Showing papers in "Computers & Structures in 1981"

TL;DR: In this article, a modified version of the Newton-Raphson method is proposed to overcome limit points in the finite element method with a fixed load level and a constraint equation.

TL;DR: In this article, a non-linear viscoelastic constitutive law for polyvinyl acetate is considered and compared with computations under conditions of relaxation and constant strain rate deformation.

TL;DR: In this paper, a small strain elastic catenary element is presented and its utility is demonstrated through static and dynamic cable problems and its accuracy and efficiency are comparable or better to some of the elements presented in the literature.

TL;DR: In this paper, a hierarchy of beam elements which include the effects of transverse shear deformation and rotary inertia is presented, and a series of constrained elements can be generated by imposing a continuous shear constraint condition on each member of the beam element family.

TL;DR: In this paper, the status and some recent developments in the application of reduction methods to nonlinear structural mechanics problems are summarized and a number of research areas which have high potential for application of the reduction methods are identified.

TL;DR: A simple flat three-node triangular shell element for linear and nonlinear analysis is presented in this article, where the stiffness matrix with 6 degrees of freedom per node is obtained by superimposing its bending and membrane stiffness matrices.

TL;DR: In this article, a quasi-three dimensional finite element analysis was used to analyze the edge stress problem in composite laminates and convergence studies were made to explore the existence of stress singularities near the free edge.

TL;DR: The objective is to design schemes that in some analyses can significantly decrease the computational effort involved when compared to a complete direct integration solution.

TL;DR: In this paper, two vector iteration methods, dynamic relaxation and first order conjugate gradient, are used to trace the postbuckling behavior of spatial structures. But the convergence to the solution is achieved by using only vectorial quantities and no stiffness matrix is required in its overall assembled form.

TL;DR: Continuation methods are considered in this paper as the collection of methods needed for the computational analysis of specified parts of the solution field of "under-determined" equations Fx = c where F: Rm → Rn, m >; n. is given and any suitable m−n of the variables x, are designated as parameters.

TL;DR: In this paper, the authors investigated the mechanisms behind the cut-off of the stress peak at the notch using the fictitious crack model (FCM), where a fictitious crack is assumed to form when the uniaxial tensile strength is exceeded.

TL;DR: In this paper, the large deflections of thin cantilever beams of nonlinear materials, subjected to a concentrated load at the free end, are analyzed using the Ludwick relation.

TL;DR: In this article, a finite element formulation for conducting large deformation analysis of laminated anisotropic shells is presented, where the element is a "degenerated" three-dimensional isoparametric element and the numerical characteristics of the element with respect to the mesh size and the use of integration orders are studied for a plate with simply supports and clamped supports.

TL;DR: In this paper, a finite-element analysis of the large-deflection theory, including transverse shear, including laminated anisotropic composite plates, is presented, showing the parametric effects of plate aspect ratio, side-to-thickness ratio, orientation of layers, and anisotropy.

TL;DR: In this paper, the Euler parameters, Lagrange's form of d'Alembert's principle, generalized speeds, quasi-coordinates, relative coordinates, and structural analysis techniques are used for solving the equations of motion of multi-body mechanical systems with flexible links.

TL;DR: In this article, a doubly curved superparamatric quadratic shell element is described as a model for the analysis of practical, non-classical structural configuration constructed of fiber reinforced laminated composites.

TL;DR: In this article, two and three-dimensional finite strips are developed for the analysis of thin and thick sectorial plates, which can be isotropic or orthotropic, of constant or variable thickness, and can have different combinations of boundary conditions.

TL;DR: In this paper, a method is described for calculating the stresses in a body during heat-treatment and calculating the remaining residual stress distribution, with special attention given to the thermo-elastic-plastic material behaviour which is highly temperature-dependent.

TL;DR: In this article, the usefulness of quasi-Newton methods for the solution of nonlinear systems of equations is demonstrated, after a review of the Newton iterative method, several quasiNewton updates are presented and tested, and a complete discussion of different methods used, of the convergence rates and of the associated computer costs.

TL;DR: In this paper, a nonlinear finite element analysis of composite beams with incomplete interaction is presented, where a simplified nonlinear model is assumed in this approach, and numerical results are compared with the test results and existing values based on other numerical methods.

TL;DR: In this article, a state determination algorithm is proposed which combines the classical Newton-Raphson method with a modified version of the state determination method to obtain the required property and to compute for accurate solutions.

TL;DR: Three tasks which can be efficiently performed using computerized symbolic manipulation are identified: generation of algebraic expressions for the stiffness coefficients of nonlinear finite elements, generation of FORTRAN source code for numerical evaluation of stiffness coefficients, and checking the correctness of the FORTRan statements for the arrays of coefficients.

TL;DR: In this paper, the authors discuss the computational aspects of this problem and discuss the requirements of a finite element solution to the problem and summarize results of two large structural crash simulation problems.

TL;DR: A total Lagrangian formulation for large deformation analysis of shells by the finite element method is presented in this article, where a special discretization in the thickness direction is employed to permit solution of shell problems without numerical difficulties.

TL;DR: An overview of the current capabilities of 36 computer programs that can be used for solution of nonlinear structural and solid mechanics problems is provided.

TL;DR: A simple technique is proposed that enables a direct second order analysis to be performed by means of first order plane frame computer programs to evaluate the effect of sway on elastic-plastic frames.

TL;DR: In this paper, an optimality criterion method for the design of structural systems under natural frequency constraints is presented, which is applied to a variety of beams and frames and results indicate the efficiency and simplicity of the method in locating the optimal design as compared to existing methods.

TL;DR: In this paper, an analysis of stresses and deformation using the finite element method in a flanged hole produced by punch stretching during a sheet metal forming process is described, which is restricted to the membrane shell theory with axisymmetric deformation.

TL;DR: In this paper, a finite element method for the analysis of non linear rubber type parts is developed using a penalty function approach, which is not based on reduced integration techniques but on a reduced constraint concept.

TL;DR: In this paper, an iterative finite element method was developed for determining stresses and strains near pin-loaded holes in finite orthotropic plates, where the contact pressure distribution was evaluated rather than assumed.