排序方式: 共有75条查询结果,搜索用时 203 毫秒
11.
The elastic analysis of a mode II Griffith crack penetrating through a decagonal quasi-crystal along the periodic axis is made within the context of the continuum theory. By using a general solution obtained previously, the problem in the case of uniform shear stress at infinity is solved, and the analytical expressions for the entire stress field disturbed by an internal crack are derived in an explicit form. The asymptotic fields of the displacement and stress around a crack tip in both phonon and phason fields indicate that the stresses near a crack tip exhibit the square-root singularity. The formula for evaluating the energy release rate is also given. If imposing that the phason field is absent, the well-known results of a mode II crack in a conventional material are recovered from the present results. 相似文献
12.
13.
14.
Plastic analysis of the crack problem in two-dimensional decagonal Al-Ni-Co quasicrystalline materials of point group 10,■
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The fundamental plastic nature of the quasicrystalline materials remains an open problem due to its essential complicacy.By developing the proposed generalized cohesive force model,the plastic deformation of crack in point group 10,10 decagonal quasicrystals is analysed strictly and systematically.The crack tip opening displacement(CTOD) and the size of the plastic zone around the crack tip are determined exactly.The quantity of the crack tip opening displacement can be used as a parameter of nonlinear fracture mechanics of quasicrystalline material.In addition,the present work may provide a way for the plastic analysis of quasicrystals. 相似文献
15.
16.
IntroductionItisshownbyavailabletheoriesandexperiments[1]thaticosahedralsymmetryquasicrystalexistinginA1_Mnalloyis 3Dquasicrystal,ithasnotsymmetryinanydimensionsin 3Dspace ;Thesocalled 2Dquasicrystalsarethattheyhavetranslationalperiodicityinonespacedirecti… 相似文献
17.
应用应力函数法,求解了二维十次对称准晶中的Ⅱ型Griffith裂纹问题。特点是把二维准晶的弹性力学问题分解成一个平面应变问题与一个反平面问题的叠加,通过引入应力函数,把平面应变问题的十八个弹性力学基本方程简化成一个八阶偏微分方程,并且求出了其在Ⅱ型Griffith裂纹情况的混合边值问题的解,所有的应力分量和位移分量都用初等函数表示出来,并且由此得出了准晶中Ⅱ型Griffith裂纹问题的应力强度因子和能量释放率。 相似文献
18.
19.
IntroductionQuasicrystalasanewstructureofsolidmatter[1,2 ]bringsprofoundnewideastothetraditionalcondensedmatterphysicsandencouragesconsiderabletheoreticalandexperimentalstudiesonthephysicalandmechanicalpropertiesofthematerial,includingtheelasticitytheoryofthequasicrystal,manyvaluableresultsweregiven[3~ 5 ].Defectsinthematerialwereobservedsoonafterthediscoveryofthequasicrystal[6 ,7].Cracksareonetypeofdefects,theirexistencegreatlyinfluencesthephysicalandmechanicalpropertiesofthequasicrystalinem… 相似文献
20.
压电陶瓷带形中Ⅲ型裂纹的精确分析解 总被引:8,自引:0,他引:8
分析无限长压电带形中的Ⅲ型裂纹问题,主要讨论了在带形边界受四种机电组合载荷情况下裂纹位于带形中平面上的情形。通过积分变换,与其相的复合边值问题分别转化为对偶积分方程组,使用对偶积分方程的熟知结果,获得了裂纹线上电弹性场的明显的解析表达式及在裂尖处一些量的强度因子和能量释放率公式。与已知的近似解比较,所得结果是以封闭形式给出的精确解。 相似文献