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Plane elasticity theory of one-dimensional hexagonal quasicrystals with point group 6 is proposed and established. As an application of this theory, one typical example of dislocation problem in the quasicrystals is investigated and its exact analytic solution is presented. The result obtained indicates that the stress components of elastic fields of a straight dislocation in the quasicrystals still first order singularity, which is the same as the general crystals, but are related with the Burgers vector of phason fields, which is different from the general crystals. 相似文献
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To determine the solutions of the well-known problem of a finite width strip with single edge crack,some results on elasto-plastic fracture analysis for metallic foams are reported.Meanwhile,in order to discuss and put an insight into the nonlinear fracture analysis,the Dugdale model for plastic deformation of this configuration for metallic foams is recommended and solved.Combining the asymptotic solution with the Dugdale model and elastic solution,the stress field in the plastic zone and the size of the plastic zone are expressed as analytical forms.Based on Williams expansion method,the estimate of the scale factor is also completed and analyzed.In view of these analytical solutions,the results show the scale factor is a useful parameter for the fracture theory of metallic foams. 相似文献
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This study presents the diffusive wave model, relevant dispersion law and the applications to the signal transduction of live cells, phason dynamics of quasicrystals, Brownian movement, electro-magnetic field and fluid dynamics fluctuation, respectively. The common features of these diffusive waves are summarized, which present diffusion as well as wave behaviour, or exactly speaking, they present a duality of diffusion and wave or the duality of wave and diffusion. Furthermore, the general nature of the motion is discussed from the point of view of Landau elementary excitation of condensed matter, this may lead to a concept of generalized elementary excitation (or generalized quasiparticle) corresponding to the diffusive wave. 相似文献
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准晶作为一种新的固态物质结构给传统的凝聚态物理学带来了深刻的变革 ,其弹性基本方程比传统晶体的弹性基本方程要复杂得多 .通过引入位移函数和应用Fourier分析与对偶积分方程理论圆满解决了在一个平底冲头作用下十次二维准晶材料的接触问题 ,得到了此材料接触问题应力与位移的解析表达式 .结果表明 ,如果接触位移在接触区域内为一常数 ,则垂直接触应力在接触边缘具有 - 1/ 2阶奇异性 ,这为准晶材料的接触变形提供了重要的力学量 . 相似文献
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范天佑 《中国科学E辑(英文版)》1996,(6)
A study on mathematical modelling on instability of fault is reported.The fracture mechanics and fracture dynamics as a basis of the discussion,and the method of complex variable function (including the conformal mapping and approximate conformal mapping) are employed,and some analytic solutions of the problem in closed form are found.The fault body concept is emphasized and the characteristic size of fault body is introduced.The effect of finite size of the fault body and the effect of the fault propagating speed (especially the effect of the high speed) and their influence on the fault instability are discussed.These results further explain the low-stress drop phenomena observed in earthquake source. 相似文献
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Since the quasicrystal (QC) was discovered as a new solid structure in 1984[1], many scien-tists have made a great deal of investigation into its structure[24] and the related general theory of elasticity and dislocation[5, 6]. Our team studied the mathematical theory of elasticity of QC, and simplified the complicated equations for elasticity of QC into one or a few partial differential equations of higher order. Then we solved the boundary or initial-boundary value problems of the equation… 相似文献
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泡沫金属材料可压缩塑性力学研究进展 总被引：2，自引：0，他引：2
对泡沫金属材料的连续本构模型与可压缩性塑性力学进行了评述,并介绍了根据J2流动理论得到的可压缩塑性力学的本构关系,以及该本构关系在求解泡沫金属材料平面应力裂纹缓慢扩展问题中的应用,并将所得结果与一般幂硬化材料中的相应结果进行了比较,从而在一定程度上揭示了可压缩塑性力学与经典塑性力学之间的关系. 相似文献