共查询到17条相似文献,搜索用时 46 毫秒
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提出了一个细观力学模型,可用于预测高体积含量非线性黏弹复合材料有效性质.该模型基于广义割线模量法、双球法以及Laplace-Carson变换技术.所提出的模型对玻璃微珠填充高密度聚乙烯(GB/HDPE)复合材料的应力应变关系进行了预测,结果与文献实验结果吻合;计算结果还表明在高体积百分比下文中所提出的方法比基于MT方法预测的粘性效应明显减弱;最后还将所提方法与线黏弹框架下的均质化模型做了比较,结果表明GB/HDPE表现出明显的非线性,线黏弹本构无法描述应变率对其力学行为的影响. 相似文献
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将通过球磨法获得的Ni2MnGa颗粒与双酚A二缩水甘油醚环氧树脂混合均匀并常温固化,制备出相应的复合材料试件;通过拉伸-卸载试验研究了NiMnGa颗粒对树脂基体的增强效果;以试验为基础,从细观力学的角度分析了NiMnGa颗粒对树脂基复合材料弹性特性的影响;采用商用有限元软件Abaqus,对NiMnGa/树脂复合材料单胞模型进行了仿真计算。分析结果表明:随着NiMnGa颗粒体积含量的增加,试件的拉伸模量和剪切模量增大、泊松比减小;随着椭圆NiMnGa颗粒长短半轴比的减小,复合材料纵向泊松比增加、纵向拉伸模量减小,横向拉伸模量呈先减后增的趋势,剪切模量则呈先增后减的趋势。通过对比可知试验值、理论值、有限元模拟值数值相近且变化趋势一致。 相似文献
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复合材料细观力学的现状和展望 总被引:1,自引:0,他引:1
复合材料性能优异、应用广泛、种类繁多、还会有新的发展。复合材料的定义尚未统一,这里指纤维增强塑料(FRP)。 从宏观看,复合材料是各向异性的层合材料。从细观看,复合材料是纤维和基体组成的多相非均质材料。一般认为纤维起主要的承力作用,而基体起保护纤维和传力作用,然而情况并非如此简单。 多数复合材料结构的工程问题,用复合材料宏观力学就能得到基本解决。在对复合 相似文献
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Yongqiang Chen Ruchao Huang Zhuping Huang Lizhi Sun 《Acta Mechanica Solida Sinica》2012,25(3):262-276
This paper studies the effective properties of multi-phase thermoelastic composites. Based on the Helmholtz free energy and the Gibbs free energy of individual phases, the effective elastic tensor, thermal-expansion tensor, and specific heats of the multi-phase composites are derived by means of the volume average of free-energies of these phases. Particular emphasis is placed on the derivation of new analytical expressions of effective specific heats at constant-strain and constant-stress situations, in which a modified Eshelby’s micromechanics theory is developed and the interaction between inclusions is considered. As an illustrative example, the analytical expression of the effective specific heat for a three-phase thermoelastic composite is presented. 相似文献
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Most piezocomposites, which have been widely used in engineering, consist of piezoelectric inclusions and a non-piezoelectric matrix. Due to the limits of fabrication technology, it is hard to avoid the matrix intermingling with other non-piezoelectric inclusions, such as cavities. The non-piezoelectric inclusions can substantially affect performance of piezocomposites. In this paper we study the electromechanical fields in piezocomposites which are composed of a non-piezoelectric matrix embedded with both piezoelectric and non-piezoelectric inclusions. Closed-form relations are obtained for the effective electroelastic moduli of a piezocomposite with both piezoelectric and non-piezoelectric inclusions. The effective properties of a 1-3 type piezocomposite with non-piezoelectric spherical inclusions are analyzed carefully and explicit formulae for the effective electroelastic properties of a 1-3-0 piezocomposite are also obtained. The analysis shows that the effect of non-piezoelectric inclusions on the electroelastic properties of piezocomposites is significant and should not be neglected. The model proposed in this paper is expected to be useful for predicting and analyzing the overall electromechanical properties of piezocomposites with a non-piezoelectric matrix containing both piezoelectric and non-piezoelectric inclusions. 相似文献
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Micromechanical theory is applied to study the nonlinear elastic and viscoelastic constitutive relations of polymeric matrix
filled with high rigidity solid particles. It is shown that Eshelby's method can be extended to the case of nonlinear matrix
and Eshelby's tensor still exists provided that Poisson's ratio of the nonlinear matrix assumes constant value in deforming
process and the rigidity of elastic filling particles is much higher than that of the matrix. A new method for averaging process
is proposed to overcome the difficulty that occured in applying the ordinary equivalent inclusion method or the self-consistant
method to nonlinear matrices. A rather simple constitutive equation is obtained finally and the strengthening effect of solid
particles to composites is investigated.
The work supported by the LNM, Institute of Mechanics, Chinese Academy of Sciences and by the National Natural Science Foundation
of China 相似文献
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A THEORY OF EFFECTIVE THERMAL CONDUCTIVITY FOR MATRIX-INCLUSION- MICROCRACK THREE-PHASE HETEROGENEOUS MATERIALS BASED ON MICROMECHANICS 总被引:1,自引:0,他引:1
The effective thermal conductivity of matrix-inclusion-microcrack three-phase heterogeneous materials is investigated with a self-consistent micromechanical method (SCM) and a random microstructure finite element method(RMFEM). In the SCM, microcracks are assumed to be randomly distributed and penny-shaped and inclusions to be spherical, the crack effect is accounted for by introducing a crack density parameter, the effective thermal conductivity is derived which relates the macroscopic behavior to the crack density parameter. In the RMFEM, the highly irregular microstructure of the heterogeneous media is accurately described, the interaction among the matrix-inclusion-microcracks is exactly treated, the inclusion shape effect and crack size effect are considered. A Ni/ZrO2 particulate composite material containing randomly distributed, penny-shaped cracks is examined as an example. The main results obtained are: (1) the effective thermal conductivity is sensitive to the crack density and exhibits essentially a linear relationship with the density parameter; (2) the inclusion shape has a significant effect on the effective thermal conductivity and a polygon-shaped inclusion is more effective in increasing or decreasing the effective thermal conductivity than a sphere-shaped one; and (3) the SCM and RMFEM are compared and the two methods give the same effective property in the case in which the matrix thermal conductivity λ1 is greater than the inclusion one λ2. In the inverse case of λ1 < λ2, the two methods agree as the inclusion volume fraction and crack density are low and differ as they are high. A reasonable explanation for the agreement and deviation between the two methods in the case of λ1 < λ2 is made. This work was supported by the National Natural Science Foundation of China and Chnese “863” High-Tech, Program. 相似文献
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Hill condition and overall properties of composites 总被引:2,自引:0,他引:2
S. Hazanov 《Archive of Applied Mechanics (Ingenieur Archiv)》1998,68(6):385-394
Summary We discuss the Hill principle's role and applications in modern micromechanics of industrial composite materials. Uniform
boundary conditions, fundamental in micromechanics, are introduced as a class of Hill solutions. Mixed uniform conditions,
basic for experimental testing, are analysed. Domains of application of the Hill principle are reviewed, like homogeneization
of heterogeneous media, definition of effective properties and size effect in heterogeneous materials. Generalization of the
Hill condition is realized for arbitrary materials, in particular for nonlinear inelastic composites with imperfect interfaces.
Received 9 September 1997; accepted for publication 23 December 1997 相似文献
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多向编织复合材料的力学性能研究 总被引:13,自引:0,他引:13
综述并评价了关于二维和三维编织复合材料的有效弹性模量研究的代表性工作,并从材料设计的思想出发,宏观与微观相结合,材料科学与力学相结合,对多向编织复合材料的宏观力学性能与细观织物结构、组分性能的关系及编织复合材料非线性行为进行了详细的理论分析和研究 相似文献