Showing papers in "Computers & Structures in 1975"

TL;DR: In this paper, a two-dimensional finite-difference technique for irregular meshes is formulated for derivatives up to the second order, where the domain in the vicinity of a given central point is broken into eight 45 degree pie shaped segments and the closest finite difference point in each segment to the center point is noted.

TL;DR: Fortran IV subroutines for the in-core solution of linear algebraic systems with a sparse, symmetric, skyline-stored coefficient matrix are presented and the application to ‘superelement’ condensation of large-scale systems is discussed.

TL;DR: In this paper, the use and importance of dynamic stiffness influence coefficients in flexural forced vibrations of structures composed of beams are described and the dynamic forces can be either harmonic or general transient forces.

TL;DR: In this article, a study is made of the approximate structural reanalysis technique based on the use of Taylor series expansion of response variables in terms of design variables in conjunction with the mixed method.

TL;DR: A mathematical system is defined herein that provides a tool for algebraic representation and processing of configurations of all kinds, where the word ‘configuration’ is used to mean any collection of physical and/or abstract objects.

TL;DR: In this paper, a generalized eigenvalue problem for a large, sparse complex matrix is solved by permutation of the matrix into a convenient banded form and by writing recursion relations for the determinant.

TL;DR: In this article, a higher order beam finite element is derived and shown to be very efficient in solving the transient dynamic problem of elastic impact and impact with permanent indentations, and the finite element solutions are found in good agreement with some existing solutions.

TL;DR: In this paper, a high precision triangular finite element is used in the present formulation, and explicit expressions for elastic stiffness and geometric stiffness matrices are presented; the use of numerical integration is avoided; the effect of transverse shear on the critical loads is brought out through two typical examples.

TL;DR: In this paper, a new approach to the optimal design of multi-stage structures is presented, where the problem considered is that of optimal sizing and configurations for minimal weight, using limit analysis under a single loading condition.

TL;DR: In this paper, two triangular mixed finite elements are developed for the linear and non-linear analysis of thin shallow shells, where the unknown variables at the finite element nodes include not only the three displacements and bending stress resultants, but also the membrane stress endants.

TL;DR: In this article, the authors derived the flexibility and stress factors of the curved pipes and flanges, taking into account the effect of the flanges to which they are normally attached.

TL;DR: A study is made of the adaptation of the hypermatrix (block matrix) scheme for solving large systems of finite element equations to the CDC STAR-100 computer using Cholesky decomposition and the mode of storage of the different submatrices to take advantage of the STAR pipeline (streaming) capability.

TL;DR: In this article, a numerical integration procedure is developed which can obtain the frequency and buckling eigenvalues and associated eigenfunctions of prestressed rotating anisotropic shells of revolution.

TL;DR: In this paper, the problem of axisymmetric finite element analysis numerical instability occurs when the elements are located too far from the symmetry axis, and it is shown to be more severely with quadratic displacement fields than with the linear ones.

TL;DR: In this article, a finite element scheme for static and free vibration analysis of box bridges with orthogonal boundaries and arbitrary combinations of straight and horizontally curved sections is described, and a variety of special purpose elements are developed to suit the behaviour characteristics of thin box sections.

TL;DR: The Dynamic Relaxation (DR) method as discussed by the authors is a well-known structural analysis technique for bending of a beam, which was originally developed by Day during the course of his investigations of complex prestressed concrete pressure vessels for nuclear reactors.

TL;DR: In this article, the stiffness coefficients corresponding to the 0th, 1st, and n th harmonics are presented in closed form, which can be readily coded into any special or general purpose structural analysis computer program, represent the exact solution to any structural model consisting of nodal displacements and forces.

TL;DR: In this paper, a unified treatment of non-linear engineering problems is undertaken and two solution algorithms are presented, one based on simple interation technique and the second following a generalised Newton-Raphson process.

TL;DR: Theoretical expressions for determining the stress response for a material exhibiting bilinear hardening behavior during elasto-plastic wave interaction and boundary reflection were presented in this article. But the results of these expressions were not validated.

TL;DR: In this paper, a methodology is developed by which one may design a stiffened cylinder of specified material, radius, and length, such that it can safely carry a given uniform axial compression with minimum weight.

TL;DR: In this paper, a shell-of-revolt model is proposed to evaluate the potential savings due to numerical optimization, and the resulting nonlinear programming problem is solved by iterated linear programming.

TL;DR: In this article, the authors considered the related inverse decomposition given by (RT)−1AR−1 = D as a basis for an efficient equation solver using partitioning (submatrix element or hyperelement organization).

TL;DR: In this article, the optimal number of cells for minimum weight design of an aircraft wing under strength and natural frequency constraints for the two cases (i) uniform loading and (ii) a tip moment have been given.

TL;DR: In this article, an analysis of the nonlinear modes of vibration of a pretwisted nonuniform cantilevered blade of unsymmetrical cross-section mounted on the periphery of a rotating disk is presented.

TL;DR: In this article, a Monte Carlo method for digital computer simulation of the strength of (steel) members and structures is presented and is applied to rolled steel beams and columns, and thin-walled cylinders.

TL;DR: In this paper, an approximate finite difference operator is suggested which overcomes the difficulty and solutions obtained by its use are compared with those obtained by regarding the support as consisting of stiff springs.

TL;DR: In this paper, the matrix exponential technique is adapted as a direct integration procedure for predicting the dynamic response due to discrete inputs, and a sample problem whose exact solution is known is solved analytically, and the response is compared with the Wilson method, as well as matrix exponential.

TL;DR: In this article, a simpler version of the frontal solution technique suitable for solving structures with large number of members is described, and facilities of the program are brought out with regard to the re-solution and re-design of a large structural problem.

TL;DR: In this article, the effect of L/R ratio (L and R are length and radius of cylinder) on the buckling behavior of cylindrical pressure vessels with torispherical head is investigated.