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1.
A higher order asymptotic solution of near-tip field is studied for plane-atrain Mode-I quasi-static steady crack growth in
the incompressible (v=1/2) elastic perfectly-plastic media. The results show that the near-tip stress and strain are fully continuous, and the
strain possesses In (A/r) singularity at the crack tip. The expressions of the stress, strain and velocity in each region are also given.
The project supported by National Natural Science Foundation of China 相似文献
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Based on the microstructure-based constitutive model established in Part I, a detailed numerical investigation on the role
of each microstructure parameter in the kinematical and kinetic evolution of polycrystalline SMA under axisymmetrical tension
loading is performed. Some macroscopic constitutive features of stress-induced martensite transformation are discussed.
The subject supported by the Research Grant Committee (RGC) of Hong Kong SAR, the National Natural Science Foundation of China
and the Provincial Natural Science Foundation of Jiangxi Province of China 相似文献
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On the continuum modeling of carbon nanotubes 总被引:6,自引:0,他引:6
Zhang Peng Huang Yonggang Philippe H. Geubelle Hwang Kehchih 《Acta Mechanica Sinica》2002,18(5):528-536
We have recently proposed a nanoscale continuum theory for carbon nanotubes. The theory links continuum analysis with atomistic
modeling by incorporating interatomic potentials and atomic structures of carbon nanotubes directly into the constitutive
law. Here we address two main issues involved in setting up the nanoscale continuum theory for carbon nanotubes, namely the
multi-body interatomic potentials and the lack of centrosymmetry in the nanotube structure. We explain the key ideas behind
these issues in establishing a nanoscale continuum theory in terms of interatomic potentials and atomic structures. 相似文献
7.
A new micromechanics constitutive model for pure dilatant transformation plasticity of structure ceramics is proposed in this
paper. Based on the thermodynamics, micromechanics and microscalet→m transformation mechanism analysis of the TZP and PSZ ZrO2-containing ceramics, an analytic expressions of the Helmholtz and complementary free energy of the constitutive element for
the case of pure dilatant transformation is derived for the first time in a self-consistent manner. By the analysis of energy
dissipation in the forward and reverse transformations, the micromechanics constitutive law is derived in the framework of
Hill-Rice's internal variable constitutive theory.
The project is supported by the National Natural Science Foundation of China. 相似文献
8.
Since piezoelectric ceramic/polymer composites have been widely used as smart materials and smart structures, it is more and
more important to obtain the closed-from solutions of the effective properties of piezocomposites with piezoelectric ellipsoidal
inclusions. Based on the closed-from solutions of the electroelastic Eshelby's tensors obtained in the part I of this paper
and the generalized Budiansky's energy-equivalence framework, the closed-form general relations of effective electroelastic
moduli of the piezocomposites with piezoelectric ellipsoidal inclusions are given. The relations can be applicable for several
micromechanics models, such as the dilute solution and the Mori-Tanaka's method. The difference among the various models is
shown to be the way in which the average strain and the average electric field of the inclusion phase are evaluated. Comparison
between predicted and experimental results shows that the theoretical values in this paper agree quite well with the experimental
results. These expression can be readily utilized in analysis and design of piezocomposites.
The project supported by the National Natural Science Foundation of China 相似文献
9.
A constitutive relation to describe pseudo-elastic deformation in shape memory alloys is presented in this paper. It is capable
of describing deformation behaviour of polycrystalline materials under triaxial stress state as well as of monocrystalline
materials under one-dimensional condition. Total strain rate is supposed to be composed of elastic strain rate and transformation
strain rate. Deformation behaviour of Cu−Zn−Sn alloy and Ti−ni alloy is simulated by use of the proposed constitutive relation.
it is shown that simulated results are in a good agreement with experimental data.
The project supported by National Natural Science Foundation of China. 相似文献
10.
本文在对结构陶瓷的四方至单斜(t→m)马氏体相变进行细观力学、热力学和微观机制分析的基础上,导出了在非比例加载条件下考虑材料的体膨胀和剪切效应的相变塑性细观本构模型。作者首次采用 Mori-Tanaka 方法以自洽的方式导出了材料构元的 Helmho-ltz 自由能及余能函数的解析表达式,它是外加宏观应力(或应变)、温度、相变夹杂体积分数以及夹杂内平均相变应变的函数,其中夹杂体积分数和平均相变应变为描述材料构元微结构变化的内变量。最后按 Hill-Rice 本构理论框架导出相变塑性屈服面方程及增量本构关系。 相似文献