共查询到19条相似文献，搜索用时 595 毫秒
1.
CHEN Jiang-ying CHEN Wei-qiu 《浙江大学学报(A卷英文版)》2007,8(7):1038-1043
The analytical solution for an annular plate rotating at a constant angular velocity is derived by means of direct displacement method from the elasticity equations for axisymmetric problems of functionally graded transversely isotropic media. The displacement components are assumed as a linear combination of certain explicit functions of the radial coordinate, with seven undetermined coefficients being functions of the axial coordinate z. Seven equations governing these z-dependent functions are derived and solved by a progressive integrating scheme. The present solution can be degenerated into the solution of a rotating isotropic functionally graded annular plate. The solution also can be degenerated into that for transversely isotropic or isotropic homogeneous materials. Finally, a special case is considered and the effect of the material gradient index on the elastic field is illustrated numerically. 相似文献
2.
Application of Hamiltonian system for two-dimensional transversely isotropic piezoelectric media 总被引：2，自引：2，他引：2
INTRODUCTION The traditional method of solving solutions of the transversely isotropic piezoelectric media belongs to Lagrange formulation so that the method of sepa- ration of variables cannot be applied due to the in- volvement of high order partial differentiation in the Euclidian space and is difficult for some problems. New theoretical system or method is a key for the investigation of piezoelectric materials. Since the foundational equations (Sosa and Pak, 1990) in transversely iso… 相似文献
3.
The normal hypervelocity impact of an Al-thin plate by an Al-sphere was numerically simulated by using the adaptive smoothed particle hydrodynamics (ASPH) method. In this method, the isotropic smoothing algorithm of standard SPH is replaced with anisotropic smoothing involving ellipsoidal kernels whose axes evolve automatically to follow the mean particle spacing as it varies in time, space, and direction around each particle. Using the ASPH, the anisotropic volume changes under strong shock condition are captured more accurately and clearly. The sophisticated features of meshless and Lagrangian nature inherent in the SPH method are kept for treating large deformations, large inhomogeneities and tracing free surfaces in the extremely transient impact process. A two-dimensional ASPH program is coded with C . The developed hydrocode is examined for example problems of hypervelocity impacts of solid materials. The results obtained from the numerical simulation are compared with available experimental ones. Good agreement is observed. 相似文献
4.
The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises＇ equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 （thin plates） and as low as 2 （very thick plates）. Results are obtained via several 2D plate models. Classical theories （CTs） and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories （HOTs） HOTsa models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed： by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized loadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution. 相似文献
5.
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
6.
QIANG Hongfu MENG Lijun 《天津大学学报(英文版)》2006,12(B09):75-78
The normal hypervelocity impact of an Al-thin plate by an Al-sphere was numerically simulated by using the adaptive smoothed particle hydrodynamics （ASPH） method. In this method, the isotropic smoothing algorithm of standard SPH is replaced with anisotropic smoothing involving ellipsoidal kernels whose axes evolve automatically to follow the mean particle spacing as it varies in time, space, and direction around each particle. Using the ASPH, the anisotropic volume changes under strong shock condition are captured more accurately and clearly. The sophisticated features of meshless and Lagrangian nature inherent in the SPH method are kept for treating large deformations, large inhomogeneities and tracing free surfaces in the extremely transient impact process. A two-dimensional ASPH program is coded with C ＋ ＋. The developed hydrocode is examined for example problems of hypervelocity impacts of solid materials. The results obtained from the numerical simulation are compared with available experimental ones. Good agreement is observed. 相似文献
7.
A practical method for computing the one-way rectangular orthotropicplate(isotropic plate as a special case)is suggested in this paper.The supported condi-tions in two opposite edges may be simply supported,continuous or supportednonsymmetrically and the other two opposite edges are slide-supported or free.A series ofsimplified formulas are given for calculating the bending moments along the cross section(loaded section),in which the acting point of the concentrated load or the center of a rec-tangular uniform load is located.The valid range and accuracy of these formulas were stud-ied and the approximate results were examined and compared extensively with those by thetriangular series solution or finite element method. 相似文献
8.
This paper focuses on obtaining an asymptotic solution for coupled heat and mass transfer problem during the solidification of high water content materials. It is found that a complicated function involved in governing equations can be approached by Taylor polynomials unlimitedly, which leads to the simplification of governing equations. The unknown functions involved in governing equations can then be approximated by Chebyshev polynomials. The coefficients of Chebyshev polynomials are determined and an asymptotic solution is obtained. With the asymptotic solution, the dehydration and freezing fronts of materials are evaluated easily, and are consistent with numerical results obtained by using an explicit finite difference method. 相似文献
9.
This paper provides an overview of models and methods for estimation of lifetime of technical components. Although the focus in this paper is on wind turbine applications, the major content of the paper is of general nature. Thus, most of the paper content is also valid for lifetime models applied to other technical systems. The models presented and discussed in this paper are classified in different types of model classes. The main classification used in this paper divides the models in the following classes： physical models, stochastic models, data-driven models and artificial intelligence, and combined models. The paper provides an overview of different models for the different classes. Furthermore, advantages and disadvantages of the models are discussed, and the estimation of model parameters is briefly described. Finally, a number of literature examples are given in this paper, providing an overview of applications of different models on wind turbines. 相似文献
10.
Analytical solution for fixed-end beam subjected to uniform load 总被引：7，自引：0，他引：7
A bi-harmonic stress function is constructed in this work. Ariy stress function methodology is used to obtain a set of analytical solutions for both ends fixed beams subjected to uniform load. The treatment for fixed-end boundary conditions is the same as that presented by Timoshenko and Goodier （1970）. The solutions for propped cantilever beams and cantilever beams are also presented. All of the analytical plane-stress solutions can be obtained for a uniformly loaded isotropic beam with rectangular cross section under different types of classical boundary conditions. 相似文献
11.
Pure bending of simply supported circular plate of transversely isotropic functionally graded material 总被引：3，自引：0，他引：3
LI Xiang-yu DING Hao-jiang CHEN Wei-qiu 《浙江大学学报(A卷英文版)》2006,7(8):1324-1328
INTRODUCTION In recent years, functionally graded materials (FGMs) have attracted more and more attention. Due to their continuously varying material properties in space on the macroscopic scale, FGMs, therefore, are usually superior to conventional fiber-matrix materi-als in mechanical behavior, especially for perform-ance under thermal loading. Now FGMs have been widely used in various fields including electronics, chemistry, optics, biomedicine, etc. Heretofore, volumes of literatu… 相似文献
12.
INTRODUCTION General solution is a convenient, effective method for solving space problems such as problems of infinite, semi-infinite and two-phase infinite media. For linear theory of piezoelasticity, Ding et al.(1996; 1997a) gave the general solution for coupled equa-tions for transversely piezoelectric media using po-tential theory. Ding et al.(1997b; 1997c) gave the general solution of plane problem. Based on the gen-eral solution, Ding et al.(1997a) presented the closed form fundam… 相似文献
13.
INTRODUCTIONInelasticity ,theproblemofasimplysup portedcircularplatesubjectedtouniformloadsisaclassicone .Timoshenkoetal.(1970 )pre sentedasolutionforanisotropiccircularplate .Dingetal.(2 0 0 0 ;2 0 0 1)obtainedtheanalyti calthree dimensionalsolutionforat… 相似文献
14.
INTRODUCTION In isotropic elasticity a class of mixed boundary value problems for elastic half-space can be classified as axisymmetric torsion. In this case the elastic field in cylinder components takes a particularly simple form consisting of only one nonzero displacement and two nonzero stress components. For this loading case, Reissner and Sagoci (1944) were possibly the first to examine a mixed boundary problem between the tangential displacement and stress on the half-space surface.… 相似文献
15.
In this paper, the axisymmetric general solutions of transversely isotropic magnetoelectroelastic media are expressed with
four harmonic displacement functions at first. Then, based on the solutions, the analytical three-dimensional solutions are
provided for a simply supported magnetoelectroelastic circular plate subjected to uniform loads. Finally, the example of circular
plate is presented.
Project supported by the National Natural Science Foundation of China (No. 10172075) and Ningbo Natural Science Foundation
for Young Scientist (No. 02J20102-13) 相似文献
16.
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
17.
EXACT SOLUTION OF AN EXTERNAL CIRCULAR CRACK IN A PIEZOELECTRIC SOLID SUBJECTED TO SHEAR LOADING 总被引：4，自引：0，他引：4
ＩＮＴＲＯＤＵＣＴＩＯＮＤｕｅｔｏｔｈｅｉｎｈｅｒｅｎｔｗｅａｋｎｅｓｓｏｒｂｒｉｔｔｌｅｎｅｓｓｏｆｐｉｅｚｏｅｌｅｃｔｒｉｃｃｅｒａｍｉｃｓ,ｔｈｅｆｒａｃｔｕｒｅｏｆｐｉｅｚｏ ｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｓｈａｓｇａｉｎｅｄｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒ ｅｓｔ.Ｍｏｓｔｐｕｂｌｉｓｈｅｄｗｏｒｋｓｄｅａｌｔｗｉｔｈｔｗｏ ｄｉｍｅｎ ｓｉｏｎａｌｓｔｕｄｙｏｆｃｒａｃｋｓｉｎｐｉｅｚｏｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｓ(Ｐａｋ ,1 990 ;Ｓｕｏｅｔａｌ.,1 992 ;ＺｈｏｎｇａｎｄＭｅｇｕｉ… 相似文献
18.
ＩＮＴＲＯＤＵＣＴＩＯＮＡｓｋｎｏｗｎ ,ｔｈｅｒｍａｌｂｅｈａｖｉｏｒｓｏｆｓｔｒｕｃｔｕｒｅｓｍｕｓｔｂｅｃｏｎｓｉｄｅｒｅｄｉｎｍａｎｙｓｉｔｕａｔｉｏｎｓ.Ｓｔｕｄｙｏｆｔｈｅｒｍａｌｅｆｆｅｃｔｏｎｄｅｆｏｒｍａｔｉｏｎｓａｎｄｓｔｒｅｓｓｅｓｏｆ 相似文献
19.
The thermal behavior of a thick transversely isotropic FGM rectangular plate was investigated within the scope of three-dimensional
elasticity. Noticing many FGMs may have temperature-dependent properties, the material constants were further considered as
functions of temperature. A solution method based on state-space formulations with a laminate approximate model was proposed.
For a thin plate, the method was clarified by comparison with the thin plate theory. The influences of material inhomogeneity
and temperature-dependent characteristics were finally discussed, through numerical examples.
Project (No. 10002016) supported by National Natural Science Foundation of China 相似文献