About LS-DYNA

LS-DYNA (Livermore Software Technology Corporation) is in the number of leading heavy finite-element design complexes.

It is multipurpose software, which is applying the explicit finite-element method.

Tensile Test

The theme of this modeling is the standard procedure of tensile test for the standard made of low-carbon structural steel 08pc (State Standard 1050), performed in laboratory with the help of tension testing machine UME-10ТМ under the standard procedure (State Standard 1497-84) with the deformation speed of 3e-4 min-1. No.18 *MAT_POWER_LAW_PLASTICITY material model from LS-DYNA library was used as the standard material model.

This model is usually used for modeling elastoplastic nonlinear deformable medium, which requires taking into account large-scale movements and conforms the flow theory with isotropic or translational strain hardening with the effect of speed hardening.

Plasticity behavior for the chosen material model was set as a strictly increasing line after converting the graphic chart of loading dependence on the absolute deformation of the standard into the true values of strain and deformation. Considering the obvious simplicity of the model, its finite-element analogue was performed in the LS-DYNA preprocessor without using off-site CAD-programs.

Imitation of the catching device of the tension testing machine was performed with the help of peg-shaped surfaces, consisting of SHELL elements. As catching device deformation was not considered, the catching device models’ material was absolute rigid (*MAT_RIGID) with average values of modulus of elasticity (Ex), Poisson's ratio (NUXY) and density (DENS).

The stretching load was applied with the help of rigid fastening of one of these surfaces and compulsory movement of the other one in the opposite direction along the vertical axis.

As a result of modeling, a typical situation of strain and deformation distribution may be described as to the whole standard and to the locally chosen sections. Well seen is the neck thinning in the place of rupture of the sample of σВ ultimate stress limit, which is verified in the real process.

Animation of the whole standard tensile procedure you can see here: