共查询到18条相似文献,搜索用时 147 毫秒
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折线型裂纹对SH波的动力响应 总被引:1,自引:0,他引:1
利用Fourier积分变换方法,得出了无限平面中用裂纹位错密度函数表示的单裂纹散射场.根据无穷积分的性质,把单裂纹的散射场分解为奇异部分和有界部分.利用单裂纹的散射场建立了折线裂纹在SH波作用下的Cauchy型奇异积分方程.根据折线裂纹散射场和所得的积分方程讨论了裂纹在折点处的奇性应力及折点处的奇性应力指数.利用所得的奇性应力定义了折点处的应力强度因子.对所得Cauchy型奇积分方程的数值求解,可得裂纹端点和折点处的动应力强度因子。 相似文献
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反平面圆形夹杂和多圆孔多裂纹相互作用问题 总被引:3,自引:0,他引:3
动用复变函数及积分方法方法求解了反平面圆形夹杂和多圆孔多裂纹相互作用问题。为解决该问题,建立了两种类型的基本解。利用叠加原理和所得的基本解没圆孔和裂纹表面取待定的基本解密度函数,可得一组Fredholm积分方程,通过积分方程组的数值求解,可以得到密度函数的离散值,进而得到应力强度因子。 相似文献
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具周期裂纹的半平面周期接触问题的奇异积分方程数值解法 总被引:1,自引:0,他引:1
运用Hilbert核的奇异积分方程的数值解法研究具任意形状裂纹的各向同性弹性半平面在周期压头作用下的周期接触问题,将所考虑问题转化为第一型或第二型的奇异积分方程组.最后给出带垂直裂纹的半平面在光滑平底压头作用下的数值结果.令α→∞时,就得到非周期经典结果. 相似文献
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基于线性压电理论,本文获得了含有中心反平面裂纹的矩形压电体中的奇异应力和电场。利用Fourier积分变换和Fourier正弦级数将电绝缘型裂纹问题化为对偶积分方程,并进一步归结为易于求解的第二类Fred-holm积分方程。获得了裂纹尖端应力、应变、电位移和电场的解析解,求得了裂纹尖端场的强度因子及能量释放率。分析了压电矩形体的几何尺寸对它们的影响。结果表明,对于电绝缘型裂纹,裂纹尖端附近的各个场变量都具有-1/2阶的奇异性,能量释放率与电荷载的方向及大小有关,并且有可能为负值。 相似文献
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剪切波作用下埋藏刚性椭圆柱与周围介质部分脱胶时的动力分析 总被引:1,自引:0,他引:1
本文利用波函数展开法和奇异积分方程技术研究了SH型反平面剪切波作用下埋藏刚性椭圆柱与周围介质部分脱胶时的动力特性.将脱胶区看作表面不相接触的椭圆弧形界面裂纹,利用波函数(Mathieu函数)展开法,并引人裂纹面的位错密度函数为未知量,将问题归结为奇异积分方程,通过数值求解积分方程获得了远场和近场物理参量,并讨论了共振特性和各参数对共振的影响. 相似文献
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圆形域多圆孔多裂纹反平面问题研究 总被引:3,自引:0,他引:3
本文运用复变函数及积分方程方法,求解了圆形域多圆孔多裂纹反平面问题,建立了两种类型的基本解。复叠加原理和所得的基本解并沿国圆孔和裂纹表面取待定的基本解密度函数,可得到一组以基本解密度函数为未知函数的Fredholm积分方程。通过该积分方程组的数值可以得到密度函数的离散值,进而得到了裂纹尖端的应力强度因子。 相似文献
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In the present paper dynamic stress intensity factor and strain energy density factor of multiple cracks in the functionally graded orthotropic half-plane under time-harmonic loading are investigated. By utilizing the Fourier transformation technique the stress fields are obtained for a functionally graded orthotropic half-plane containing a Volterra screw dislocation. The variations of the material properties are assumed to be exponential forms which the equilibrium has an analytical solution. The dislocation solution is utilized to formulate integral equation for the half-plane weakened by multiple smooth cracks under anti-plane deformation. The integral equations are of Cauchy singular type at the location of dislocation which are solved numerically to obtain the dislocation density on the faces of the cracks. The dislocation densities are employed to determined stress intensity factor and strain energy density factors (SEDFs) for multiple smooth cracks under anti-plane deformation. Numerical examples are provided to show the effects of material properties and the crack configuration on the dynamic stress intensity factors and SEDFs of the functionally graded orthotropic half-plane with multiple curved cracks. 相似文献
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The two-dimensional thermoelastic crack problem in bonded dissimilar media or in a half-plane medium is considered. The proposed method for solving this problem consists of two parts. In the first part, complex potential functions are derived which are enforced to satisfy the continuity conditions across the interface, while the second part consists of the derivation of singular integral equations by introducing the dislocation functions along the crack border which are solved numerically. For both half-plane and two bonded half-plane problems associated with an insulated crack, the thermal stress intensity factors are computed numerically by using the appropriate interpolation formulae. The results compared with those of the homogeneous case given in the literature show that the method proposed here is effective, simple and general. 相似文献
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The interaction of a general plane P wave and an elastic cylindrical inclusion of infinite length partially debonded from
its surrounding viscoelastic matrix of infinite extension is investigated. The debonded region is modeled as an arc-shaped
interface crack between inclusion and matrix with non-contacting faces. With wave functions expansion and singular integral
equation technique, the interaction problem is reduced to a set of simultaneous singular integral equations of crack dislocation
density function. By analysis of the fundamental solution of the singular integral equation, it is found that dynamic stress
field at the crack tip is oscillatory singular, which is related to the frequency of incident wave. The singular integral
equations are solved numerically, and the crack open displacement and dynamic stress intensity factor are evaluated for various
incident angles and frequencies.
The project supported by the National Natural Science Foundation of China (19872002) and Climbing Foundation of Northern Jiaotong
University 相似文献
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The stress fields are obtained for a functionally graded half-plane containing a Volterra screw dislocation.The elastic shear modulus of the medium is considered to vary exponentially.The dislocation s... 相似文献
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The strain energy density theory is used to determine the direction of crack propagation in the case of an inclined crack in a half-plane thermopiezoelectric sheet subjected to uniform heat flow. Based on the Stroh's formulation and the thermoelectroelastic Green's function, a system of singular integral equations for the unknown thermal analog of dislocation density defined on the crack faces is presented and used to calculate the corresponding strain energy density. The direction of crack extension is then determined by way of the minimum strain energy density criterion. The study shows that the criterion is easy-to-use for thermal fracture problems. 相似文献
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A. A. Hejazi M. Ayatollahi R. Bagheri M. M. Monfared 《Archive of Applied Mechanics (Ingenieur Archiv)》2014,84(1):95-107
In this study, the transient response of multiple cracks subjected to shear impact load in a half-plane is investigated. At first, exact analytical solution for the transient response of Volterra-type dislocation in a half-plane is obtained by using the Cagniard-de Hoop method of Laplace inversion and is expressed in explicit forms. The distributed dislocation technique is used to construct integral equations for a half-plane weakened by multiple arbitrary cracks. These equations are of Cauchy singular type at the location of dislocation solved numerically to obtain the dislocation density on the cracks faces. The dislocation densities are employed to determine dynamic stress intensity factors history for multiple smooth cracks. Finally, several examples are presented to demonstrate the applicability of the proposed solution. 相似文献
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Qin Qinghua 《Acta Mechanica Sinica》1998,14(4):339-352
A solution is presented for a class of two-dimensional electroelastic branched crack problems. Explicit Green's function for
an interface crack subject to an edge dislocation is developed using the extended Stroh formulation allowing the branched
crack problem to be expressed in terms of coupled singular integral equations. The integral equations are obtained by the
method that models a kink as a continuous distribution of edge dislocations, and the dislocation density function is defined
on the line of the branch crack only. Competition between crack extension along the interface and kinking into the substrate
is investigated using the integral equations and the maximum energy release rate criterion. Numerical results are presented
to show the effect of electric field on the path of crack extension.
The work was supported by the Australian Research Council through a Queen Elizabeth II fellowship and by the Australian Academy
of Science through the J.G. Russell Award. 相似文献
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《International Journal of Solids and Structures》2007,44(5):1608-1627
The stress fields in an orthotropic half-plane containing Volterra type climb and glide edge dislocations under plane stress condition are derived. The dislocation solutions are utilized to formulate integral equations for dislocation density functions on the surface of smooth cracks embedded in the half-plane under in-plane loads. The integral equations are of Cauchy singular type which are solved numerically. The dislocation density functions are employed to evaluate modes I and II stress intensity factors for multiple cracks with different configurations. 相似文献