Tied Contact (/INTER/TYPE2)

This interface ensures a full force and moment equilibrium.

Figure 1. Interface TYPE2 - Tied

There are four formulations are available to describe this connection.

• Default spotweld formulation
• Optimized spotweld formulation
• Formulation with failure
• Penalty formulation

Spot_flag=0

Figure 2.

When the flag is set to 0, the spotflag formulation is a default formulation:

• Based on element shape functions
• Generate hourglass with under-integrated elements
• Give a connection stiffness function of secondary node localization
• Recommended with fully-integrated shells (main)
• Recommended for connecting brick secondary nodes to brick main segments (mesh transition without rotational freedom)

Spot_flag=1

Figure 3.

When the flag is set to 1, the spotflag formulation is an optimized formulation:

• Based on element mean rigid motion
• No hourglass problem
• Constant connection stiffness
• Recommended with under-integrated shells (main)
• Recommended for connecting beam, spring, and shell secondary nodes to brick main segments

Using these options, these two failure criteria can be defined:

Rupt= 0 (independent rupture parameters):

Failure when Max_N_Dist or Max_T_Dist are reached (default)

Rupt= 1 (coupled rupture parameters):

Failure when $\sqrt{{\left(\frac{N\_Dist}{Max\_N\_Dist}\right)}^2+{\left(\frac{T\_Dist}{Max\_T\_Dist}\right)}^2}>1$

The main goal for interface TYPE2 using penalty method is to tie secondary node to main segment without any kinematic constraints. Using the penalty method may avoid

"INCOMPATIBLE KINEMATIC CONDITIONS"

.