共查询到20条相似文献,搜索用时 22 毫秒
1.
宋福民 《应用数学和力学(英文版)》1998,19(11):1103-1113
I.IntroductionOwingtothefactthatthesystemwithwhicheconomics,biologyandsoonaredefinitelyconcernedtohaveuncertainty,includingthatcausedbyrestrictiononknowledge.asformathematicaltreatment,generallytheycanonlybedescribedbymeansofdifferentialinclusionsinsteadofdifferentialequations.Itiswell-knownthatthederivativex')ofasolutionx.)tothedifferentialequationx'(t)=f(t,x(t))inheritsthereqularityproperitiesofthemapfandthefunctionx(').Thisisnolongerthecasewithdifferentialinclusionsandisoneofthereasonswhyt… 相似文献
2.
The periodic problem of evolution inclusion is studied and its results are used toestablish existence theorems of periodic solutions of a class of semi-linear differential inclusion.Also existence theorem of the extreme solutions and the strong relaxation theorem are given forthis class of semi-linear differential inclusion. An application to some feedback control systems isdiscussed. 相似文献
3.
In this paper, the new forms of the differential equations of motion of the systems with higher-order nonholonomic constraints are obtained at first, and then the equivalence between these equations and the known equations is demonstrated. Finally an example is given to illustrate the application of our new equations. 相似文献
4.
A class of implicit fuzzy differential inclusions(IFDIs) are introduced and studied.Some existence theorems under different conditions are proved with the selection theorems for the open situation and the closed situation,respectively.A viable solution for a closed IFDI is proved to exist under the tangential condition.As an application,an implicit fuzzy differential equation,which comes from the drilling dynamics in petroleum engineering,is analyzed numerically.The obtained results can improve and extend some known results for fuzzy differential inclusions(FDIs) and fuzzy differential equations(FDEs),which might be helpful in the analysis of fuzzy dynamic systems. 相似文献
5.
A class of nonlinear elliptic problems driven by p(x)-Laplacian with a nonsmooth locally Lipschitz potential is considered.By applying the version of the nonsmooth three-critical-point theorem,the existence of three solutions to the problems is proved. 相似文献
6.
A way to extend operators in spaces of continuous functions to spaces of continuous set-valued functions is proposed. This extension is developed through the Steiner selections of the set-valued functions. Their properties and characteristics of the convergence of sequences of operators of this class are studied. In Part Ⅱ of this series some applications to approximation theory will be shown. 相似文献
7.
薛大为 《应用数学和力学(英文版)》1985,6(6):501-509
A method for establishing generalized variational principle is proposed in this paper. It is based on the analysis of mechanical meaning and it can be applied to problems in which the variational principles are needed but no corresponding variational principle is available. In this paper, the Hu-Washizu ’s generalized variational principle and the Hu’s generalized principle of complementary energy are derived from the mechanical meaning instead of from the generalization of the principle of minimum potenlial energy and the correct proofs of these two generaleed variational principles are given. It is also proved that this is wrong if one beleives that σij, eij and ui are independent variables each other based on the reason that these three kinds of variables are all contained in these two generalized variational principles. The condition of using these two variational principles in a correct manner is also explained. 相似文献
8.
We introduce the notion of almost expansive sequences and curves and study their ergodic and asymptotic properties in a Hilbert
space H. We apply our results to study the asymptotic behavior of solutions to the quasi-autonomous expansive type evolution system
(du/dt)(t) + f(t) ∈ Au(t) on [0, ∞). 相似文献
9.
(王志华)(张凤祥)TWOPOINTSBOUNDARYVALUEPROBLEMSINBANACHSPACES¥WangZhihua;ZhangFengxiang(DepartmentofMathematics.LanzhouUniversity.La... 相似文献
10.
IntroductionItiswell_knownthattheextensiontheoremofthelinearfunctionalisoneofthebasictheoremsinfunctionalanalysis.Ithasbeenextendedtomanyforms,and ,ofcourse,hasfoundmanyimportantapplicationinsuchfieldsasnonsmoothanalysis,optimizationandvariationalproble… 相似文献
11.
A new class of g-η-monotone mappings and a class of generalized implicit variational-like inclusions involving g-η-monotone mappings are introduced. The resolvent operator of g-η-monotone mappings is defined and its Lipschitz continuity is presented.An iterative algorithm for approximating the solutions of generalized implicit variationallike inclusions is suggested and analyzed. The convergence of iterative sequences generated by the algorithm is also proved. 相似文献
12.
A new system of the set-valued mixed quasi-variational-like inclusions (SS-MQVLI) involving H-η-monotone operators is studied in general Banach spaces without uniform smoothness. By using the resolvent operator technique of H-η-monotone opera-tors, a new iterative algorithm for finding approximate solutions to SSMQVLI is proposed. It is shown that the iterative sequences generated by the algorithm converge strongly to the exact solution of SSMQVLI under appropriate assumptions. These obtained new re-sults have extended and improved previous results. 相似文献
13.
