摘要:

AbstractThe evaluation of solar pressure effects over the antenna reflectors for communication satellites is becoming more and more important, since the diameters of such devices tend to be increased. For this purpose, a statistical approach based on the Monte Carlo method has been developed, as described in this paper, within a research project of the European Space Agency (ESA). In this way, detailed simulations can be carried out easily, thus allowing for analysing different geometrical and technological solutions and for defining an adequate compromise between antenna gain and pointing control capability of the satellite.

ISSN:1069-8299    

DOI:10.1002/cnm.1640091002

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe paper presents a filtering algorithm which corrects the results of measurements of certain physical quantities if any additional information about the measured values is known. The algorithm is very effective in one‐dimensional as well as in two‐dimensional problems where additional constraints are presented in the form of differential equations. For example, this technique can be used to correct the measurements of certain dynamic quantities if some information about motion of examined bodies is known. It can also be used to correct the strain field measurements if the conditions of continuity of strain field are inclu

ISSN:1069-8299    

DOI:10.1002/cnm.1640091003

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA computer simulation is made of cellular convection in an anisotropic atmosphere in an attempt to more closely approximate the observed values with those obtained from mathematical models. A finite‐element Galerkin technique, with Taylor approximation and Crank–Nicolson, is employed and comparisons are made with the author's earlier finite‐element models of isotropic convection and with finite‐difference models. It is found that postulates from physics on the effect of anisotropy on cellular atmospheric convection, with its increase in the aspect ratio, are well modelled with this finite‐element

ISSN:1069-8299    

DOI:10.1002/cnm.1640091004

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe use of micromechanically based constitutive equations for contact interfaces leads to technically relevant parameters to ill‐conditioned finite‐element equations. In the paper an augmented Lagrangian technique is employed to overcome this difficulty and to provide a good converging algori

ISSN:1069-8299    

DOI:10.1002/cnm.1640091005

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractAn adaptive finite‐element (FE) method for the solution of two‐dimensional transient dynamic problems is described. The computational domain is represented by an unstructured assembly of linear triangular elements, and the mesh adaption is achieved by regenerating the grid using an error indication procedure coupled with an automatic mesh generator. Problems involving shock and wave propagation are solved to illustrate the numerical performance of the met

ISSN:1069-8299    

DOI:10.1002/cnm.1640091006

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe paper presents two complementary variational formulations of Trefftz‐type elements wherein the piece‐wise assumed displacement approximations a priori fulfil the governing differential equations over the element subdomain. The two formulations are such that either the displacement conformity or the reciprocity of the conjugate tractions is enforced at the element interfaces, one more strongly than the other. This is achieved through linking the piece‐wise approximations either through an auxiliary displacement or a boundary traction frame. The two formulations concern solid mechanics and structures.Although for hybrid elements monotonic convergence in energy cannot be warranted, in practice the two presented formulations yield opposite bounds on the energy provided that the number of internal Trefftz functions is sufficiently

ISSN:1069-8299    

DOI:10.1002/cnm.1640091007

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the paper the BEM and FEM results have been compared in the context of 2D electromagnetic field analysis in a zoned medium with eddy current subregions. The practical problem concerning the turbogenerator end region has been discussed. The magnetic flux density over the surface of the end package and the current density in the non‐magnetic pressure plate have been analyse

ISSN:1069-8299    

DOI:10.1002/cnm.1640091008

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:1069-8299    

DOI:10.1002/cnm.1640091009

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:1069-8299    

DOI:10.1002/cnm.1640091010

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:1069-8299    

DOI:10.1002/cnm.1640091001

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY