摘要:

AbstractMagnetoelastic buckling of a ferromagnetic beam‐plate has been experimentally and theoretically studied by many investigators. A great discrepancy between the experimental results and the theoretical predictions has stimulated related studies. It has been supposed that the discrepancy could be attributed to the finite size of the test piece; this case has not yet been solved exactly, or even numerically.In this study the boundary element method is applied to solve for the magnetic field distribution around the finite specime

ISSN:0029-5981    

DOI:10.1002/nme.1620230702

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA posteriorierror estimates and adaptive mesh refinements are now on a rigorous mathematical foundation for linear, elliptic boundary‐value problems of second order. Yet, for non‐linear problems only a few results have been obtained till now. In this paper we consider as a non‐linear model problem the two‐dimensional fluid flow with free surface and show how results from lineara posterioritheory can be used to control the non‐linear iteration and to refine the mesh adaptively. A numerical example shows that, similar to linear problems, considerable improvement of the accuracy is obtained by an adaptive mesh refinement and that the influence of singularities on the order of convergence d

ISSN:0029-5981    

DOI:10.1002/nme.1620230703

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper discusses the finite element analysis of the flexural interaction between an elastic plate and an elastic half‐space. The applicability of certain Mindlin‐type plate elements, based on reduced integration techniques, to this class of interaction problem is investigated. A series of numerical computations reveal that those elements which possess spurious zero‐energy modes are deficient in modelling properly the interaction phenomenon. It is also found that the ‘heterosis’ plate element reported in the literature is capable of modelling the plate‐elastic medium interaction very

ISSN:0029-5981    

DOI:10.1002/nme.1620230704

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe efficiency of a field‐consistent two‐noded linear curved axisymmetric shear‐flexible shell element is shown to be due to the removal of both shear and membrane locking. Typical applications illustrate how the field‐consistent representation dramatically improves performance, and allows greater flexibility in tailoring element design to satisfy specific proble

ISSN:0029-5981    

DOI:10.1002/nme.1620230705

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA new mixed finite element mesh division and its recursion algorithm are proposed for the solution of two‐dimensional field problems with open boundaries. The scheme is applied to a pin insulator in open space. The results are in close agreement with those of an established technique for modelling field problems. The advantage of the mixed element mesh division over the star point radial ray division of the ballooning technique and its application to a three‐dimensional mesh division are brought

ISSN:0029-5981    

DOI:10.1002/nme.1620230706

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe paper presents a solution to the problem of dynamic optimization of framed structures for which the design variables are not only the sizes of the members but also the positions of the joints. The optimal design obtained is the least weight design which satisfies a specific frequency requirement plus upper and lower bounds on the design variables. The design algorithm is an iterative solution of the Kuhn‐Tucker optimality criterion. The procedure is to modify an initial design to first obtain the desired fundamental frequency and then, while this frequency is held constant, to minimize the weight.The most important features of the algorithm are (a) a small number of design iterations is needed to reach an optimal or near‐optimal design, (b) structural elements with a wide variety of size‐stiffness may be used.The design procedure is illustrated with some numerical examples. The results show that the method is rapidly convergent and the optimized configurations are determined in a small number of redesign cycles. The procedure has been completely automated in a computer program on the HP 45 desk‐top c

ISSN:0029-5981    

DOI:10.1002/nme.1620230707

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper discusses a mathematical model governing the galvanic corrosion phenomenon and surveys the research efforts which have been applied to find a solution to the above problem. The authors classify these techniques into three categories. The first is the finite difference method (FDM), the second is the finite element method (FEM) and the last is the boundary element method (BEM).

ISSN:0029-5981    

DOI:10.1002/nme.1620230708

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractEarly attempts to derive curved beam and shell elements in a curvilinear system were dramatically unsuccessful. This was wrongly attributed to the failure of these elements to recover strain‐free rigid body displacement modes in a curvilinear co‐ordinate description. Recent evidence points to a ‘membrane locking’ phenomenon that arises when constrained strain fields corresponding to inextensional bending are not ‘consistently’ recovered. This accounts for, more completely and precisely, the failure of such elements.In this paper, a simple linear two‐nodedC0continuous thick curved beam element based on a curvilinear deep shell theory is derived free from shear and membrane locking. Lack of consistency in the shear and membrane strain‐field interpolations in their constrained physical limits (Kirchhoff and inextensional bending limits, respectively) causes very poor convergence due to locking and severe spurious oscillations in stress predictions. Error estimates for these are made and verified. Field‐consistent strain interpolations remove these errors and produce the most efficient linear

ISSN:0029-5981    

DOI:10.1002/nme.1620230709

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractReduction method and computational procedures are presented for reducing the size of the analysis model and the number of degrees of freedom used in predicting the non‐linear response of symmetric anisotropic panels. The two key elements of the method are (a) operator splitting, or decomposition of the characteristic arrays of the finite element model into sums of orthotropic and non‐orthotropic contributions, (b) application of a reduction method through the successive use of the finite element method and the classical Rayleigh‐Ritz technique. The finite element method is first used to generate a small number of global approximation vectors (or modes). Then the amplitudes of these modes are computed by using the classical Rayleigh‐Ritz technique.The global approximation vectors are selected to be those commonly used in single (or multiple) parameter perturbation techniques, namely a non‐linear solution corresponding to zero non‐orthotropic arrays and a number of its derivatives with respect to an anisotropic tracing parameter (and possibly, to a load or arc‐length parameter in the solution space). The size of the analysis model used in generating the global approximation vectors is identical to that of the corresponding orthotropic structure.The effectiveness of the proposed reduction method is demonstrated by means of a numerical example, and its potential for solving quasi‐symmetric non‐linear problems of anisotropic pa

ISSN:0029-5981    

DOI:10.1002/nme.1620230710

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractMixed methods solved by an iterative process have been shown to provide an inexpensive procedure for improving the results of standard displacement analysis. This paper shows the possibilities present in their application to dynamic problems, where again accuracy improvement is achieved at small additional expense.The advantages of the formulation presented are particularly noteworthy in explicit forms where the difficulties of ‘hour‐glass’ modes associated with minimal integration rules ae avoided without cost inc

ISSN:0029-5981    

DOI:10.1002/nme.1620230711

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY