摘要:

AbstractA method is described which calculates the fluid flow pattern for any generalized Newtonian fluid forced through the narrow annular space between two concentric cylindrical surfaces. The inner surface is engraved with a number of identical equally spaced spiral channels of small constant pitch angle but of varying cross‐sectional area. For equal flow into the spiral passages, the pressure distribution along them is described by a quasi‐linear ordinary difference‐differential equation. A finite element approximation is employed to solve this equation for the pressure and resultant flow field. The method is illustrated by calculating and comparing flow patterns through two different spiral geome

ISSN:0029-5981    

DOI:10.1002/nme.1620230102

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA hybrid method, which consists in using the finite element method for fixed bodies and analytical techniques for moving ones, was developed for the thermal analysis of tribological situations. Unlike the well‐known finite element method, the hybrid method gives accurate results even at high sliding speed. From a practical point of view, both computer time and storage requirements are greatly reduced. The method appears as a valuable technique to predict surface temperature in mechanical assemblie

ISSN:0029-5981    

DOI:10.1002/nme.1620230103

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn examination is made of suppression techniques used to obtain global monotonicity when applying iterative processes to the determination of the zeros of residual functions in linear vibration analysis. It is shown that, when computational errors are taken into account, induced instability is a ubiquitous feature of this class of techniques. A method of inhibiting this instability behaviour is presented which at the same time avoids missing zeros between the restarting value and the last determined zero on restarting the iteration.

ISSN:0029-5981    

DOI:10.1002/nme.1620230104

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe interface boundary between two domains with different conductivity is to be determined from the impedance measured at the domain surface. This is an inverse problem. Two approaches, influence coefficient approach and boundary integral approach, using a boundary element model are presented. To examine the validity of the approaches, numerical experiments are carried out for a two‐dimensional field, and the suitability and limitation of the methods for application to impedance plethysmography are discusse

ISSN:0029-5981    

DOI:10.1002/nme.1620230105

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA flat shell element which utilizes the linear strain triangle (LST) for membrane representation and a plate‐bending element labelled DKL (for discrete Kirchhoff element with Loof nodes) previously derived by the authors in Reference 1, is presented. This element is free from the deficiencies of displacement incompatibility, singularity with coplanar elements, inability to model intersections and low order membrane strain representation, which are associated with existing faceted shell elements. The results of the numerical examples indicate that the convergence characteristics of this element are goo

ISSN:0029-5981    

DOI:10.1002/nme.1620230106

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractIn this paper, a simplified, economical and highly accurate method for large deformation, post‐buckling, analyses of frame‐type structures is presented. Using the concepts of polar‐decomposition of deformation, an explicit expression for the tangent stiffness matrix of a member/element of the frame, that accounts for the nonlinear bending‐stretching coupling, is derived in closed form, at any point in the load‐deformation path. The ranges of validity of the present simplified approach are discussed. Several example problems to demonstrate the feasibility of the present approach, over ranges of deformation that are well beyond those likely to occur in practical large frame structures, are

ISSN:0029-5981    

DOI:10.1002/nme.1620230107

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe hierarchical concept applied to eigenvalue problems is considered. An error indicator is derived from the pertinent Rayleigh quotient. The indicator serves as an estimation ‘a posteriori’ of the relative change in an eigenvalue for a hierarchical refinement. A numerical example is inclu

ISSN:0029-5981    

DOI:10.1002/nme.1620230108

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA finite element procedure for solving multidimensional phase change problems is described. The algorithm combines a temperature formulation with a finite element treatment of the differential equation and discontinuous integration within the two‐phase elements to avoid the necessity of regularization. A new criterion for the computation of the iteration matrix is proposed. It is based on a quasi‐Newton correction of the Jacobian matrix for conduction problems without change of phase. A set of test problems with exact solution is analysed and demonstrates that the procedure can accurately evaluate the front position and temperature history with a reasonable computational eff

ISSN:0029-5981    

DOI:10.1002/nme.1620230109

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractIn solving the Buckley‐Leverett problem, the use of higher order Hermitian polynomials at the frontal location and lower order ones elsewhere in the solution domain yields an enhanced frontal definition. This improvement is achieved without a significant increase in computational effor

ISSN:0029-5981    

DOI:10.1002/nme.1620230110

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinematics of degenerated finite elements using explicit integration are investigated, in particular for geometric nonlinear applications. Two representations of the nodal rotational degrees‐of‐freedom are investigated; the first adopts the infinitesimal representation of rotations, while the second uses a valid large rotation representation. A method of explicit integration is presented which satisfies rigid body rotations under arbitrary large rotations. The accuracy and convergence of these formulations are investiga

ISSN:0029-5981    

DOI:10.1002/nme.1620230111

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY