摘要:

AbstractThe boundary element method as it applies to two‐dimensional elastostatic problems is implemented with quadratic variation in boundary variables and geometry. Additional parameters are associated with nodes at segment intersections to allow for discontinuous tractions. Supplementary equations consistent with linear elasticity are used to augment the regular boundary integral equations for certain mixed and displacement boundary conditions. Zoning or subregionalization capabilities are included to provide solutions to piecewise nonhomogeneous problems or problems on regions of irregular shape. Example problems are given to demonstrate the accuracy of the techniqu

ISSN:0029-5981    

DOI:10.1002/nme.1620190103

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA simple two‐step corrective technique is presented in this paper for evaluating stress intensity factors in crack problems. In the first step an approximate evaluation of the stress intensity factor was made by considering the cracked plate to be of infinite size. The stresses of the problem were relaxed by the stresses of the infinite body which corresponds to the approximate value of the stress intensity factor. The expected discrepancy in the value of SIF by the infinite plate approximation was corrected in the second step where the existing residual stresses are equilibrated at the cracked plate by using any of the conventional finite element techniques and the corrective value of the stress intensity factor is calculated by using an appropriate collocation formula. The method was applied to three typical plane problems of cracked plates with satisfactory result

ISSN:0029-5981    

DOI:10.1002/nme.1620190104

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA method is proposed for the approximate evaluation of normal displacements and normal stresses on the plane of two coplanar cracks located inside an infinite isotropic elastic solid and subjected to normal internal pressure. The formulation results in a single integral equation for the unknown normal stresses on the plane of the cracks. Numerical results are given for the stress intensity factorKIof two coplanar circular cracks and two coplanar elliptical cracks opened up under a uniform internal pressure.

ISSN:0029-5981    

DOI:10.1002/nme.1620190105

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractAn examination is made of displacement trial functions found in the quadratic isoparametric representation of an arc. Special attention is given to the quality of curvature change description and to effective manipulation of the trial functions. Various interpolation formulae are derived which have relevance to curved shell finite element design under Love‐Kirchhoff assumption

ISSN:0029-5981    

DOI:10.1002/nme.1620190106

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractIn this paper, the application of successive block overrelaxation methods to obtain the deflection of a skew plate are compared, although the techniques herein are applicable to a wider range of problems. An algorithm for the direct solution of the submatrices comprising the two‐line blocks of the skew grid is presented and the results are compared with the block (line and peripheral) overrelaxation method

ISSN:0029-5981    

DOI:10.1002/nme.1620190107

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThin‐walled members subject to generalized loading may be modelled by using a finite element approach with conventional stress and strain parameters. A solution method for a class of problems that would use these elements is described. A numberical example of an elastic beam is give

ISSN:0029-5981    

DOI:10.1002/nme.1620190108

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractIn this study, three boundary element method approaches are compared by solving a typical problem in linear elastodynamics. The first approach formulates and solves the problem in the real time domain in conjunction with a time‐stepping algorithm. The other two approaches formulate and solve the problem in the Laplace and the Fourier transformed domains, which necessitates a numerical inversion of the results to the time domain. The results obtained compare favourably with available analytic solutions. A detailed tabulation of the computer time and memory requirements of each approach is presente

ISSN:0029-5981    

DOI:10.1002/nme.1620190109

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA numerical method for solving finite dimensional structural optimization problems with constraints on natural frequency and on buckling is formulated. The method treats nondifferentiable repeated eigenvalues that have been shown to systematically arise in structural optimization. Recent results on differentiability of eigenvalues are used to develop a generalized gradient projection method for structural optimization. The algorithm is shown to overcome technical difficulties associated with nondifferentiability of repeated eigenvalues. The method is used to solve buckling and vibration optimization problems in which repeated eigenvalues occur.

ISSN:0029-5981    

DOI:10.1002/nme.1620190110

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA finite element technique, for efficient solution of a class of 3‐D elasticity problems, is presented. In this method, standard 2‐D finite elements are used along with a ‘connector’ element. An element, previously used to model material interfaces, is shown to provide the properties for use as a ‘connector’ element, if input variables are redefined. The accuracy of the technique is illustrated with a samp

ISSN:0029-5981    

DOI:10.1002/nme.1620190111

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe computational methods used to predict and optimize the thermal‐structural behaviour of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems.Therefore mixed time integration methods for transient thermal analysis of structures are being developed. This proposed methodology would be readily adaptable to existing computer programs for structural thermal analysi

ISSN:0029-5981    

DOI:10.1002/nme.1620190112

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY