Showing papers in "Computers & Structures in 1972"

TL;DR: A technique of digital simulation of multivariate and/or multidimensional Gaussian random processes (homogeneous or nonhomogeneous) which can represent physical processes germane to structural engineering is presented.

TL;DR: Preliminary studies indicate that for many shell problems this variable grid technique will yield improved efficiency as well as a simple method for handling curved boundaries and varying stress patterns.

TL;DR: In this article, a solution to the problem of minimum mass design of multi-purpose trusses for which the design variables are not only the areas of the bars but also the positions of the joints is provided.

TL;DR: In this paper, a stochastic method of analysis of offshore towers subjected separately to random sea waves and to strong motion earthquakes is presented. Butts et al. used the Pierson-Moskowitz wave height spectrum along with linear wave theory to define a stationary random sea state as caused by wind generated surface waves.

TL;DR: An iterative approach which combines the advantages of a finite element method and a standard finite difference technique is developed for the analysis of plates on elastic foundation subjected to general loadings and arbitrary edge support conditions as mentioned in this paper.

TL;DR: In this paper, the optimal design of a statically determinate or indeterminate truss of a given layout is presented by which necessary and sufficient conditions for global optimality may be derived when an upper bound is prescribed for the compliance of the truss under one or several sets of loads and a lower bound for the cross sectional area of each bar.

TL;DR: In this article, a transformation of variables is employed to reduce the optimization to a solution of a linear programming problem, which is suitable for practical design of structures with no restriction on the number and types of loading conditions, tendon configuration or number of prestressing stages.

TL;DR: In this article, a 3D finite element analysis of laminated composite plates in bending is presented, where an isoparametric solid element with a cubic displacement expansion in planform and a linear variation through the thickness is used to model each layer of the laminate.

TL;DR: In this article, a displacement-type finite element method is applied to reduce the governing partial differential equations to a set of simultaneous nonlinear ordinary differential equations of motion of a lumped mass system connected by three-dimensional elements.

TL;DR: In this article, the Newmark Method with appropriately chosen parameters is shown to be superior to a modally uncoupled precise integration operator for many nonlinear structural response problems, including forced dynamic structural response.

TL;DR: An ‘MCODE’ technique is introduced which forms an array in order to keep track of the degrees of freedom of the various matrices and vectors at all levels of substructuring.

TL;DR: In this article, a polynomial representation over each finite element of the excitation cross spectral density function is introduced, which allows the spatial integrations involved in evaluating the modal force cross spectral matrix to be carried out in closed form and this matrix can be calculated by an automatic computer process.

TL;DR: In this article, a method to improve convergence is presented, based on an expression of the matrix of changes in stiffness as a linear combination of two matrices, which is then modified to further improve convergence separately for each component of the unknown displacement vector.

TL;DR: In this article, a digital computer program for the geometrically nonlinear static and dynamic response of arbitrarily loaded shells of revolution is described, which is based upon Sanders' nonlinear thin shell theory for the conditions of small strains and moderately small rotations.

TL;DR: A review of previous analytical and experimental work on steel beam-to-column connexions is presented in this article, where the authors focus on the column web behaviour for con-nections in which only the column portion of the con-nexion fails and the formulation of a finite element analysis is outlined which is used to model connexion behaviour.

TL;DR: A brief review of the development of current Pol's is presented and the concept of the POLO system is presented, a machine independent prototype computer system whose purpose is to provide engineers with an environment in which they can develop their own computer-aided design environment.

TL;DR: Dynamic programming has been found a useful technique for the synthesis of optimal layouts for braced frameworks, provided that the interconnection between different parts of the structure is relatively simple.

TL;DR: In this article, the nonlinear relaxation method in conjunction with finite difference approximation is utilized to solve the governing differential equations of flat membranes, and the results are presented in a form convenient for direct engineering use.

TL;DR: In this article, the authors derived expressions for the pseudo forces and contributions to the tangent stiffness matrix for geometric and material nonlinearities using the basic principle of virtual work and a computional procedure is presented which evaluates the effects of non-linearities through the use of finite difference expressions.

TL;DR: In this article, the stiffness matrices for a circular and annular element are presented, with a minimal of programming effort, for any continuous beam program can be modified to include the analysis of circular plates by simply coding the appropriate stiffness and load coefficients given in the note.

TL;DR: In this article, a theoretical and numerical comparison is made of five finite element formulations which have been presented for the nonlinear elastic analysis of planar structures, and three solution procedures are used to apply these formulations to a group of problems that cover a wide range of types of nonlinearity.

TL;DR: In this paper, a transient response finite difference solution in space and time for the shell of revolution equations derived by Sanders is presented, based on a checkerboard half-spacing mesh configuration that allows the use of lower order difference expressions than those normally used for accuracy.

TL;DR: An approximate computational algorithm is derived which permits a refined element analysis to be altered on a small capacity computer and is based upon the dynamic normal mode method and an accompanying solution technique known as ·dynamic relaxation”.

TL;DR: In this paper, two finite element formulations involving use of linear and cubic approximating models for solution of one-dimensional deformations in porous elastic soil media are compared, such factors as accuracy, stability, and computational effort that affect the selection of a solution scheme for practical applications are examined.

TL;DR: In this paper, the stress result and non-local theories of shear and moment interaction at fully plastic sections are critically reviewed and practical lower bound relationships for shear, moment and axial force interaction of plastic, rectangular and T-sections are derived.

TL;DR: In this paper, an incremental digital computer program is developed for the analysis of castellated beams in the elastic and plastic domains, which treats the beam as a Vierendeel Truss chord and vertical elements obey moment, shear and axial force interaction relationships developed earlier.

TL;DR: In this paper, a Fourier series slope-deflection technique has been developed as a means of analyzing curved girder bridge systems, which may contain orthotropic decks, incorporating both pure and warping torsional effects as well as bending effects.

TL;DR: In this paper, a finite element procedure is presented for solving thin shell problems of arbitrary geometry and boundary conditions, where the actual smoothly curved shell surface is approximated by the assemblage of flat triangular plate elements.

TL;DR: In this paper, an interactive design and analysis algorithm for prestressed concrete girders is discussed, guided by the engineer, which selects, from tabulated standard crosssections and associated combinations of prestressing forces and eccentricities, the cross-section, prestressing force, and eccentricity to satisfy the problem constraints.

TL;DR: In this article, an arbitrary doubly curved quadrilateral element is developed which is compatible, has rigid body freedoms and flexible geometry based on a non-shallow shell theory, and the membrane energy is computed from the displacements and the bending energy from the rotations.