Table of Contents

SGRA2

Plane or axisymmetric state

Description

Mechanical analysis, Grenoble 2nd gradient method, in large deformations.

The element is defined by 9 nodes specified in NODES in the order indicated in the figure. Nodes 1, 3, 5, and 7 have 6 DoF ($u_1$, $u_2$, $v_{11}$, $v_{12}$, $v_{21}$, $v_{22}$), whereas nodes 2, 4, 6, and 8 only have 2 DoF ($u_1$, $u_2$). The central node 9 has 4 DoF ($\lambda_{11}$, $\lambda_{12}$, $\lambda_{21}$, $\lambda_{22}$), that have a different signification from ($v_{11}$, $v_{12}$, $v_{21}$, $v_{22}$) but occupy the same position.

Type: 207

Implemented by: P. Besuelle, J-P. Radu (2002)

Files

Prepro: SGRA2A.F
Lagamine: SGRA2B.F

Input file

Title (A5)
TITLE“SGRA2” in the first 5 columns
Control data (3I5)
NELEMNumber of elements
ISPSMAS0
INSIG= 0 → No initial stress
= 1 or 2 → Initial stresses
Initial stresses - Only if INSIG > 0 (4G10.0)
If INSIG=1: $\sigma_y=\sigma_{y0}+yd\sigma_{y}$
If INSIG=2: $\sigma_y=min(\sigma_{y0}+yd\sigma_y,0)$
SIGY0 $\sigma_{y0}$ effective stress $\sigma_y$ at the axes origin
DSIGYEffective stress gradient along Y axis
AK0X$k_0$ ratio $\sigma_x/\sigma_y$
AK0Z$k_0$ ratio $\sigma_z/\sigma_y$ (if AK0Z=0, AK0Z=AK0X)
Definition of the elements (6I5/9I5)
NINTENumber of integration points (1, 4, or 9)
LMATM“Classic” mechanical law
LMATF“Second gradient” material law
NODES(9)List of nodes

Results

Stresses (in global axes):
4 “classic” mechanical stresses: $\sigma_x$, $\sigma_y$, $\sigma_{xy}$, $\sigma_z$
8 “second gradient” mechanical stresses: $\Sigma_{111}$, $\Sigma_{112}$, $\Sigma_{121}$, $\Sigma_{122}$, $\Sigma_{211}$, $\Sigma_{212}$, $\Sigma_{221}$, $\Sigma_{222}$

Internal variables:
Internal variables of the “classic” mechanical law
Internal variables of the “second gradient” mechanical law