The eXtended FEM (X-FEM) [1] is able to simulate arbitrary initiation and propagation of multiple cracks for brittle and ductile material.

  • Advantage

    • Minimizes the mesh sensitivity

    • Achieves the numerical convergence

  • Current implementation [2] [ex]

    • 2D plain strain and 3D shell

    • Crack surfaces described by level-set functions

    • Cohesive fracture processing zone [kw]

    • Phantom node approach [kw]

    • Criteria for initializing and advancing cracks [kw]

      • Maximum principal stress for brittle material

      • Effective plastic strain (EPS) for ductile material

    • Crack propagation direction [kw]

      • Maximum principal direction of total strain

      • EPS center

    • Material length scale for ductile cracks [kw]

    • Multiple cracks [kw]

    • Support pre-crack definition [3]

    • Explicit analysis

  • Limitation

    • Crack propagating cell-by-cell

    • Crack segment is straight in each cell

 

  • Application​​​

    • Post-failure analysis in shell

Strain regularization based on material length scale

EPS center