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1.
各向异性材料界面周期刚性线夹杂的反平面问题   总被引:3,自引:1,他引:2  
刘又文 《应用数学和力学》2001,22(10):1037-1042
研究了两种各向异性材料界面含周期分布刚性线夹杂的反平面剪切问题。运用复变函数方法,获得了封闭形式解答,并给出了刚性线尖端应力场公式,从该文解答的特殊情形,可直接导出各向同性材料界面以及均匀各向异性材料中相应问题的公式,其极限情形与已有的结果吻合。  相似文献   

2.
研究了圆弧形界面刚性线夹杂的平面弹性问题.集中力作用于夹杂或基体中的任意点,并且无穷远处受均匀载荷作用.利用复变函数方法,得到了该问题的一般解答.当只含一条界面刚性线夹杂时,获得了分区复势函数和应力场的封闭形式解答,并给出刚性线端部奇异应力场的解析表达式.结果表明,在平面荷载下界面圆弧形刚性线夹杂尖端应力场和裂纹尖端相似具有奇异应力振荡性.对无穷远加载的情况,讨论了刚性线几何条件、加载条件和材料失配对端部场的影响.  相似文献   

3.
圆形界面刚性线夹杂的反平面问题   总被引:1,自引:1,他引:0  
研究了在反平面集中力和无穷远纵向剪切作用下,不同弹性材料圆形界面上有多条刚性线夹杂的问题.运用Riemann-Schwarz解析延拓技术与复势函数奇性主部分析方法,首次获得了该问题的一般解答,求出了几种典型情况的封闭解,并给出了刚性线夹杂尖端的应力场分布A·D2结果表明,在反平面加载的情况下圆形界面刚性线夹杂尖端应力具有平方根奇异性,无奇异性应力振荡;应力场与刚性线夹杂的形状,加载方式和材料性质有关.退化结果与已有的解答完全吻合.  相似文献   

4.
本文采用线场分析方法对理想弹塑性材料有限宽板中心裂纹在裂纹面上受两对反平面集中力的情形进行弹塑性分析,求得了裂纹线附近的弹塑性解析解、裂纹线上的塑性区长度随外荷载的变化规律及有限宽板具有中心裂纹的承载力·本文的分析不受小范围屈服假设的限制,并且不附加其他假设条件,其结果在裂纹线附近足够精确·  相似文献   

5.
复合材料拼接平面的周期裂纹问题   总被引:1,自引:1,他引:0  
本文考虑了由两种带周期裂纹的不同材料拼接时的问题,已知每一周期裂纹两侧相对于平动的位移(准周期的)和其上外应力的合主矢量。问题化为在周期裂纹和拼接线上的Hilbert奇异积分方程,并导出了计算应力强度因子的数学计算公式。  相似文献   

6.
易志坚  严波 《应用数学和力学》2001,22(10):1058-1066
裂纹线场分析方法目前已发展成为裂纹弹塑性分析的一种独立方法,这一方法极大地简化了裂纹弹塑性问题的复杂性和数学上的困难,可求出各型裂纹的弹塑性场在裂纹线附近足够精确的解答,但是,以前采用这一方法求解时,均是针对一些具体问题进行的,没有给出裂纹线附近弹塑性分析的一般步骤和匹配方程的一般形式。该文针对理想弹塑性I型平面应力裂纹问题,按线场分析方法,给出了裂纹线附近弹塑性分析一般步骤,并针对一具体问题,给出了求解的过程和结果。  相似文献   

7.
研究了各向异性双材料中匀速运动螺型位错与界面刚性线的干涉问题.运用Riemann Schwarz解析延拓技术与复势函数奇性主部分析方法,获得了该问题的一般弹性解答,求出了界面含一条和两条刚性线情况下的封闭形式解,并给出了刚性线尖端的应力强度因子和作用于运动位错上的像力的显式表达式.结果表明,位错速度增大可以削弱位错对应力强度因子的反屏蔽效应;位错速度越大,位错平衡点越靠近刚性线,退化结果与已有的解答完全吻合.  相似文献   

8.
本文将刚性线夹杂与弹性圆夹杂的相互作用,归为解一个标准的柯西型奇异积分方程,获得了刚性夹杂端点的应力强度因子及夹杂的界面应力.  相似文献   

9.
汪文帅  袁宏婷 《应用数学》2019,32(3):715-728
通过引入广义复变函数方法,研究含裂纹和刚性体夹杂物的反平面模型的一维正方准晶问题.对于一维正方准晶,考虑周期平面为(x_1, x_2),含有宏观裂纹或刚性线夹杂,具有准周期x_3方向的原子结构存在相位位移,本文重点研究相位位移对相关物理量的影响.利用广义复变函数方法,将这两个模型简化为Riemann-Hilbert问题,得到反平面的声子场与相位场的封闭解.同时求得声子场和相位场的应力强度因子的显式解,这在断裂力学和工程领域具有广泛的应用价值.结果表明,反平面情形下,含裂纹和刚性体夹杂物的声子和相位的应力强度因子,与声子场和相位场的耦合无关.  相似文献   

10.
研究了无穷远纵向剪切和面内电场共同作用下,压电复合材料圆形夹杂中螺型位错与界面裂纹的电弹耦合干涉作用.运用Riemann-Schwarz 对称原理,并结合复变函数奇性主部分析方法,获得了该问题的一般解答.作为典型算例,求出了界面含一条裂纹时基体和夹杂区域复势函数和电弹性场的封闭形式解.应用广义Peach-Koehler公式,导出了位错力的解析表达式.分析了裂纹几何参数和材料的电弹性常数对位错力的影响规律.结果表明,界面裂纹对位错力和位错平衡位置有很强的扰动效应,当界面裂纹长度达到临界值时,可以改变位错力的方向.该结果可以作为格林函数研究圆形夹杂内裂纹和界面裂纹的干涉效应.其公式的退化结果与已有文献完全一致.  相似文献   

11.
12.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

13.
As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years (2001-2005). The main topics are: convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.  相似文献   

14.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

15.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

16.
正Guest Editors:Hong Chen,Shanghai Jiao Tong University,Shanghai,China Guohua Wan,Shanghai Jiao Tong University,Shanghai,China David Yao,Columbia University,New York,USA Scope:Healthcare delivery worldwide has been fraught with high cost,low efficiency and poor quality of patient care service.For the field of operations research(OR),healthcare offers some of the biggest challenges as well as best opportunities in  相似文献   

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18.
In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p(R^n) into the Lebesgue space L^p with p 〈 1.  相似文献   

19.
In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.  相似文献   

20.
Due to the resolution of current laser technology, the accuracy of corneal topography as measured by the videokeratoscope is no longer adequate to provide precise enough data for refractive surgery or for the fitting of customized contact lenses. We present an algorithm for recovering corneal topography that makes use of modern differential geometric techniques and numerical descent in Sobolev spaces. We believe this algorithm may be used with the photo- and videokeratoscope to increase the accuracy of the recovered corneal topography.  相似文献   

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