8. Specific objects for formulation XFEM

8.1. Item MODELX

(o) '. CONTACT. MODELX ': V K8 long = 1

This object contains the model name XFEM. It is used for verification when LIAISON_XFEM = OUI.

8.2. Item CARAXF

(o) '. CONTACT. CARAXF ': V R long = ZCMXF * NZOCO

 Object indexed by the contact area number.

Index on the area	Description	DEFI_CONTACT	Question MMINF*
1	Integration type	INTEGRATION	MMINFI	INTEGRATION
2	Parameter value COEF_REGU_CONT	COEF_REGU_CONT	MMINFR	COEF_AUGM_CONT COEF_REGU_CONT
3	Parameter value COEF_REGU_FROT	COEF_REGU_FROT	MMINFR	COEF_AUGM_FROT COEF_REGU_FROT
4	Coulomb coefficient of friction	COULOMB	MMINFR	COEF_COULOMB
5	Friction in zone 0 — NON 3 — OUI	FROTTEMENT	MMINFI	FROTTEMENT_ZONE
			MMINFL	FROTTEMENT_ZONE
6	Initial value of the Tresca threshold	SEUIL_INIT	MMINFR	SEUIL_INIT
7	Surfaces initially in contact 0 — NON 1 — OUI	CONTACT_INIT	MMINFI	CONTACT_INIT
8	Not used
9	Suppression algorithm LBB 0 — NON 1 — VERSION1 2 — VERSION2	ALGO_LAGR	MMINFI	ALGO_LAGR
10	Bilateral contact on zone 0 — NON 1 — OUI	GLISSIERE	MMINFL	GLISSIERE_ZONE
11	Parameter value COEF_STAB_CONT	COEF_STAB_CONT	MMINFR	COEF_STAB_CONT
12	Parameter value COEF_PENA_CONT	COEF_PENA_CONT	MMINFR	COEF_PENA_CONT
13	Parameter value COEF_STAB_FROT	COEF_STAB_FROT	MMINFR	COEF_STAB_FROT
14	Parameter value COEF_PENA_FROT	COEF_PENA_FROT	MMINFR	COEF_PENA_FROT
15	Parameter out-of-mesh projection	TOLE_PROJ_EXT	MMINFR	TOLE_PROJ_EXT
16	Relationship type for CZM 0 — PAS DE CZM 1 — CZM_EXP_REG 2 — CZM_LIN_REG	RELATION	MMINFR	RELATION
			MMINFL	CONT_XFEM_CZM
17	Algorithm for contact 1 — STANDARD 2 — AVANCE 3 — PENALISATION 4 — CZM	ALGO_CONT	MMINFR	CZM_FERMETURE
			MMINFL	ALGO_CONT_PENA
18	Algorithm for friction 1 — STANDARD 2 — AVANCE 3 — PENALISATION	ALGO_FROT	MMINFL	ALGO_FROT_PENA

8.3. Item XFIMAI

(o) '. CONTACT. XFIMAI ': V K8 long = NZOCO

 Object indexed by the contact area number.

This object stores the master crack number associated with each contact zone. It is used to find the

name of a crack associated with a given contact zone.

8.4. Item XNRELL

(o) '. CONTACT. XNRELL ': V K24 long = NFIS

This object stores the name of the object for each master crack. LISEQ associated with this crack. Let NFIS be the number of cracks in model X- FEM (object NFIS in model X- FEM) and let fiss the crack with index i in the list of cracks in model X- FEM. (object. FISS from model X- FEM). Finally, let v_sdline be a pointer to access object XNRELL. We then have:

v_sdline (i) = fiss//”. LISEQ “

The object. LISEQ associated with a crack stores the equality relationships to be applied to satisfy condition LBB as part of a mixed formulation for contact in X- FEM (cf. [D4.10.02], §3.5.2 for the complete description of this object). The equality relationships to be applied are calculated by xConta.f90. Equal relationships are applied either:

• by xRela_elim.f90, if you want to keep only one degree of freedom, among all the degrees of freedom linked by the equality relationship, when writing the linear system to be solved (ELIM_ARETE = “ELIM”, in DEFI_CONTACT);

• by xfem_rel_lin.F90, if we want to keep all the degrees of freedom in writing the linear system to be solved and if we impose the conditions of equality using Lagrange multipliers (ELIM_ARETE = “DUAL”, in DEFI_CONTACT).

8.5. Item MAESCX

(o) '. CONTACT. MAESCX ': V K24 long = ZMESX * NTMAE

This object is the equivalent, in the context of the formulation of the contact X- FEM in large swings, of the object MAESCL, used in the formulations FEM. It should be noted that in the case of multi-cracking, all the enriched elements X- FEM associated with a given crack will not necessarily calculate contributions to contact integrals (cf. [D4.10.02], §3.3.8 for more details). These elements are distinguished by the fact that they do not define contact facets, i.e. sub-elements used to calculate an integral over the crack surface (cf. [D4.10.02], §4.4).

Index on the slave knit	Description
1	Value of the mesh index in the mesh
2	Number of the zone to which the mesh belongs
3	Number of integration points If the element does not contribute to contact integrals: 1 is stored
4	Enriched mesh status * 1: Heaviside enriched mesh, * 2: Crack-Tip enriched mesh, * 3: Heaviside-Crack-Tip enriched mesh. If the element does not contribute to contact integrals: the opposite of the status is stored. Either: * -1: Heaviside enriched mesh, * -2: Crack-Tip enriched mesh, * -3: Heaviside-Crack-Tip enriched mesh.
5	Value of the crack index in the list of cracks seen by the mesh (object XMAFISdu model X- FEM, cf. [D4.10.02], §4.6.4)