Ellipsoidal Surface to Segment Contact (TYPE15)
TYPE15 interface between surfaces made up of 4-node or 3-node segments and hyper-ellipsoids is a penalty contact interface without damping.
![](../../../images/solvers/theory_interfaces_type_15_f1.png)
Figure 1. No Contact is Detected
Interface stiffness is a nonlinear increasing function of penetration, computed in order to avoid penetrations up to half the ellipsoid:
- Input stiffness factor
![](../../../images/solvers/theory_interfaces_type_15_f2.png)
Figure 2. Penetration is Detected
A Kinematic Time Step is computed so that the element does not cross the line Lt within one time step.
A friction coefficient m is input.
Interface takes into account sliding/rolling effects.
Coulomb Friction condition is expressed as:
for each penetrated element