ISSN:0029-5981    

DOI:10.1002/nme.1620141202

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThis paper is mainly concerned with a new structural optimization method based upon the concept of duality in convex programming. This rigorous formulation permits justification of many intuitive procedures which are used in the classical optimality criteria approaches. Furthermore, the dual algorithms proposed in this paper do not suffer from the drawbacks inherent to the optimality criteria approach. The selection of the set of active constraints does not introduce any difficulty and is achieved correctly in all cases. The subdivision of the design variables in an active and passive group is intrinsically contained in the dual formulation. The efficiency of the dual algorithms is shown with reference to some problems for which the classical methods do not lead to satisfactory results.

ISSN:0029-5981    

DOI:10.1002/nme.1620141203

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractSeveral types of smoothing technique are considered which generate continuous approximation (i.e. nodal values) for vorticity and pressure from finite element solutions of the Navier–Stokes equations using quadrilateral elements. The simpler schemes are based on combinations of linear extrapolation and/or averaging algorithms which convert elementwise. Gauss point values to nodal point values. More complicated schemes, based on a global smoothing technique which employ the mass matrix (consistent or lumped), are also presented.An initial assessment of the accuracy of the several schemes is obtained by comparing the approximate vorticities with an analytical function. Next, qualitative vorticity comparisons are made from numerical solutions of the steady‐state driven cavity problem. Finally, applications of smoothing techniques to discontinuous pressure fields are demonstra

ISSN:0029-5981    

DOI:10.1002/nme.1620141204

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractAlgorithms are described for checking the topological consistency of two‐ or three‐dimensional meshes. Two‐dimensional meshes may include mixtures of triangles, quadrilaterals and other polygons with optional edge or centre nodes; three‐dimensional meshes may include mixtures of cuboids and tetrahedra with optional edge; sie or interna

ISSN:0029-5981    

DOI:10.1002/nme.1620141205

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe computational aspects are examined for the numerical analysis of inelastic structures and continua. In this context, the tracing of quasistatic and dynamic motions is considered with particular emphasis on the interaction of nonlinear and transient problems.In the first part, explicit and implicit solution schemes are developed for the numerical integration of inelastic first‐order rte processes governing creep, viscoelasticity and viscoplasticity. In the second part, the exposition is extended to second‐order inertial problems and in particular to the field of dynamic plasticity, devoting special attention to the kinematics of finite deformation probl

ISSN:0029-5981    

DOI:10.1002/nme.1620141206

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe boundary control problem of optimal heating of an infinitely long slab with tempertue‐dependent thermal conductivity, subjected to a convection and radiation boundary condition, is analysed by numerical methods.In order to reformulate the optimal control problem of distributed parameter systems as a mathematical programming problem of finite dimension, a space, co‐ordinate is discretized by use of the finite element method, while the Runge–Kutta method is utilized for time integrations. Finally, the performance index of the optimal control problem is minimized by the conjugate gradient method of optimiz

ISSN:0029-5981    

DOI:10.1002/nme.1620141207

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractEarlier publications demonstrated the capability of the EPIC‐3 code to perform high velocity impact computations in three dimensions.1,2These capabilities were demonstrated with simplified material and sliding surface models in a core‐contained computer program. This paper presents recent developments which include more comprehensive material and sliding surface formulations, and an expanded computer program which can handle problems of unlimited size by beffering data between disc files and core. The EPIC‐3 code is based on an explicit, finite element, Lagrangian formulation which uses constant strain tetrahedral ele

ISSN:0029-5981    

DOI:10.1002/nme.1620141208

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620141209

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620141210

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620141211

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY