*SECTION_SHELL_XFEM  [1[ex]

  • Section definition for X-FEM shell element formulation 

   Card 1

 
  • ELFORM=52 for 2D plain strain, where BASELM has to be set to 13.

                      =54 for 3D shell, where BASELM can be set to eith 2 or 16.

   Card 3

 
  • MCID: material ID defined in *MAT_COHESIVE_TH [2]. If not defined, there is no cohesive fracture processing zone. It is recommended to define MCID for brittle material. 

  • BASELM: base element formulation (see ELFORM)

  • DOMINT=0 for phantom element integration (recommended) [3]

  • FAILCR: criterion for initializing and advancing crack

                    =1: maximum tensile strength. The value is defined in *MAT_COHESIVE_TH with MCID.

​                           This is typically for brittle material.

            ​        =-1: critical effective plastic strain (EPS). The value is defined in FS. If LS>0, the crack

                           advances only when the regularized EPS at the crack tip is greater than FS. [4]

                           This is typically for ductile material.

  • PROPCR: option to determine crack propagation direction

                     =0: maximum principal direction of total strain. Recommended to use FAILCR=1.

                     =2: center of EPS. Recommended to use FAILCR=-1. [5]

  • FS: critical value for FAILCR=-1.

  • LS>0 turns on regularization for FAILCR=-1. It defines the radius of a circular regularization zone (material length scale) in a 2D locally projected domain at crack tip. [4]

  • NC>0 defines number of cracks allowed. NC<0 activates element erosion for cracked XFEM elements.

*SECTION_SHELL_EFG  [6[ex]

  • Section definition for EFG shell element formulation 

   Card 1

 
 
 
 
 
 
 
 
 
  • ELFORM=41 is more suitable for crashworthiness analysis
                    =42 is more suitable for sheet metal forming analysis

*SECTION_SOLID_EFG  [7[ex]

  • Section definition for EFG solid element formulation 

    Card 1

 
  • ELFORM=42 is for tetrahedron background mesh. It is recommended to use this formulation in 3D TET-based adaptive  EFG.

    Card 2 and 3

 
  • IEBT=3 and IDIM=2 are the recommended setting with the best computational efficiency. In case of ELFORM=41 with HEX/PENT mesh, IDIM=-1 has the best efficiency. [8]

  • IPS=1 turns on the pressure smoothing. [9]

*SECTION_SOLID_PERI  [10[ex]

  • Section definition for Peridynamics solid element formulation 

   Card 1

 
 
  • ELFORM=48 defines Peridynamic solid formulation

    • For 3D solid, it automatically detects and supports tetrahedron (TET), hexahedron (HEX) and pentahedron (PENT)​. (see related keywords) [ex]

    • For thin layers in laminate, it automatically detects and supports 3-node triangular and 4-node quadrilateral elements. (see related keywords) [ex]

 

*SECTION_SOLID_SPG  [ex]

  • Section definition for SPG solid element formulation 

   Card 1

 
  • ELFORM=47 defines SPG solid formulation. It accepts FEM solid mesh as input, and automatically converts the FEM nodes to SPG particles. Note that ESORT in *CONTROL_SOLID must be zero when using SPG. Otherwise, the code runs the simulation with FEM, no matter the section is flagged to SPG or not.

   Card 2​

  • DX, DY DZ: define the normalized support sizes in x-, y-, z-directions. [11] Default values are recommended.

  • KERNEL: defines the type of kernel approximation. [12]

  • SMSTEP: defines the interval of time steps to perform kernel update. [13] Default value is recommended.

   Card 3

 
  • IDAMFS & STRETCH defines SPG material failure model. [14]

  • ISC defines particle-based self contact. [15]