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HIGHER ORDER ASYMPTOTIC FIELDS AT THE TIP OF A SHARP V-NOTCH IN A POWER-HARDENING MATERIAL

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Acta Mechanica Solida Sinica 2002年第2期15卷 102-110页

作者： Wang Weiwei kuang zhenbang Shanghai Jiao Tong Univ Dept Engn Mech Shanghai 200240 Peoples R China

The higher order asymptotic fields at the tip of a sharp V-notchin a power-hardening material for plane strain problem of Mode I arederived. The order hierarchy in powers of r for various hardeningexponents n and notch angles β is obtained. The angulardistributions of stress for several cases are plotted. Theself-similarity behavior between the higher order terms is *** is found that the terms with higher Order can be neglected for theV-notch angle β>45°.

关键词： asymptotic V-notch higher order terms power-hardening

CYCLIC DEFORMATION BEHAVIOR OF ZIRCALOY-4 AT DIFFERENT TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 219-225页

作者： XIAO Lin GU Haicheng kuang zhenbang(Xi’an Jiaotong University, China Xi'an Jiaotong Univ Xi'an China

Fatigue lifetime curves of Zircaloy-4 at different temperatures were measured, and the fatigued dislocation configurations were investigated using transmission electron microscopy. Ii was found that prismatic slip is the primary deformation mode. for Zircaloy-4fatigued at RT prismatic plus Pyramidal slip at 400℃,and prismatic plus (0001) basic slip at 600℃. The corresponding dislocation configurations are parallel dislocation lines al RT, elongated cells at 400℃ and two sets of mutually Perpendicular dislocation bands at 600℃.respectively. The relationship among. fatigue deformation mode, dislocation configuration and lifetime is discussed.

关键词： Zircaloy-4,.fatigue dislocation configuration slip system

Some variational principles in electroelastic media under finite deformation

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Science China(Physics,Mechanics & Astronomy) 2008年第9期51卷 1390-1402页

作者： kuang zhenbang Department of Engineering Mechanics,Shanghai Jiaotong University,Shanghai 200240,China Department of Engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

It is proposed that the universal thermodynamic energy variational principle is in-cluded in the first law of thermodynamics. Some variational principles in the elec-troelastic media under finite deformation are derived from this universal thermo-dynamic variational principle. It is suggested that in the general electroelastic analysis the environment should be considered together with the discussed elec-troelastic medium. For the variational principle of nonlinear electroelastic media the variation of the electric potential is coupled with the virtual displacement,and the variation of the initial volume should be considered. The Maxwell stress in the initial configuration is naturally derived from this variational principle and it is unique in the second order precision.

关键词： first law of thermodynamics variational principle the electroelastic media the governing equation

PROPAGATION OF SURFACE ACOUSTIC WAVES IN PRESTRESSED ANISOTROPIC LAYERED PIEZOELECTRIC STRUCTURES

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Acta Mechanica Solida Sinica 2003年第1期16卷 16-23页

作者： Liu Hua kuang zhenbang Cai Zhengming Wang Tiejun Wang Zikun Department of Engineering Mechanics Shanghai Jiaotong UniversityShanghai 200240China Department of Engineering Mechanics Xi’an Jiaotong UniversityXi’an 710048China

The propagation of surface acoustic waves in layered piezoelectric structureswith initial stresses is investigated. The phase velocity equations are obtained for electricallyfree and shorted cases, respectively. Effects of the initial stresses on the phase velocity and theelectromechanical coupling coefficient for the fundamental mode of the layered piezoelectricstructures are discussed. Numerical results for the c-axis oriented film of LiNbO_3 on a sapphiresubstrate are given. It is found that the fractional change in phase velocity is a linear functionwith the initial stresses, and the electromechanical coupling factor increases with an increase ofthe absolute values of the compressive initial stresses. The results are useful for the design ofsurface acoustic wave devices.

关键词： surface acoustic waves layered piezoelectric structure phase velocity electromechanical coupling coefficient

Finite Eement Facture Aalysis of the Main Arm of Tower Cranes with the 3-D Cracks

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上海交通大学学报 2004年第Z2期38卷 171-175页

作者： Zongjie Cao zhenbang kuang Changping Li Department of Engineering Mechanics Shanghai Jiaotong University Shanghai200240 China Department of Mechanical Engineering Aeronautic University of Air ForceChangchun 130022 China Department of Engineering Mechanics Shanghai Jiaotong University Shanghai200240 China Department of Mechanical Engineering Aeronautic University of Air ForceChangchun 130022 China

In this paper the local solutions of displacement fields in front of three-dimensional cracks are introduced and a new singular element of three-dimensional crack problems is constructed, and a new method for calculating stress intensity factors of three-dimensional crack problems is presented. With the present method, the structural strength of with longitudinal closed cracks under axial tensions is analyzed. It is possible for the crack to propagate because there are ring tensile stresses near joints of the main arm in tower cranes under axial press stresses. The stress and the stress intensity factor are calculated at joints on the main arm of tower cranes. Influences of welding residual stress on stress intensity factors and stresses are discussed.

关键词： stress intensity factor residual stress singular finite element crack

A MIXED ELECTRIC BOUNDARY VALUE PROBLEM FOR AN ANTI-PLANE PIEZOELECTRIC CRACK

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Acta Mechanica Solida Sinica 2003年第2期16卷 110-115页

作者： Huang Zhenyu kuang zhenbang (Department of Engineering Mechanics,Shanghai JiaotongUniversity,Shanghai 200240,China) Department of Engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

The analytical continuation method is adopted to solve a mixed electric boundary value problem for a piezoelectric medium under anti-plane *** crack face is partly conductive and partly *** results show that the stress intensity factor is identical with the mode Ⅲ stress intensity factor independent of the conducting *** the electric field and the electric displacement are dependent on the electric boundary conditions on the crack faces and are singular not only at the crack tips but also at the junctures between the impermeable part and conducting portions.

关键词： piezoelectric medium fracture mechanics mixed boundary value problem

FRACTAL ANALYSIS OF FRACTURE SURFACE OF WELDED JOINT UNDER LOW CYCLE FATIGUE

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Acta Metallurgica Sinica(English Letters) 1993年第3期6卷 172-178页

作者： NI Yushan CHENG Guangxu kuang zhenbang Xi’an Jiaotong University,China doctorate student,Institute of Engineering Mechanics,Xi’an Jiaotong University,Xi’an 710049,China Xi'an Jiaotong Univ Xi'an China

Hausdorff dimension of fracture surface roughness of welded joint,both welding metal and heat-affected *** pressure vessel steel 16MnR,tested under strain-controlled low-cycle fatigue,was examined with computer vision srstem and by two-dimensional variation method. Results show that it decreases with the increase of cyclic hysteresis *** Hausdorff di- mension variation at heat-affected zone is greater than that of weld *** is believed that the greater the fractal dimension is,the longer the fatigue life will be.

关键词： welded joint low-cycle fatigue fractograph Hausdorff dimension

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波在双孔隙与单孔隙介质界面上的反射与透射

力学学报 2006年第3期38卷 330-338页

作者：代智军赵社戌匡震邦上海交通大学工程力学系上海200240

基于Biot理论和双重孔隙介质理论研究了弹性波在双重孔隙介质与流体饱和单一孔隙介质界面的反射和透射问题,在界面上假定裂缝孔隙流体相对于固体骨架的位移为零,推导了反射系数和透射系数的计算公式,数值讨论了反射系数和透射系数随入... 详细信息

基于Biot理论和双重孔隙介质理论研究了弹性波在双重孔隙介质与流体饱和单一孔隙介质界面的反射和透射问题,在界面上假定裂缝孔隙流体相对于固体骨架的位移为零,推导了反射系数和透射系数的计算公式,数值讨论了反射系数和透射系数随入射角和频率的变化关系．同时,讨论了双重孔隙介质中3种压缩波 (P-1,P-2和P-3波)和一种剪切波(S波)的频散和衰减特性．

关键词：双重孔隙介质频散衰减反射和透射

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考虑路径相关性的非比例循环塑性本构模型

力学学报 1999年第4期31卷 484-492页

作者：赵社戌匡震邦华侨大学土木工程系泉州362011 上海交通大学工程力学系上海200240

根据非比例加载下金属材料响应的延迟特性及加载路径相关性，选取沿应力迹法向的塑性应变的累积量作为非比例加载影响的度量，相应给出反映非比例附加强化的变量，并假设其模量和强化率与加载路径的几何参数相关．为反映由于非比例加载... 详细信息

根据非比例加载下金属材料响应的延迟特性及加载路径相关性，选取沿应力迹法向的塑性应变的累积量作为非比例加载影响的度量，相应给出反映非比例附加强化的变量，并假设其模量和强化率与加载路径的几何参数相关．为反映由于非比例加载而引起的材料强化的异向效应，在Valanis的塑性内时响应方程中引入与加载路径几何性质有关的应力项，构成非比例循环塑性本构关系．对316和304不锈钢材料在一些典型非比例循环加载路径下的应力响应进行了理论预测，与Benallal等及McDowell的实验结果取得了良好的一致．

关键词：非比例循环加载路径相关性塑性本构关系