PCNTX2

Format

Example

Definitions

Comments

1. The property identification number must be that of an existing PCONT Bulk Data Entry. Only one PCNTX2 property extension can be associated with a particular PCONT.
2. PCNTX2 is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS = EXPDYN. It is ignored for all other subcases.
3. PCNTX2 is only valid for tied contact specified using the TIE Bulk Data Entry. The PID field on the TIE entry can be used to reference the PCNTX2 entry.
4. Interface TYPE2 is a kinematic condition, no other kinematic condition should be set on any nodes of the slave surface.
5. The default value for SRCHDIS is the average of the mater segments.
6. If IGNORE = 1 or 2, the slave nodes without a master segment found during the searching are deleted from the interface;

   If IGNORE = 1 and SRCHDIS is blank, then the default value of the distance for searching closest master segment is the average size of the master segments;

   If IGNORE = 2 and SRCHDIS is blank, then the distance for searching closest master segment is computed as follows for each slave node:

   d₁ = 0.6 * (T_s + T_m)

   d₂ = 0.05 * Tmd

   SRCHDIS = max(d₁ , d₂)

   Where,

   T_s

   Thickness of the element connected to the slave node, for solids T_s = 0.0

   T_m

   Thickness of master segment, for solids T_m = Element volume / Segment area

   T_md

   Master segment diagonal

7. Master nodes of an interface TYPE2 may be slave nodes of another interface TYPE2 if the hierarchy level of the first interface is lower than the hierarchy level of the second interface. Hierarchy levels are only available with FSPOT=2.
8. For failure (FSPOT = 20, 21, or 22), it could model glue connection. In this case, the force in slave node will be scaled by reduced force coefficient $f_N$ ( $f_T$ ), which is computed as:(1)
   $$\begin{array}{l}{f}_N=\text{min}\left\{\sqrt{\frac{{\left({\sigma }_N^{\text{max}}\right)}^2}{\text{max}\left[{\left({\sigma }_N(t)\right)}^2,{10}^{-20}\right]}},1\right\}\hfill \\ f_T=\text{min}\left\{\sqrt{\frac{{\left({\sigma }_T^{\text{max}}\right)}^2}{\text{max}\left[{\left({\sigma }_T(t)\right)}^2,{10}^{-20}\right]},1}\right\}\hfill \end{array}$$

   The reduced force is compared to the maximum value:

   If ${\sigma }_N<{\sigma }_N^{\text{max}}$ , then $f_N$ = 1, which means the force will not be reduced.

   If ${\sigma }_N<{\sigma }_N^{\text{max}}$ , then $f_N=\sqrt{\frac{{\left({\sigma }_N^{\text{max}}\right)}^2}{\text{max}\left[{\left({\sigma }_N(t)\right)}^2,{10}^{-20}\right]}}$ , which means the force will then be reduced.

   Here the maximum value will be defined by you with:

   $\begin{array}{l}{\sigma }_N^{\text{max}}=f(\dot{\sigma })\cdot \text{SNTID}\left(\frac{\Delta X_N}{\text{FDIST}}\right)\hfill \\ {\sigma }_T^{\text{max}}=f(\dot{\sigma })\cdot \text{STTID}\left(\frac{\Delta X_N}{\text{FDIST}}\right)\hfill \\ f(\dot{\sigma })=\text{FSTR}\cdot \text{SRTID}\left(\frac{\dot{\sigma }}{\text{FSTRATE}}\right)\hfill \end{array}$

   Where,

   ${\sigma }_N^{\text{max}}$

   Maximum normal stress value defined by SNTID

   ${\sigma }_N(t)$

   Normal stress

   ${\sigma }_N^{\text{max}}$

   Maximum tangential stress value defined by STTID

   ${\sigma }_T(t)$

   Tangential stress

   FSTR

   Input constant stress factor

   SRTID

   Input variable coefficient

   SNTID and STTID

   Input stress-displacement tables

   Once the rupture criterion (defined by Rupt) is reached, the contact will be deleted.

9. If RUPT = 1, the failure criterion is:(2)
   $$\sqrt{{\left(\frac{\text{ND}}{\text{MAXND}}\right)}^2+{\left(\frac{\text{TD}}{\text{MAXTD}}\right)}^2}>1$$
10. If FSPOT = 30, slave mass/inertia/stiffness distribution to the master node is based on the Kirschoff model: bi-cubic form functions are used instead of linear (standard formulation). It allows a softer contact behavior since the element shape curvature is taken into account in the force/moment transmission.
11. If IDELG = 1, then when a 4-node shell, a 3-node shell or a solid element is deleted, it is also removed from the master side of the interface (kinematic condition is suppressed on relative slave nodes).
12. If IFILT is set to 1, the normal and tangential stresses are filtered with an alpha filter, as: (3)
    $${\sigma }_N(t)=\text{ALPHA}\times {\sigma }_N(t)+(1-\text{ALPHA})\times {\sigma }_N(t-1)$$
    (4)
    $${\sigma }_T(t)=\text{ALPHA}\times {\sigma }_T(t)+(1-\text{ALPHA})\times {\sigma }_T(t-1)$$
13. FSPOT = 25 (penalty formulation) will keep the penalty formulation during the whole run. The slave node (of this contact) could also be the slave node of another kinematic option, like rigid body. The penalty stiffness is constant, calculated as the mean nodal stiffness of master and slave side. The stiffness factor, STFAC, may be used to modify it, if needed. The penalty stiffness will be multiplied by STFAC. A critical viscous damping coefficient (VISC) allows damping to be applied to the interface stiffness.