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1.
We introduce two types of differential inclusions with Hukuhara derivative and consider properties of these inclusions. For differential inclusions of the second type, we give different definitions of a solution, prove theorems on the existence of an ordinary solution, and establish the compactness of the set of these solutions. __________ Translated from Neliniini Kolyvannya, Vol. 10, No. 2, pp. 229–246, April–June, 2007.  相似文献   

2.
We substantiate the averaging method for controlled linear differential equations with delay and Hukuhara derivative. __________ Translated from Neliniini Kolyvannya, Vol. 9, No. 3, pp. 376–385, July–September, 2006.  相似文献   

3.
We substantiate the method of complete or partial averaging for differential inclusions that contain the Hukuhara derivative and are subject to pulse influence at fixed times. __________ Translated from Neliniini Kolyvannya, Vol. 10, No. 3, pp. 416–432, July–September, 2007.  相似文献   

4.
We obtain sufficient conditions for the unique solvability of the initial-value problem for linear integro-differential equations. __________ Translated from Neliniini Kolyvannya, Vol. 8, No. 3, pp. 388–403, July–September, 2005  相似文献   

5.
The stress state of a three-dimensional body with inclusions bounded by surfaces with singular lines (sets of corner points) and a conical point is studied. By determining the asymptotics of displacements and stresses at the singularities of interfaces and using the generalized elastic potentials of single and double layers, the problem posed is reduced to a system of singular integral equations. The results obtained are used to analyze the stress state of a body with a circular conical inclusion  相似文献   

6.
Using a generalization of the numerical-analytic method, we establish conditions for the existence of solutions periodic in t with period T for a system of partial integro-differential equations with pulse action.__________Translated from Neliniini Kolyvannya, Vol. 8, No. 1, pp. 123–131, January–March, 2005.  相似文献   

7.
考虑老化的混凝土粘弹性分数导数模型   总被引:10,自引:1,他引:10  
混凝土是一种具有分形结构的材料。采用分数微积分模型来研究具有分形结构材料的老化规律目前尚未见到。本文的目的是采用含分数阶导数的类标准线性体来模拟考虑老化的混凝土的蠕变和松弛规律。给出了分数导数与Abel核之间的关系。讨论了类标准线性体的蠕变柔量和松弛模量及其在考虑老化的混凝土中的应用。与传统的混凝土流变模型相比较表明,类标准线性体可以更好地同时拟合混凝土在不同龄期的蠕变和松弛曲线。而且其形式简单、统一,在计算过程中需要调整的参数很少。可以预见,类标准线性体在混凝土的结构设计和计算中将有着广泛的应用前景。  相似文献   

8.
准晶体颗粒复合智能材料具有优异的物化性能和应用前景。不同于传统的各向同性材料,三维立方准晶体材料包含声子场,相位子场,及声子-相位子耦合场。为更好地研究准晶体颗粒夹杂问题,揭示准晶体材料夹杂问题的物理现象,本文利用本征应变公式和柯西留数定理,考虑椭球体夹杂,获得了三维立方准晶材料夹杂问题的Eshelby张量,并给出了统一的表达式。进而,当三维立方准晶夹杂形状为球形、棒状、扁平状和带状时,获得了封闭形式的三维立方准晶Eshelby张量表达式。同时,给出了椭球体长径比变化时Eshelby张量的变化规律,这对研究准晶体颗粒夹杂问题具有重要的理论意义。  相似文献   

9.
Summary We consider an integro-differential equation describing a Newtonian dynamics with long-range interaction for a continuous distribution of mass in R. First, we deduce unique existence and regularity properties of its solution locally in time, and then we investigate a scaling limit. As limit dynamics a nonlinear wave equation is determined. Technically, we rely on the connection of the Newtonian dynamics to a system of an integro-differential equation and a partial differential equation. Basic for our considerations is the study of the regularity properties of the solution of that system. For that purpose we exploit its similarity to a certain strongly hyperbolic system of partial differential equations. (Accepted August 21, 1995)  相似文献   

10.
构造任意分布且相互影响的多个圆形刚性夹杂模型的复应力函数,采用复变函数方法,达到满足各个夹杂的边界条件,利用坐标变换和围线积分将求解方程组化为线性代数方程组,推导出了圆形刚性夹杂任意分布的界面应力解析表达式,算例对多夹杂与单夹杂两种模型的界面应力最大值进行了对比,同时还给出了界面应力最大值随夹杂间距的变化规律,求出了刚性夹杂的合理间距。本文发展的分析方法为研究夹杂材料的细观机理探索了一条有效的分析途径。  相似文献   

11.
The structural theory of short-term damage is generalized to the case where the matrix of a particulate composite has microdamages and the inclusions deform nonlinearly. The basis for this generalization is the stochastic elasticity equations of a porous-matrix particle-reinforced composite. Microvolumes of the matrix meet the Huber-Mises failure criterion. A balance equation for damaged microvolumes is derived. The balance equation and the equations relating macrostresses and macrostrains of a particulate composite with porous matrix and physically nonlinear inclusions constitute a closed-form system. The system describes the coupled processes of physically nonlinear deformation and microdamage. Algorithms for calculating the microdamage-macrostrain relationship and plotting deformation diagrams are proposed. Uniaxial tension curves are plotted for the case where the material of inclusions is linearly hardening__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 2, pp. 3–11, February 2005.  相似文献   

12.
Most piezocomposites, which have been widely used in engineering, consist of piezoelectric inclusions and a non-piezoelectric matrix. Due to the limits of fabrication technology, it is hard to avoid the matrix intermingling with other non-piezoelectric inclusions, such as cavities. The non-piezoelectric inclusions can substantially affect performance of piezocomposites. In this paper we study the electromechanical fields in piezocomposites which are composed of a non-piezoelectric matrix embedded with both piezoelectric and non-piezoelectric inclusions. Closed-form relations are obtained for the effective electroelastic moduli of a piezocomposite with both piezoelectric and non-piezoelectric inclusions. The effective properties of a 1-3 type piezocomposite with non-piezoelectric spherical inclusions are analyzed carefully and explicit formulae for the effective electroelastic properties of a 1-3-0 piezocomposite are also obtained. The analysis shows that the effect of non-piezoelectric inclusions on the electroelastic properties of piezocomposites is significant and should not be neglected. The model proposed in this paper is expected to be useful for predicting and analyzing the overall electromechanical properties of piezocomposites with a non-piezoelectric matrix containing both piezoelectric and non-piezoelectric inclusions.  相似文献   

13.
含有随机夹杂非均匀体的有效弹性模量   总被引:1,自引:0,他引:1  
在对含有随机夹杂的非均匀体求有效弹性模量时,一般多根据Eshelby的等效夹杂法,但由于该方法没有充分考虑非均匀体内部的微结构,所以其理论具有一定的局限性。本文认为Kunin的微结构理论与Eshelby的等效夹杂法相比更具一般性,因而本文采用了文[9]中一些合理的思想,摒弃了其中不合理的假设,并且建立了一种新的理论模型.最后,本文针对球夹杂的情况给出了非均匀体有效弹性模量依赖于夹杂体积份数的关系,并将该结果与文[10]中的结果进行了比较.  相似文献   

14.
We study a variational problem describing an incoherent interface between a rigid inclusion and a linearly elastic matrix. The elastic material is allowed to slip relative to the inclusion along the interface, and the resulting mismatch is penalized by an interfacial energy term that depends on the surface gradient of the relative displacement. The competition between the elastic and interfacial energies induces a threshold effect when the interfacial energy density is non-smooth: small inclusions are coherent (no mismatch); sufficiently large inclusions are incoherent. We also show that the relaxation of the energy functional can be written as the sum of the bulk elastic energy functional and the tangential quasiconvex envelope of the interfacial energy functional.  相似文献   

15.
分数导数型本构关系描述粘弹性梁的振动分析   总被引:2,自引:1,他引:2  
陈立群  程昌钧 《力学季刊》2001,22(4):512-516
本文研究粘弹性梁在周期激励作用下的受迫振动问题。梁的材料满足Kelvin-Volgt分数导数型本构关系。基于动力学方程、本构关系和应变-位移关系建立了小变形粘弹性梁的振动方程。采用分离变量法分析粘弹性梁的自由振动,导出模态坐标满足的常微分-积分方程和模态函数满足的常微分方程,对于两端简支的截面梁给出了固有频率和模态函数。对于简谐激励作用下粘弹性梁的受迫振动,利用模态叠加得到了稳态响应。最后给出数值算例说明本文方法的应用。  相似文献   

16.
IntroductionMoreandmoreproblemsinscienceandengineeringhaveconcernedthestabilityanalysisoftheviscoelasticstructuresduetotheirbroadapplications .In [1]CederbaumandMondappliedthemultiple_scalesmethodtotreatstabilityofaviscoelasticcolumnunderaperiodicaxiall…  相似文献   

17.
A new resolution-enhancing technique called derivative artificial compression method is developed with multi-dimensional extension. The method is constructed via applying high-resolution difference schemes on derivative equations of conservation laws. In this way, one could overcome the defect of accuracy decay at extreme points that has plagued almost all high-resolution schemes. The new method has high resolution, low dissipation and low diffusion properties, and could enhance the resolution (of numerical solution) both at discontinuities and at extreme points. Numerical experiments are implemented using initial value problems of single conservation law, one-dimensional shock-tube problem, two-dimensional Riemann problems, double Mach reflection problem, and a shock reflection from a wedge. Resolutions of discontinuities, extremes and fine structures are compared between the original TVD scheme, TVD scheme with artificial compression method and TVD scheme with derivative artificial compression method.  相似文献   

18.
We present new fixed-point theorems for weakly sequentially upper-semicontinuous maps. These results are then used to establish existence principles for second-order differential equations and inclusions.  相似文献   

19.
This paper describes a method for determining the strain state of a thin anisotropic plate with elastic arbitrarily arranged elliptical inclusions. Complex potentials are used to reduce the problem to determining functions of generalized complex variables, which, in turn, comes down to an overdetermined system of linear algebraic equations, solved by singular expansions. This paper presents the results of numerical calculations that helped establish the influence of rigidity of elastic inclusions, distances between inclusions, and their geometric characteristics on the bending moments occurring in the plate. It is found that the specific properties of distribution of moments near the apexes of linear elastic inclusions, characterized by moment intensity coefficients, occur only in the case of sufficiently rigid and elastic inclusions.  相似文献   

20.
This paper is devoted to the modelling of thin elastic plates with small, periodically distributed, piezoelectric inclusions, in view of active controlled structure design. The initial equations are those of linear elasticity coupled with the electrostatic equation. Different kinds of boundary conditions on the upper faces of inclusions are considered, corresponding to different ways of control: Dirichlet, Neumann, local or nonlocal mixed conditions. We compute effective models when the thickness a of the plate, the characteristic dimension ε of the inclusions, and ε / a tend together to zero. Other situations will be considered in two forthcoming papers. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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