An elasto-viscoplastic simplified law
Mechanical analysis of visco-plastic isotropic solids undergoing large strains.
Isotropic hardening is assumed.
Prepro: LLEV.F
| Plane stress state | YES |
| Plane strain state | YES |
| Axisymmetric state | YES |
| 3D state | NO |
| Generalized plane state | NO |
| Line 1 (2I5, 60A1) | |
|---|---|
| IL | Law number |
| ITYPE | 65 |
| COMMENT | Any comment (up to 60 characters) that will be reproduced on the output listing |
For IANA = 1 (plane stress state)
| MLAW | the method used to calculate the increments of stress = 0 $\rightarrow$ Backword Euler method = 1 $\rightarrow$ Radial Return method = 2 $\rightarrow$ Decomposed mode method |
| MANA | = 0 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda} = 0$ = 1 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda}_{eq}$ $\Rightarrow$ $\dot{\sigma}_{eq}$ = 2 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda}_{eq}$ $\Rightarrow$ $\dot{\varepsilon}_{eq}$ = 3 The tangent matrix obtained by the consistent condition |
Else (plane strain and axisymmetric state)
| MLAW | the method used to calculate the increments of stress 0 $\rightarrow$ Radial Return method 1 $ \rightarrow$ Implicit integration method 2 $\rightarrow$ Modified implicit integration method |
If MLAW = 0 (Radial return method)
| MANA | = 0 $\rightarrow$ The tangent matrix obtained by setting $\dot{\omega} = 0$ = 1 $\rightarrow$ The tangent matrix obtained by setting $\dot{\sigma}_{eq}$ = $\dot{\sigma}_{eq}^{trial}$ = 2 $\rightarrow$ The tangent matrix obtained by setting $\dot{\sigma}_{eq}$ $\Rightarrow$ $\dot{\varepsilon}_{eq}$ |
Else (other methods)
| MANA | = 0 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda}_{vp} = 0$ = 1 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda}_{vp}$ $\Rightarrow$ $\dot{\sigma}_{eq}$ = 2 $\rightarrow$ The tangent matrix obtained by setting $\dot{\lambda}_{eq}$ $\Rightarrow$ $\dot{\varepsilon}_{eq}$ |
| Line 1 (4G10.0) | |
|---|---|
| E | YOUNG's elastic modulus |
| $\nu$ | POISSON's ratio. |
| AC | parameter for $\sigma - \varepsilon$ relation |
| AM | parameter for $\sigma - \varepsilon$ relation |
Where: \[\hat{\sigma}_{eq}=AC*\hat{D}_{eq}^{AM}\]
| $\hat{\sigma}_{eq}$ | the equivalent deviatoric stress |
| $\hat{D}_{eq}$ | the equivalent deviatoric velocity of deformation |
4
The stresses are the components of CAUCHY stress tensor in global (X,Y,Z) coordinates.
| SIG(1) | $\sigma_{XX}$ |
| SIG(2) | $\sigma_{YY}$ |
| SIG(3) | $\sigma_{XY}$ |
| SIG(4) | $\sigma_{ZZ}$ |
4
| Q(1) | element thickness (t) in plane stress state and generalized plane state 1 in plane strain state circumferential strain rate ($\dot{varepsilon}_{\theta}$) in axisymmetric state |
| Q(2) | current yield limit in tension, its initial value is $R_{eo}$ |
| Q(3) | equivalent deviatoric strain $\hat{\varepsilon}_{eq}$ |
| Q(4) | equivalent deviatoric stress $\sigma_{eq}$ |
| Q(5) | critères de fractures |
| Q(10) |