摘要:

AbstractA new elastic‐plastic hybrid/mixed finite‐element method, presented in this paper, is used for the numerical analysis of non‐uniform tension and buckling behaviour of square sheet metal under the diagonal tensile condition. The total displacement, stress and strain fields as well as their evolution up to a critical buckling condition are obtained for comparison with the experimental results by using the Moire method. It is found that the FEM can be a useful tool for studying the complex elastic‐plastic deformation problem in sheet‐metal forming

ISSN:0748-8025    

DOI:10.1002/cnm.1630060402

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractCyclic symmetric structures are those that posses a circumferentially periodic geometry, e.g. gear wheels, bladed discs, etc. Accurate prediction of their static and dynamic characteristics is essential to ensure optimum design. An analysis of the entire structure is often prohibitively costly. Through illustrative examples, the essential features of an analysis scheme exploiting the geometric periodicity are brought out. Avoiding much of the mathematics, the underlying principle (termed the‘eiψrelationship’) for both static and dynamic analysis is explained. The parallel to the special case of axisymmetric structures is d

ISSN:0748-8025    

DOI:10.1002/cnm.1630060403

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper presents an algorithm for the solution of the inverse problem for a matrix differential equation of the formAẍ+Bẋ+Cx=0. In the method use is made of the Taylor formula for a matrix function of many variables. It is shown that the algorithm is always convergent. The paper includes a description of the appropriate algorithms and numerical examp

ISSN:0748-8025    

DOI:10.1002/cnm.1630060404

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe accuracy of some first and second‐order methods for solving the time‐dependent one‐dimensional constant‐coefficient advection‐diffusion equation are compared theoretically on the basis of the dominant error terms in their modified equivalent partial differential equations. A new very stable three‐point (in space) third‐order implicit method is then developed by combining two second‐order methods. The accuracies of the various methods are then compared by means of

ISSN:0748-8025    

DOI:10.1002/cnm.1630060405

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA new penalty method for determining the natural frequencies and normal modes of acoustic cavities is presented. The acoustic medium is described in terms of the displacement field. A new easy‐toimplement penalty function method is employed to enforce the irrotationality condition. This new method has significant advantages when compared to classical penalty function methods since it is more stable with respect to the penalty paramete

ISSN:0748-8025    

DOI:10.1002/cnm.1630060406

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA new boundary element formulation in the time domain is presented for the displacement and stress analysis of quasistatic, linear, viscoelastic problems under the action of body forces. The well‐known concept of the particular integral is adopted for an efficient treatment of the volume integral and to improve the numerical accuracy. The stress kernels and particular integrals are derived using the elastic‐viscoelastic correspondence principle. Numerical results are compared with the derived exact solutions to demonstrate the method and its accur

ISSN:0748-8025    

DOI:10.1002/cnm.1630060407

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractOperator splitting for evolution equations which involve non‐linear differential operators is investigated. The occurrence of third‐orderaccurate multifactor splittings which are characterized by all‐positive fractional steps and which involve at most four factors is discovered. This result is surprising, as a recent investigation by Sheng (1989), of evolution equations involving general linear operators, establishes that no third‐orderaccurate factional‐step splitting having all‐positive fractional steps exists, regardless of the number of factors attempted. However, the present investigation indicates it is unlikely that Sheng's result has much bearing on the existence of positive‐step splittings for non‐linear equations. In addition to the result mentioned above, withn= 3, 4, 5, another case is exhibited of a non‐linear equation which permits all‐positive step,n‐thorder splittings requiring onlyn+ 1 factors. Indeed, a pathological case is examined of a partial differential equation with an annihilating operator which permitsk‐factor,nth‐order splittings, fork>1 andn>1. Thus, for the non‐linear case, one should expect only the unexpected. Finally, the idea of equivalent splittings for linear aganist non‐linear equations is considered. For a particular equation, all splittings having five factors or less, which are obtained by considering a linearization are shown applicable also to the non‐linear case. However, there exists a four‐factor all‐positive step splitting of the non‐linear equation which is not

ISSN:0748-8025    

DOI:10.1002/cnm.1630060408

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe non‐standard ordinary differential equations (ODEs), resulting from minimum‐weight design of pinned columns in buckling, with or without the minimum cross‐section constraints, are converted to an equivalent standard non‐linear ODE system by using trivial ODE and interval mapping techniques. The ODE system is then directly and efficiently solved by the robust ODE code COLSYS. The longitudinal shapes and switching interface points sought are given explicily as part of the solutions with the accuracy satisfying the user pre‐specified error tolerances. Compared with the analytical solutions, the numerical results obtained by this approach can be considered to be numerica

ISSN:0748-8025    

DOI:10.1002/cnm.1630060409

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper describes an example of a numerical solution of an overland flow problem where a box scheme which is unconditionally stable nevertheless has to have a limit on the time step.

ISSN:0748-8025    

DOI:10.1002/cnm.1630060410

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0748-8025    

DOI:10.1002/cnm.1630060411

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY