摘要:

AbstractA general Finite Volume Method (FVM) for the analysis of structural problems is presented. It is shown that the FVM can be considered to be a particular case of finite elements with a non‐Galerkin weighting. For structural analysis this can readily be interpreted as equivalent to the unit displacement method which involves mainly surface integrals. Both displacement and mixed FV formulations are presented for static and dynamic problem

ISSN:0029-5981    

DOI:10.1002/nme.1620370202

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe zone method is applied to non‐orthogonal curvilinear grids for the computation of radiative heat transfer. The interchange areas are calculated by the Monte Carlo technique which has been fitted with a generalized ray tracing procedure. The method is applied to two complex three‐dimensional (3‐D) cases where in homogeneities are present in the radiation space (non‐uniform gas properties and/or shadowing effects), and the gas is taken as gray. For comparison purposes, the same examples are worked out with the discrete transfer method. Very small discrepancies are found between the two methods for the surface heat fluxes, but the gas volumetric radiative sources are much more sensitive to inhomogeneities in the gas phase, resulting in higher discrepancies for these terms. The method can be readily extended to incorporate real gases and scattering

ISSN:0029-5981    

DOI:10.1002/nme.1620370203

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractUsing the finite element method a numerical procedure is developed for the solution of the two‐dimensional frictional contact problems with Coulomb's law of friction. The formulation for this procedure is reduced to a complementarity problem. The contact region is separated into stick and slip regions and the contact stress can be solved systematically by applying the solution technique of the complementarity problem. Several examples are given to demonstrate the validity of the present formulatio

ISSN:0029-5981    

DOI:10.1002/nme.1620370204

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAn element‐free Galerkin method which is applicable to arbitrary shapes but requires only nodal data is applied to elasticity and heat conduction problems. In this method, moving least‐squares interpolants are used to construct the trial and test functions for the variational principle (weak form); the dependent variable and its gradient are continuous in the entire domain. In contrast to an earlier formulation by Nayroles and coworkers, certain key differences are introduced in the implementation to increase its accuracy. The numerical examples in this paper show that with these modifications, the method does not exhibit any volumetric locking, the rate of convergence can exceed that of finite elements significantly and a high resolution of localized steep gradients can be achieved. The moving least‐squares interpolants and the choices of the weight function are also discussed in this

ISSN:0029-5981    

DOI:10.1002/nme.1620370205

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe feasibility of conducting a detailed analysis of pile driving using a finite element technique is examined in this paper, taking into account the non‐linear behaviour of undrained clayey soil and tracing the penetration of the pile into the soil. A three‐dimensional model is used for this purpose, which is handled by two‐dimensional analysis due to the axisymmetric nature of the problem. A non‐linear time‐domain dynamic analysis is performed in which the hammer blows on the pile are represented by a periodic forcing function, and the pile penetration is treated using a frictional contact slideline algorithm. The model is applied 10 the driving of a concrete pile in a cl

ISSN:0029-5981    

DOI:10.1002/nme.1620370206

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAn hybrid stress element formulation based on internal, incompatible displacements is used to develop efficient Mindlin plate elements. The 4‐node quadrilateral Mindlin plate element is derived from a modified energy functional. Both displacements and stresses are defined in the natural co‐ordinate interpolation system. The assumed stress field is obtained by tensor transformation and so chosen as to ensure that the element is co‐ordinate invariant and stable. Shear locking is avoided through an appropriate identification of the internal, incompatible displacement field. The role played by incompatible displacements in the formulation of hybrid stress elements for thin and moderately thick plates is discussed. Numerical applications are presented to illustrate the accuracy and reliability of the suggested Mindlin plate el

ISSN:0029-5981    

DOI:10.1002/nme.1620370207

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAdopting anupdated Lagrangianapproach, thegeneralframework for the fully non‐linear analysis ofthin‐walledframed structures is developed using asimple, two‐node,C0‐model (HMB2). The governing equations are derived based on a consistent linearization of anincremental mixedvariational principle of modified Hellinger/Reissner type with independent assumptions for displacement and strain fields. All coupled significant modes of deformations, i.e. stretching, bending, shear, torsion and warping, are accounted for in the generalized‐beam theory employed. Emphasis is placed on devising effective solution procedures to deal withfinite rotationsin space, particularly with regard to their effect on the derivations ofload‐correctionmatrices corresponding toconfiguration‐dependentexternally applied forces/moments. The effectiveness and practical usefulness of present model are demonstrated through a number of test problems involving beam assemblages undergoing large displacements and rotat

ISSN:0029-5981    

DOI:10.1002/nme.1620370208

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractStructural dynamic equations with unilateral constraints upon the displacements, velocities and accelerations are employed in order to represent vibrating elastic structures with normal, oblique impact and friction interaction points.For obtaining a numerical integration scheme the Lagrange multipliers and a minimum work approach are employed at each time step. The algorithm is presented as an extension of the generalized Newmark scheme. It seems to retain the asymptotic features of the original one.The reduction of the number of dynamic degrees of freedom of the unilaterally constrained structures is carried out by representing the equations of motion in modal co‐ordinates of the unconstrained structure and truncating the dynamic contributions of higher modes.The presented techniques have been verified by investigating free longitudinal vibroimpact motion laws of an elastic vibroconverter and free longitudinal and bending vibration of a vibroconverter interacting with a moving rigid body by oblique impact and friction force

ISSN:0029-5981    

DOI:10.1002/nme.1620370209

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractNumerous engineering problems, especially those in electromagnetics, often require the treatment of the unbounded continua. Mapped infinite elements have been developed for the solution of 3‐D magnetic vector potential equations in infinite domain that may be used in conjunction with the standard finite elements. The electromagnetic field equations are written in terms of the magnetic vector potential for the infinite domain, and 3‐D mapped infinite eiement formulation based on these equations is presented in detail. A series of magnetostatics and eddy current problems are solved to demonstrate the validity and efficiency of the procedure. These numerical results indicate that the combined finite–infinite element procedure is computationally much more economical for the solution of unbounded electromagnetic problems, especially when using the vector potential formulation, as the number of system equations decreases substantially compared to the finite element only procedure. The present procedure shows promise for the treatment of large practical industrial 3‐D eddy current problems with manageable computer re

ISSN:0029-5981    

DOI:10.1002/nme.1620370210

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620370211

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY