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1.
An analytical solution is obtained for a rotating multiferroic composite hollow cylinder made of radially polarized piezoelectric and piezomagnetic materials. Both the number of layers and the stacking sequence of the composite cylinder can be arbitrary. General mechanical, electric and magnetic boundary conditions can be applied at both the inner and outer cylindrical surfaces. The state space method is employed so that only a 2×2 matrix is involved in the whole solving procedure. In the numerical experiments, the distributions of elastic, electric as well as magnetic fields in an internally pressurized rotating BaTiO3/CoFe2O4 composite hollow cylinder subjected to different boundary conditions are presented graphically. The results clearly show that the stress fields in a multiferroic composite cylinder are controllable. 相似文献
2.
INTRODUCTION Piezoelectric symmetric structures always play an important role in the use of piezoelectric materials (Olesiak and Pyryev, 1995; Ding et al., 2003; Wu et al., 2003). To improve the durability of this kind of piezoelectric structures, functionally gradient piezo- electric materials (FGPM) have been developed and used to produce these devices such as sensors and actuators (Hauke et al., 2000; Zhu et al., 1995). For the case when a rectangular plate made of function- ally gr… 相似文献
3.
黄上恒 《商丘师范学院学报》2000,16(4):36-38
研究了同时处于机械与电学载荷之下的压电陶瓷柱体表面裂纹前缘的应力场和电位移场。求得了应力及电位移的奇异性阶数和相应的两个强度因子。 相似文献
4.
ＮＴＲＯＤＵＣＴＩＯＮＴｅｍｐｅｒａｔｕｒｅｆｉｅｌｄｃｈａｎｇｅｗｉｌｌｐｒｏｄｕｃｅｔｈｅｒ ｍａｌｓｔｒｅｓｓｅｓｉｎｓｔｒｕｃｔｕｒｅｓ.Ｉｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｄｉｆｆｅｒｅｎｔｍａｔｅｒｉａｌｓｇｅｎｅｒａｔｅｄｉｆｆｅｒｅｎｔｓｔｒｅｓｓｒｅ ｓｐｏｎｓｅｓ ,ａｎｄｔｈａｔｉｎｓｏｍｅｃａｓｅｓ,ｔｈｅｒｍａｌｓｔｒｅｓｓ ｅｓａｒｅｌａｒｇｅｅｎｏｕｇｈｔｏｃａｕｓｅｓｔｒｕｃｔｕｒｅｆａｉｌｕｒｅ .Ｓｏｉｔｉｓｍｅａｎｉｎｇｆｕｌａｎｄｉｍｐｏｒｔａｎｔｔｏｓｔｕｄｙｄｙ… 相似文献
5.
The separation of variables method was successfully used to resolve the spherically symmetric dynamic thermoelastic problem for a spherically isotropic elastic hollow sphere. Use of the integral transform can be avoided by means of this method, which is also appropriate for an arbitrary thickness hollow sphere subjected to arbitrary thermal and mechanical loads. Numerical results are presented to show the dynamic stress responses in the uniformly heated hollow spheres. 相似文献
6.
The separation of variables method was successfully, used to resolve the spherically symmetric dynamic thermoelastic problem
for a spherically isotropic elastic hollow sphere. Use of the integral transform can be avoided by means of this method, which
is also appropriate for an arbitrary thickness hollow sphere subjected to arbitrary thermal and mechanical loads. Numerical
results are presented to show the dynamic stress responses in the uniformly heated hollow spheres.
Project supported by the National Natural Science Foundation of China (Nos. 10172075, 10002016) 相似文献
7.
ＩＮＴＲＯＤＵＣＴＩＯＮＰｉｅｚｏｅｌｅｃｔｒｉｃｃｅｒａｍｉｃｍａｔｅｒｉａｌｓｈａｖｅｍａｎｙａｐｐｌｉｃａｔｉｏｎｓｉｎｍｏｄｅｒｎｔｅｃｈｎｏｌｏｇｉｅｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｐｉｅｚｏｅｌｅｃｔｒｉｃｐｒｏｐｅｒｔｉｅｓ.Ｂｕｔｃｒａｃｋｓａｒｉｓｉｎｇｆｒｏｍｔｈｅｉｒｉｎｔｒｉｎｓｉｃｂｒｉｔｔｌｅｎｅｓｓｏｆ ｔｅｎｃａｕｓｅｐｉｅｚｏｅｌｅｃｔｒｉｃｃｏｍｐｏｎｅｎｔｓｆａｉｌｕｒｅ .Ｓｔｕｄｙｏｆｗｈａｔｃａｕｓｅｓｔｈｉｓｒｅｑｕｉｒｅｓｔｈｅｏｒｅｔ… 相似文献
8.
We made a theoretical study of the carrier distribution and electromechanical fields in a free piezoelectric semiconductor rod of crystals of class 6 mm. Simple analytical expressions for the carrier distribution, electric potential, electric field, electric displacement, mechanical displacement, stress, and strain were obtained from a 1D nonlinear model reduced from the 3D equations for piezoelectric semiconductors. The distribution and fields were found to be either symmetric or antisymmetric about the center of the rod. They are qualitatively the same for electrons and holes. Numerical calculations show that the carrier distribution and the fields are relatively strong near the ends of the rod than in its central part. They are sensitive to the value of the carrier density near the ends of the rod. 相似文献
9.
In this study, Fabrikant (1989, 1991)'s new results in potential theory were used to obtain the exact and complete solution
for the problem of a penny-shaped crack in an infinite transversely isotropic piezoelectric body subjected to antisymmetric
point loads (point charges and normal point forces); then the complete solution for the problem of one-sided loading of a
penny-shaped crack was obtained by the superposition of the symmetric loading solution in Chen and Shioya (1999) and the antisymmetric
one presented here; and then the reciprocity theorem of piezoelectric media was used to deal with the problem of interaction
between arbitrarily located point forces and a point charge with a penny-shaped crack and obtained the exact expressions of
the crack faces' normal displacement in terms of elementary functions and some non-singular integrals; and finally obtained
the normal displacement of the positive and negative faces of the crack under many loading cases as shown in figures for an
infinite PZT-4 piezoelectric ceramic body weakened by a penny-shaped crack.
Project (19872060) supported by the Natural Science Foundation of China. 相似文献
10.
LAU C.W.H. LIM C.W. LEUNG A.Y.T. 《浙江大学学报(A卷英文版)》2005,6(9):962-966
INTRODUCTION Piezoelectricity is an electromechanical phe- nomenon which couples elasticity and electricity through the existence of pressure induced electrical field or electric induced stress field. The piezoelectric materials are usually surface bonded in patches or fully embedded in the host structure, so that the structure becomes a laminated piezoelectric beam. Tzou and Gadre (1989), Lee (1990), Crawly and Lazarus (1991) developed laminated plate models incorporating the piezoelect… 相似文献
11.
INTRODUCTION Piezoelectric bimorphs (or benders), a special type of piezoelectric device, which can produce flexural deformation significantly larger than the length or thickness deformation of the individual piezoelectric layers, have been widely used as elec- troacoustic transducers, medical devices and micro- robot due to their characteristics of easy miniaturiza- tion, high positioning accuracy, sensitive response, and large displacement (e.g., Shirley and Hampton, 1978; Ha and Kim, 2… 相似文献
12.
为了研究空芯光纤中氩气的放电特性,利用有限元软件 COMSOL Mutiphysics 基于流体模型对长为50mm 空芯光纤中的气体放电过程进行仿真,得到氩气放电过程中等离子体的主要参数分布,如电子密度、离子密度、电势、空间电荷密度、电场强度等。同时分析了气压对放电过程的影响,结果表明,气压对气体放电的影响主要体现在电子密度与阴极侧的电场强度上,随着气压的逐渐增大,阴极侧的电场强度也随之增加,阴极侧电子密度则保持不变,但在空芯光纤中央区域,电子密度的增大较为明显。 相似文献
13.
Based on the theories of three-dimensional elasticity and piezoelectricity, and by assuming appropriate boundary functions, we established a state equation of piezoelectric cylindrical shells. By using the transfer matrix method, we presented an analytical solution that satisfies all the arbitrary boundary conditions at boundary edges, as well as on upper and bottom surfaces. Our solution takes into account all the independent elastic and piezoelectric constants for a piezoelectric orthotropy, and satisfies continuity conditions between plies of the laminates. The principle of the present method and corresponding results can be widely used in many engineering fields and be applied to assess the effectiveness of various approximate and numerical models. 相似文献
14.
15.
INTRODUCTION For moderate thickness plate containing notches or holes, neither plane stress nor plane strain theory can describe its true deformation states (Jin and Hwang, 1989). This well known drawback has mo- tivated many analytical and numerical studies carried out to determine the effect of plate thickness on the in-plane stress distribution. Pioneering work on the along depth stress components, i.e. the K-M gener- alized plane strain theory was proposed by Kane and Mindlin (1956)… 相似文献
16.
This paper discusses the validity of (adaptive) Lagrange generalized plain finite element method (FEM) and plate element method
for accurate analysis of acoustic waves in multi-layered piezoelectric structures with tiny interfaces between metal electrodes
and surface mounted piezoelectric substrates. We have come to conclusion that the quantitative relationships between the acoustic
and electric fields in a piezoelectric structure can be accurately determined through the proposed finite element methods.
The higher-order Lagrange FEM proposed for dynamic piezoelectric computation is proved to be very accurate (prescribed relative
error 0.02%–0.04%) and a great improvement in convergence accuracy over the higher order Mindlin plate element method for
piezoelectric structural analysis due to the assumptions and corrections in the plate theories. The converged Lagrange finite
element methods are compared with the plate element methods and the computed results are in good agreement with available
exact and experimental data. The adaptive Lagrange finite element methods and a new FEA computer program developed for macro-
and micro-scale analyses are reviewed, and recently extended with great potential to high-precision nano-scale analysis in
this paper and the similarities between piezoelectric and seismic wave propagations in layered structures and plates are stressed.
Project supported by SRF for ROCS, SEM of China and partially by Zhejiang Provincial Natural Science Foundation (NSF) of China. 相似文献
17.
研究两种规则三维物体（如极长的长方体和圆柱体）横截面的温度分布,利用复势分析法得出这两种平面温度场的复势,并且数值模拟出温度的分布图像。 相似文献
18.
周兰 《喀什师范学院学报》2007,28(3):40-45
电势零点的选取有一定的任意性,但不是完全任意的,它受到一定的限制.电势零点的选取受到一定的限制并有其自身规律,电荷分布在有限区域及电荷分布扩展到无限远处时,电势零点的选择及零点选取不同时电势能否叠加、如何叠加等问题都是值得探讨的. 相似文献
19.
ＩＮＴＲＯＤＵＣＴＩＯＮＡｓｗｅｋｎｏｗ ,ｔｈｅｃｏｍｐｕｔａｔｉｏｎａｌｐｉｅｚｏｅｌｅｃｔｒｉｃｄｙｎａｍｉｃｅｑｕａｔｉｏｎｓｆｏｒｈｉｇｈｆｒｅｑｕｅｎｃｙａｃｏｕｓｔｉｃｗａｖｅｐｒｏｐａｇａｔｉｏｎｓｗｅｒｅｏｒｉｇｉｎａｌｌｙｅｘｐａｎｄｅｄｆｒｏｍｔｈｅｇｅｎｅｒａｌｃｏｍｐｕｔａｔｉｏｎａｌｓｔｒｕｃｔｕｒａｌｍｅｃｈａｎｉｃｓ,ａｎｄｔｈｅｆｉｎｉｔｅｅｌｅｍｅｎｔｍｅｔｈｏｄｓ(ＦＥＭ)ｉｎｉｔｉａｌｌｙｆｒｏｍａｅｒｏｓｐａｃｅａｎｄｃｉｖｉｌｅｎｇｉｎｅｅｒｉｎｇ .Ｔｈｅ… 相似文献
20.
The free vibration and transient wave in a prestressed Rayleigh-Timoshenko beam subject to arbitrary transverse forces are analyzed by the newly developed method of reverberation-ray matrix （MRRM）. The effects of shear deformation and rotational inertia are taken into consideration. With a Fourier transform technique, the general wave solutions with two sets of unknown amplitude coefficients are obtained in the transformed domain for an unbonded prestressed beam under the action of arbitrary external excitations. From the coupling at joints and the compatibility of displacements in each member, the free and forced vibration responses of a beam with various boundary conditions are finally evaluated through certain numerical algorithms, Results are presented for a simply-supported beam subject to either a point fixed load or moving load. Good agreement with the finite element method （FEM） is obtained. The present work is instructive for high-speed railway bridge design and structural health monitoring. 相似文献