共查询到20条相似文献,搜索用时 109 毫秒
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在一些重大装备中存在一类重要部组件,即由周围刚性构件和中间垫层构件组合而成的多层回转预紧垫层结构,因垫层材料往往选择橡胶、硅泡沫等高分子材料,计算其在役受力响应时,涉及预紧、粘弹性非线性、结构尺度差异大的几何细节描述等复杂问题,目前还缺乏对涉及该问题进行高保真和高效率数值计算的方法研究。依托自主开发的有限元并行计算框架PANDA,设计实现了一种粘弹性非线性有限元并行算法和程序,在曙光5000A并行系统上通过算例验证了程序计算结果的正确性,探讨了预条件子对程序并行效率的影响。显示程序具有较好的并行计算能力,为复杂工程结构中的大规模粘弹性非线性有限元并行分析提供了有效的工具。 相似文献
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弹性平面扇形域问题及哈密顿体系* 总被引:12,自引:4,他引:8
通过变量代换及变分原理,将平面弹性扇形域的方程导向哈密顿体系,从而可用分离变量法、本征函数展开等方法求解扇形域的分析单元,这样便可以与有限元的程序系统相结合。显示了哈密顿体系、辛数学的应用潜力。 相似文献
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介绍了在C#平台下开发面向对象的不连续变形分析(DDA)程序的过程,以及块体的数据结构、DDA计算流程和动画显示方法。原DDA理论用最短距离法确定块体角角接触中的侵入边,该法在凸角侵入凹角时会出现误判。针对这一问题,提出了用角平分线法确定角角接触的侵入边。通过两个算例,验证了程序的正确性,并比较了有无开闭迭代的区别,以及罚函数法与增广拉格朗日(Lagrange)法对求解的不同影响。 相似文献
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不同模量弯压柱的解析解 总被引:17,自引:1,他引:16
依据不同模量弹性理论用流动坐标系及分段积分法导出复合荷载作用下弯压柱的解析解,建立了中性轴、应力、应变、位移的计算公式,并编制相应的有限元程序进行计算,与解析解进行误差对比.最后对不同模量计算结果与经典力学同模量计算结果进行分析对比,得出两种理论计算结果的差异,并提出对该类结构计算的合理建议. 相似文献
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采用基于混合物理论的多孔介质模型,给出粘性流体饱和两相多孔介质非线性动力问题的控制场方程以及相应边值和初值问题的提法,用Galerkin加权残值法导出罚有限元公式,并给出该非线性方程组的迭代求解方法。考虑了体积分数和渗透率与变形相关的情况。用编制的有限元程序计算分析了一维多孔柱体在脉冲载荷作用下的瞬态响应,数值结果表明文中方法正确有效。 相似文献
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Bo Ping Wang 《Finite Elements in Analysis and Design》1991,7(4):325-329
The problem of minimum-weight design of structures with several natural-frequency constraints is considered in this paper. The problem is solved by using a combined finite element method and sequential linear programming (FEM-SLP) formulation. The unique features of the present approach include the use of the assumed mode reanalysis formulation for the repeated eigensolution and the associated sensitivity analysis. The present approach has been implemented using the general-purpose finite element program
. Two examples are included to illustrate the effectiveness of the present approach. 相似文献
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基于参数变分原理的非均质材料弹塑性有限元分析的Voronoi单元法 总被引:1,自引:0,他引:1
在非均质材料的有限元数值模拟中,采用了Voronoi单元(VCFEM)以克服经典位移元的局限性.基于参数变分原理和二次规划法进行了Voronoi单元的二维弹塑性分析A·D2推导了有限元列式并形成最终的二次规划求解模型.研究了非均质材料微观夹杂对整体力学性能的影响.数值算例证明了该方法的正确和可行性. 相似文献
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The use of object-oriented programming techniques in the development of parallel, finite element analysis software enhances code reuse and increases efficiency during application development. In this paper, an object-oriented programming framework developed by the authors is utilized in the implementation of parallel finite element software for modeling of the resin transfer molding manufacturing process. The motivation for choosing the resin transfer molding finite element application and implementing it with the object-oriented framework is that it was originally developed and parallelized in a functional programming paradigm thus offering the possibility of direct comparisons. Discussion of the software development effort and performance results are presented and analyzed.Mathematics Subject Classifications (2000) 65M60, 65Y05. 相似文献
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Y.I. Özdemir 《Finite Elements in Analysis and Design》2012,48(1):1400-1408
Analyzing thick plates as a construction component has been of interest to structural engineering research for several decades. In particular, thick plates resting on elastic foundations are more specific. Mindlin's plate theory for thick plate analysis and the Winkler theory for elastic foundation analyses have wide applications. The current research considers analysis of isotropic plates on a Winkler foundation according to Mindlin's plate theory. The analysis uses a higher order plate element to avoid shear locking phenomena in the plate. The main features of this element are representation of real displacement functions of the plate perfect and shear locking do not occur at the plates modeled with this element. Derivation of the equations for finite element formulation for thick plate theory uses fourth-order displacement shape functions. A computer program using the finite element method, coded in C++, analyzes the plates resting on an elastic foundation. The analysis involves a 17-noded finite element. The study's graphs and tables assist engineers' designs of thick plates resting on elastic foundations. The study concludes with the computer-coded program, which allows effective use for the shear locking-free analysis of thick Mindlin plates resting on elastic foundations. 相似文献
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Numerical solution of a long-term average control problem for singular stochastic processes 总被引:1,自引:0,他引:1
P. Kaczmarek S. T. Kent G. A. Rus R. H. Stockbridge B. A. Wade 《Mathematical Methods of Operations Research》2007,66(3):451-473
This paper analyzes numerically a long-term average stochastic control problem involving a controlled diffusion on a bounded
region. The solution technique takes advantage of an infinite-dimensional linear programming formulation for the problem which
relates the stationary measures to the generators of the diffusion. The restriction of the diffusion to an interval is accomplished
through reflection at one end point and a jump operator acting singularly in time at the other end point. Different approximations
of the linear program are obtained using finite differences for the differential operators (a Markov chain approximation to
the diffusion) and using a finite element method to approximate the stationary density. The numerical results are compared
with each other and with dynamic programming.
This research has been supported in part by the U.S. National Security Agency under Grant Agreement Number H98230-05-1-0062.
The United States Government is authorized to reproduce and distribute reprints notwithstanding any copyright notation herein. 相似文献
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不可压缩流动的数值模拟是计算流体力学的重要组成部分. 基于有限元离散方法, 本文设计了不可压缩Navier-Stokes (N-S)方程支配流的若干并行数值算法. 这些并行算法可归为两大类: 一类是基于两重网格离散方法, 首先在粗网格上求解非线性的N-S方程, 然后在细网格的子区域上并行求解线性化的残差方程, 以校正粗网格的解; 另一类是基于新型完全重叠型区域分解技巧, 每台处理器用一局部加密的全局多尺度网格计算所负责子区域的局部有限元解. 这些并行算法实现简单, 通信需求少, 具有良好的并行性能, 能获得与标准有限元方法相同收敛阶的有限元解. 理论分析和数值试验验证了并行算法的高效性 相似文献
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A numerical implementation of sizing and shape design sensitivity analysis of structural systems is presented, using the versatility and convenience of an existing finite element structural analysis code and its database management system. The finite element code used in the implementation presented is the Engineering Analysis Language (EAL), which is based on a hybrid method of analysis. Design sensitivity computations are carried out using the database management system of EAL, without writing a separate program and a separate database. Accurate design sensitivity results are obtained without the uncertainty of numerical accuracy associated with selection of finite difference perturbations. Sizing design parameters, such as crossectional area of beams and thickness of plates, and shape design parameters are considered in this paper. Structural performance measures considered include displacement and stress. 相似文献
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We investigate definability in the set of isomorphism types of finite semilattices ordered by embeddability; we prove, among
other things, that every finite semilattice is a definable element in this ordered set. Then we apply these results to investigate
definability in the closely related lattice of universal classes of semilattices; we prove that the lattice has no non-identical
automorphisms, the set of finitely generated and also the set of finitely axiomatizable universal classes are definable subsets
and each element of the two subsets is a definable element in the lattice. 相似文献
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Bert Jüttler Ulrich Langer Angelos Mantzaflaris Stephen E. Moore Walter Zulehner 《PAMM》2014,14(1):961-962
Isogeometric analysis (IGA) is a recently developed simulation method that allows integration of finite element analysis (FEA) with conventional computer-aided design (CAD) software [1,3]. This goal requires new software design strategies, in order to enable the use of CAD data in the analysis pipeline. To this end, we have initiated G + SMO (Geometry+Simulation Modules), an open-source, C++ library for IGA. G + SMO is an object-oriented, template library, that implements a generic concept for IGA, based on abstract classes for discretization basis, geometry map, assembler, solver and so on. It makes use of object polymorphism and inheritance techniques to provide a common framework for IGA, for a variety of different basis-types which are available. A highlight of our design is the dimension independent code, realized by means of template meta-programming. Some of the features already available include computing with B-spline, Bernstein, NURBS bases, as well as hierarchical and truncated hierarchical bases of arbitrary polynomial order. These basis functions are used in continuous and discontinuous Galerkin approximation of PDEs over (non-)conforming multi-patch computational (physical) domains. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献