XFEM elements allow simulations where the unknown fields are enriched through the partition of unity concept. Two elements are currently available for 2D XFEM simulations: TrPlaneStress2dXFEM (subclass of TrPlaneStress2d) and PlaneStress2dXfem (subclass of PlaneStress2d).
| Keyword | TrPlaneStress2dXFEM |
| Description | Two dimensional 3-node triangular XFEM element |
| Specific parameters | [czmaterial #(in)] [nipcz #(in)][useplanestrain #(in)] |
| Parameters | czmaterial: Interface material for the cohesive zone. (If no material is specified, traction free crack surfaces are assumed.) |
nipcz: Number of integration points used on each segment of the cohesive zone. |
|
useplanestrain: If plane strain or plane stress should be assumed. 0 implies plane stress and 1 implies plane strain. |
|
| Unknowns | Two continuous (standard) DOFs (u-displacement, v-displacement) and a variable number of enriched DOFs (can be continuous or discontinuous). |
| Approximation | - |
| Integration | Elements cut by an XFEM interface are divided into subtriangles. |
| Features | - |
| CS properties | - |
| Loads | - |
| Nlgeo | - |
| Status | - |
| Note | Test case: sm/xFemCrackVal.in |
| Keyword | PlaneStress2dXfem |
| Description | Two dimensional 4-node quad XFEM element |
| Specific parameters | [czmaterial #(in)] [nipcz #(in)][useplanestrain #(in)] |
| Parameters | czmaterial: Interface material for the cohesive zone. (If no material is specified, traction free crack surfaces are assumed.) |
nipcz: Number of integration points used on each segment of the cohesive zone. |
|
useplanestrain: If plane strain or plane stress should be assumed. 0 implies plane stress and 1 implies plane strain. |
|
| Unknowns | Two continuous (standard) DOFs (u-displacement, v-displacement) and a variable number of enriched DOFs (can be continuous or discontinuous). |
| Approximation | - |
| Integration | Elements cut by an XFEM interface are divided into subtriangles. |
| Features | - |
| CS properties | - |
| Loads | - |
| Nlgeo | - |
| Status | - |
| Note | Test cases: sm/xFemCrackValBranch.in, sm/xfemCohesiveZone1.in, benchmark/xfem01.in |