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laws:evpirs
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EVP-IRS
Description
Elastic‑visco‑plastic constitutive law for solid elements at constant temperature
The model
This law is used for a mechanical analysis of elastic‑visco‑plastic isotropic solids undergoing large strains.
Strain‑rate effects and isotropic hardening or recovery are included.
Files
Prepro: LIRSI.F
Lagamine: IRSI2S.F, IRSI2E.F, IRSI2A.F, IRSI3D.F
Availability
| Plane stress state | YES |
| Plane strain state | YES |
| Axisymmetric state | YES |
| 3D state | YES |
| Generalized plane state | YES |
Input file
Parameters defining the type of constitutive law
| Line 1 (2I5, 60A1) | |
|---|---|
| IL | Law number |
| ITYPE | 40 |
| COMMENT | Any comment (up to 60 characters) that will be reproduced on the output listing |
Integer parameters
| Line 1 (2I5) | |
|---|---|
| NINTV | number of sub‑steps used to integrate numerically the constitutive equation in a time step. |
| ICRIFR | = 0 : nothing |
| = 1 : fracture criterion is computed | |
Real parameters
| Line 1 (7G10.0) | |
|---|---|
| E | YOUNG’s elastic modulus |
| ANU | POISSON’s ratio |
| AN | strain rate exponent ($n$) |
| B | strain rate coefficient ($B$) |
| AM | hardening exponent ($m$) |
| H1 | hardening coefficient ($H_1$) |
| AQ | recovery exponent ($q$) |
| Line 2 (4G10.0) | |
| H2 | recovery coefficient ($H_2$) |
| AKO | initial yield limit ($K_o$) |
| ANI | strain exponent $(\bar{\sigma} = C \bar{\varepsilon}^n)$ only for the criterion of fracture |
| RHO | specific mass |
Stresses
Number of stresses
= 6 for 3-D state
= 4 for the other cases.
Meaning
The stresses are the components of CAUCHY stress tensor in global (X,Y,Z) coordinates.
For the 3-D state:
| SIG(1) | $\sigma_{xx}$ |
| SIG(2) | $\sigma_{yy}$ |
| SIG(3) | $\sigma_{zz}$ |
| SIG(4) | $\sigma_{xy}$ |
| SIG(5) | $\sigma_{xz}$ |
| SIG(6) | $\sigma_{yz}$ |
For the other cases:
| SIG(1) | $\sigma_{xx}$ |
| SIG(2) | $\sigma_{yy}$ |
| SIG(3) | $\sigma_{xy}$ |
| SIG(4) | $\sigma_{zz}$ |
State variables
Number of state variables
= 24
List of state variables
| Q(1) | = element thickness (t) in plane stress state |
| = 1 in plane strain state | |
| = circumferential strain rate ($\dot{\varepsilon}_{\theta}$) in axisymmetric state | |
| = 0 in 3-D state | |
| = element thickness (t) in generalized plane state | |
| Q(2) | current yield limit in tension; its initial value is $K_o$ |
| Q(3) | hydrostatic stress ($\sigma_m$) |
| Q(4) | equivalent inelastic strain ($\bar{\varepsilon}^p$) |
| Q(5) | plastic work per unit |
| Q(6) | total strain energy per unit volume |
| Q(8)$\rightarrow$Q(11) | failure criteria |
| Q(12) | equivalent stress ($\bar{\sigma}$) |
| Q(13) | localisation indicator (Vilotte) : increment of |
| Q(14) | cumulated $\varepsilon_{eq}$ |
| Q(15) | $\varepsilon_{xx}$ |
| Q(16) | $\varepsilon_{yy}$ |
| Q(17) | $\varepsilon_{zz}$ |
| Q(18) | $\varepsilon_{xy}$ |
| Q(19) | $\dot{\varepsilon}_{eq}$ |
| Q(24) | actualised specific mass |
laws/evpirs.txt · Last modified: 2020/08/25 15:46 (external edit)