陶明德 《应用数学和力学(英文版)》1990,11(2):159-164
This paper applies Lagrangian method to discuss the sudden starting of a floating body in deep water and the analytical solutions are obtained. It is known from the numerical results that the disturbing domain extends and the dynamic pressure also increases when the breadth of the floating body keeps constant and its depth increases. 相似文献
14.
Shi-Jun Liao 《国际流体数值方法杂志》1997,24(9):863-873
In this paper the general BEM proposed previously by Liao is applied to solve some 2D strongly non-linear differential equations, even including those whose governing equations and boundary conditions do not contain any linear terms. It is shown that the proposed general BEM is really valid for general non-linear problems, so that it can be applied to solve high-dimensional, strongly non-linear problems in engineering. © 1997 by John Wiley & Sons, Ltd. Int. j. numer. methods fluids 24: 863–873, 1997. 相似文献
15.
工程中已发展了许多矩阵特征值问题的近似求解方法,由Duncley法给出固有频率基频的下界,Rayleigh-Ritz近似法建立的方程,给出基频的上界,以及通常的矩阵迭代法给出的矩阵的固有频率程序中是以某一元素迭代前后比值确定的,这样实际上很难说是上界或下界。Collatz包含定理仅适用于对称标准特征值问题,可以给出特征值上、下界。采用矩阵Cholesky三角分解的原理,把Collatz包含定理推广到适用于具有对称矩阵的一般结构系统的广义征值问题,对于分解刚度矩阵或质量矩阵可给出基频,或最高因有频率。为了验证理论的正确性,给出了算例。 相似文献
16.
SHI-JUN LIAO 《国际流体数值方法杂志》1996,23(8):739-751
In this paper the basic idea of homotopy in topology is applied to give a kind of high-order BEM formulation for general non-linear problems governed by non-linear differential operators which need not contain any linear operators at all. As a result, the traditional BEM for non- linear problems is just a special case of the proposed method. Three simple examples are used to show the effectiveness of the proposed quite general BEM for non-linear problems. 相似文献
17.
丁协平 《应用数学和力学(英文版)》2004,25(6):618-626
By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature. 相似文献
18.
K. Yamasaki H. Nagahama 《ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik》2008,88(6):515-520
The J‐integral (a path‐independent energy integral) formalism is the standard method of analyzing nonlinear fracture mechanics. It is shown that the energy density of deformation fields in terms of the homotopy operator corresponds to the J‐integral for dislocation‐disclination fields and gives the force on dislocation‐disclination fields as a physical interpretation. The continuum theory of defects gives a natural framework for understanding the topological aspects of the J‐integral. This geometric interpretation gives that the J‐integral is an alternative expression of the well‐known theorem in differential geometry, i.e., the Gauss‐Bonnet theorem (with genus = 1). The geometrical expression of the J‐integral shows that the Eshelby's energy‐momentum (the physical quantity of the material space) is closely related to the Einstein 3‐form (the geometric objects of the material space). 相似文献
19.
B.X. Xu M.Z. Wang 《ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik》2007,87(1):59-69
Eshelby proved in 1957 that the strain field within a homogeneous ellipsoidal inclusion embedded in an infinite isotropic media is uniform, when the eigenstrain prescribed in the inclusion is uniform. This uniform strain field property was conjectured to hold exclusively for the ellipsoidally shaped inclusions. In recent studies the authors have discovered the arithmetic mean properties of the strains for N‐fold (N is greater than 2 but unequal to 4) rotational symmetrical inclusions with uniform eigenstrains, called the arithmetic mean theorem of the Eshelby tensors. In this paper, we investigate the two‐dimensional rotational symmetrical inclusions with rotational symmetrical eigenstrains. It is shown that for N‐fold (N is greater than 4) rotational symmetrical inclusions with the same fold rotational symmetrical eigenstrains which are constant on the boundary of the inclusion, the arithmetic mean of the strains at N rotational symmetrical points presents special properties: For the points outside the inclusion, the arithmetic mean vanishes; for the points inside the inclusion, the arithmetic mean is in direct proportion to the eigenstrain on the boundary of the inclusion, with the coefficient tensor equal to the Eshelby tensor for circular inclusions. It is followed that the average strain over the inclusion domain and the line average of strains along a concentric circle inside the inclusion also equal the eigenstrains on the boundary of the inclusion multiplied by the Eshelby tensor for circular inclusions. These properties obtained in this paper can be safely reduced to the results for uniform eigenstrains shown in our former works. 相似文献
20.
In this paper, we will give conditions under which the equilibrium set of multi-degree-of-freedom non-linear mechanical systems with an arbitrary number of frictional unilateral constraints is attractive. The theorems for attractivity are proved by using the framework of measure differential inclusions
together with a Lyapunov-type stability analysis and a generalisation of LaSalle’s invariance principle for non-smooth systems.
The special structure of mechanical multi-body systems allows for a natural Lyapunov function and an elegant derivation of
the proof. Moreover, an instability theorem for assessing the instability of equilibrium sets of non-linear mechanical systems
with frictional bilateral constraints is formulated. These results are illustrated by means of examples with both unilateral
and bilateral frictional constraints. 相似文献