Showing papers in "Computer Methods in Applied Mechanics and Engineering in 1989"

TL;DR: Galerkin/least-squares finite element methods for advective-diffusive equations are presented in this paper, and a convergence analysis and error estimates are presented.

TL;DR: A portable, power operated, hand cultivator comprising a frame having a motor supported thereon which oscillates two or more generally vertically disposed cultivator tines extending downwardly from the frame.

TL;DR: In this paper, five different techniques for a posteriori error estimation of adaptive finite element methods for linear elliptic boundary value problems are presented, referred to as the residual estimation method, the duality method, subdomain residual method, a method based on interpolation theory, and a post-processing method.

TL;DR: In this paper, the problem of designing h-p meshes which are optimal in some sense is addressed, and an optimization algorithm is developed based on these criteria and is applied to several model one-dimensional and two-dimensional elliptic boundary-value problems.

TL;DR: The combined scheme easily out-performs ordinary h-refinement for strongly unsteady flows that require a grid change every 5–10 timesteps, yielding a very effective adaptive refinement method for this class of problems.

TL;DR: A multi-element group, domain decomposition algorithm for solving linear nonsymmetric systems arising in finite element analysis based on the generalized minimum residual procedure originally proposed by Saad and Shultz is presented.

TL;DR: The theoretical analysis of the mixed and hybrid exponential fitting methods is extended to the case of a non-zero source term and their upwinding features are analysed.

TL;DR: Possible ways of developing accurate and efficient finite volume methods for complex, incompressible flows are discussed and examples of a finite volume method for general two-dimensional flows are presented.

TL;DR: In this article, the Lagrange multiplier method and convolution theory are used to formulate design sensitivities for nonlinear transient thermal systems, which are expressed in explicit form with respect to variations in structural shape and the conventional design quantities, i.e., material properties, applied loads, prescribed boundary conditions and initial conditions.

TL;DR: In this paper, a finite strip approach is presented for the determination of buckling stresses and natural frequencies of vibration of prismatic plate structures of finite length which have diaphragm ends.

TL;DR: In this paper, the edge-elements with degrees of freedom associated with the edges of the mesh are shown to fit the scattering problem just as well, with no penalty in terms of computational time and with the expected additional advantage of not generating spurious modes when applied to the problem of the eigenmodes of resonating cavities.

TL;DR: A unified approach for explicit structural design sensitivity analysis of linear elastic systems is presented in this paper, where first-order sensitivity expressions involving the complete set of design variable, including shape design parameters, are derived for general response functional.

TL;DR: A new approach to the construction of preconditioners of systems of mesh equations arising from finite element approximations of elliptic boundary value problems based on the idea of a multilevel decomposition of the mesh domain into small elementary subdomains is proposed.

TL;DR: In this paper, an efficient and reliable computational procedure is proposed for the analysis of interaction between high-speed vehicles and flexible structures, where the vehicle nominal motion is considered as an unknown part of the problem.

TL;DR: In this paper, half-space problems for the Boltzmann equation are used in order to derive boundary conditions for gas flows past an obstacle at the level of fluid mechanics, and they also appear to describe transitions between flows with strongly contrasted Knudsen numbers.

TL;DR: This paper surveys some recent developments in the numerical solution of nonlinear differential/algebraic equation (DAE) systems of the form 0 = F ( t, y, y '), where ∂F ∂y' may be singular.

TL;DR: In this paper, a combination of the method of characteristics and of the finite element method is applied to solve numerically a stationary free boundary problem of hydrodynamic lubrication with cavitation.

TL;DR: In this paper, the authors proposed a new formulation which removes all shear and membrane locking mechanisms from the finite element equations of the structural C0 shell, plate and beam elements, and employed full integration with the proposed formulation to eliminate zero energy modes problem, and/or softening effects associated with the use of the reduced integration in C0 plate and shell element applications.

TL;DR: In this article, the authors describe the features of the JET shell element, a new thin shell curved finite element, based on Marguerre's theory, and give an explanation of the element, choice, difficulties encountered and their solutions, the resulting element and its capabilities, through various examples in linear, nonlinear and instability analysis.

TL;DR: In this article, a finite analytic numerical method is developed to solve two-point boundary value problems of ordinary differential equations, where the basic idea of the finite analytic method is the incorporation of the local analytic solution of the governing equation in the numerical solution of boundary value problem.

TL;DR: In this article, a corotational total Lagrangian (CR-TL) formulation using the Von Karman assumption is presented for the analysis of nonlinear shell problems, which is applicable for the nonlinear analysis of shell structures with large rotations but moderate deformations.

TL;DR: An implicit/explicit finite element based algorithm for the solution of 2D steady compressible viscous high speed flows is presented in this paper, where a structured grid is employed in the vicinity of solid walls and the implicit form of the algorithm is implemented in this region.

TL;DR: A Lagrangian time discretization is introduced for the Euler equations of inviscid incompressible flows, using the least square projection onto the manifold of volume preserving diffeomorphisms, and a combinatorial algorithm is obtained.

TL;DR: In this article, a variational principle for compressible and incompressible linear isotropic elasticity involving four dependent variables: the strain tensor, the augmented stress tensor and pressure and displacement was proposed.

TL;DR: In this paper, a formulation for high order directional differentiation of functions defined through integration is presented, which is used for sensitivity analysis in optimal shape design problems by the finite elements method.

TL;DR: In this article, the problem of finite bimaterial plates with an interfacial crack subject to a uniaxial loading was studied by using the eigenfunction expansion variation method (EEVM).

TL;DR: In this paper, a non-conforming method for spectral element domain decomposition is presented, which allows for greater flexibility in spectral element decomposition, as well as direct spectral element-finite element coupling.