共查询到19条相似文献,搜索用时 156 毫秒
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非理想界面弹性层/压电柱结构中SH波的传播特性 总被引:1,自引:0,他引:1
研究了各向同性弹性层与压电柱之间非理想连接时沿周向传播的SH波的频散特性.弹性层表面力学自由;弹性层与压电柱之间应力连续、位移间断.通过求解控制方程,将问题的解用Bessel函数表示,利用界面条件和边界条件得到频散方程,然后对其进行数值求解,分析了界面性态、材料常数和几何尺寸对SH波传播特性的影响. 相似文献
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研究了PMN-PT 压电层/弹性(金刚石) 基底结构中表面波的传播特性,压电层表面是机械自由的,电学边界条件分为电学开路和电学短路,压电层与基底之间采用理想连接. 得到了满足控制方程和边界条件的电弹场以及弹性波在结构中传播时的频散方程,通过数值算例分析了压电材料PMN-PT 的极化方向对弹性波频散曲线和机电耦合系数的影响,以及不同极化方向时弹性位移和电势随结构深度方向的变化,结果可为PMN-PT 压电材料在高频声表面波器件中的应用提供有价值的理论参考. 相似文献
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目前有关圆柱结构中的环向SH波研究仅限于实心柱体与圆柱壳体结构。由于无法直接获得圆柱洞体中传播的SH表面波的解析解,对比研究了实心柱体和多种不同类型的圆柱壳体中的环向SH波,从波结构、应变能密度幅值分布与壳体厚度的关系讨论洞体内SH表面波的存在性。建立柱坐标系下均匀弹性材料与功能梯度材料环向SH波的波动方程;分别求得方程的贝塞尔函数解和幂级数渐近解;进一步计算得到其频散曲线、波结构与应变能密度幅值。结果表明:幂级数方法可用于计算圆柱型结构中的变系数波动方程,且具有较高的精度;圆柱型结构中环向SH波的能量集中在外表面或次外表面,并随着壳体厚度的增加,能量集中现象更为明显;通过应变能密度幅值分布规律推论出圆柱洞体内表面无法传播环向SH表面波。最后,针对均质结构和梯度结构,采用反证法证明了无法得到满足洞体内SH表面波衰减条件的解析解,从而证明了该推论。 相似文献
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SH波在正交各向异性功能梯度无限长条中心裂缝处的散射 总被引:3,自引:0,他引:3
研究了正交各向异性功能梯度材料无限长条中心裂缝对SH波的散射问题,为方便起见,材料两个方向的剪切模量和密度假定为指数模型.通过Fourier积分变换,将问题转化为对偶积分方程的求解.然后,用Cop-son方法求解对偶积分方程,定义了标准动应力强度因子,通过数值算例,讨论了在SH波作用下,裂缝尖端的标准动应力强度因子与入射波的频率、材料参数之间的关系. 相似文献
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蜂窝材料的弹性波传播特性 总被引:2,自引:1,他引:1
通过研究蜂窝材料的弹性波频散关系,分析了其弹性波传播特性. 采用基于小波理论的分析方法,将材料参数和位移均展开为双正交周期小波基函数的形式,利用Bloch定理将波动方程转化为特征值方程,求解该方程得到3种典型结构------正方、三角与六角排列的铝(Al)和聚丙烯(PP)蜂窝材料的频散关系,并进行了比较分析. 结果显示:结构形式的不同显著地影响其波动特性,而制作材料的不同则没有影响;3种结构形式都不存在完全带隙,但正方和三角形结构在一定的传播方向范围内存在方向带隙,而六角形结构则在任何方向都不存在方向带隙;与正方结构相比,三角结构在相同孔隙率下,在更广的传播方向内和更低的频率下,能产生较宽的方向带隙. 相似文献
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Studied is the problem of a periodic array of cracks in a functionally graded piezoelectric strip bonded to a homogeneous piezoelectric material. The properties of the functionally graded piezoelectric strip, such as elastic modulus, piezoelectric constant and dielectric constant, are assumed in exponential forms and vary along the crack direction. The crack surface condition is assumed to be electrically impermeable or permeable. Integral transform and dislocation density functions are employed to reduce the problem to the solution of a system of singular integral equations. The effects of the periodic crack spacing, material constants and the geometry parameters on the stress intensity factor, the energy release ratio and the energy density factor are studied. 相似文献
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具有压电材料弹性环形板的屈曲 总被引:3,自引:0,他引:3
对在不同位置粘有任意多对压电片的弹性环形板在电压和径向压力作用下的轴对称屈曲进行了研究.根据压电效应的等效作用量,初参数法以及传递矩阵方法得到了环板屈曲的特征方程.对不同位置及不同宽度的压电片,计算了结构的屈曲载荷.并得到了稳定性边界曲线. 相似文献
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《Acta Mechanica Solida Sinica》2016,(5)
The velocity dispersion and attenuation of shear horizontal(SH) waves in a layered piezoelectric structure loaded with viscous liquid is studied,where the(1- x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3[PMN-xPT]single crystal is chosen as the piezoelectric layer.The PMN-xPT is being polarized along[011]_c and[001]_c so that the macroscopic symmetries are mm 2 and 4 mm,respectively.For the nonconductive liquid,the electrically open and shorted conditions at the interface between the liquid and the piezoelectric layer are considered.The phase velocity equations are derived analytically.The effects of the electrically boundary condition,the viscous coefficient and mass density of liquid as well as the thickness of the PMN-xPT layer on the phase velocity and attenuation are graphically illustrated.The results show that the phase velocity for the[011]_c polarized PMN-0.29 PT is much smaller than that for the[001]_c polarized PMN-0.33 PT,and the effects of viscous coefficient and piezoelectric layer thickness on the phase velocity for the[011]_c case are stronger than that for the[001]_c case.In addition,the electrical boundary conditions have an obvious influence on the propagation behaviors.These results can be useful for the designs and applications of acoustic wave devices and liquid biosensors. 相似文献
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Abo-el-nour N. Abd-alla Fatimah A. Alsheikh 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(9):843-857
This paper is devoted to study a problem of reflection and refraction of quasi-longitudinal waves under initial stresses at
an interface of two anisotropic piezoelectric media with different properties. One of the two media is aluminum nitride, which
is considered the down piezoelectric medium and the above medium is chosen as PZT-5H ceramics. The two piezoelectric media
welded are assumed to be anisotropic of a type of a transversely isotropic crystals (hexagonal crystal structure, class 6 mm).
The equations of motion and constitutive relations for the piezoelectric media have been written. Suitable boundary conditions
are used to obtain the reflection and refraction coefficients. For an incidence of quasi-longitudinal plane waves, four independent-type
amplitude ratios of elastic displacement components for plane waves, called quasi-longitudinal (qP) and quasi-shear vertical
(qSV) waves, are shown to exist. Also, it is observed that there exist four dependent amplitude ratios of electric potential,
which are proportional to the previous four types. Finally, it is found that the coefficients of reflection and refraction
are functions of angle of incidence, elastic constants, piezoelectric potential parameters and the initial stresses. Numerical
computations and the results obtained are depicted graphically. In the end, a particular case has been reduced from the present
study. This investigation is considered important because the initial stresses in such practical problems are inevitable and
may result in frequency shift, a change in the velocity of surface waves and controlling the selectivity of a filter compensation
of the devices. 相似文献
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A general solution and the application of space axisymmetric problem in piezoelectric material 总被引:9,自引:0,他引:9
AGENERALSOLUTIONANDTHEAPPLICATIONOFSPACEAXISYMMETRICPROBLEMINPIEZOELECTRICMATERIALWangZi-kung(王子昆)ChenGeng-chao(陈庚超)(XianJiao... 相似文献
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M. Liu 《Journal of the mechanics and physics of solids》2003,51(5):921-944
A new experimental technique for accelerated fatigue crack growth tests was recently developed (Du et al., 2001). The technique, which uses piezoelectric actuators, enables application of cyclic loading at frequencies several orders higher than that by mechanical loading. However, the validity of this technique relies on the equivalence between piezoelectric and mechanical loading. In this paper, the behavior of an interfacial crack between a piezoelectric material and an elastic material under in-plane electric loading is studied. The displacement mismatch along a bonded interface due to electric potential loading on the piezoelectric material is modeled by inserting an array of uniformly distributed dislocations along the interface. By means of Fourier transformation methods, the governing equations are converted to an integral equation, which is then converted to a standard Hilbert problem. A closed form solution for stresses, electric field, and electric displacements along the bonded interface is obtained. The results agree very well with those obtained from numerical simulations. The results show that the closed form solution is accurate not only for far field distributions of stresses and electric variables, but also for the asymptotic distributions near the crack tip. The solution also suggests the likelihood of domain switching in the piezoelectric material near the crack tip, a process that may influence the interfacial fracture resistance. 相似文献
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本文研究了含非完整界面的功能梯度压电复合材料的Ⅲ型裂纹问题.此裂纹垂直于非完整界面,采用弹簧型力电耦合界面模型模拟非完整界面.界面两侧材料的性质,如弹性模量、压电常数和介电常数均假定呈指数函数形式且沿着裂纹方向变化.运用积分变换法将裂纹面条件转换为奇异积分方程,并使用Gauss-Chebyshev方法对其进行数值求解.根据算例结果讨论了一些退化问题并分析了裂纹尖端强度因子与材料的非均匀系数和非完整界面参数的关系. 相似文献
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Spherical-symmetric steady-state response of piezoelectric spherical shell under external excitation 总被引:3,自引:0,他引:3
IntroductionWiththerapiddevelopmentofthescienceandtechnology ,moreandmorecomplexmechanismandstructuresareputintouse,suchasflexiblerobot,flexiblearm ,aircraftandspacestation .Researcherspaymoreattentiontotheproblemofeffectivedynamicdetectionandcontrolofsu… 相似文献