Table of Contents
CZM3D
3D cohesive zone model
Still under development (?) - Last update: 2005 (C. Lequesne)
Description
This element models the fracture of a material in case of monotonous loading or fatigue.
This element, which models an interface of the crack, is composed with 4 nodes and linked with a 4 nodes foundation (ICODE=11), which models the other interface.
Direction convention: The normal direction is defined by the vector cross product $\vec{n} = \vec{12} \wedge \vec{13}$ for the cohesive element and the foundation. The two normal vectors must penetrate the foundation.
This element uses the cohesive law of Xu and Needleman (ITYPE=295), and can be coupled with the fatigue computed with the 3D Lemaitre and Chaboche fatigue damage law in the BLZ3D element and ARB law.
Notes:
- In case of fatigue it is required that ILIEN is equal to 1 (Prepro: 2nd line and 65th column)
- In symmetric case, the symmetric plan must be the CZM3D and not the foundation
Type: 224
Implemented by: C. Lequesne (2005)
Files
Prepro: CZM3DA.F
Lagamine: CZM3DB.F
Input file
| Title (A5) | |
|---|---|
| TITLE | “CZM3D” in the first 5 columns |
| Control data (2I5) | |
| NELEM | Number of elements |
| IMICRO | See details below |
| Definition of the elements (5I5/4I5) | |
| NINTE | Number of integration points (1, 4, or 9) |
| LMATM | Constitutive law |
| IFOND | Number of linked foundation |
| IFAT | Fatigue or not |
| ISYM | Symmetric case or not |
| NODES(4) | List of nodes |
IMICRO
If =0, the tolerance of the distance between foundations and CZM3D nodes is 1.0E-4.
If =1, the tolerance is changed to 1.0E-6.
Results
Stress:
Normal stress $T_n$
Shear stress $T_p$ and $T_s$
Internal variables:
- The first ones are the variables computed by the constitutive law (cf. FCZM in law section)
- The next ones is about the contact geometry:
- ISEG: The number of the linked foundation's segment
- DUN: The normal separation
- DDUT: The shear separation
- DDUN: The normal separation rate