7.2. Rezoning Requirements and Limitations

Rezoning is available for 2D and 3D analyses. All multiframe restart files must be available.

Following are the supported analysis types, elements, materials, loads, boundary conditions, and other rezoning requirements:

Support Category Support Details

Solid elements

Contact elements

  • Pair-based contact only.[e]

  • TARGE169

  • CONTA172 with any of the following valid KEYOPT settings:

    KEYOPT(1) = 0, 1
    KEYOPT(2) = 0, 1, 2, 3, 4
    KEYOPT(3) = 0
    KEYOPT(4) = 0, 1, 2, 3
    KEYOPT(5) = 0, 1, 2, 3, 4
    KEYOPT(6) = 0, 1, 2, 3
    KEYOPT(7) = 0, 1, 2, 3
    KEYOPT(8) = 0 , 2
    KEYOPT(9) = 0, 1, 2, 3, 4
    KEYOPT(10) = 0, 1, 2
    KEYOPT(11) = 0
    KEYOPT(12) = 0, 1, 2, 3, 4, 5, 6
    KEYOPT(14) = 0
    KEYOPT(18) = 0, 1, 2

  • TARGE170

  • CONTA174 with any of the following valid KEYOPT settings:

    KEYOPT(1) = 0, 1
    KEYOPT(2) = 0, 1, 2, 3, 4
    KEYOPT(3) = 0
    KEYOPT(4) = 0, 1, 2, 3
    KEYOPT(5) = 0, 1, 2, 3, 4
    KEYOPT(6) = 0, 1, 2, 3
    KEYOPT(7) = 0, 1, 2, 3
    KEYOPT(8) = 0, 2
    KEYOPT(9) = 0, 1, 2, 3, 4
    KEYOPT(10) = 0, 1, 2
    KEYOPT(11) = 0
    KEYOPT(12) = 0, 1, 2, 3, 4, 5, 6
    KEYOPT(14) = 0
    KEYOPT(18) = 0, 1, 2

Contact pair behavior

  • Rigid-flexible[f]

  • Flexible-flexible

  • Self-contact

Surface-effect elements

Materials
Analysis types

Loads and boundary conditions (BCs)[i][j]

  • Displacements, forces, velocity (transient analysis), acceleration (transient analysis), pressures, and nodal temperatures (BF,TEMP).

  • Tabular displacements, forces, velocity (transient analysis), acceleration (transient analysis), and pressures that are functions of time only.

  • Fluid-penetration loads applied to contact elements (SFE).[k]

  • Translational acceleration inertial loads in the global Cartesian direction (ACEL).

  • Rotational-motion inertia loads (OMEGA, DOMEGA, CGOMGA, DCGOMG, CGLOC).[l]

Region to be remeshed[m]

  • The selected nodes inside the region must have the same nodal coordinate system.

  • Boundary nodes can have different nodal coordinate systems.

  • Elements must be of the same element type, material, element coordinate system, and real constant.

  • If two regions with different attributes require remeshing, remesh the regions separately.[n]

  • Node and element components defined in remesh regions are lost during remeshing.[o]

Files

  • .rst, .rdb, .rdnn , .rnnn (where nnn is the substep in which rezoning is initiated), .ldhi, and .cdb.

[a] B-bar method only (KEYOPT(1) = 0).

[b] All stress states (KEYOPT(3)) are supported: plane strain, plane stress, axisymmetric, and generalized plane strain. Pure displacement formulation (KEYOPT(6) = 0) or mixed u-P formulation (KEYOPT(6) = 1) is supported. Plane stress with tabular input of thickness is not supported.

[c] Layered solid elements (KEYOPT(3) = 1) are not supported.

[d] Works with REMESH,READ only.

[e] General contact is not supported.

[f] Target elements and pilot node cannot be remeshed.

[g] Only normal and tangential pressures applied on SURF153 and SURF154 are supported. (That is, rezoning support is available only for pressure on faces 1 and 2 for SURF153 and pressure on faces 1, 2 and 3 for SURF154.)

[h] For linear analyses with linear elastic materials and small-deflection effects (NLGEOM,OFF), the iterative Newton Raphson solution procedure is set automatically. The smallest possible number of substeps must also be set (either directly via NSUBST or indirectly via DELTIM) to a value that ensures remeshing. Minimum required substeps = 2.

[i] Do not remove nodal constraints (DDELE, FDELE, BFDELE, SFDELE) during solution before rezoning or remeshing. DDELE supports the following degrees of freedom: UX, UY, UZ, ROTX, ROTY, ROTZ, and TEMP in a rezoning analysis.

[j] SFCONTROL Is not supported.

[k] CONTA172, CONTA174.

[l] Component-based inertia loads (CMACEL, CMOMEGA, CMDOMEGA, CMROTATE) are not supported.

[m] Initial state is not supported.

[n] For more information, see Hints for Remeshing Multiple Regions .

[o] Node and element components associated with nonlinear adaptivity criteria are preserved.

The conditions specified apply only to the region to be remeshed. No limitations exist for other regions, although the analysis type itself must support rezoning.