Mechanical APDL Structural Analysis Guide

Constant Symbol Meaning

C1 σmax maximum normal contact stress [ 1 ]

δ contact gap at the completion of debonding

n

C2 c

maximum equivalent tangential contact

stress [ 1 ]

C3 τmax

tangential slip at the completion of debond-

ing

C4 δt

C5 η artificial damping coefficient

flag for tangential slip under compressive

normal contact stress; must be 0 (off ) or 1

(on)

C6 β

1. For contact elements using the force-based model (see the description of KEYOPT(3) for CONTA175,
   CONTA176, and CONTA177), input a contact force value for this quantity.

To model bilinear material behavior with tractions and critical fracture energies, use TB,CZM with TBOPT
= CBDE. You also input the following material constants with the TBDATA command:

Constant Symbol Meaning

C1 σmax maximum normal contact stress [ 1 ]

critical fracture energy density (energy/area)

for normal separation [ 2 ]

C2 Gcn

maximum equivalent tangential contact

stress [ 1 ]

C3 τmax

critical fracture energy density (energy/area)

for tangential slip [ 2 ]

C4 Gct

C5 η artificial damping coefficient

flag for tangential slip under compressive

normal contact stress; must be 0 (off ) or 1

(on)

C6 β

1. For contact elements using the force-based model (see the description of KEYOPT(3) for CONTA175,
   CONTA176, and CONTA177), input a contact force value for this quantity.


2. For contact elements using the force-based model (see the description of KEYOPT(3) for CONTA175,
   CONTA176, and CONTA177), this quantity is critical fracture energy.

The following is an example of how to define a cohesive zone material with the TB and TBDATA
commands:

TB,CZM,,,,CBDD! bilinear behavior with tractions and separation distances

TBDATA,1,C1,C2,C3,C4,C5,C6

For more information on defining a cohesive zone material in a contact analysis, see Cohesive Zone
Material for Contact Elements in the Material Reference.

12.3.4. Result Output.

All applicable output quantities for contact elements are also available for debonding:

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Interface Delamination and Failure Simulation