摘要:

AbstractThis paper is concerned with the time‐dependent deformation of a spherical capsule suspended in a viscous fluid. The basic assumptions are that (a) the flow in the fluid regions is governed by the Stokes' equations, (b) the deformation is small, and (c) the membrane is purely elastic. Condition (b) requires either the elastic time scale to be small in comparison with a characteristic flow time (i.e., a sufficiently stiff membrane and/or a sufficiently weak flow field) or the inside fluid to be highly viscous. It also allows us to employ a linearly elastic constitutive equation for the membrane, as first approximation. The general results obtained are compared with corresponding results for surface tension droplets. The case of sedimentation in a quiescent fluid, a capsule freely suspended in a linear flow field, and steady‐state results for quadratic flow fields (with emphasis on circular Poiseuille flow) are stud

ISSN:0044-2267    

DOI:10.1002/zamm.19850650102

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19850650105

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractIn this paper we study the convergence of energy integrals, stress tensors and frequencies of free vibrations for non‐homogeneous and porous elastic bodies with a periodic structure of period ε as ε → 0. The results are based on the estimates for solutions of the boundary value problem of the elasticity system with rapidly oscillating periodic coefficients, obtained in [4],

ISSN:0044-2267    

DOI:10.1002/zamm.19850650106

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19850650110

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe mechanical properties of thin films often differ from those of bulk material and depend on technological parameters. But they can be determined in the coating‐substrate composite directly by means of ultrasonic surface waves. For thin layers in relation to wavelength, the displacement field within the layer is expanded in powers d/Λ. The corresponding equation system given for the general case is evaluated for elastic and viscous coatings in lowest order of d/Λ. An elastic covering layer causes a relative change in velocity proportional to ω η d where the factor is determined by the elastic and inertial differences between film and substrate. By a viscous coating the surface wave is attenuated proportional to ω3ηd. The elastic case confirms in the first order the results of a plate theory approximation given formerly by Achenbach and Keshava. However, their higher order terms prove to be incomplete from the viewpoint of the present systematic ex

ISSN:0044-2267    

DOI:10.1002/zamm.19850650111

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19850650113

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe present paper deals with B V Ps in the theory of semipermeability potentials. Both the cases of interior and boundary semipermeability problems are studied. After the formulation of the problems in terms of hemivariational inequalities and the definition of the regularised problems an existence result is proved. The proof is constructive and may be used for the approximation of the solution of the problem. Finally, the developed method is applied to certain similar problems arising in the theory of elasticity.

ISSN:0044-2267    

DOI:10.1002/zamm.19850650116

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractIn der Arbeit wird eine implizite Differenzenmethode (Gitterparameter h, τ) zur Berechnung der schwachen Lösung einer eindimensionalen Stefan‐Aufgabe betrachtet, wobei die Enthalpiefunktion geeignet approximiert wird (Parameter Δ). Unter Schwachen Regularitätsvoraussetzungen werden Fehlerabschätzungen für diese Methode gefunden. Hauptresultat ist eine Konvergenzordnung von O(Δ1/4+ h½ + τ½) in

ISSN:0044-2267    

DOI:10.1002/zamm.19850650117

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19850650121

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractSeveral theorems are proved which guarantee the existence of implicitly defined functions and inverse functions, respectively, in prescribed domains. As applications, error bounds for inaccurate solution maps of implicit systems of equations and for approximate zeros of systems of equations are derived.

ISSN:0044-2267    

DOI:10.1002/zamm.19850650122

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY