摘要:

AbstractThis study presents the finite element analysis for the transient heat transfer problems by introducing the Fourth‐dimension concept. Time is treated as an additional dimension in the solution domain thereby Increasing the number of dimensions by one. For instance, a three‐dimensional transient problem can be considered as a four‐dimensional problem in thex,y,z,tdomain and a two‐dimensional transient problem can be considered as a three‐dimensional steady‐state problem in thex,y,tdomain, respectively. The variational principle of the finite element method and the techniques existing for steady‐state problems can be directly utilized. Numerical calculations were performed for heat conduction problems, laminar‐turbulent convective heat transfer problems, and radiative heat tr

ISSN:0029-5981    

DOI:10.1002/nme.1620170302

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA finite element analysis of strain‐softening materials is presented in which the shear band of prescribed thickness is assumed to exist within elements where maximal stress intensity is reached. The incremental stiffness matrix of the element is derived including shear band deformation. Examples presented in the Paper demonstrate that the load‐displacement curve and the displacement field are not sensitive to the mesh size used in the solut

ISSN:0029-5981    

DOI:10.1002/nme.1620170303

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractSplitting methods for time‐dependent partial differential equations usually exhibit a drop in accuracy if boundary conditions become time‐dependent. This phenomenon is investigated for a class of splitting methods for two‐space dimensional parabolic partial differential equations. A boundary‐value correction discussed in a paper by Fairweather and Mitchell for the Laplace equation with Dirichlet conditions, is generalized for a wide class of initial boundary‐value problems. A numerical comparison is made for the ADI method of Peaceman‐Rachford and the LOD method of Yanenko applied to problems with Dirichlet boundary conditions and non‐Dirichlet bounda

ISSN:0029-5981    

DOI:10.1002/nme.1620170304

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThis paper presents a method of developing a family of 1/rntype infinite elements for the analysis of problems definite in unbounded media. The proposed method is a direct extension of the conventional finite element method. The resulting improper integrals are integrated exactly over the infinite element domains. Two numerical examples in elastic half‐space static problems are investigated to illustrate the applicability and accuracy of the method. The use of the proposed infinite elements yields excellent results and preserves all the advantages of the finite element metho

ISSN:0029-5981    

DOI:10.1002/nme.1620170305

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620170306

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620170307

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA multidomain boundary element formulation for the analysis of general two‐dimensional plane strain/stress crack problems is presented. The numerical results were accurate and efficient. The analyses were performed using traction singular quater‐point boundary elements on each side of the crack tip(s) with and without transition elements. Traction singular quarter‐point boundary elements contain the correct √rdisplacement and 1/√rtraction variations at the crack tip. Transition elements are appended to the traction singular elements to model the √rdisplacement variation. The 1/√rtraction singularity is not represented with these elements. Current research studies for the crack propagation analysis of quasi‐static and fatigue fracture problem

ISSN:0029-5981    

DOI:10.1002/nme.1620170308

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620170309

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA finite difference method for the large deformation elastic‐plastic analysis of spherical caps is applied to predict the collapse strength of initially imperfect deep spherical shells. Twelve uniformly loaded hemispherical shell models with flat spots at their apex are analysed. For each model, a number of shallow spherical regions containing the flat spot are selected from its domain. One of these selected shallow regions yields a minimum buckling pressure; this minimum value is taken as the theoretical buckling load for the shell model under consideration. Present solutions are in good agreement with existing experimental and empirical results. The good comparison suggests that initially imperfect deep spherical shells may be analysed by using a much simpler mathematical model—the spherical cap—and thus the analytical cost may be greatly reduced. This also demonstrates that the collapse of imperfect spherical shells is primarily a local phenomenon and therefore dependent on local geometry. Consequently, the presence of initial imperfections must be fully taken into consideration in any large deformation inelastic buckling analysis before such analysis can be expected to quantitatively predict the collapse strength of practical shell struc

ISSN:0029-5981    

DOI:10.1002/nme.1620170310

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA singular finite element is developed for direct calculation of combined modes I and II stress intensity factors for planar rectilinear anisotropic structures subject to arbitrary loading. Twelve‐node conventional elements are used in conjunction with a linear elastic fracture mechanics enrichment of the same element which is formed into a four‐element macro‐element. Example problems show this formulation to be exceptionally accurate and results are presented for a variety of modern fibre‐reinforced composites in simple mode I extension and in mixed mode I and II situations. In addition, it is shown that the meshes for accurate results are relatively coarse and thus calculations are quite eco

ISSN:0029-5981    

DOI:10.1002/nme.1620170311

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY