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laws:cntcq
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CNTCQ
Description
Constitutive law for unilateral contact with friction, for thin 3D shell elements.
The model
This law is used for mechanical analysis of unilateral contact with friction in 3D state for shells.
Contact can occur on both sides of shell.
A penalty method is chosen to represent the contact.
COULOMB behaviour is assumed, with constant friction coefficient.
Files
Prepro: LCNTCQ.F
Lagamine: CNTCQ4.F
Availability
| Plane stress state | NO |
| Plane strain state | NO |
| Axisymmetric state | NO |
| 3D state | YES |
| Generalized plane state | NO |
Input file
Parameters defining the type of constitutive law
| Line 1 (2I5, 60A1) | |
|---|---|
| IL | Law number |
| ITYPE | 98 |
| COMMENT | Any comment (up to 60 characters) that will be reproduced on the output listing |
Integer parameters
| Line 1 (I5) | |
|---|---|
| NINTV | Number of sub-step to calculate the contact |
Real parameters
| Line 1 (5G10.0) | |
|---|---|
| RIGP | Penalty coefficient on pressure, $K_p$ |
| RIGT | Penalty coefficient on shear, $K_{\tau}$ (default = RIGP) |
| FRTCN | COULOMB's coefficient = $\Phi$ |
| COHES | Cohesion parameter for Tresca's law = B |
| TAUMX | Maximum value imposed for shear stress |
Stresses
Number of stresses
3
Meaning
| SIG(1) | = p : Pressure |
| > 0 in compression | |
| SIG(2) | = $\tau$ : Shear |
| > 0 according with local coordinates of shell | |
| SIG(3) | = $\tau$ : Shear |
| > 0 according with local coordinates of shell |
State variables
Number of state variables
6
List of state variables
| Q(1) | IELD: State of contact |
| = -1 : No contact | |
| = 0 : No sliding (elastic state in Tresca law, $\rvert\rvert\tau\rvert\rvert$ = FRTCN.$p$+COHES) | |
| = 1 : Sliding (plastic state, always if FRTCN = 0 and TAUMX = 0) | |
| Q(2) | ISEG: Number of foundation segment in contact |
| Q(3) | DIS: Penetration distance |
| Q(4) | ICONT: Index of contact |
| = 0 : Contact if DIS < 0 | |
| = 2 : No contact b/c of normal consistency or b/c abs(DIS) > DMAX | |
| = 11, 12 or 13 (only for foundation with triangular segments) : No contact but contact possible with a neighbouring segment | |
| Q(5) | VR: Relative sliding speed |
| Q(6) | VS: Relative sliding speed |
laws/cntcq.txt · Last modified: 2020/08/25 15:46 (external edit)
