bluuebunny/crossref_metadata_2025 huggingface dataset:
Inclusion of transverse normal strain effects into the finite element formulation of Timoshenko beams
Authors: Abdel‐Rahman Hamdy H. , Baluch Mohammed H. , Al‐Hejji Ali I.
Published: February 2008

A new finite element model has been developed for the analysis of thick beams that incorporates the influence of transverse normal strain in addition to the effect of transverse shear strain. It has been shown that the inclusion of the normal strain effect into Timoshenko beam formulation, in the new model, results in the modification of the element force vector only, where a new term is added, while keeping the flexural and shear contributions to the element stiffness matrix unchanged. Comparisons between closed form solutions, Timoshenko beam results and the results of the new model for isotropic beams of depth to span ratio of up to 0.5, show that the new development reduces the errors with respect to exact solutions to almost a half at a very little extra expense.
An implicit implementation of harmonic balance method for non‐linear dynamic systems
Authors: Cheung Y.K. , Iu V.P.
Published: February 2008

A simple numerical algorithm is developed for the implementation of the harmonic balance method to analyse periodic responses of a general dynamic system having geometrical non‐linearities of the quadratic and cubic types. The resulting non‐linear algebraic equations which are not explicitly determined are solved by non‐linear equation routines available in most mathematical libraries. Various non‐linear responses, such as the combinational resonances of a hinged‐clamped beam, the non‐linear effect on degenerate vibration modes of a square plate and the non‐linear oscillation of thin rings, are presented to demonstrate the versatility of the algorithm.
Yield surfaces for perforated plates
Authors: König M.
Published: February 2008

A method is presented by which elastoplastic constitutive relations for the solid material equivalent to a perforated plate can be obtained, by performing numerical experiments employing the finite element method. The method is applied to a plate of elastic‐perfectly plastic material, perforated in an equilateral triangular penetration pattern of circular holes. The following situations are considered: plane stress, as existing in thin plates under in‐plane loading, generalized plane strain, which approximates the behaviour of thick plates subjected to in‐plane loading and the plate bending condition. First results have been obtained for the plane stress situation. These results show that, for the case of monotonic loading, the elastoplastic behaviour is nearly isotropic in the plane of the plate, whereas under cyclic loading below the limit load, the equivalent solid material exhibits distortional hardening.
Displacement control for the non‐linear analysis of reinforced concrete structures
Authors: May I.M. , Naji J.H. , Ganaba T.H.
Published: February 2008

This paper describes a comparison between displacement and load control for the non‐linear Finite element analysis of reinforced concrete structures. The analysis of three examples subjected to in‐plane loading using both the initial stiffness and the modified Newton‐Raphson methods with various tolerances is discussed. Two methods have been used in order to avoid spurious unloading in the displacement control method. The comparisons for the examples analysed show that the use of displacement control gives significant savings in computer time compared with that used for load control, in addition to being able to plot falling branch load‐deflection responses.
A mixed finite element method for the stationary semiconductor continuity equations
Authors: Miller J.J.H. , Wang S. , Wu C.H.
Published: February 2008

We discuss a finite element approximation of the semiconductor continuity equations based on quadrilateral and hexahedral space discretizations. This method can be regarded as an extension to higher dimensions of the well‐known one‐dimensional Scharfetter‐Gummel scheme. The existence, uniqueness and error estimates of the solution is discussed. Using a lumping technique we get a linear system similar to that obtained from the conventional box‐scheme. We also discuss the evaluation of the approximate terminal currents, which are shown to be convergent and conservative.
Consistent linearization in elasto‐plastic shell analysis
Authors: Ramm E. , Matzenmiller A.
Published: February 2008

The present paper is directed towards elasto‐plastic large deformation analysis of thin shells based on the concept of degenerated solids. The main aspect of the paper is the derivation of an efficient computational strategy placing emphasis on consistent elasto‐plastic tangent moduli and stress integration with the radial return method under the restriction of ‘zero normal stress condition’ in thickness direction. The advantageous performance of the standard Newton iteration using a consistent tangent stiffness matrix is compared to the classical scheme with an iteration matrix based on the infinitesimal elasto‐plastic constitutive tensor. Several numerical examples also demonstrate the effectiveness of the standard Newton iteration with respect to modified and quasi‐Newton methods like BFGS and others.
Approximations to non‐normal random variables in structural reliability analysis
Authors: Bury Karl V.
Published: February 2008

Modern reliability analyses of large structural system designs require substantial computing times, and need to be repeated frequently in the process of design optimization. In the important case when underlying random variables are not normally distributed, the widely used approximation scheme by Rackwitz and Fiessler further increases the computational requirement by a substantial factor. This paper proposes a simple alternative approximation scheme which requires significantly less computation than the Rackwitz‐Fiessler algorithm, at an acceptable loss of accuracy.
Maguerre‐Mindlin shallow shell elements
Authors: Krause Gerhard
Published: February 2008

Two isoparametric Lagrangian shallow shell elements are presented: a 4‐node element QUAD4 and a 9‐node element QUAD9. These elements are based on Mindlin/Reissner plate elements as described in a series of papers. These elements are sophisticated by adding conventional membrane stiffness and membrane‐bending coupling terms based on Maguerre's approximate shallow shell theory. This results in double curved shell elements which originally possess severe membrane locking behaviour. This defect is overcome in the same way as the shear locking problem is solved.
Simple finite element codes in Occam on a transputer
Authors: Bettess Peter , Downie Martin J.
Published: February 2008

In recent years attention has turned from conventional ‘von Neumann’ computers to totally new computer architectures. Many surveys of these developments are available and a number of conferences have been held on the topic. One extremely interesting development is the transputer, or so‐called computer on a chip, designed and developed by the British company, Inmos. This exciting innovation has been backed by the SERC, who have launched an initiative entitled ‘Engineering Applications of Transputers’. Under the terms of this initiative, it is possible for British academics to obtain short term loans of transputer equipment, in order to evaluate it and to prepare more extensive research proposals, which would exploit the transputer. The authors obtained a loan of a single transputer board, for 8 months and were able to develop some programs for finite element analysis and for discrete vortex modelling of fluid flows. This paper describes the work carried out on finite elements. The purpose of the paper is to list and describe some simple working finite element programs written in Occam and to draw attention to their novel features.
Free vibrations of Mindlin plates using the finite element method: Part 1. Square plates with various edge conditions
Authors: Al Janabi Bahaa S. , Hinton E. , Vuksanovic Dj.
Published: February 2008

This paper presents a parametric study of the free vibrations of square plates with various thickness‐to‐span ratios and different boundary conditions. The numerical analysis of these problems has been undertaken using the finite element method. In particular, a nine‐noded, quadrilateral Mindlin plate element has been adopted. The effects of rotatory inertia and shear deformation are included in this model. Results obtained by the finite element analysis are compared with results from various sources. It is suggested that this study might be used to supplement existing benchmark tests.
Finite element analysis of temperatures and stresses in a single‐pass butt‐welded pipe—influence of mesh density and material modelling
Authors: Karlsson C.T.
Published: February 2008

Single‐pass girth butt welding of a carbon‐manganese pipe is studied numerically using the finite element codes ADINAT/ADINA. A rotationally symmetric finite element model is employed in both the thermal and mechanical analysis. This model is used to investigate the influence on the residual stress state of pipe geometry, mesh density and material modelling. The results from the present study are compared with previous results from two different FE analyses and an experimental investigation. One of the FE analyses was fully three dimensional and the other employed shell elements. The calculated residual stresses were found to differ significantly only when different material models were employed. The thermal strain seemed to be the material parameter with the largest influence on the residual stress state. Especially the changes in thermal strain during phase transformations seemed to have a great influence. This means that the temperature field should be determined accurately enough to predict when and where the different phase transformations occur. Almost the same residual stresses were obtained for two pipes with different pipe geometries and weld parameters.
A quadrilateral 2‐D finite element based on mixed interpolation of tensorial components
Authors: Dvorkin Eduardo N. , Vassolo Sara I.
Published: February 2008

A quadrilateral 2‐D finite element for linear and non‐linear analysis of solids is presented. The element is based on the technique of mixed interpolation of tensorial components. It is shown that the new element is reliable and efficient, being apt, therefore, to be used in routine engineering applications.
Solutions of a steady state free surface seepage problem on a Hypercube concurrent computer
Authors: Wang Kai‐Ping , Bruch J.C.
Published: February 2008

The advantages of using a multi‐CPU concurrent computer in solving a steady state free surface seepage problem are studied. The underlying computational task is the solution of a large set of linear equations with a projection operation numerous times. In the study, both Jacobi and SOR iteration methods with projection in a modified alternating iteration scheme are used to solve the problem with varied number of nodes (CPUs) and the timing results are compared between a 32 node Hypercube Concurrent Computer and a VAX 11/780 (single CPU). In addition, the performance and the feasibility of the Hypercube Concurrent Computer are discussed by comparing with the number of nodes used and with the VAX 11/780.
A new partitioning strategy for efficient re‐analysis of large structural systems
Authors: Noor Ahmed K. , Peters Jeanne M.
Published: February 2008

A computational procedure is presented for the re‐analysis of large unsymmetric structural systems. The procedure is based on a novel partitioning strategy in which the responses of both the original and modified structures are approximated by linear combinations of symmetric and antisymmetric response vectors (or modes), each obtained by using a fraction of the degree of freedom of the finite element model of the structure. The other key elements of the procedure are: (a) lumping of the large number of design variables into a single tracing parameter; (b) operator splitting or restructuring of the governing finite element equations to delineate the symmetric and antisymmetric vectors constituting the responses of the original and modified structures; and (c) a stable and efficient iterative process for generating the response of the modified structure. The re‐analysis procedure is applied to linear static analysis of framed structures. Design modifications consisted of removing members resulting in topologically unsymmetric structures. The potential of the procedure on multiprocessor computers is discussed and its effectiveness is demonstrated by means of two numerical examples.
Accurate pore pressure calculation in undrained analysis
Authors: Griffiths D.V. , Li C.O.
Published: February 2008

A simple procedure for accurate calculation of pore pressures in undrained elasto‐plastic materials is described. An 8‐node element is used, with ‘reduced’ integration during stress redistribution, and ‘full’ integration to form the global stiffness matrix for the modified Newton—Raphson procedure. An analysis of passive earth pressure in an undrained soil is used to demonstrate the algorithm and computed results are compared with a closed‐form solution.
Aspects of modelling and computation in the analysis of metal forming
Authors: St. Doltsinis I.
Published: February 2008

A synopsis is presented of the numerical finite element methodology currently in use at the Institute for Computer Applications (ICA) for the simulation of industrial forming processes. The development of the method is based on the inelastic properties of the material with an extension towards the inclusion of elastic effects and accounts for the thermal phenomena occurring in the course of the deformation. An essential constituent of the computational procedure is the treatment of the unsteady contact developing between the workpiece material and the tool during forming, and of the associated friction phenomena. Automatic mesh generation and variable discretization adaptable to the development of the numerical solution are of importance for industrial applications. These aspects are presented and discussed. Furthermore, solution techniques for thermomechanically coupled problems are considered and investigated with respect to their numerical properties. Application to industrial forming processes is demonstrated by means of three‐dimensional hot rolling and of superplastic sheet forming.
Finite element method for gas‐lubricated bearings
Authors: Cifuentes Arturo O. , Bock Timothy L. , Coppolino Robert N.
Published: February 2008

This paper presents a finite element method for the study of gas‐lubricated bearings. The fluid is assumed to be compressible, and the effect of the molecular mean free path has been incorporated into the formulation. A variational statement for the governing equation is derived and used to formulate a non‐linear quadrilateral finite element that has been incorporated into a standard code (MSC/NASTRAN). This constitutes a useful analysis tool for designers, especially in cases of complex bearing geometry. The results obtained with this method agree well with analytical solutions obtained by other authors for simple geometric configurations.
Discrete optimal design of trusses with stress and frequency constraints
Authors: John K.V. , Ramakrishnan C.V.
Published: February 2008

The problem of structural optimization of trusses subject to stress and frequency constraints is considered from a practical viewpoint. Assuming that the choice of members has to be from a discrete set of available sections, the solution is attempted using a mathematical programming approach and an approximate two‐step procedure involving a continuous variable optimization followed by a discrete programming algorithm. The latter approach is highly promising for problems involving stress and frequency constraints. Detailed results are presented using several benchmark problems.
Behaviour of plate elements based on the first‐order shear deformation theory
Authors: Averill R.C. , Reddy J.N.
Published: February 2008

A study of the behaviour of shear deformable plate finite elements is carried out to determine why and under what conditions these elements lock, or become overly stiff. A new analytical technique is developed to derive the exact form of the shear constraints which are imposed on an element when its side‐to‐thickness ratio is large. The constraints are expressed in terms of the nodal degrees of freedom, and are interpreted as being either the proper Kirchhoff constraints or spurious locking constraints. To gain a better understanding of locking phenomena, the constraints which arise under full and reduced integration are derived for various plate elements. These include bilinear, biquadratic, eight‐node serendipity and heterosis elements. These analytical findings are compared with numerical results of isotropic and laminated composite plates, verifying the role that shear constraints play in determining the behaviour of thin shear deformable elements. The results of the present study lead to definitive conclusions regarding the origin of locking phenomena and the effect of reduced integration.
Simulating curved elements by offsets: rationale and application to shells of revolution
Authors: Cook Robert D.
Published: February 2008

In a previous note, curved arch elements were simulated by attaching rigid offsets to nodes of straight elements. The procedure was physically motivated. Here the offsets method is derived by shell theory and is seen to lie in the context of standard assumed‐displacement field finite‐element theory. Application to shells of revolution is provided.
Dynamic analysis of thin‐walled structures using polynomial and exact solutions: application to thin‐walled pipes
Authors: Kanarachos A.E. , Koutsidis N. , Spentzas C.N.
Published: February 2008

We present a combined or mixed method for the dynamic analysis of thin‐walled structures, based on the superposition of beam and shell strains and displacements. Polynomial or exact shape functions are used for the interpolation of the shell displacements, while discrete degrees of freedom are introduced instead of the generalized von Karman coefficients. Special attention has been given to the integration schemes, because of the combined beam and shell behaviour of the considered structures. The stability and accuracy of the four‐point integration scheme are studied by using the z‐transform. The method is applied to thin‐walled pipes and is also compared to the von Karman approach.
Area moments and areas of beam cross‐sections numerically determined
Authors: Stelzer J.F.
Published: February 2008

Sometimes beam cross‐sections with strange geometries occur. Then it is tedious to calculate the values which are needed for a beam analysis, such as the area, the centre of gravity, the inertia‐, centrifugal‐and polar moments, the position of the main inertia axes, and the resistance moments. It might also be of interest to observe the changing of these values if the cross‐section is rotated. This paper gives a program executing these tasks using numerical methods. The program is in C since this language is of growing interest to modern programmers.
A one point integrated assumed strain 4‐node Mindlin plate element
Authors: Kebari H.
Published: February 2008

The 4‐node assumed strain elements are among the best elements available today but the bending moments at their full integration points oscillate severely. This paper presents a one point integrated version of the 4‐node assumed strain plate element of Bathe‐Dvorkin. A Taylor series expansion approach is used to accommodate the linear variation of strains/stresses within the element and hence to stabilize the spurious zero energy modes. An extensive number of benchmark results are presented and compared.
Design of an optimal grid for finite element methods in incompressible fluid flow problems
Authors: Ramaswamy B. , Akin J.E.
Published: February 2008

Finite element solutions of improved quality are obtained by optimizing the location of nodes of the finite element grid, while keeping the number of degrees of freedom fixed. The formulation of the grid optimization problem is based on the reduction of error associated with interpolation of the exact solution, using functions from the finite element space. Element sizes are selected as design variables: length in R and area in R. Approximate optimal conditions are introduced to obtain a set of operationally useful equations that can be used as guidelines for construction of improved grids. Example problems are given for illustrations.
AN ALGORITHM FOR GENERATION OF SHAPE FUNCTIONS IN SERENDIPITY ELEMENTS
Authors: ZAVARISE G. , VITALIANI R. , SCHREFLER B.
Published: February 2008

An algorithm to calculate shape function values at specific points is presented. It applies to three‐dimensional serendipity elements with variable node numbers per side and, as a particular case, to plane and truss elements. The procedure is shown for the two‐dimensional case using the natural orthogonal reference system of the element and is then generalized to the three‐dimensional case. The source code of the described algorithms written in Fortran 77 is included.
THE MAGIC OF GAUSS QUADRATURE
Authors: CHAN A.H.C.
Published: February 2008

For those who are working with the finite element method, one may somehow wonder why a n point Gauss‐Legendre quadrature formula can integrate a 2n—1 order polynomial exactly. The purpose of this note is to unravel the secret.
MULTIPLE LEVEL DYNAMIC SUBSTRUCTURE ANALYSIS
Authors: YUAN MINGWU , XIONG SHANJI , CHEN XIAOHONG
Published: February 2008

An exact multiple‐level dynamic substructure technique was developed by a combination of WYD algorithm and static multiple‐level substructuring technique. This method is essentially different from the traditional mode component synthesis. The eigenvalues and eigenvectors created by the method are the eigenpairs for the whole structure and not for the components of structure. On the other hand, the dynamic response by using mode superposition can also be implemented in substructure level. This algorithm actually is an exact substructuring technique which means that substructuring itself did not introduce any additional error except the round‐off when a structure was split into some arbitrary subdomains and the error of WYD or mode superposition themselves. It is no longer necessary to assume any connective condition on the interface between substructures. This method makes the capacity of dynamic analysis of a structural analysis program unlimited. It is especially attractive for the programs on microcomputers. Of course, the method leads to a frequent I/O for a subsequent search of the files from each substructure. It is time consuming compared to the mode component synthesis. But the potential still exists to improve the efficiency by using parallel computation on concurrent computers. In this paper the theory and procedure of the algorithm are presented.
SIMULATION OF STRAIN LOCALIZATION: A REAPPRAISAL OF THE COSSERAT CONTINUUM
Authors: DE BORST RENÉ
Published: February 2008

Classical continuum models, i.e. continuum models that do not incorporate an internal length scale, suffer from pathological mesh‐dependence when strain‐softening models are employed in failure analyses. In this contribution the governing field equations are regularized by adding rotational degrees‐of‐freedom to the conventional translational degrees‐of‐freedom. This so‐called elasto‐plastic Cosserat continuum model, for which an efficient and accurate integration algorithm and a consistent tangent operator are also derived in this contribution, warrants convergence of the load—deflection curve to a unique solution upon mesh refinement and a finite width of the localization zone. This is demonstrated for an infinitely long shear layer and a biaxial test of a strain‐softening elasto‐plastic von Mises material.
SIMULATION OF NON‐LINEAR VARIABLE DAMPERS USING ENERGY SIMILARITY
Authors: RAKHEJA S. , AHMED A.K.W.
Published: February 2008

A local equivalent linearization methodology is proposed to simulate non‐linear shock absorbers and dual‐phase dampers in the convenient frequency domain. The methodology based on principle of energy similarity, characterizes the non‐linear dual‐phase dampers via an array of local damping constants as function of local excitation frequency and amplitude, response, and type of non‐linearity. The non‐linear behaviour of the dual‐phase dampers can thus be predicted quite accurately in the entire frequency range. The frequency response characteristics of a vehicle model employing non‐linear dual‐phase dampers, evaluated using local linearization algorithm, are compared to those of the non‐linear system, established via numerical integration, to demonstrate the effectiveness of the algorithm. An error analysis is performed to quantify the maximum error between the damping forces generated by non‐linear and locally linear simulations. The influence of damper parameters on the ride improvement potentials of dual‐phase dampers is further evaluated using the proposed methodology and discussed.
THREE NODE TRIANGULAR BENDING ELEMENTS WITH ONE DEGREE OF FREEDOM PER NODE
Authors: HAMPSHIRE J.K. , TOPPING B.H.V. , CHAN H.C.
Published: February 2008

This investigation assesses the bending performance of triangular plate elements with only three translational degrees of freedom per node in which the out‐of‐plane degree of freedom is the only displacement considered. A review is presented of three element formulations followed by the results of a series of case studies which illustrate the element behaviour. Results obtained from elastic theory and finite element analysis using more complex element formulations are given for comparative purposes.
SIMULATION OF BLASTING INDUCED ROCK MOTION USING SPHERICAL ELEMENT MODELS
Authors: TAYLOR LEE M. , PREECE DALE S.
Published: February 2008

Control of the rock motion associated with blasting can have significant economic benefits. For example, surface coal mining can be made more efficient if the overburden material can be cast further with explosives, leaving less work for mechanical equipment. The final muck pile shape in every type of surface and underground blasting is controlled by the blasting induced motion of the rock. A theoretically sound method of predicting rock motion will be beneficial to understanding the blasting process.
A MICROSTRUCTURAL FINITE ELEMENT MODEL FOR GRANULAR SOLIDS
Authors: LIAO CHING L. , CHANG CHING S.
Published: February 2008

A microstructural finite element model (MFEM) for granular material considering the microstructure of material is presentented. In the MFEM method, a volume of large number of particles is represented by an element consisting of a few nodal points. The stiffness matrix of the element is then formulated based on the contact stiffness and the packing arrangement of the particles. The method can be easily applied in the framework of finite element technique to solve boundary value problems in practical situations. Applicability of the model is evaluated by comparing the results of MFEM model with that from DEM model.
MODELLING OF SOIL CREEP WITH THE DISCRETE ELEMENT METHOD
Authors: KUHN MATTHEW R. , MITCHELL JAMES K.
Published: February 2008

The discrete element method (DEM) was used to stimulate creep processes in granular materials. The authors present the main features of the numerical model, which include a new viscous mechanism for particle sliding, a new feedback technique for maintaining constant stress during creep, and a scaling technique that allowed monitoring the long‐term creep behaviour of a granular assembly. The creep behaviour of the numerical model exhibited the essential characteristics of soil creep—a creep rate that decreased rapidly with time, an increase in the creep rate with the applied deviator stress, and the beginning of creep rupture. The model's numerical performance is discussed, and representative results are presented.
EFFICIENT SOLUTION PROCEDURES FOR SYSTEMS WITH LOCAL NON‐LINEARITIES
Authors: IBRAHIMBEGOVI&Cacute ADNAN , WILSON EDWARD L.
Published: February 2008

This paper presents several methods for enhancing computational efficiency in both static and dynamic analysis of structural systems with localized non‐linear behaviour. A significant reduction of computational effort with respect to brute‐force non‐linear analysis is achieved in all cases at the insignificant (or no) loss of accuracy. The presented methodologies are easily incorporated into a standard computer program for linear analysis.
A MATERIAL‐INDEPENDENT METHOD FOR EXTENDING STRESS UPDATE ALGORITHMS FROM SMALL‐STRAIN PLASTICITY TO FINITE PLASTICITY WITH MULTIPLICATIVE KINEMATICS
Authors: CUITIÑO A. , ORTIZ M.
Published: February 2008

We provide a method for automatically extending small‐strain state‐update algorithms and their correspondent consistent tangents into the finite deformation range within the framework of multiplicative plasticity. The procedure, when it applies, operates at the level of kinematics and, hence, can be implemented once and for all independently of the material‐specific details of the constitutive model. The versatility of the method is demonstrated by a numerical example.
WAVELET BASED GREEN'S FUNCTION APPROACH TO 2D PDEs
Authors: AMARATUNGA KEVIN , WILLIAMS JOHN R.
Published: February 2008

We describe how wavelets may be used to solve partial differential equations. These problems are currently solved by techniques such as finite differences, finite elements and multigrid. The wavelet method, however, offers several advantages over traditional methods. Wavelets have the ability to represent functions at different levels of resolution, thereby providing a logical means of developing a hierarchy of solutions. Furthermore, compactly supported wavelets (such as those due to Daubechies) are localized in space, which means that the solution can be refined in regions of high gradient, e.g. stress concentrations, without having to regenerate the mesh for the entire problem. To demonstrate the wavelet technique, we consider Poisson's equation in two dimensions. By comparison with a simple finite difference solution to this problem with periodic boundary conditions we show how a wavelet technique may be efficiently developed. Dirichlet boundary conditions are then imposed, using the capacitance matrix method described by Proskurowski and Widlund and others. The convergence of the wavelet solutions are examined and they are found to compare extremely favourably to the finite difference solutions. Preliminary investigations also indicate that the wavelet technique is a strong contender to the finite element method.
CURVILINEAR COMPOSITE TRIANGULAR ELEMENT OF CLASS C
Authors: MEJAK GEORGE
Published: February 2008

A triangular composite element with 15 degrees of freedom is introduced. It is shown that after an appropriate modification of the Zlámal coordinate transformation this element can be employed as a reference element to curvilinear triangular element of class C with nine degrees of freedom. A complete list of the basis functions, together with a procedure for their automatic generation are included.
AEROTHERMODYNAMIC ANALYSIS FOR AXISYMMETRIC PROJECTILES AT SUPERSONIC/HYPERSONIC SPEEDS
Authors: NUSCA MICHAEL J.
Published: February 2008

An aerothermodynamic design code for axisymmetric projectiles has been developed using a viscous‐inviscid interaction scheme. Separate solution procedures for the inviscid and the viscous (boundary layer) fluid dynamic equations are coupled by an iterative solution procedure. Non‐equilibrium, equilibrium and perfect gas boundary layer equations are included. The non‐equilibrium gas boundary layer equations assume a binary mixture (two species; atoms and molecules) of chemically reacting perfect gases. Conservation equations for each species include finite reaction rates applicable to high temperature air. The equilibrium gas boundary layer equations assume infinite rate reactions, while the perfect gas equations assume no chemical reactions. Projectile near‐wall and surface flow profiles (velocity, pressure, density, temperature and heat transfer) representing converged solutions to both the inviscid and viscous equations can be obtained in less than two minutes on minicomputers. A technique for computing local reverse flow regions is included. Computations for yawed projectiles are accomplished using a coordinate system transformation technique that is valid for small angle‐of‐attack. Computed surface pressure, heat transfer rates and aerodynamic forces and moments for 1.25 &le Mach No. &le 10.5 are compared to wind tunnel and free flight measurements on flat plate, blunt‐cone, and projectile geometries such as a cone‐cylinder‐flare.
ON EVALUATION OF TRANSVERSE STRESSES IN LAYERED SYMMETRIC COMPOSITE AND SANDWICH LAMINATES UNDER FLEXURE
Authors: MANJUNATHA B.S. , KANT T.
Published: February 2008

This paper attempts to evaluate the transverse stresses that are generated within the interface between two layers of laminated composite and sandwich laminates by using Cℴ finite element formulation of higher‐order theories. These theories do not require the use of a fictitious shear correction coefficient which is usually associated with the first‐order Reissner‐Mindlin theory. The in‐plane stresses are evaluated by using constitutive relations. The transverse stresses are evaluated through the use of equilibrium equations. The integration of the equilibrium equations is attempted through forward and central direct finite difference techniques and a new approach, named as, an exact surface fitting method. Sixteen and nine‐noded quadrilateral Lagrangian elements are used. The numerical results obtained by the present approaches in general and the exact surface fitting method in particular, show excellent agreement with available elasticity solutions. New results for symmetric sandwich laminates are also presented for future comparisons.
AUTOMATIC DESIGN OF REINFORCEMENT IN CONCRETE PLATES AND SHELLS
Authors: LOURENÇO PAULO B. , FIGUEIRAS JOAQUIM A.
Published: February 2008

The problem of designing reinforced concrete plates and shells has interested researchers for a long time. The recent development of the computers' performance and storage capacity combined with powerful numerical methods revealed the need of a clear procedure to design elements subjected to membrane and flexure forces. In the present study this problem is formulated based on the equilibrium conditions and an iterative procedure is suggested. The computational code based on this approach is given, as well as some examples of the method.
DERIVATION OF THIN PLATE BENDING ELEMENTS WITH ONE DEGREE OF FREEDOM PER NODE: A SIMPLE THREE NODE TRIANGLE
Authors: OÑATE E. , CERVERA M.
Published: February 2008

A general methodology for deriving thin plate bending elements with a single degree of freedom per node is presented. The formulation is based on the combination of a standard C0 finite element interpolation for the deflection field with an independent approximation of the curvatures which are expressed in terms of the deflection gradient along the sides using a finite volume‐like approach. The formulation is particularized for the simplest element of the family, i.e. the three node triangle with three degrees of freedom. The potential of the new element is shown through different examples of application.
ON RECOVERY OF STRESSES FOR A MULTI‐LAYERED BEAM ELEMENT
Authors: WISNIEWSKI K. , SCHREFLER B.A.
Published: February 2008

The stress recovery procedures discussed in the present paper refer to a multi‐layered element of assembled Timoshenko beam elements. Directly calculated stresses for a multi‐layered beam model strongly depend on properties of the approximation functions, and are unrealistic. Thus, an enhanced procedure which circumvents the limitations of the interface variables model, and hierarchical model is proposed. Each material layer of the beam element is covered by one quadrilateral 9‐node element, providing a parabolic approximation of displacements. The stresses are evaluated using 2 × 2 Gauss points, projected to corner nodes, and smoothed within material layers. Numerical calculations show very good accordance of stresses yielded by this procedure with 2D results.
THE IMPLICATIONS OF ORGANIZATIONAL LEARNING FOR ORGANIZATIONAL COMMUNICATION: A REVIEW AND REFORMULATION
Authors: Lundberg Craig C. , Brownell Judi
Published: February 2008

This manuscript explores the contributions of organizational learning to organizational communication. The study of organizational communication is seen in multi‐dimensional terms as the study of how meanings are created, stored, distributed, and modified in the service of organizational performance and change. An overview of organizational communication is provided and organizational learning and its main assumptions are explained. The authors then demonstrate how the incorporation of organizational learning concepts into organizational communication theory permit the integration and extension of much of what is known about how organizational members communicate, learn, and change. An integrative model is presented which explains how individual and organizational understandings are interrelated.
COMPETITIVE DECISION MAKING IN DECLINING INDUSTRIES
Authors: Lamont Bruce T. , Hoffman James J. , Forte Monique
Published: February 2008

This paper expands the theory of competitive decision making in declining industries. Kelley and Thibaut's theory of interdependence is used to analyze and explain the use of competitive and cooperative strategies among competitors. The analysis suggests that although the use of competitive strategies is more likely, cooperative strategies should produce higher performance. Several barriers to, and facilitators of, the use of cooperative strategies in declining industries are identified, and their prescriptive implications are discussed.
THE GREAT DUTCH WORK DISABILITY EPIDEMIC: CULTURAL CONSTRUCTION AND INSTITUTIONAL ACTION
Authors: Hooijberg Robert , Price Richard H. , Talsma Akkeneel
Published: February 2008

We propose that institutional actors do not just ceremonially comply with the cultural values in their environment, as institutional theorists have suggested. Instead, we argue that institutional actors can use conflicting cultural values as tools to further their interests and, in doing so, affect significant social problems and cause unanticipated changes in their core goals and policies. To present support for that proposition, we describe an epidemic of work disability that occurred in the Netherlands between 1967 and 1988. The epidemic is examined in light of conflicting Dutch cultural conceptions of the meaning of work and the meaning of economic security in the welfare state. The behavior of key institutional actors, including the government, medical institutions, employers, and labor unions, is examined to identify their roles in the epidemic. We assert that, by pursuing its own interests while upholding Dutch cultural values, each institutional actor produced conditions in which the work disability epidemic could occur.
EMPLOYEE GRIEVANCES: AN APPLICATION OF THE LEADER‐MEMBER EXCHANGE MODEL
Authors: Cleyman Kelly L. , Jex Steve M. , Love Kevin G.
Published: February 2008

Using the Leader‐Member Exchange (LMX) model as a guide, this study examined the relationship between the quality of information exchange between an employee and his or her immediate supervisor and the intention to file grievances. One hundred twenty‐five unionized automotive employees completed a measure of quality of information exchange and responded to eight vignettes representing hypothetical work situations. Employees rated each vignette in terms of their intention to file a grievance if faced with that situation. It was hypothesized that employees who perceived a high quality information exchange relationship with their supervisors would be less likely to file grievances than employees who perceived a low quality information exchange relationship. When the intent to file measure was aggregated across all vignettes, the hypothesis was supported When the vignettes were categorized into three different types of grievance situations through a principal components analysis, quality of information exchange was related only to grievance filing over issues pertaining to time at work. Implications of these findings for both employee grievance research and grievance prevention are discussed.
STRONG HYPOTHESIS TESTING IN ORGANIZATIONS: ALTERNATIVE APPROACHES TO THE EVALUATION OF PRACTICAL SIGNIFICANCE
Authors: Svyantek Daniel J. , Ekeberg Steven E.
Published: February 2008

Organizational decision‐makers require information presented in ways that allow them to make informed decisions on the effectiveness of change interventions. Current statistical methods do not provide enough information about the practical value of organizational interventions to decision‐makers. It is proposed that a strong hypothesis testing strategy provides a partial answer to this problem. The hypothesis testing method presented here uses Bayesian statistics to test null hypotheses other than the traditional Ho = 0. A description of the evaluation of a change project in six manufacturing plants of a large United States corporation is provided. The data from this project is used to show how both statistical and practical significance may be tested using this hypothesis testing method. The applicability of the strong hypothesis testing approach to the assessment of organizational change is then discussed, and recommendations are made for evaluations conducted in field settings.
MODERATORS OF THE RELATIONSHIP BETWEEN JOB SATISFACTION AND NURSES' INTENTION TO QUIT
Authors: Eberhardt Bruce J. , Pooyan Abdullah , Moser Steven B.
Published: February 2008

This study investigated possible moderating effects on the relationship between job satisfaction and nurses' intention to quit. Using data collected from 327 registered nurses in three large private hospitals, moderator regression analysis revealed significant main and moderating effects for employee age. When the effects of education, employment status, and marital status were controlled, the main and moderating effects of age on the relationship between job satisfaction and nurses' intention to quit remained significant. Alternative explanations of the results are discussed, along with implications of the findings for nursing turnover research.
PRODUCT‐MARKET/INTERNATIONAL DIVERSIFICATION AND CORPORATE PERFORMANCE
Authors: Simmonds Paul G. , Lamont Bruce T.
Published: February 2008

The performance effects of product‐market and international diversification were examined in a sample of 156 U.S. corporations. Three sets of performance measures were used: (1) profitability, (2) risk‐adjusted returns, and (3) growth. Results suggest independent effects on profitability, and interactive effects on risk‐adjusted returns and growth. Results also clarify seemingly conflicting findings on product‐market and international diversification effects on performance.
A FRAMEWORK FOR THE APPLICATION OF UNCERTAINTY REDUCTION (UCR) THEORY TO SERVICE ENCOUNTERS
Authors: Smith William L.
Published: February 2008

We often know what comes next from the first few words of a conversation or interaction. If the interaction is in the context of a service encounter, whether for the customer or the service provider, those first few words may lead to satisfactory or unsatisfactory perceptions of service quality. This paper presents a communications perspective on the initial interaction of the service encounter in order to suggest a new way service quality issues may be addressed It examines the service encounter from the perspective of uncertainty reduction (UCR) theory. Interpersonal communication theories can inform service system designers and service managers with regard to the service encounter. Reducing uncertainty between customers and service workers in the service encounter should increase perceived service quality experiences. The twelve propositions presented represent the types of issues that might be addressed by future empirical studies.
EXPATRIATE TURNOVER TENDENCIES IN SAUDI ARABIA: AN EMPIRICAL EXAMINATION
Authors: Bhuian Shahid N. , Al‐Jabri Ibrahim M.
Published: February 2008

The authors explore turnover tendencies among expatriate employees in Saudi Arabia They: (1) discuss the novelty of expatriates in Saudi Arabia; (2) review the literature on employee turnover tendency and its correlates—job satisfaction and employee characteristics; (3) hypothesize a negative relationship between extrinsic job satisfaction and expatriate turnover tendencies, a negative relationship between general job satisfaction and expatriate turnover tendencies, no relationship between intrinsic job satisfaction and expatriate turnover tendencies, and no relationship between expatriate characteristics and expatriate turnover tendencies, and (4) empirically lest the hypotheses with a sample of expatriate employees. Results provide strong support for most of the hypotheses except “pay,” one of the extrinsic job satisfaction variables, and “job feedback,” one of the intrinsic job satisfaction variables.
COMMUNICATED KNOWLEDGE AS A LEARNING FOUNDATION
Authors: Page West G. , Dale Meyer G.
Published: February 2008

Organizational learning capabilities are embedded in organizational communication systems and processes related to knowledge creation and articulation. The emergence of new organizational forms (such as horizontal organizations) in rapidly‐changing environments and hyper‐competitive markets underscores the need to better understand these foundational sources of learning. In fact, the reason horizontal organizations may find success is that their structure is intended to promote communications systems and processes which enhance a knowledge‐response sequence similar to a stimulus‐response sequence associated with learning. These systems permit managers to quickly gather information, respond with agility in making decisions, and continue to make ongoing adjustments. Firms which understand the need to build their communications capabilities may be characterized as meta‐learning organizations. Resource‐based theory suggests that communications systems and processes are thus sources of competitive advantage. Future empirical research on organizational learning may progress by evaluating specific measures of communication process as proxies for learning processes.
ENHANCING CORPORATE VENTURE PERFORMANCE THROUGH ORGANIZATIONAL LEARNING
Authors: Gnyawali Devi R. , Grant John H.
Published: February 2008

Despite the growing body of literature on both organizational learning (OL) and corporate venture development (CVD), very few attempts have been made to establish connections between these two literature streams. While existing literature provides some evidence that OL may facilitate the process of CVD, several interesting research issues remain unexamined. We know very little about (a) what type of learning processes are effective at various stages of CVD; and (b) whether and how knowledge created through various OL processes enhances venture performance. These research issues are examined in this paper by integrating the literature from OL and CVD. We develop a conceptual model that integrates organizational learning with the antecedents and outcomes of CVD. We argue that (a) organizational learning in CVD occurs through two distinct and yet complementary processes; (b) productive organizational learning occurs when organizations vary their emphases on different types of learning depending upon the stages of CVD; and (c ) different types of learning are associated with different types of venture outcomes. Propositions are developed and implications are discussed to facilitate empirical research.