摘要:

AbstractThis paper describes the stages of development of an optimum structural design scheme. Any attempt to generate the optimum scantlings of a structure of even moderate complexity usually poses nonlinear programming problems for which there exist no universally accepted solution method. The structure considered here is a complete compartment of a single‐hulled ship acted upon by multiple load cases. The elastic responses under four different load types are obtained by a quasi finite elementanalysisroutine developed specifically for this purpose. Sequential linear programming (SLP) with appropriate artifices to achieve rapid convergence has been successfully employed as anoptimizationroutine to minimize the object function, which in this case was the total weight of the major structural members. The test problem has 490 basic degrees‐of‐freedom, 21 free design variables and more than 100 mixed constraints, the majority of which are nonlinear implicit stress functions. The method is then applied to a number of cases representative of small warship designs. Suggestions for future extensions and general conclusions are included at the end of the

ISSN:0029-5981    

DOI:10.1002/nme.1620201002

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractContour plots of finite element solutions, especially for derivatives, often are discarded due to poor plotting algorithms. This note shows how a smoothing scheme based on a minimum surface theory can significantly improve the quality of the graphical results. The scheme proposed is compared with many other smoothing schemes, including least squares, on a simple problem.

ISSN:0029-5981    

DOI:10.1002/nme.1620201003

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe simulation of a large‐scale gas transmission network involves the numerical solution of a large system of initial valued, stiff algebraic/differential equations. Rapid changes in the solution are present due to the disturbances generated by the varying consumer demand and the operation of network controlling devices such as compressors. This paper discusses the design of an efficient variable‐step integrator for the solution of the problem. Two sets of strategies are presented for implementing the variable‐step integrator; one for the implicit numerical method such as the diagonally implicit Runge–Kutta methods, and the other for the linearly implicit Rosenbrock‐type method. The performance of the numerical methods implemented are compared with the British Gas simulation program PAN on a number of large, realistic transmission

ISSN:0029-5981    

DOI:10.1002/nme.1620201004

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe approach of Cermak and Zlamal1for solving quasilinear parabolic equations is modified and improved. The modified approach leads to a normal system of ODE, which may be solved with a standard program. The numerical solution of a specially selected example is compared with the exact solution. The method is applied on a system of quasilinear parabolic equations, which describes a real process—crystallization of a metal ingo

ISSN:0029-5981    

DOI:10.1002/nme.1620201005

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe optimality conditions for the optimal shape remodelling of linearly elastic plates are obtained by introducing the total variation of a function defined on a variable domain, although the variation of a function has been taken on a fixed domain in most literature on calculus of variations. Using these optimality conditions, a solution scheme involving an iterative algorithm is proposed, together with several numerical examples.

ISSN:0029-5981    

DOI:10.1002/nme.1620201006

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper presents the modelling of open shells, such as those used in roof construction, by means of a single‐layered, pin‐jointed truss. The latter exhibits several advantages over existing framework models, such as, for example, statical determinacy and the capacity to cope with arbitrary material constants. In the present article, the truss model is developed for and applied to the numerical analysis of shells subject to the membrane hypothesis. However, the same statically determinate model forms the basis for a computational scheme for analysing shells according to the more formal, statically indeterminate bending theory; the latter application of the truss model will be presented in a subsequent pa

ISSN:0029-5981    

DOI:10.1002/nme.1620201007

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper presents a simple scheme for analysing shells subject to the Kirchhoff–Love hypothesis. The method combines a previously developed, statically determinate truss model with the static‐geometric analogy of elastic thin shell theory. In this way, both in‐plane and flexural mid‐surface actions are obtained by simply repeating the elementary computations performed on an essentially ‘membra

ISSN:0029-5981    

DOI:10.1002/nme.1620201008

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA simple but versatile numerical technique using generalized finite difference discretization has been developed for heat transfer problems involving high convective heat flow, irregular geometry and high local thermal gradients. Upwind differencing is utilized to stabilize the numerical oscillations often induced in convection‐dominated heat transfer problems. An arbitrary irregular mesh scheme is adopted to treat the irregular geometry and to achieve high accuracy in zones having high thermal gradients. To demonstrate the validity of the formulation procedure, results predicted from the present scheme are compared with the analytical solution for a problem having a regular boundary. Application to a typical metal‐forming process having curved boundaries is then inclu

ISSN:0029-5981    

DOI:10.1002/nme.1620201009

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620201010

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractFinite deformations of a nonlinear viscoelastic rubber layer bonded to a uniformly rotating rigid cylinder and indented by another rigid cylinder are studied by the finite element method. The problem formulation includes both material and geometric nonlinearities. The effect of the change in the thickness of the layer, its speed of rotation and its material properties on the pressure distribution at the contact surface, and other aspects of the deformation of the layer, are studied.

ISSN:0029-5981    

DOI:10.1002/nme.1620201011

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY