共查询到20条相似文献,搜索用时 31 毫秒
1.
A two-scale analysis (TSA) method for predicting the heat transfer performance of composite materials with the random distribution of same-scale grains is presented. First the representation of the materials with the random distribution is briefly described. Then the two-scale analysis formulation of heat transfer behavior of the materials with random grain distribution of small periodicity is formally derived by means of construction way for each cell. Finally the numerical result on the heat transfer parameters of composite materials is shown. The numerical result shows that TSA is effective to predict the heat transfer performance of composite materials with random grain distribution. 相似文献
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A finite element model based on statistical two-scale analysis for equivalent heat transfer parameters of composite material with random grains 总被引:1,自引:0,他引:1
In this paper, a new finite element model based on statistical two-scale analysis for predicting the equivalent heat transfer parameters of the composite material with random grains is presented and its convergence, its error result and the symmetry, positive property of equivalent heat transfer parameters matrix are also proved. Firstly, some definitions of the probability space and the composite material with random grains are described and the STSA formulation predicting the equivalent heat transfer parameters of the composite material are briefly reviewed. Next, a finite element formulation and its corresponding procedure for the composite material with random grains is described. Then, the convergence, the error estimate and the symmetry, positive property of the equivalent heat transfer parameters matrix computed by FE based on STSA are proved. The numerical result shows the validity of the FE model based on STSA and the convergence and the symmetry, positive property of the equivalent heat transfer parameter matrix of the composite material with random grains by the FE model. 相似文献
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We consider a second order elliptic equation with known rapidly oscillated coefficient. The equation appears to describe such problems as heat transfer in composite materials, flow in non-homogeneous porous media as well as in many others. For the periodic coefficient the averaging procedure is well known. The non-periodic case is still a challenging problem. We present a two-scale extension approach and apply it on one numerical example in 2D. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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This study develops a novel multiscale computational method for thermoelastic problems of composite materials with orthogonal periodic configurations. Firstly, the multiscale asymptotic analysis for these multiscale problems is given successfully, and the formal second-order two-scale approximate solutions for these multiscale problems are constructed based on the above-mentioned analysis. Then, the error estimates for the second-order two-scale (SOTS) solutions are obtained. Furthermore, the corresponding SOTS numerical algorithm based on finite element method (FEM) is brought forward in details. Finally, some numerical examples are presented to verify the feasibility and effectiveness of our multiscale computational method. Moreover, our multiscale computational method can accurately capture the local thermoelastic responses in composite block structure, plate, cylindrical and doubly-curved shallow shells. 相似文献
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Martin Heida 《Applicable analysis》2013,92(7):1243-1264
The heat transfer problem in a polycrystal with nonlinear jump conditions on the grain boundaries will be homogenized using the method of stochastic two-scale convergence developed by Zhikov and Pyatnitskii [V.V. Zhikov and A.L. Pyatnitskii, Homogenization of random singular structures and random measures, Izv. Math. 70(1) (2006), pp. 19–67] and recently extended by the author [M. Heida, An extension of stochastic two-scale convergence and application, Asympt. Anal. (2010) (in press)]. It will be shown that for monotone Lipschitz jump conditions differentiable in 0, the nonlinearity vanishes in the limit. Additionally, existing Poincaré inequalities will be extended to more general geometric settings with the only restriction of local C 1-interfaces with finite intensity. In particular, the result can now be applied to the Poisson–Voronoi tessellation. 相似文献
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In this paper, we shall present a new second-order and two-scale approximate solution of boundary value problems for the linear elasticity systems with quasi-periodic structures by multi-scale analysis. The computation of strain and stress is presented here. This idea can apply to the damage computation of composite materials. Because the computation of the local stress by this method having more precision, it can provide some inspiration for construct optimal design. Finally numerical results show that the method presented in this paper is effective and reliable. 相似文献
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T. A. Yakubenko 《Computational Mathematics and Mathematical Physics》2006,46(6):1073-1080
Effective properties of composite and porous materials are determined by using an approach based on two-scale asymptotic expansions. Explicit approximate formulas are derived for the effective moduli of composite and porous materials of elongated structures. A numerical method is proposed for finding solutions to cell problems, which are used to determine “exact” effective moduli. Examples are computed for a two-dimensional porous medium with variously shaped pores and various degrees of “elongation.” The effective moduli produced by the explicit approximate formulas prove to be similar to those found by numerically solving cell problems. 相似文献
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Multiscale computational method for nonstationary integrated heat transfer problem in periodic porous materials 下载免费PDF全文
Zhiqiang Yang Junzhi Cui Ziqiang Wang Yang Zhang 《Numerical Methods for Partial Differential Equations》2016,32(2):510-530
This article discusses multiscale analysis and numerical algorithm for the nonstationary integrated heat transfer problem with rapidly oscillating coefficients. The multiscale asymptotic expansion of the solution for this kind of problems is presented first. Then, error estimates of the multiscale approximate solution are derived, and a numerical algorithm based on the multiscale method for temperature field is introduced. Finally, using some numerical models, we verify the validity and relevancy of the proposed algorithm. The numerical results show that the algorithm is effective to predict the heat transfer performance of porous materials, and support the convergence theorem reported in this article. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 32: 510–530, 2016 相似文献
11.
In this paper, one specific kind of heat transfer problem with nonlinear Stefan-Boltzmann conditions are considered in a three
dimensional multi-layer domain. Theoretical results for forward and inverse problems are presented. Numerical simulations
of specific models from applications are provided to demonstrate the heat transfer process in the composite materials of forward
problem. One reconstruction method is proposed to find the corrosion part, and the numerical examples show that the reconstruction
algorithm is effective. 相似文献
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整周期复合材料弹性结构的有限元计算 总被引:4,自引:0,他引:4
1.引言周期性复合材料与周期结构的弹性力学问题,由于其材料特征剧烈振荡,且周期很小,问题相当复杂,除了一些特殊的和简单的问题可以用解析法求解外,多数问题很难或不可能用解析法求解,需要采用数值方法计算,有限元法无疑是最有效的方法之一.用细观力学方法研究复合材料的力学问题时,需要涉及纤维的排列情况,纤维和基体的性能,界面的分布情况,以及细观的几何参数和物理参数等.由于复合材料细观构造的不均匀性和不规则性,损伤和缺陷的存在,以及许多难以精确测定的因素,使得复合材料的细观力学问题十分复杂,不作出一些简化… 相似文献
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W. J. Lee Y. J. Kim N. H. Kang I. M. Park Y. H. Park 《Mechanics of Composite Materials》2011,46(6):639-648
A new numerical method is proposed to predict the effect of particle clustering on grain boundaries in a ceramic- particle-reinforced
metal matrix composite on its mechanical properties, and micromechanical finite-element simulation of stress–strain responses
in composites with random and clustered arrangements of ceramic particles are carried out. A particular material modeled and
analyzed is a TiC-particle-reinforced Al matrix composite processed by powder metallurgy. A representative volume element
of a composite microstructure with 5 vol.% TiC is reconstructed based on the tetrakaidecahedral grain boundary structure by
using a modified random sequential adsorption. The model proposed in this study accurately represents the stress concentrations
and particle-particle interactions during deformation of the powder-metallurgy-processed composite. A comparison with the
random-arrangement model shows that the present numerical approach is more accurate in simulating the behavior of the composite
material. 相似文献
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Yang Gufan Yamamoto Masahiro Cheng Jin 《Mathematical Methods in the Applied Sciences》2008,31(11):1297-1314
In this paper, we discuss nonstationary heat transfer problems in composite materials. This problem can be formulated as the parabolic equation with Stefan–Boltzmann interface conditions. It is proved that there exists a unique global classical solution to one‐dimensional problems. Moreover, we propose a numerical algorithm by the finite difference method for this nonlinear transmission problem. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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具有小周期孔隙复合材料弹性结构的双尺度有限元分析 总被引:6,自引:1,他引:5
对于具有小周期孔隙复合材料弹性结构,在双尺度渐近分析理论结果的基础上提出了双尺度有限元计算格式,并给出了严格的误差估计. 相似文献
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《Communications in Nonlinear Science & Numerical Simulation》2010,15(6):1565-1574
The homotopy analysis method (HAM) is used to develop an analytical solution for the thermal performance of a radial fin of rectangular and various convex parabolic profiles mounted on a rotating shaft and losing heat by convection to its surroundings. The convection heat transfer coefficient is assumed to be a function of both the radial coordinate and the angular speed of the shaft. Results are presented for the temperature distribution, heat transfer rate, and the fin efficiency illustrating the effect of thickness profile, the ratio of outer to inner radius, and the angular speed of the shaft. Comparison of HAM results with the direct numerical solutions shows that the analytic results produced by HAM are highly accurate over a wide range of parameters that are likely to be encountered in practice. 相似文献
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在模糊随机因素影响下的多层圆筒结构的稳态热传导问题的区间数解法 总被引:1,自引:0,他引:1
在多层圆筒结构稳态热传导分析中,根据给定固体壁两侧表面温度总传热量公式,首先推导出当边界温度为随机变量情况下总传热量函数统计参数的均值和方差;然后推导出在导热系数为模糊数,边界温度为随机数下的总传热量的区间表达式.通过比较可以知道由区间数算法得到的区间最大,由概率统计算法得到的区间最小.并给出了两者的相对误差公式.最后引进粗糙集中的上、下近似集,提出用一个参数来统一定义模糊和随机区间进行稳态结构的热传导分析. 相似文献