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压电双材料界面钝裂纹附近螺型位错的屏蔽效应与发射条件

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固体力学学报 2011年第6期32卷 574-580页

作者：宋豪鹏高存法南京航空航天大学航空宇航学院南京210016

研究了压电双材料界面钝裂纹附近螺型位错的屏蔽效应与发射条件.应用保角变换技术,得到了复势函数与应力场的封闭形式解,讨论了位错方位、双材料电弹常数及裂纹钝化程度对位错屏蔽效应和发射条件的影响.结果表明,Burgers矢量为正的螺型... 详细信息

研究了压电双材料界面钝裂纹附近螺型位错的屏蔽效应与发射条件.应用保角变换技术,得到了复势函数与应力场的封闭形式解,讨论了位错方位、双材料电弹常数及裂纹钝化程度对位错屏蔽效应和发射条件的影响.结果表明,Burgers矢量为正的螺型位错可以降低界面钝裂纹尖端的应力强度因子(屏蔽效应),屏蔽效应随位错方位角及位错与裂纹尖端距离的增大而减弱,压电双材料中螺型位错对裂纹的屏蔽效应强于相应弹性双材料中螺型位错对裂纹的屏蔽效应;位错发射所需的临界无穷远加载或电位移随位错方位角及裂纹钝化程度的增加而增大;最可能的位错发射角度为零度即位错最可能沿裂纹前方发射.论文解答的特殊情况与已有文献一致.

关键词：螺型位错压电双材料界面钝裂纹屏蔽效应位错发射

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螺型位错偶极子与界面钝裂纹的干涉效应

应用力学学报 2011年第1期28卷 50-54,109页

作者：徐政坤宋豪鹏张家界航空工业职业技术学院张家界427000 湖南大学长沙410082

研究了螺型位错偶极子与界面钝裂纹的干涉效应。应用保角变换技术,得到了复势函数与应力场的封闭解析解,讨论了位错偶极子方位、臂长及裂纹钝化程度对位错偶极子屏蔽效应和发射条件的影响。结果表明,与单个螺型位错不同,螺型位错偶极子... 详细信息

研究了螺型位错偶极子与界面钝裂纹的干涉效应。应用保角变换技术,得到了复势函数与应力场的封闭解析解,讨论了位错偶极子方位、臂长及裂纹钝化程度对位错偶极子屏蔽效应和发射条件的影响。结果表明,与单个螺型位错不同,螺型位错偶极子与x轴夹角在一定范围内时才可以降低界面钝裂纹尖端的应力强度因子(屏蔽效应),屏蔽效应随偶极子臂长的增大而增强,随裂纹钝化程度的增大而增强,屏蔽区域也随裂纹钝化程度的增大而增大;位错偶极子发射所需的临界无穷远加载随偶极子臂长的增加而减小,随位错方位角及裂纹钝化程度的增加而增大;最可能的位错偶极子发射角度为0。螺型位错偶极子的发射比单个螺型位错的发射要困难。本文解答的特殊情况与相关文献给出的解答一致。

关键词：螺型位错偶极子界面钝裂纹保角变换屏蔽效应发射条件

The solution of a wedge disclination dipole interacting with an annular inclusion and the force acting on the disclination dipole

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Chinese Physics B 2008年第12期17卷 4592-4598页

作者：宋豪鹏方棋洪刘又文 College of Mechanics and Aerospace Hunan University

The interaction between a wedge disclination dipole and an elastic annular inclusion is investigated. Utilizing the Muskhelishvili complex variable method, the explicit series form solutions of the complex potentials in the matrix and the inclusion region are derived. The image force acting on the disclination dipole centre is also calculated. The influence of the location of the disclination dipole and the thickness of the annular inclusion as well as the elastic dissimilarity of materials upon the equilibrium position of the disclination dipole is discussed in detail. The results show that a stable equilibrium point of the disclination dipole near the inclusion is found for certain combinations of material constant. Moreover, the force on the disclination dipole is strongly affected by the position of the disclination dipole and the thickness of annular inclusion. The repulsion force increases （or the attraction force reduces） with the increase of the thickness of the annular inclusion. An appropriate critical value of the thickness of the annular inclusion may be found to change the direction of the force on the disclination dipole. The present solutions include previous results as special eases.

关键词： wedge disclination dipole annular inclusion image force

Shielding effect and emission criterion of a screw dislocation near an interfacial blunt crack

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Chinese Physics B 2009年第4期18卷 1564-1569页

作者：宋豪鹏方棋洪刘又文 College of Mechanics and Aerospace Hunan University

Shielding effect and emission criterion of a screw dislocation near an interracial blunt crack are dealt with in this paper. Utilizing the conformal mapping technique, the closed-form solutions are derived for complex potentials and stress fields due to a screw dislocation located near the interracial blunt crack. The stress intensity factor on the crack tips and the critical stress intensity factor for dislocation emission are also calculated. The influence of the orientation of the dislocation and the morphology of the blunt crack as well as the material elastic dissimilarity on the shielding effect and the emission criterion is discussed in detail. The results show that positive screw dislocations can reduce the stress intensity factor of the interfacial blunt crack tip （shielding effect）. The shielding effect increases with the increase of the shear modulus of the lower half-plane, but it decreases with the increase of the dislocation azimuth angle. The critical loads at infinity for dislocation emission increases with the increase of emission angle and curvature radius of blunt crack tip, and the most probable angle for screw dislocation emission is zero. The present solutions contain previous results as special cases.

关键词： screw dislocation interracial blunt crack shielding effect emission criterion

Elastic behaviour of an edge dislocation near a sharp crack emanating from a semi-elliptical blunt crack

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Chinese Physics B 2010年第1期19卷 409-416页

作者：方棋洪宋豪鹏刘又文 College of Mechanics and Aerospace Hunan University

The interaction between an edge dislocation and a crack emanating from a senti-elliptic hole is dealt with. Utilizing the complex variable method, closed form solutions are derived for complex potentials and stress fields. The stress intensity factor at the tip of the crack and the image force acting on the edge dislocation are also calculated. The influence of the morphology of the blunt crack and the position of the edge dislocation on the shielding effect to the crack and the image force is examined in detail. The results indicate that the shielding or anti-shielding effect to the stress intensity factor increases acutely when the dislocation approaches the tip of the crack. The effect of the morphology of the blunt crack on the stress intensity factor of the crack and the image force is very significant.

关键词： edge dislocation blunt crack shielding effect image force

纵向剪切下含共焦椭圆孔椭圆夹杂中压电螺位错的干涉效应

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中南林业科技大学学报 2011年第2期31卷 115-121页

作者：余敏刘又文宋豪鹏中南林业科技大学流变力学与材料工程研究所湖南长沙410004 湖南大学机械与运载工程学院湖南长沙410082

研究了无穷远纵向剪切和面内电势共同作用下压电螺型位错与含共焦椭圆孔椭圆夹杂的电弹干涉问题。运用复变函数的分区全纯理论、柯西型积分、应力函数奇性主部分析方法与Rieman边值理论,获得了位错位于基体区域时应力场的级数形式精确解... 详细信息

研究了无穷远纵向剪切和面内电势共同作用下压电螺型位错与含共焦椭圆孔椭圆夹杂的电弹干涉问题。运用复变函数的分区全纯理论、柯西型积分、应力函数奇性主部分析方法与Rieman边值理论,获得了位错位于基体区域时应力场的级数形式精确解,讨论了夹杂内部孔洞和裂纹对基体内位错干涉的扰动规律,并由此导出了位错像力以及应力强度因子(SIF)和电位移强度因子(EDIF)的解析表达式。定量分析结果表明:夹杂内部的椭圆孔对位错与夹杂的干涉起了扰动作用,明显增强了软夹杂对位错的吸引作用,降低了硬夹杂对位错的排斥作用。椭圆夹杂的形状对位错与夹杂的干涉也有着不可忽视的影响,随着椭圆夹杂曲率的增大,对位错的吸引或排斥力增大。基体中的位错对软夹杂中的钝裂纹具有反屏蔽效应,而对硬夹杂中的钝裂纹具有屏蔽效应。

关键词：压电螺位错椭圆夹杂共焦椭圆孔复变函数方法位错力应力强度因子

Behavior of an Extended Dislocation near an Elliptical Blunt Crack

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Chinese Physics Letters 2009年第9期26卷 196-199页

作者：宋豪鹏方棋洪刘又文 College of Mechanics and Aerospace Hunan University Changsha 410082

一个椭圆的钝裂缝附近的扩大脱臼的行为被调查。在 Shockley partials 和由分离反应以及扩大脱臼排放标准为扩大脱臼的形成叠差错精力的批评价值之间的平衡分离被开发。当扩大脱臼趋于到钝裂缝，结果证明平衡分离增加。如果叠的差错精... 详细信息

一个椭圆的钝裂缝附近的扩大脱臼的行为被调查。在 Shockley partials 和由分离反应以及扩大脱臼排放标准为扩大脱臼的形成叠差错精力的批评价值之间的平衡分离被开发。当扩大脱臼趋于到钝裂缝，结果证明平衡分离增加。如果叠的差错精力比得上为在完美的媒介的分离的批评精力，完全的脱臼能分裂在钝裂缝附近形成扩大脱臼。为扩大脱臼排放的批评压力紧张因素(SIF ) 与叠的差错精力和钝裂缝尖端的弯曲半径增加。而且，为扩大脱臼排放的批评 SIF 是比为边脱臼排放的批评 SIF 远低的。

关键词：裂纹扩展临界应力强度因子椭圆行为扩展位错位错发射分解反应曲率半径

螺型位错与含共焦裂纹弹性椭圆夹杂的干涉效应

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湖南大学学报（自然科学版） 2007年第9期34卷 62-66页

作者：刘又文宋豪鹏方棋洪湖南大学力学与航空航天学院湖南长沙410082

研究了基体与夹杂中任意位置螺型位错与含共焦裂纹弹性椭圆夹杂的干涉问题,运用复变函数的分区全纯理论、柯西型积分、应力函数奇性主部分析方法与Rieman边值理论,将问题归结为一个初等复势函数方程的求解.获得了基体与夹杂区域复势函... 详细信息

研究了基体与夹杂中任意位置螺型位错与含共焦裂纹弹性椭圆夹杂的干涉问题,运用复变函数的分区全纯理论、柯西型积分、应力函数奇性主部分析方法与Rieman边值理论,将问题归结为一个初等复势函数方程的求解.获得了基体与夹杂区域复势函数的级数形式精确解,导出了裂纹尖端应力强度因子解析表达式和作用于位错的像力公式.计算结果表明:夹杂中的裂纹对于位错与夹杂的干涉具有强烈的扰动效应,它增强软夹杂对位错的吸引,减弱硬夹杂对位错的排斥,甚至将排斥转变为吸引.裂纹尖端附近的应力强度因子等值线表明,螺型位错位于裂纹尖端附近特定区域时对于裂纹扩展具有屏蔽效应.

关键词：应力强度因子含共焦裂纹弹性椭圆夹杂螺型位错位错力

Shielding effect of a nano-circular inclusion acting on semi-infinite wedge cracks

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Chinese Physics B 2013年第1期22卷 421-425页

作者：宋豪鹏高存法 College of Aerospace Engineering State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics & Astronautics

The model of a screw dislocation near a semi-infinite wedge crack tip inside a nano-circular inclusion is proposed to investigate the shielding effect of nano inclusions acting on cracks. Utilizing the complex function method, the closed-form solutions of the stress fields in the matrix and the inclusion region are derived. The stress intensity factor, the image force, as well as the critical loads for dislocation emission are discussed in detail. The results show that the nano inclusion not only enhances the shielding effect exerted by the dislocation, but also provides a shielding effect itself. Moreover, dislocations may be trapped in the nano inclusion even if the matrix is softer than the inclusion. This helps the dislocation shield crack, and reduces the dislocation density within the matrix.

关键词： screw dislocation wedge crack nano inclusion shielding effect