bluuebunny/crossref_metadata_2025_split huggingface dataset:
An identification method applied to an orthotropic plate bending experiment
Authors: Kernevez J. P. , Knopf‐Lenoir C. , Touzot G. , Verchery G. 
Published: August 2005

AbstractThe paper presents a method of identification of material behaviour parameters. The method is applied to a simple example: the identification of orthotropic parameters using a plate bending test. A number of results are presented concerning the choice of numerical algorithm, the experimental protocole (number and locations of test points, loading) and the sensitivity of the method on experimental errors.
Higher‐order horizontally‐curved beam finite element including warping for steel bridges
Authors: El‐Amin Fathalla M. , Kasem Mohamed A. 
Published: August 2005

AbstractThe flexural stiffness for a horizontally curved beam element is developed for nodal parameters wi, (∂w/∂s)i, βi, (∂β/∂s)i, (∂2β/∂s2)i, (∂3β/∂s3)i by assuming a cubic displacement function for vertical deflection w, and a seventh order polynomical function for the angle of twist β, along the length of the curved beam. The element gives good accuracy with even coarse mesh for the analysis of horizontally‐curved steel beam with open thin‐walled bisymmetrical cross‐section.Warping restraint is considered in the derivation of the stiffness matrix, which has considerable influence on the behavior and design of steel bridges curved in‐plan. The results obtained from such a new element are compared with those given by a lower order finite element, developed previously by the first author, and with theoretical solutions for the particular problem.
Application of the adaptive random search to discrete and mixed integer optimization
Authors: Kelahan R. C. , Gaddy J. L. 
Published: August 2005

AbstractIn this study, a random search technique, previously applied to continuous optimization problems, is adapted and applied to discrete and mixed integer problems. The development of the method and the procedure for applying the method are discussed in detail. Three discrete and one mixed integer problems, efficiencies can be made. The radom search procedure demonstrated perfect reliability in locating the optima. Improved efficiencies resulted for each of the examples are improved optimal solutions were found in two cases.
Optimal design of dynamically loaded continuous structures
Authors: Haug Edward J. , Feng T‐T. 
Published: August 2005

AbstractA computational algorithm is developed and applied for optimization of beam and plate structures, subject to constraints on transient dynamic response. A continuous design formulation is retained, with dynamic response governed by partial differential operator equations. Adjoint equations are employed for sensitivity analysis and a function space gradient projection optimization approach is presented. Finite element analysis methods are applied for solution of the system dynamic and adjoint differential equations. Displacement constrained beam and plate minimum weight examples are solved, with a variety of boundary conditions.
Two step explicit finite element method for tsunami wave propagation analysis
Authors: Kawahara Matsuto , Takeuchi Norio , Yoshida Takaharu 
Published: August 2005

AbstractNumerical analysis of tsunamis applying the finite element method is presented based on the shallow water wave equation. To discretize time, a two step explicit method is used. The scheme is the extension of the Lax‐Wendroff finite difference method. The present finite element method is used for the analysis of the Tokachi‐oki Earthquake tsunami problem and compared with the tide gauge records. The conclusion of this paper is that the present method is suitable for the prediction of the tsunami wave propagation problem.
The indirect design of fluid channels using a global variational method with trial functions not satisfying the prescribed boundary conditions: II cupling method
Authors: Hendry J. A. 
Published: August 2005

AbstractA global variational method (GVM) not requiring the boundary conditions to be incorporated in the trial functions is described. The method is outlined for a linear differential equation and the extensions necessary to handle the non‐linear problem of the indirect design of a compressible fluid channel described. The method requires a suitable estimate of a parameter, but the results obtained for the non‐linear problem indicate that the actual value of this parameter is not critical (provided that a sufficeintly large number of trial functions is used). Comparisons are made with the results from an alternative GVM approach described in Davies and Hendry.1
Plasticity analysis by a non‐conforming plane element
Authors: Cochet J. F. , Dhatt G. S. , Aribert J. M. 
Published: August 2005

AbstractA non‐compatible rectangular element with 12 degrees‐of‐freedom (DF) has been developed by Wilson et at.5 for analyzing 2‐dimensional problems. The superior convergence properties of this element as compared with the 8 DF element for linear elasticity problems with important bending have been demonstrated in References 2, 5. The purpose of this study is to assess the compartive efficiency of these two rectangular elements for an estimation of collapse loads in plasticity problems. For convenience, the 12 DF and 8 DF element will be represented by Q6 and Q4 respectively.
Solution of water networks by sparse matrix methods
Authors: Chin K. K. , Gay R. K. L. , Chua S. H. , Chan C. H. , Ho S. Y. 
Published: August 2005

AbstractA computer program for Water Network analysis has been developed usingy sparse matrix techniques for solution. The method used is the successive linearization method where the set of equations [Q]=[Y][H] is solved. In the process, two subroutines for node reordering to preserve sparsity of the Jacobian matrix and a subroutine for solving the matrix by the Doolittle method are included. The method is user oriented and requires a minimum amount of input data and effort. Networks of up to 200 nodes and 300 pipes may be analysed on an IBM 1130 computer with 16K words of memory.
Large deflection analysis of frame structures by fictitious forces
Authors: Kohnke Peter C. 
Published: August 2005

AbstractA new procedure is presented for the analysis of geometrically non‐linear frame structures. It assumes small strains and uses ‘fictitious forces’ based on the rotation from the initial configuration. The procedure also uses total displacements rather than incremental displacements. The procedure is valid for rotation up to 180 degrees and converges in a relatively small number of iterations.
Three‐dimensional finite element analysis for through‐wall crack in thick plate
Authors: Yagawa G. , Nishioka T. 
Published: August 2005

AbstractA superposition method, in which analytical and finite element solutions are combined through the variational principle, is presented for determining the three‐dimensional stress intensity factors of the through‐wall crack. Cumbersome volume integral due to the singular terms at the crack tip is carried on by applying the least squares methods to the results obtained by the Legendre‐Gauss quadrature. Several numerical calculations are made based on the present method, showing that the three‐dimensional effects cannot be neglected especially for the cases of larger Poisson's raito. The comparison of the present method with the other finite element methods proposed for determining the three‐dimensional stress intensity factors indicates that the former has the obvious superiority to the latters in respect to the numbers of elements and nodal points necessary to obtain reasonable results.
A finite difference perturbation procedure for non‐linear elastic stability problems
Authors: Naschie M. S. El , Galaly I. , Athel S. 
Published: August 2005

AbstractA finite difference perturbation scheme is developed which allows a simple solution to a wide class of non‐linear difurcation problems. The analysis shows that in order to determine the inital post bucking behaviour accurately, it is not necessary to solve more than the linear eigenvalue difference equation with similar accuracy.
Lumped mass matrices with non−zero inertia for general shell and axisymmetric shell elements
Authors: Surana Karan S. 
Published: August 2005

AbstractA diagonal lumped mas formulation with non−zero inertia terms is presented for Ahmad's general shell element. The effect of co−ordinate transformation of the mas matrix is demonstrated. Due to arbitray co−ordinate transformation on nodal variables, the diagonal lumped mas matrix becomes a banded matrix of half bandwidth three. It is shown that with some approximations this matrix can be made diagnoal without effecting the results appreciably. Numerical examples are presented to illustrate the accuracy of the formulation. Similar lumped mass matrix formulation is also given for axisymmetric shell elements.
Thin plate semiloof element for structural analysis–including stability and natural vibrations
Authors: Martins R. A. F. , Owen D. R. J. 
Published: August 2005

AbstractThis paper presents a thin plate element formulated along parallel lines to the general three−dimensional Semiloof shell element. This plate version possesses only one half of the total number of degrees−of−freedom of the shell element and has the advantqage that the formulation of the strains and other terms is very much simplified. The element is first assessed in static situations and then its performance in the solution of eigenvalue problems is considered.
Central difference approximations to the heat transport equation
Authors: Lillington J. N. , Shepherd I. M. 
Published: August 2005

AbstractThis paper analyses the oscillatory nature of central difference approximations to the heat transport equation when convection is the important mechanism of heat transport. The effects of three different boundary conditions, various heat source profiles, the Peclet Number and the parity of the number of meshes on the amplitudes of these oscillations are described. A boundary condition is presented which suppresses the oscillations to insignificant amplitudes in the one−dimensional situation.
An accurate method of dynamic condensation in structural analysis
Authors: Leung Andrew Yee‐Tak 
Published: August 2005

AbstractA new and efficient method of dynamic condensation is presented. It reduces the order of dynamic matrices without intoroducing further approximation by representing the passive co−ordinates in terms of the active ones exactly. The resulting frequency dependent eigenvalue problem is solved by a combined technique of Sturm sequence and subspace iteration. Examples are given for a space frame and a substructure problem. Results are compared to the complete solution.
On the Zienkiewicz three− and four−time−level schemes applied to the numerical integration of parabolic equations
Authors: Wood W. L. 
Published: August 2005

AbstractThe Zienkiewicz three− and four−time level schemes as proposed for vibration problems1 and adapted for the numerical integration of the diffusion equation after finite element discretization. Conditions are found for A0 stability and the methods are studied for their representation of the solution of y1=−λy. Methods used by various authors for linear and non−linear parabolic problems are compared. For the three time−level scheme a Liniger exponential fit of e−λ0Δt with a larger value of λ0Δt and the fully implicit scheme give the most promising results. The four time−level scheme is so much less amenable to control as to make it unsuitable for these problems.
The collapsed cubic isoparametric element as a ingular element for crack probblems
Authors: Pu S. L. , Hussain M. A. , Lorensen W. E. 
Published: August 2005

AbstractFor the 12−node quadrilateral isoparametric elements, it is shown that the inverse square root singularity of the strain field at the crack tip can be obtained by the simple technique of collapsing the quadrilateral elements into triangular elements around the crack tip and placing the two side nodes of each side of the triangles at 1/9 and 4/9 of the length of the side from the tip. This is analogous to placing the mid−side nodes at quarter points in the vicinity of the crack tip for the quadratic isoparametric elements. The advantages of this method are that the displacement compatibility is satisfied throughout the region and that there is no need of special crack tip elements. The stress intensity factors can be accurately obtained by using general purpose programs having isoparametric elements such as NASTRAN.
The numerical solution of two‐dimensional, steady flow problems by the finite element method
Authors: Moult A. , Burley D. , Rawson H. 
Published: August 2005

AbstractFinite element equivalents of the equations governing shearing and buoyancy driven flows are derived, and reduced to upwind forms suitable for the solution of problems in which the Reynolds and Rayleigh numbers are large. A modification to the central difference iterative method is studied which increases the Reynolds and Rayleigh numbers for which a central difference form may be used. A comparison is made between the results obtained using the central and upwind forms of the finite element method and those predicted by finite difference methods in the case of flow in a cavity. A mesh refinement study is made. The upwind forms of the finite element equations are applied to the solution of a complex flow problem involving the flow of glass in a throated furnace in the case of constant‐ and temperature‐ dependent viscosity and conductivity.
Application of quasi‐linearization to studies on diffusioin flames
Authors: Sriramulu V. 
Published: August 2005

AbstractA method by which the numerical difficulties that one encounters while attempting to solve the differential equations which describe a diffusion flame can be circumvented is the quasi‐linearization technique. Application of this method in conjunction with difference approximations transforms the equations into tri‐diagonal matrices which can be inverted by the Thomas method. Since this is an iterative method initial profiles are generated by employing Burke‐Schumann kinetics. This method is found to be superior to the marching techiques that are frequently used in the analyses of diffusion flames.
The application of the least squates finite element method to Abel's integral equation
Authors: Balasubramanian R. , Norrie D. H. , De Vries G. 
Published: August 2005

AbstractAbel's integral equation is the governing equation for certain problems in physics and engineering, such as radiation from distributed sources. The finite element method for the soultion of this non‐linear equation is presented for problems with cylindrical symmetry and the extension to more general integral equations is indicated. The technique was applied to an axisymmetric glow discharge problem and the results show excellent agreement with previously obtained solutions.
Finite element analysis of elastic–plastic materials displaying mixed hardening
Authors: Axelsson K. , Samuelsson A. 
Published: August 2005

AbstractThe problem of non‐radial loading (in the stress space) of structures of elastic–plastic metals is discussed. A concept of combined isotropic and kinematic hardening is proposed. For a material displaying such mixed hardening, constitutive equations are derived and incorporated in a finite element program for the analysis of elastic–plastic 2D‐structures. When determining the numerical solution of the non‐linear equations, the program enables the investigator to select an optimal combination of step by step and iteration procedures. The computed results are compared with experimental results and with results from calculations based on the overlay model, Reference 25.
A numerical method for the determination of optimal surface temperatures of steel ingots
Authors: El‐Gidny T. M. , Townsend P. 
Published: August 2005

AbstractA numerical method is presented for the determination of control temperatures to be applied to the surface of a steel ingot to induce a predetermined temperature distribution within the ingot. The one‐dimensional case of an infinite plate is considered and the problem converted to one of static optimization which is then solved using a partial quadratic interpolation technique.
Hybrid‐stress models for elastic–plastic analysis by the initial‐stress approach
Authors: Spilker R. L. , Pian T. H. H. 
Published: August 2005

AbstractTwo alternative numerical methods are presented, based on the assumed‐stress hybrid finite element model and the initial‐stress approach, for the elastic–plastic small‐deflection analysis of structures under static loading. The use of the initial‐stress approach results in a set of simultaneous linear algebraic incremental equations to be solved at each loading step, with the elastic stiffness matrix remaining unchanged throughout the loading process and the effects of plasticity included as equivalent element loads. The derivation of these alternative methods differs in the assigning of the incremental stress which satisfies equilibrium; in one case it is the actual stress increment while in the other it is a fictitious stress increment. An equilibrium imbalance correction is included in each of these methods to prevent drifting of the solution during the incremental process. Example solutions are presented which demonstrate the accuracy of the two methods and permit comparisons of the relative efficiencies of the two methods.
A direct linear system solver with small core requirements
Authors: Recuero A. , Gutierrez J. P. 
Published: August 2005

AbstractThis paper present an algorithm and its corresponding FORTRAN IV program which solves a system of simultaneous equations of the type generated in structural analysis. It is based on the Gauss elimination method, so it is a direct method. But it only needs to have in core as many equations as it can contain, with a minimum of two. The program offers the following advantages: (a) Takes into account zeros to avoid operations. (b) Considers very big numbers in the diagonal, corresponding to boundary conditions, to avoid operations. (c) It can handle several load cases either simultaneously or in groups, at choice.
Finite element analysis of stress intensity factors for plane extension and plate bending problems
Authors: Yagawa G. , Nishioka T. 
Published: August 2005

AbstractThis paper deals with the finite element calculation of the stress intensity faactors for plane extension and plate bending problems. On the basis of the plate theory including the effect of transverse shear deformation, the influences of plate thickness, crack length and plate width on the stress intensity faotors are investigated. The numeriacal analyses are carried out using the superposition method of analytical and finite element solutions. It is found that the present stress intensity factors calculated for cracked plates under plane extension as well as bending compare favorably with the analytical ones.
Nonlinear rebound of a rod after impact against a deformable barrier
Authors: Garnet Hyman , Armen Harry 
Published: August 2005

AbstractThe nonlinear impact of a vehicle against a deformable barrier and its subsequent rebound from that barrier are simulated. A one‐dimensional elastoplastic model represents the vehicle as a series of rod finite elements and the barrier as a single mass, nonlinear spring. The solution procedure utilizes variable time step integration, contains an error control and eliminates numerical instabilities. A limited study assesses the influence of system parameters on both structure and occupants. The chief objective, however, is to establish the feasibility of the proposed treatment of this class of problems. Some results obtained appear, at first, to contradict intuition. It is observed that modelling a deformable barrier as rigid can lead to unconservative results with respect to structural response of the vehicle.
Application of backward differentiation methods to the finite element solution of time‐dependent problems
Authors: Zlatev Zahari , Thomsen Per Grove 
Published: August 2005

AbstractThe application of finite element methods to parabolic partial differential equations leads to large linear systems of first‐order ordinary differential equations. Very often these systems are stiff and difficulties arise in their numerical solution. We attempt to analyse the problem of how to select numerical methods for the solution of such linear systems.
On an efficient use of CST elements
Authors: Subramanian G. , Krishnan A. 
Published: August 2005

AbstractSimilar and similarly oriented CST elements have the same stiffness matrix, and therefore similar shapes generated by the assembly of such elements possess the same stiffness matrix. This property and the matrix condensation technique may be judiciously combined to simplify the study of large structures, which may otherwise incur large core requirements and time and involve the solution of a great number of equations. In this paper the idea is developed to indicate its full potential. In illustration, results from examples on the determination of stresses around a small hole in a large plate are presented.
Residual correction applied to a sequence of block tridiagonal matrices
Authors: Brown R. Leonard 
Published: August 2005

AbstractThe decomposition of a block tridiagonal matrix into the product of block lowe and upper matrices is described. The cost of solving a block tridiagonal system of equations is given and compared to profile gaussian elimination. The desirability of a less expensive method is coupled to physical intuition about a common problem of solving a slowly varying sequence of such systems to motivate an iterative method based on residual correction. The method is described and convergence criteria are derived. An expression of the cost is developed and is shown to compare favourably with decomposition in many cases. Problems and advantages in computer implementation of the method are discussed and results of tests of a particular implementation on a well‐known problem are given.
Conforming approximations for Kirchhoff plates and shells
Authors: Peano Alberto 
Published: August 2005

AbstractFinite element interpolations of arbitrary polynomial degree which are exactly and minimally C1 continuous across interelement boundaries are studied. A perspective view of the techniques proposed by other authors is presented and some new possibilities are considered. The problem is discussed with reference to the plate and shell finite element approximations, based on the principle of minimum potential energy. The approach also permits identification of sufficient conditions for guaranteeing full rank of stiffness matrices based on modified principles of potential energy. The results of this analysis can be used to investigate the linear dependencies among nodal variables which also occur in the formulation of other fourth‐order problems.
An accurate method for two‐point boundary value problems
Authors: Walker J. D. A. , Weigand G. G. 
Published: August 2005

AbstractA new second‐order accurate method for the solution of two‐point boundary value problems on a uniform mesh is given; the local truncation error is obtained for use with the deferred correction process. The method is compared with existing second‐order techniques and is shown to produce more accurate results for a number of linear and nonlinear example problems.
Finite element representation and pressure stiffness in shell stability analysis
Authors: Loganathan K. , Chang S. C. , Gallagher R. H. , Abel J. G. 
Published: August 2005

AbstractIn the light of recent contributions by Batoz1 and Hibbitt,2 two aspects of finite element formulations for shell stability analysis are examined. The first is the consistency of the shell strain‐displacement equations employed; the second is the proper representation of ‘follower forces’—pressures that are always normal to the deforming surface. Numerical studies of an arch indicate that improper representation of either of these factors can have a significant effect on predicted buckling loads. Numerical studies of an arch indicate that improper representation of either of these factors can have a significant effect on predicted bukling loads.