bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inverse analysis of an embankment on soft clay by extended Bayesian method
Authors: Honjo Yusuke , Wen‐Tsung Liu , Guha Soumitra 
Published: August 2005

AbstractA new type of indirect inverse analysis procedure is proposed to overcome the difficulties the geotechnical inverse analyses are encountering (such as unstability and non‐uniqueness of the solutions as well as multicollinearity). These difficulties are eased by combining the objective information (i.e. the observation data) and the subjective information (i.e. the prior information) in an appropriate manner by so‐called extended Bayesian method. The method is based on a new view on Bayesian model proposed by Akaike. The problem of model identification in the inverse analysis is also tackled by applying well‐known AIC but of the Bayesian version. A case study on an embankment on soft clay is presented to illustrate the effectiveness of the new method. A rather thorough review on the geotechnical inverse analysis is also presented to indicate the necessity of the proposed procedure. An appendix is attached to summarize the statistical background of the new method.
Unified 3D critical state bounding‐surface plasticity model for soils incorporating continuous plastic loading under cyclic paths. Part II: Calibration and simulations
Authors: Crouch Roger S. , Wolf John P. 
Published: August 2005

AbstractA systematic calibration procedure for the constitutive model gUTS using conventional triaxial data for all but one of the material constants is described. Typical ranges for the constants for clay and sand are specified together with default values. When all default values are adopted, just eight material constants need to be determined (gUTS‐lite). A comprehensive series of 49 simulations on clays, silt and sands in loose and dense states under a wide range of monotonic and cyclic stress paths, initial states and drainage conditions provide very satisfactory agreement with experimental results.
A simple hypoplastic constitutive model for sand
Authors: Wu Wei , Bauer Erich 
Published: August 2005

AbstractThe paper presents a hypoplastic constitutive model for the three‐dimensional non‐linear stress–strain and dilatant volume change behaviour of sand. The model is developed without recourse to the concept in elastoplasticity theory such as yield surface, plastic potential and decomposition into elastic and plastic parts. Benefited from the non‐linear tensorial functions available from the representation theorem the model possesses simple mathematical formulation and contains only four material parameters, which can be easily identified with triaxial compression tests. Comparison of the predictions with the experimental results shows that the model is capable of capturing the salient behaviour of sand under monotonic loading and is applicable to both drained and undrained conditions.
Transient response of reservoir–dam–soil systems to earthquakes
Authors: Guan F. , Moore I. D. , Lin G. 
Published: August 2005

AbstractA direct time‐domain numerical procedure is proposed to analyse the transient dynamic response of two‐dimensional reservoir–dam–soil systems. The reservoir extends to infinity and the dam is supported by an unbounded soil. The structure with either linear or non‐linear material properties is modelled by the Finite Element Method (FEM). The soil is assumed to be an elastic, isotropic and homogeneous half‐space represented by a boundary condition in the form of generalized impedance determined by the transient Lamb's solution due to a uniformly distributed traction imposed on the free surface, Guan and Novak.1 Moreover, a technique is developed to include the influence of the reservoir on the dam in terms of nodal accelerations along their interface at different time steps. The advantages of the proposed procedure are obvious. For example, it avoids any additional discretization of the boundaries except the soil–dam interface, and the influence matrix of the fluid is obtained explicitly using shape functions defined at the upstream face of the dam without the finite analysis of the reservoir so that it works very efficiently. Numerical results for a system consisting of reservoir, elastic dam and foundation subjected to the San Fernando, 1971 earthquake ground motion are presented.
Boundary element analysis of stresses in an axisymmetric soil mass undergoing consolidation
Authors: Chopra Manoj B. , Dargush Gary F. 
Published: August 2005

AbstractA time domain boundary element method (BEM) for evaluating stresses in an axisymmetric soil mass undergoing consolidation has been developed. Previous BEM work on axisymmetric poroelasticity for boundary displacements and pore pressures is extended to permit the computation of stresses at both boundary and interior points. The stress formulation preserves the surface‐only discretization.The boundary displacement integral equation is progressively differentiated to obtain the related stress and strain integral equations. Explicit expressions for the steady‐state axisymmetric fundamental solutions are derived in this process. The transient components of the integrands are obtained directly from the transformation of the three‐dimensional kernels into a cylindrical system. Numerical implementation of these integral equations is carried out within a general purpose BEM computer code and several illustrative examples are presented to validate the method.
An elasto‐plastic constitutive model for soft rock with strain softening
Authors: Adachi T. , Oka F. 
Published: August 2005

AbstractDense sands, overconsolidated clays and soft rocks exhibit strain‐hardening and strain‐softening behaviour in a certain range of confining pressure. The aim of the present paper is to construct a constitutive model of soft rock that can describe not only the strain‐hardening behaviour, but also the strain‐softening behaviour. An elasto‐plastic constitutive model for soft rock is derived by introducing a stress history tensorThe preliminary idea was first reported in the reference, the conference paper16. This paper is a complete version of the theory with interpretations and experimental validations
. The model is evaluated through a comparison of the calculated results and the experimental results of tests on sedimentary soft rock (porous tuff). In addition, the applicability of the model to numerical analyses is discussed in relation to the uniqueness of the solution in initial and boundary value problems.
A comparison of field measured and numerically simulated seasonal ground movement in unsaturated clay
Authors: Thomas H. R. , Zhou Z. 
Published: August 2005

AbstractThis paper presents the results of a numerical simulation of field measured seasonal ground movement. The constitutive model employed was proposed as a practical method of modelling the complex stress/strain behaviour of unsaturated soil. Its use within a consolidation‐type analysis is explored here, as a means of assessing its suitability for practical application. Comparisons are given of numerical results and field measured behaviour over a 9 month period of time. Overall good correlation is achieved, covering a series of drying and wetting cycles. Confidence can thus be ascribed to the performance of the constitutive model.
Three‐dimensional joint elements applied to concrete‐faced dams
Authors: Justo J. L. , Segovia F. , Jaramillo A. 
Published: August 2005

AbstractIn the study of concrete‐face dams it is essential to provide joint elements; otherwise the calculated stresses at the facing will be non‐allowable. Three‐dimensional joint elements must be simple so as not to increase in excess the CPU time. Seven non‐incremental joint elements have been formulated or developed, and their relative advantages discussed. It is shown that quasi‐linear or linear joint elements at the perimeter of the solid elements can have calculation advantages, specially for interfaces with ‘no tension’ resistance.A system of thin solid finite elements (FE) joints at the face may reproduce qualitatively the displacements and stresses, but not quantitatively. With a system of quasi‐linear elements placed at the boundaries of the solid FE we have been able to predict correctly the displacements, strains and joint openings at Cethana concrete‐faced rockfill dam.
Parametric variational principle for elastic–plastic consolidation analysis of saturated porous media
Authors: Hong‐Wu Zhang 
Published: August 2005

AbstractFinite element procedures for numerical solution of various engineering problems are often based on variational formulations. In this paper, a parametric variational principle applicable to elastic‐plastic coupled field problems in consolidation analysis of saturated porous media is presented. This principle can be used to solve problems where materials are inconsistent with Drucker's postulate of stability, such as in non‐associated plasticity flow or softening problems. The finite element formulation was given, and it can be solved by either the conventional method or a parametric quadratic programming method.
Approximate factorizations with modified S/P consistently ordered M‐factors
Authors: Beauwens R. 
Published: August 2005

AbstractPreconditioned iterative methods are widely used to solve linear systems such as those arising from the finite element formulation of boundary value problems and approximate factorizations are widely used as preconditioners. The ordering of the unknowns is therefore an important issue because it has a strong influence on the convergence behaviour of the iteration method while it is also a decisive aspect for their parallel implementation. Consistent orderings are attractive for parallel implementations and it has been shown that some subclasses of these orderings also enhance the convergence behaviour of the associated iteration methods. This has in particular been shown for the so‐called S/P consistent orderings. A wider definition of this class of orderings has recently been proposed and we investigate here how approximate factorizations should be implemented when using such more general orderings (still called S/P consistent) in order to keep their expected high convergence properties. A simple practical conclusion is suggested, supported by both theoretical and numerical arguments.
Properties of generalized conjugate gradient methods
Authors: Weiss Rüdiger 
Published: August 2005

AbstractThe solution of linear systems has considerable importance for the computation of problems resulting from engineering, physics, chemistry, computer science, mathematics, medicine and economics. The calculation of costly and time‐consuming problems, e.g. crash tests, simulation of the human lung and skin, calculation of electrical and magnetical fields, thermal analysis and fluid dynamics, to name only a few, has become possible with the recent developments of advanced computer architectures and iterative solvers. Generalized conjugate gradient (CG) methods are the most important iterative solvers because they converge very quickly under certain conditions. Therefore they are widely used and in a rapid further development.The purpose of this paper is to present new results for the convergence of generalized CG methods. A convergence result for non‐symmetric and non‐positive definite matrices is given that includes the classical theory for symmetric, positive definite matrices as a special case.The norm of the residuals resulting from CG methods may oscillate heavily. Different remedies for smoothing this sequence have been proposed, for example by van der Vorst. Schönauer introduced in the 1980s a smoothing algorithm to get a norm nonincreasing function of the iteration index. For this algorithm a complete theoretical analysis is given. A surprising result is obtained showing that the smoothing algorithm is in a sense optimal. Convergence estimates are derived therefrom. A geometric interpretation of the smoothing algorithm is given showing the propagation of the errors.It should be stressed that a smooth convergence of the residuals is not equivalent to a smooth convergence of the errors which is the proper aim. A class of error minimizing methods can be easily derived from the theory.
Variable‐step multilevel preconditioning methods, I: Self‐adjoint and positive definite elliptic problems
Authors: Axelsson O. , Vassilevski P. S. 
Published: August 2005

AbstractWhen solving large size systems of equations by preconditioned iterative solution methods, one normally uses a fixed preconditioner which may be defined by some eigenvalue information, such as in a Chebyshev iteration method. In many problems, however, it may be more effective to use variable preconditioners, in particular when the eigenvalue information is not available.In the present paper, a recursive way of constructing variable‐step of, in general, nonlinear multilevel preconditioners for selfadjoint and coercive second‐order elliptic problems, discretized by the finite element method is proposed. The preconditioner is constructed recursively from the coarsest to finer and finer levels. Each preconditioning step requires only block‐diagonal solvers at all levels except at every k0, k0 ≥ 1 level where we perform a sufficient number ν, ν ≥ 1 of GCG‐type variable‐step iterations that involve the use again of a variable‐step preconditioning for that level.It turns out that for any sufficiently large value of k0 and, asymptotically, for ν sufficiently large, but not too large, the method has both an optimal rate of convergence and an optimal order of computational complexity, both for two and three space dimensional problem domains.The method requires no parameter estimates and the convergence results do not depend on the regularity of the elliptic problem.
A general theory of finite elements. II. Applications
Authors: Oden J. Tinsley 
Published: August 2005

AbstractIn Part I of the this paper, topological properties of finite element models of functions defined on spaces of finite dimension were examined. In this part, a number of applications of the general theory are presented. These include the generation of finite element models in the time domain and certain problems in wave propagation, kinetic theory of gases, non‐linear partial differential equations, non‐linear continuum mechanics, and fluid dynamics.
Derivation of stiffness matrices for problems in plane elasticity by Galerkin's method
Authors: Szabo Barna A. , Lee George C. 
Published: August 2005

AbstractSolution of plane elastic problems by piecewise linear approximation is outlined. This method is based upon Galerkin error distribution technique, which leads to simultaneous algebraic equations identical to those associated with the Finite Element Method. In addition, this method permits definition of the discretization error, which can be computed once the displacement components are known. Properties of the interpolation functions are discussed, and a sequence of internally compatible plane elastic elements is defined.
Finite element solution to an elastica problem of beams
Authors: Tada Yasuo , Lee George C. 
Published: August 2005

AbstractIn this study, finite element solution procedures are developed for an elastica problem of inextensible beams. The element stiffness matrices are obtained by using Galerkin's method. Results of a numerical example compare reasonably well with those obtained by using the elliptical integral.Extensions of this research are currently being made to include membrane effects of beams and to develop plate element stiffness matrices for elastica problems of plate structures.
Application of the simultaneous iteration method to undamped vibration problems
Authors: Jennings Alan , Orr D. R. L. 
Published: August 2005

AbstractThe simultaneous iteration method of obtaining eigenvalues and eigenvectors is employed for the solution of undamped vibration problems. This method is of significance when a few of the dominant eigenvalues and eigenvectors are required from a large matrix, and hence is particularly suitable for vibration problems involving a large number of degrees of freedom. It is shown that advantage may be taken of both the symmetry and the band form of the mass and stiffness matrices, thus making it feasible to process on a computer larger order vibration problems than can be processed using transformation methods. A method of allowing for body freedom is given and some numerical tests are discussed.
An economical method for determining the smallest eigenvalues of large linear systems
Authors: Wright G. C. , Miles G. A. 
Published: August 2005

AbstractThe general eigenvalue problem Ax = λBx as arising from vibration problems tackled by the finite element method is often solved by the economization method in which the two matrices are reduced to a more manageable size and approximate answers are obtained.This paper analyses the method in a more mathematical way than previous accounts and leads to a definition of the optimum set of variables to be retained during the reduction. An extension to the method is suggested which allows the approximate eigenvalue to be improved and bounds are obtained on the eigenvalues of the full problem before reduction.An estimate is made of the calculation involved in the method and it is concluded, by reference to examples, that the extended method leads to a more efficient algorithm.
Solution of the compressible flow equations
Authors: Gelder D. 
Published: August 2005

AbstractA technique is described for solving the compressible flow equations in subsonic flow. The general quasi‐linear equation ∇.g∇v = 0 is considered with g a function of ∇v. ∇v, and iterations of the form ∇.gn∇vn+1 = 0 are analysed, where g0 is suitably chosen and gn defined from vn for n≥1. This approach is applied to the compressible flow equations in terms of a velocity potential ø: monotonic convergence is predicted and at each iteration the error is multiplied by a factor less than the square of the greatest Mach number in the solution.Reliable convergence has been obtained in practice solving the linear equation for øn+1 by a finite difference method. The alternative of working in terms of the stream function ψ is discussed, and also discretization by the finite element method.
The piecewise‐linear analysis of two connecting structures including the effect of clearance at the connections
Authors: Scholes A. , Strover E. M. 
Published: August 2005

AbstractA method of analysis is presented for two structures which have connections with clearance. It is assumed that the behaviour of the structures is described, by the movement of discrete nodes and that as the load on the structure changes, clearances open or close between corresponding nodes on the structures; each time this occurs the stiffness of the combined structure changes because its configuration has changed. Between these changes, the structure will behave linearly and the overall behaviour can be described as piecewise linear. Applications include diesel engine crankshafts with bearing clearances and the wrap‐around problem in pin‐and‐eye connections.
Finite element method applied to the problem of stability of a non‐conservative system
Authors: Barsoum Roshdy S. 
Published: August 2005

AbstractThe finite element method is applied to the stability analysis of structural systems subject to non‐conservative forces. The development of the method is general, but the specific application considered here is the stability of thin‐walled members subject to follower forces. The method predicts the type of instability, whether it be buckling or flutter. Example problems, for which exact solutions are known, illustrate the accuracy and convergence characteristic of the finite element formulation.
An annular segment finite element for plate bending
Authors: Sawko F. , Merriman P. A. 
Published: August 2005

AbstractA stiffness matrix for a finite element having the planform of an annular segment is derived using the displacement approach. Numerical problems involved in the derivation are discussed and rapid convergence to exact solutions is demonstrated on three sample problems. It is concluded that the new element will be of great value to engineers concerned with the analysis of slabs of bridge decks curved in plan.
A static and dynamic finite element shell analysis with experimental verification
Authors: Klein Stanley 
Published: August 2005

AbstractA system of finite element shell analysis codes, called SABOR/DRASTIC, is used to analyse a complex two‐layered shell of revolution under static and dynamic asymmetric loads. The dynamic analysis is compared with experimentally measured response. In this linear elastic analysis, emphasis is placed on the inherent flexibility of the finite element method in modelling the complex structural geometry of a given test specimen. Static studies, which involve variations in important shell parameters, and dynamic studies, which provide a successful correlation with experiment, are used to illustrate both the detail and the generality with which shell analyses may now be performed with confidence.
The solution of structural equilibrium equations by the conjugate gradient method with particular reference to plane stress analysis
Authors: Yettram A. L. , Hirst M. J. S. 
Published: August 2005

AbstractA computer program is described for the analysis of plates in extension using the equivalent plane‐framework idealization. The conjugate gradient method is adopted to solve the resulting large number of simultaneous equations. Performance figures are quoted for the program when used on an ICL KDF9 machine with a restriction of 18K on the available core store. The method is generally shown to provide a satisfactory solution to a heavy computational task and thus permits the solution of very large structural systems on a small computer.
A powerful hybrid method in finite element analysis
Authors: Rao A. K. , Raju I. S. , Murty A. V. Krishna 
Published: August 2005

AbstractAn important limitation of finite element analysis, namely, the need for a large number of small elements in regions of finite or infinite stress concentrations and the difficulties of convergence in such cases, is well known. Rao1 suggested a possibility of overcoming this by developing hybrid techniques combining continuum and finite element concepts. In such techniques, each region of stress concentration is covered by one large ‘primary element’ whose description includes term(s) identifying the type and order of concentration, while the remaining structure is split into a few ‘secondary elements’ which are conventional finite elements. In this paper a procedure incorporating this concept is developed and its effectiveness is clearly demonstrated by successful application to two important examples, one of them with stress singularities. The concept, in fact, can be applied equally well to other two‐ and three‐dimensional problems of continua with discontinuities and concentrations.
Linear programming methods of displacement analysis in elastic‐plastic frames
Authors: Baronas R. P. , Chyras A. A. 
Published: August 2005

AbstractThe analysis is aimed at determination of displacements in elastic‐perfectly plastic frames, in the case of monotonically increasing loads. Spread of partial plasticity from hinges and change of geometry on the conditions of equilibrium are not included. Extremum energy principles and linear programming methods are employed to solve the problem. Both the kinematic and the static formulations of the problem are presented. The mathematical models of the formulations constitute a dual pair of linear programming problems.