Cohesive interface material - cohInt

A simple interface material with generally different stiffness in compression, tension and shear. It is intended for simulating a contact with low stiffness in tension and high in compression. The parameter transitionOpening specifies initial gap embedded in an element which causes transition from tension to compression. For example, transitionOpening=0.01 m means that there exists the embedded gap which needs displacement jump 0.01 m to close. Traction-separation law for normal direction takes the following form:
$\displaystyle =$ (223)
$\displaystyle =$ (224)
$\displaystyle =$ (225)
$\displaystyle =$ (226)
$\displaystyle =$ (227)

where smoothMag controlls smoothing magnitude. Tangential stiffness for normal direction is found by differentiating Eq. (223)
$\displaystyle =$ (228)
  (229)

Shear stiffness remains constant during all possible loadins and there is no influence of normal direction.


Table 48: Cohesive interface material - summary.
Description Cohesive interface material
Record Format cohInt (in) # kn(rn) # ks(rn) # [ stiffCoeffKn(rn) #] [ smoothMag(rn) #] [ transitionOpening(rn) #]
Parameters - material number
  - kn (penalty) stiffness in compression
  - ks stiffness in shear
  - stiffCoeffKn ratio (tensile stiffness / compression stiffness)
  - smoothMag smoothing parameter for transition between tensile/compressive behavior
  - transitionOpening embedded gap in the element
Supported modes _1dInterface,_2dInterface,_3dInterface


Borek Patzak
2018-01-02