摘要:

AbstractA finite prism approach for the approximate analysis of three‐dimensional solids is proposed. The approach is based on a semi‐algebraic assumed stress hybrid model, according to Pian's scheme. Prismatic solids with various end conditions can be analysed with a traditional matrix‐displacement procedure, thus enlarging the possibilities offered by analogous compatible m

ISSN:0029-5981    

DOI:10.1002/nme.1620240402

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIt is shown how the various norms of the coefficient matrix of a set of finite difference equations can, in many cases, be employed in an easy, straightforward fashion to find sufficient conditions for stability in situations involving non‐periodic boundary conditions and variable coefficients. With the aid of the easily computed norms, particularly the infinite norm, one does not have to rely on the necessary condition provided by the spectral radius, which has been the main basis of criticism of the matrix method in the pas

ISSN:0029-5981    

DOI:10.1002/nme.1620240403

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAn alternating method, in conjunction with the finite element method and an analytical solution for an elliptical flaw in an infinite solid, is used to determine the mixed mode stress intensity factors for surface flaws. This finite element alternating method leads to an inexpensive procedure for routine evaluation of accurate stress intensity factors in complex structural components containing surface flaws and subject to mixed‐mode loading. A variety of numerical examples is presente

ISSN:0029-5981    

DOI:10.1002/nme.1620240404

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractExactly integrated isoparametric plane stress elements behave poorly in flexure. The 4‐noded element ‘locks’, with errors that progress indefinitely as element aspect ratio increases. Reduced integration of the shear strain energy eliminates this locking entirely. The 8‐noded element does not lock, but improves in performance with reduced integration of shear strain energy. Both elements, with their original shape functions, show severe shear stress oscillations in flexure. In this paper we attribute these oscillations to the lack of ‘consistency’ of shear strain fields derived directly from independent field‐variable interpolations. We derive error models for specific tractable examples which can confirm the accuracy of this conceptual scheme through digital computation using the finite element models. A field‐consistent redistribution strategy for the shear strain field is offered as an elegant procedure to free the elements of spurious oscillations and give a ‘lock

ISSN:0029-5981    

DOI:10.1002/nme.1620240405

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA monomial treatment for solving mixed equality/inequality constrained generalized geometric programs is presented. The method is shown to be equivalent to a Newton–Raphson procedure carried out in log space on the equality constraints at the same time that a cutting plane procedure is performed on a convex region constrained within the feasible region of the inequality constraints. Known limitations of this monomial treatment are outlined and a technique for improving the efficiency of the GGP method is suggested. A discussion of how other methods of solving mixed equality/inequality constrained GGP problems compare to the monomial treatment is presented and two example problems are solve

ISSN:0029-5981    

DOI:10.1002/nme.1620240406

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe object of this paper is to analyse by the finite element method the dynamic responses of a flat plate subjected to various moving loads. First of all the actual continuous flat plate was replaced by a discrete system composed of isoparametric rectangular plate elements. And then the elementary and overall stiffness and mass matrices were determined and the natural frequencies and mode shapes of the flat plate were solved. Next, the Newmark direct integration method was used to find the dynamic responses of the flat plate.The effects of eccentricity, acceleration and initial velocity of the moving load, and the effect of span length were the key points of study. The dynamic behaviour of a multi‐span flat plate supported by the beam members of rigid plane frames and subjected to the action of a series of moving loads (in identical or opposite directions) were also investigate

ISSN:0029-5981    

DOI:10.1002/nme.1620240407

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn this paper mathematical and computational aspects of device modelling are treated. Four main subjects are discussed; the analytical model, the discretizations, the non‐linear and the linear systems of equations. On the one hand the most commonly used numerical techniques are described; on the other hand several new techniques are presented. Noteworthy new techniques are the generalized upwind box scheme and the mixed variable approach. Aspects such as the choice of variables and the singularly perturbed nature of the problem are treated. Properties of the matrices involved are presented in a systematic way. Throughout the paper a standard one‐dimensional diode is used to illustrate the concepts involved. Finally several realistic two‐dimensional examples are

ISSN:0029-5981    

DOI:10.1002/nme.1620240408

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620240409

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620240410

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620240401

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY