Showing papers in "Computer Methods in Applied Mechanics and Engineering in 1985"

TL;DR: In this paper, it is shown that consistency between the tangent operator and the integration algorithm employed in the solution of the incremental problem plays crucial role in preserving the quadratic rate of asymptotic convergence of iterative solution schemes based upon Newton's method.

TL;DR: In this paper, a large body of experimental and theoretical literature on friction is critically reviewed and interpreted as a basis for models of dynamic friction phenomena, and a continuum model of interfaces is developed which simulate key interface properties identified in Part I.

TL;DR: In this article, a local multiplicative split of the deformation gradient into volume-preserving and dilatational parts is proposed, without relying on rate forms of the weak form of momentum balance.

TL;DR: By assuming from the outset hyperelastic constitutive behavior, an alternative approach to finite deformation plasticity and viscoplasticity is proposed whereby the need for integration of spatial rate constitutive equations is entirely bypassed.

TL;DR: In this paper, the basic equations to model the coupling between strain and damage behaviors are written within the framework of the thermodynamics of irreversible processes, and the damage is represented by a scalar internal variable which expresses the loss of strength of materials during such processes as fatigue, ductile or creep strains.

TL;DR: The two-and three-dimensional contact algorithms used in the finite element programs developed at the Lawrence Livermore National Laboratory are described in this article, where the penalty methods are used to obtain solutions to almost all of the structural problems.

TL;DR: Making use of a perturbed Lagrangian formulation, a finite element procedure for contact problems is developed for the general case in which node-to-node contact no longer holds, which leads naturally to a discretization of the contact interface into contact segments.

TL;DR: In this article, a new plane-stress triangular element is derived using the free formulation of Bergan and Nygard, which possesses nine degrees of freedom: six corner translations and three corner normal rotations.

TL;DR: In this paper, a displacement methodology for Mindlin elements, recently employed in the development of an efficient, four-node quadrilateral (MIN4), is the basis for a three-node, explicitly integrated triangular element (MIN3).

TL;DR: In this paper, the stabilization vector γ can be obtained naturally by taking the partial derivatives with respect to the natural coordinates, and the components of the stresses and stresses can be expressed in terms of a set of orthogonal coordinates.

TL;DR: In this paper, a finite element-based solution procedure for high-speed inviscid compressible flow problems is described, which is computationally more efficient than the one-step Taylor-Galerkin approach and better suited for implementation on the modern generation of vector computers.

TL;DR: In this article, a Rayleigh-Ritz analysis of the nonlinear system of ordinary differential equations resulting from the finite element discretization is reduced by means of Rayleigh Ritz analysis, and the basis vectors are chosen to be the current tangent eigenmodes together with some modal derivatives that indicate the way in which the spectrum is changing.

TL;DR: Algorithms whose resource needs grow only linearly with problem size are developed, which will fully exploit the ‘parallel-processing’ capability available in the new generation of multi-processor computers.

TL;DR: A new Petrov-Galerkin method for convection-dominated flow problems which is conservative and satisfies the discrete maximum principle is presented, which possesses no spurious crosswind diffusion and gives very accurate solutions.

TL;DR: In this paper, a finite element formulation for the analysis of nonuniform and localized deformations in rate-dependent single crystals is presented, but the main focus is on issues relating to the formulation and implementation of finite element methods for crystalline solids.

TL;DR: An adaptive finite element method is proposed which involves an automatic mesh refinement in areas of the mesh where local errors are determined to exceed a pre-assigned limit.

TL;DR: It is shown that cost-efficient methods for structural sizing may be advantageously extended to shape optimal design problems and a new general optimization algorithm is presented that combines mixed approximations and dual methods.

TL;DR: In this article, a rigorous stability analysis is provided for mixed time integration for first-order semidiscretizations, where different time steps and different integrators are used in different parts of the mesh.

TL;DR: In this article, a streamline upwind approximation for treating advectiondominatcd transport is presented, which is quite simple to implement with existing finite element methods and is used in a two-dimensional finite element computer program.

TL;DR: The ‘quadratic-upwind’ approximation emerged as the most satisfactory of the discretizations investigated and was also found to give more accurate results than standard upwind differencing.

TL;DR: In this article, a concise survey of the literature related to the large deformation elasto-plasticity problems including unilateral contact and friction is presented together with an extension of the friction law for large deformability analysis.

TL;DR: In this paper, a technique for determining derivatives (fluxes or stresses) from finite element solutions is developed, which is a generalization to higher dimensions of a procedure known to give highly accurate results in one dimension.

TL;DR: Time-accurate methods for unsteady problems on a fixed mesh are considered, and important advantages of the Galerkin formulation are lost as the time step is increased, leading naturally to the study of an important class of methods which are called characteristicGalerkin methods.

TL;DR: In this article, a general iterative procedure for solving mixed, Lagrangian, finite element equations is introduced, which allows a dramatic improvement in accuracy of simple, irreducible, formulations to be achieved in a few "resolutions".

TL;DR: In this paper, a series of flow calculations were conducted for a model annular dump diffuser, and various numerics issues were studied. Among those issues, the influences of the numerical schemes and their interaction with the grid distribution were investigated.