Abatmet-Some basic studies and developments for adaptive procedures in large strain finite element analysis are presented an evaluation of higher-order elements, two pointwise indiitors for errors in stresses, a mesh generator for remeshing on the deformed contiffuration of the body, and a general mapping scheme for transferring solution variables across models. The methods discus4 constitute t...

From the constraint imposition aspects in 3D to friction regularization, various ideas are exposed in this paper. A variation of the Rockafellar Lagrangian is proposed which results in continuous second-order derivatives if Lagrange multiplier estimates are greater or equal than one. This fact allows the adoption of a full second-order (i.e. Lagrange–Newton) method avoiding sequential unconstra...

The strength and ductility of concrete improve under multi-axial compressive stress due to confinement effect. Some parameters are effective for considering the confinement in concrete and various stress-strain models were developed by different researchers. Longitudinal and transverse reinforcement steels can influence on confinement in reinforced concrete members. In this paper, various stres...

In this article, Finite Element Method (FEM) and Eulerian-Lagrangies Algorithm (ELA) formulation were used to numerically simulate the impact of several low-velocity projectiles with water surface. Material models which were used to express behavior of air and water included Null material model. For the projectiles, rigid material model were applied. Results were validated by analyzing the impa...

The previous energetic variational analysis of critical loads and of the choice of finite strain measure for structures very weak in shear, remaining in a state of small strain, is extended to the initial postcritical behavior. For this purpose, consideration of the transverse deformation is found to be essential. It is shown that imperfection sensitivity of such structures, particularly lamina...

slab method of analysis has been used for solving metal forming problems for a long time. however it has been restricted to plane strain and axisymmetric problems due to limitations in its formulations. in this paper a new formulation has been proposed so that it could be applied to three dimensional problems in metal forming. a parametric slab has been considered in this analysis and the force...