scholarly journals Finite Element Formulation for Large Strain Beam Model. (Part 2). Updated Lagrangian Formulation.

1996 ◽  
Vol 44 (507) ◽  
pp. 221-226
Author(s):  
Masabumi ISHIHARA
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Lagrangian Formulation ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Beam Model ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian

Non-Conservative and Conservative Loads in Geometrically Nonlinear Shells

2003 ◽  
Author(s):  
Cho W. S. To ◽  
Meilan L. Liu
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Small Strain ◽  
Shell Structures ◽  
Element Formulation ◽  
Geometrically Nonlinear ◽  
Hybrid Strain ◽  
Shell Elements ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian

Responses of geometrically nonlinear shell structures under combined conservative and non-conservative loads are investigated and presented in this paper. The shell structures are discretized by the finite element method and represented by the hybrid strain based three node flat triangular shell elements that were developed previously by the authors. The updated Lagrangian formulation and the incremental Hellinger-Reissner variational principle are employed. Features such as large or small strain deformation, finite rotation, updated thickness so as to account for the “thinning effect” due to large strain deformation, and inclusion or exclusion of the mid-surface director field are incorporated in the finite element formulation. Representative results of two examples are included to demonstrate the capability, accuracy and efficiency of the computational strategy proposed.

A Simple Total-Lagrangian Finite-Element Formulation for Nonlinear Behavior of Planar Beams

2018 ◽  
Author(s):  
Enrico Babilio ◽  
Stefano Lenci
Keyword(s):  
Finite Element ◽  
Theoretical Model ◽  
Finite Difference ◽  
Shear Angle ◽  
Difference Schemes ◽  
Finite Element Formulation ◽  
Finite Difference Schemes ◽  
Element Formulation ◽  
Beam Model ◽  
Lagrangian Finite Element

The present contribution reports some preliminary results obtained applying a simple finite element formulation, developed for discretizing the partial differential equations of motion of a novel beam model. The theoretical model we are dealing with is geometrically exact, with some peculiarities in comparison with other existing models. In order to study its behavior, some numerical investigations have already been performed through finite difference schemes and other methods and are reported in previous contributions. Those computations have enlightened that the model under analysis turns out to be quite hard to handle numerically, especially in dynamics. Hence, we developed ad hoc the total-lagrangian finite-element formulation we report here. The main differences between the theoretical model and its numerical formulation rely on the fact that in the latter the absolute value of the shear angle is assumed to remain much smaller than unity, and strains are piecewise constant along the beam. The first assumption, which actually simplifies equations, has been taken on the basis of results from previous integrations, mainly through finite difference schemes, which clearly showed that, while other strains can achieve large values in their range of admissibility, shear angle actually remains small. The second assumption led us to define a two-nodes constant-strain finite element, with a fast convergence, in terms of number of elements versus solution accuracy. Although, at the present stage of this ongoing research, we have only early results from finite elements, they appear encouraging and start to shed new light on the behavior of the beam model under analysis.

Analysis of the Large Plastic Deformation Involved in Wear Processes Using the Finite Element Method With an Updated Lagrangian Formulation

1987 ◽  
Vol 109 (2) ◽  
pp. 330-337 ◽  
Author(s):  
Nobuo Ohmae
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Equivalent Stress ◽  
Lagrangian Formulation ◽  
The Finite Element Method ◽  
Large Plastic Deformation ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian ◽  
Element Method

Large plastic deformation caused by friction for high purity copper was investigated using the finite element method with an updated Lagrangian formulation. The phenomenological background of this large plastic deformation was studied with a scanning electron microscope, and the nucleation of voids similar to those obtained for copper rolled to over 50 percent reduction was observed. Void nucleation was found to correlate with the agglomeration of over-saturated vacancies formed under high plastic strains. The computer-simulation analyzed such heavy deformation with an equivalent stress greater than the tensile strength and with an equivalent plastic strain of 0.44. Crack propagation was discussed by computing the J-integrals.

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