摘要:

AbstractA nonlinear theory of nonsimple thermoelastic materials with voids is established. The continuous dependence upon initial state and supply terms of smooth thermodynamic processes is studied.

ISSN:0044-2267    

DOI:10.1002/zamm.19930730202

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19930730206

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractAn exact solution for the creeping flow past a porous spherical shell has been obtained using the Stokes&Brinkman equations. Expressions for the velocities and pressure fields both inside and outside of porous spherical shell are obtained and the force acting on the shell is also determined. It is found that the drag on a porous spherical shell is smaller as compared to the shell with solid core. Several limiting cases of the solution are also discussed. In particular it is shown that the solution obtained using Darcy's law can be derived easily with the appropriate choice of boundary conditions.

ISSN:0044-2267    

DOI:10.1002/zamm.19930730207

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractLiapunov's direct method in an extended version suitable, for spatially continuous systems is used to derive sufficient conditions for the stability of marine risers. The method has its origin in considering the system energy and represents a dynamic extension of Lagrange's static stability approach which relates the existence of a positive definite potential energy to stability. Since the direct method utilizes only the differential equation and the boundary conditions to construct energy‐like functions from which stability statements are deduced, it is not necessary to solve the system equations. The applicability of the method to nonlinear systems makes it possible to include the nonlinear hydrodynamic drag force due to the sea water in the stability analysis. As an example, the dynamic stability of the vertical riser equilibrium position is analysed here for pinned‐pinned boundary conditions, resulting in a confirmation of the “stability limit” already known through purely static stability a

ISSN:0044-2267    

DOI:10.1002/zamm.19930730208

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractFor forced nonlinear oscillators, different subharmonic vibrations are investigated analytically by higher approximations, checked by computer algebra, and numerically by a damped Newton procedure combined with a continuation algorithm (BIFPACK package by R. Seydel). Especially for a damping value which leads to a frequency region with chaotic behaviour, second subharmonic vibrations appear with amplitudes of the same size as for the harmonic vibrations, whereas third subharmonic vibrations appear only for lower frequencies. This gives an explaination for the existence of second and later on of third subharmonic periodic windows in the period doubling route to chaos.

ISSN:0044-2267    

DOI:10.1002/zamm.19930730209

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19930730213

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractFor a given disk Z circular including approximation of the range of the complex exponential function ez= {ez: z ∈ Z} is considered. The optimal covering disk {ζ: |ζ — w| ≦ D/2} ⊇ ez, with the diameter D which is equal to the diameter of the closed range ez, is d

ISSN:0044-2267    

DOI:10.1002/zamm.19930730214

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19930730215

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19930730216

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19930730217

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY