摘要:

AbstractThis article presents the derivation of a very straightforward approximate procedure for the analysis of a continuous flexible member. Since very large deformations are anticipated, a shooting method is utilized along with Newton‐type iteration for improved estimates. The resulting computer program is used to compare with exact solutions for a new example

ISSN:0029-5981    

DOI:10.1002/nme.1620150302

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractA method for calculating natural frequencies and mode shapes of large structural systems with substructures and the subspace iteration is developed. The method uses only substructural stiffness matrices and the mass matrix for each finite element of the system. The mass matrix for the entire structure or any of its substructures need not be computed. However, efficiency of the method is improved when mass matrix for the entire structure is computed and saved in the computer core. No approximating assumptions are made. Thus, natural frequencies and mode shapes for the finite element model employed are the same with or without the substructuring algorithm. This is demonstrated by computing first ten natural frequencies and the corresponding mode shapes for an open truss helicopter tail‐boom structur

ISSN:0029-5981    

DOI:10.1002/nme.1620150303

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractA complementary energy method for the stability analysis of plates is presented. Buckling loads of rectangular plates with different boundary conditions are obtained, and the convergence of the solution is studied.

ISSN:0029-5981    

DOI:10.1002/nme.1620150304

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractNumerical convergence of first‐ and second‐order plate‐bending elements is investigated. Using iso‐parametric formulation, general bilinear and biquadratic quadrilaterals, with the three moment components and the transverse deflection as dependent variables, are obtained. The same elements are also used as degenerate triangles by collapsing one side. A constant bending moment patch test, applied numerically to the elements, indicated poor performance for linear triangles, while the bilinear, quadratic and biquadratic elements behaved well, with exact results in uniform meshes. Further numerical examples showed the same general trend as the patch test. Although bilinear, quadratic and biquadratic elements were always able to yield the correct solutions with mesh refinements, the linear triangles were in general unable t

ISSN:0029-5981    

DOI:10.1002/nme.1620150305

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractA simple, efficient finite element method has been presented for the solution of a variety of scalar field problems in two dimensions. It is based on the mapping of the physical problem domain into an ‘image’ domain in thew‐plane. The governing equation(s) and the boundary conditions in the physical plane are also appropriately transformed into thew‐plane. The processes of standard finite element analysis are then implemented to obtain a solution in thew‐plane.The method has been explained in detail, with illustrative examples where appropriate; it has several important advantages over the standard finite element method, particularly for the solution of infinite or semi‐infinite domain problems. The method has been demonstrated to be simple, efficient, economical and potentially capable of dealing with a large repartoire of two‐dimensional problems, including non‐homogeneity, no

ISSN:0029-5981    

DOI:10.1002/nme.1620150306

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe complete two‐dimensional partial differential equations for developing laminar flow in a circular tube have been treated by a finite difference analysis. Property variation with temperature, especially that of viscosity, is allowed for in a flexible manner. The continuity and momentum equations, and then the energy equations, are solved by direct elimination at each axial step, and marching procedure used in the axial direction. A new technique is that the stepwise energy balance is rigidly satisfied throughout by using it as a constituent equation in place of the ‘explicit’ wall thermal boundary condition normally used.The analysis predicts the complete developing hydrodynamic and thermal fields, together with friction factors and heat transfer coefficients. It has been tested for a range of fluid velocity and thermal boundary conditions and for various fluids, including high viscosity oils, water and air.Data for constant wall heat flux have already been published.1,2Predictions for constant wall temperature presented here are for forced and combined convection and are compared with experimental data of Test3and Zeldin and Sch

ISSN:0029-5981    

DOI:10.1002/nme.1620150307

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

ISSN:0029-5981    

DOI:10.1002/nme.1620150308

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe side and corner flow rules for viscoplastic materials with singular yield surfaces are discussed and applied in numerical solution of several boundary‐value problems. The differences in predictions of displacement and stress fields for different flow rules are demonstrate

ISSN:0029-5981    

DOI:10.1002/nme.1620150309

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractThe notion of thermodynamic consistency of a finite difference scheme is introduced in connection with steady compressible flow simulation. This concept requires that the finite difference scheme must lead to solutions which are consistent with the Second Law of Thermodynamics, whatever the grid sizes employed. Thus, in addition to the usual consistency with the conservation equations of mass, momentum and energy, the solutions of the finite difference equations must satisfy thermodynamic restrictions. The scheme proposed by Singhal and Spalding for the computation of plane, isentropic flow is generalized in a thermodynamically consistent way to handle inviscid, adiabatic but non‐isentropic plane flow. Numerical solutions are obtained for a model problem using both the original and the extended methods. The results are compared with analytical predictions of shock‐expansion theory. The effectiveness and the thermodynamic consistency of the new formulation is demonstra

ISSN:0029-5981    

DOI:10.1002/nme.1620150310

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY

摘要:

AbstractClosed form finite element solutions are obtained for the uniformly loaded membrane inRn,n= 2,3 discretized with first‐order elements. It is verified on this model that the pointwise error in the displacement is 0(h2log 1/h). Slopes converge pointwise at the optimal rate 0(h

ISSN:0029-5981    

DOI:10.1002/nme.1620150311

出版商:John Wiley&Sons, Ltd    

年代:1980

数据来源: WILEY