ISSN:0029-5981    

DOI:10.1002/nme.1620121002

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620121003

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractAn iterative algorithm is presented: it builds a continuous stress and displacement solution starting from the solution of a classical displacement finite element analysis. The modified solution satisfies the virtual work principle, and is much better than the starting solution. The algorithm is very easily included in existing programs. A number of examples shows the efficiency of the method.

ISSN:0029-5981    

DOI:10.1002/nme.1620121004

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractIn the stressed‐skin analysis of metal structures it is vital to have a simple yet accurate treatment of the shear deformation of profiled metal sheeting. A suitable theory is developed in this paper for the two important cases of sheeting fastened to the supporting structure through every and alternate troughs of the corrugations. Various practical factors are taken into account. The results of an extensive series of numerical investigations are presented as a simple equation and a set of table

ISSN:0029-5981    

DOI:10.1002/nme.1620121005

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe ‘Block Iterative Finite Element Preprocessed Scheme’ (BIFEPS) for finite element simulation combines two independent steps. In the ‘finite element preporcessing step’, spatial information about the finite element mesh is analysed and all integrals arising from the application of the Galerkin method are evaluated and stored on a permanent sequential storage unit (such as tape or disk). In the ‘block iterative step’, the preprocessed information is retrieved from permanent storage and the matrix equation is assembled and solved in an efficient manner according to a generalization of the block successive over‐relaxation iterative method. Significant advantages over common finite element simulation techniques are achieved in terms of both computer core requirements and execution time. Numerical experiments show that the advantages of BIFEPS are greatest for large, non‐linear simu

ISSN:0029-5981    

DOI:10.1002/nme.1620121006

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe finite element method is applied to a typical problem in the optimal control theory. A finite element formulation is first set up, and then applied, as an example, to a problem of minimizing the transfer time of a low‐thrust rocket vehicle between the orbits of Earth and Mars. A procedure which combines the gradient projection technique with the Newton‐Raphson method is introduced to obtain numerically the solution of the minimum time transfer problem from the discretized functional. Numerical results show that the application of the finite element method to optimal control problems seems promising as well as encourag

ISSN:0029-5981    

DOI:10.1002/nme.1620121007

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe stability of time integration for a semidiscretization of structures and continua where the mesh is partitioned into subdomains integrated simultaneously by explicit and implicit methods is considered. Stability in energy is proven for linear systems subject to the Courant condition in the explicit subdomain for a central difference explicit and trapezoidal implicit integrator. Numerical examples are presented to demonstrate the procedure.

ISSN:0029-5981    

DOI:10.1002/nme.1620121008

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe general nine point isoparametric transformation is analysed with respect to a triangle with two straight sides and one curved side. Point placements are determined on the curved side which ensure that the Jacobian of the transformation remains positive inside and on the boundary of the triangle. Special cases of the transformation are considered which lead to implied curves of the form of symmetric cubics, parabolas, and explicit cubics respectively, thus enabling isoparametric transformations to match a variety of boundary shapes.

ISSN:0029-5981    

DOI:10.1002/nme.1620121009

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractComputablea‐posteriorierror estimates for finite element solutions are derived in an asymptotic form forh→ 0 wherehmeasures the size of the elements. The approach has similarity to the residual method but differs from it in the use of norms of negative Sobolev spaces corresponding to the given bilinear (energy) form. For clarity the presentation is restricted to one‐dimensional model problems. More specifically, the source, eigenvalue, and parabolic problems are considered involving a linear, self‐adjoint operator of the second order. Generalizations to more general one‐dimensional problems are straightforward, and the results also extend to higher space dimensions; but this involves some additional considerations. The estimates can be used for a practicala‐posterioriassessment of the accuracy of a computed finite element solution, and they provide a basis for the design of adaptive finite elem

ISSN:0029-5981    

DOI:10.1002/nme.1620121010

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620121011

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY