferous partical moves in the porous and the streaming potential appears. 相似文献
12.
Directing toward the flow design of cantilever anti slide piles, the thesis which is based on foundation coefficient method and finite element method mainly analyzes service behavior influences by changing several design parameters, such as cross section 相似文献
13.
Based on the fluid saturated biphasic porous media model deduced from mixture theory,a finite element formulation with u S u F p variables for dynamic response analysis is given out.This method overcomes the difficulty of choosing suitable penalty parameter in penalty finite element method,and the accuracy of pressure distribution obtained with the mixed finite element method is higher than the penalty finile element method.An iterative solution method is suggested to solve the system of equations whose coefficient matrices are non positive definite.It is concluded from patch test that the order of interpolation function for pressure variables must be higher than that of displacement variables of solid phase. 相似文献
14.
In the research of electrical impedance tomography (EIT), each calculation may produce a large amount of data(such as conductance , resistance etc.). The rule of these data is not clear and is hard to understand. How to express the calculation result by means of image in order that such parameters as conductance and resistance can be grasped from the image is significant in analyzing and understanding the calculation result and is helpful to the doctor. This paper has discussed the realization of the post-process of finite element method in electrical impedance tomography and we have developed the software of the post-process of finite element method using Visual C++ .NET and OpenGL. Some problems in drawing the contour line and color contour band have been solved properly. 相似文献
15.
The extended finite element method(XFEM) presented in recent years is a new and effective method for discontinuity analysis,especially fracture problem analyses.The basic XFEM principle is introduced and the technique for fracture analysis is presented.The fracturing process of a gravity dam is simulated by XFEM,and the rules of stresses and displacements distribution are analyzed.Compared with the classical finite element method,the crack growth in the gravity dam can be modeled by XFEM without making the crack surface associate with the finite element mesh and setting dense mesh near the crack tip as well as remeshing after crack growth.The cumbersome work and disadvantages in conducting fracturing analysis by the finite element method thus can be avoided.The predominance of this method for dam fracturing analysis is displayed. 相似文献
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17.
刚性陶瓷瓦热防护系统概率设计分析方法 总被引：2，自引：0，他引：2
针对高超声速飞行器中广泛应用的陶瓷瓦热防护系统,结合有限元法和蒙特卡洛模拟建立了其概率热分析系统,提出了刚性陶瓷瓦热防护系统尺寸概率设计方法。建立了刚性陶瓷瓦热防护系统的二维有限元模型,考虑了热传导系数、比热容和表面辐射率等材料属性参数以及热防护系统各层厚度的不确定性,得到系统温度场的概率分布特性和系统热防护性能对各参数的灵敏度,并对系统的热可靠性进行了评估。算例表明：文中提出的方法对热防护系统设计过程中合理确定陶瓷瓦厚度和在保证系统性能的前提下有效减轻重量具有指导价值。 相似文献
18.
According to an analysis of three-dimensional convection diffusion problems and object-oriented programming method,the classes of finite element models for convection diffusion problems are designed in C++.There are vector classes,matrix classes,element classes,material classes and method classes of finite element among these classes.On the basis of these classes,an object-oriented finite element program for three-dimensional convection diffusion problems is accomplished,which is able to simulate similar problems.The program's reuse,maintenance expansion and integration with other ones are easier than traditional ones which are designed with structural language,it can be applied to a large universal computational software for science and engineering. 相似文献
19.
采用非线性有限元分析程序ABAQUS对无粘结体外预应力CFRP片材加固简支钢筋混凝土T形梁后进行数值模拟,该模拟梁共4根分别为3根梁侧对称加固,1根为梁底加固均为四点波形齿锚固预应力CFRP带。对比结果显示,数据模拟与试验结果在构件屈服以前的承载力、变形以及极限承载力吻合程度较好,构件屈服以后的变形差别较大,因此,可在一定程度上有效替代试验分析方法。依据吻合程度最好的TL3参数设计了“两点锚固”和“四点锚固”的模型进行模拟分析。通过对锚固点数及加固量改变的对比分析可知,依据加固构件的弯矩改变各段加固量及布置锚固点数的方法既可以保证加固效果不降低,又可以节约CFRP材料。 相似文献
20.
The frequency aperture given in this paper is a new method that describes the fracture aperture composition. The aperture curve plays a role in describing the aperture distribution and uniformity. In particular, the frequency hydraulic aperture is of great importance in seepage analysis. It overcomes limitations of hydraulic aperture and mean aperture. Based on existing information, the result of example calculation shows that the hydraulic aperture e h equals to the median aperture e 50 . This paper also obtains that the frequency hydraulic aperture e sh equals to e 48 through finite element numerical modeling for various type of random fracture. 相似文献