7次软物质准晶的裂纹扩展问题的分析

An Analysis of the Crack Problem of the Soft-matter Quasicrystals with 7-fold Symmetry

以软物质准晶的流体动力学理论为基础,讨论含Griffith中心裂纹矩形试样的7次软物质准晶的动力学裂纹扩展,采用有限差分法求解得到一些有效的数值结果 .考查裂纹尖端处应力场的时空变化规律,进而研究此处的应力强度因子随时间的变化,揭示了软物质准晶的动力学物理特性.并以7次对称软物质准晶为例验证了第二类软物质准晶的较稳定的力学性质,得出软物质准晶的裂纹扩展过程是弹性应力与流体应力竞争的结果 .同时,分析了其特有的声子-相位子耦合效应.

From the perspective of the theory of hydrodynamics of soft-matter quasicrystals,the dynamic crack propagation in soft-matter quasicrystals with 7 mm symmetry was discussed,of which is the rectangular sample with a Criffith crack in the center. The method of finite difference was applied to solve the problem and some effective numerical results were obtained. The spatial-domain variation about the stress field around the crack tip was investigated,further more the variation of the dynamics stress intensity factor versus time at this point was studied. The dynamic physical characteristics of the soft-matter quasicrystals were revealed,and the safety mechanics behavior of the second kind of soft-matter quasicrystals was checked,for which 7-fold soft-matter quasicrystals was a case,and it was concluded that the cracking process of soft-matter quasicrystals is a process of competition between action of elastic stress and fluid stress to each other. At the same time,the peculiar phonon-phason coupling effect was analyzed.