摘要:

AbstractFinite element interpolations of arbitrary polynomial degree which are exactly and minimallyC1continuous across interelement boundaries are studied. A perspective view of the techniques proposed by other authors is presented and some new possibilities are considered. The problem is discussed with reference to the plate and shell finite element approximations, based on the principle of minimum potential energy. The approach also permits identification of sufficient conditions for guaranteeing full rank of stiffness matrices based on modified principles of potential energy. The results of this analysis can be used to investigate the linear dependencies among nodal variables which also occur in the formulation of other fourth‐order problem

ISSN:0029-5981    

DOI:10.1002/nme.1620140903

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractIn this paper the computer code Duvorol, dealing with the computation of three‐dimensional rolling contact with dry friction, is described. It is based on the variational principle of Duvaut and Lions for dry friction, which leads to an incremental theory. The relevant properties of Duvorol are:1Generality. All half‐space steady‐state rolling contact problems with Hertzian normal contact can be treated.2Reliability. The total tangential force is always found with reasonable accuracy by a standard discretization.3Speed. On an IBM 370/158 the calculation of a case then takes only several se

ISSN:0029-5981    

DOI:10.1002/nme.1620140904

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractAn accurate nonlinear analysis procedure for calculating the displacement stresses and system buckling loads of geometrically imperfect truss structures is developed. The investigation considers both local and system imperfections. This nonlinear analysis takes first‐order geometrically nonlinear effects into account. The accuracy of the analysis procedure is confirmed by comparison with analytical and experimental results for truss structures drawn from the literature. The results show that local and system imperfections can have strong influence on the behaviour of truss structures and therefore should be taken into account. It is shown that nonlinear effects play a major role in the phenomena and therefore simplified analyses that neglect nonlinear effects are inadequat

ISSN:0029-5981    

DOI:10.1002/nme.1620140905

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractAn incremental force–displacement relation is derived using the finite element matrix method to study the inelastic bending of beams including transverse shear. Solutions are obtained for the case of a cantilever beam with a point load and a simply supported beam with distributed loading considering and also ignoring the effect of transverse shear. They show good agreement for those cases where solutions are available. Also, the effect of transverse shear is found to be quite significan

ISSN:0029-5981    

DOI:10.1002/nme.1620140906

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA new second‐order accurate method for the solution of two‐point boundary value problems on a uniform mesh is given; the local truncation error is obtained for use with the deferred correction process. The method is compared with existing second‐order techniques and is shown to produce more accurate results for a number of linear and nonlinear example pro

ISSN:0029-5981    

DOI:10.1002/nme.1620140907

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA simple, yet effective, finite element approach to aerodynamic problems is presented. A better approximation of the geometry is obtained by the mapping of airfoils into near‐circles. The mapping serves in homogenizing the gradients of the problem by magnifying regions of high gradients such as the leading and trailing edges while geometrically condensing the lower gradient regions on the main part of the airfoil. The mapping also permits the use of an effective automated mesh generation scheme that greatly reduces the amount of preparatory work involved in finite elements. To limit the size of the solution domain, an asymptotic analytical solution, with unknown coefficients, is assumed on a finite radius outer contour. The coefficients are obtained along with the finite element nodal unknowns. An accrued advantage of this patching asymptotic procedure is its ability to obtain the lift as a solution variable without having to resort to the numerical integration of the pressure field over the body. Solutions to non‐lifting and lifting bodies are obtai

ISSN:0029-5981    

DOI:10.1002/nme.1620140908

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractWe introduce a finite element model for stress analysis of threaded connections. Instead of modelling individual threads, the thread zone is replaced by a layer of elements with orthotropic properties. The principal directions of orthotropy depend upon the thread geometry and upon the direction of load, which is not necessarily knowna priori. Both conventional and tapered threads are considered. The latter problem is nonlinear, as the number of threads in contact is a function of the load. Numerical results for conventional and tapered threads agree well with theoretical and exeprimental results in the literature.

ISSN:0029-5981    

DOI:10.1002/nme.1620140909

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractOrthogonal base functions that are complete first‐order polynomials but contain higher order terms are developed for normalized rectangular and triangular elements. To obtain exact expressions for kinetic energy under rigid body rotation, an internal node is introduced at the centroid of each element. Then the corresponding mass matrix is both diagonal and consistent. A mixed variational formulation is used in the derivation of spatially discretized field equations. Central Difference time integration is utilized to provide sample results which are compared with other numerical or analytical solution

ISSN:0029-5981    

DOI:10.1002/nme.1620140910

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA combination of a two‐dimensional finite element process and a Fourier series in the third dimension, well known in linear applications, is shown to be a possible and efficient way of analysing plastic and visco‐plastic behaviour. The economy of the process as contrasted with full three‐dimensional solutions is illust

ISSN:0029-5981    

DOI:10.1002/nme.1620140911

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractIn the light of recent contributions by Batoz1and Hibbitt,2two aspects of finite element formulations for shell stability analysis are examined. The first is the consistency of the shell strain‐displacement equations employed; the second is the proper representation of ‘follower forces’—pressures that are always normal to the deforming surface. Numerical studies of an arch indicate that improper representation of either of these factors can have a significant effect on predicted buckling loads. Numerical studies of an arch indicate that improper representation of either of these factors can have a significant effect on predicted buklin

ISSN:0029-5981    

DOI:10.1002/nme.1620140912

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY