RADPRM, SH4NRP

Bulk Data Entry Controls the full projection of 4-node shell elements in NLGEOM implicit analysis.

Table 1. Definitions
Parameter Values Description
SH4NRP <0, 1, or 2>

Default = 0 in NLGEOM subcase

Default = 1 in IMPDYN subcase

0
The full projection for warped QEPH shell elements will be deactivated. This option may improve the implicit nonlinear analysis with QEPH warped shell elements, if the rigid rotation of warped elements is small enough.
1
The full projection for warped elements will be applied only to internal force calculation. This option provides accurate results, if it converges successfully, but convergence issues could be encountered with very warped elements.
2
The full projection for warped QEPH shell elements will be activated for the stiffness matrix to stay consistent with the internal force calculation. This option can improve the convergence of implicit nonlinear analysis with QEPH warped shell elements at the cost of some additional calculations.

In the case of finite rigid rotations with warped shell elements, RADPRM, SH4NRP, 1 provides accurate results. If convergence difficulties are encountered, RADPRM, SH4NRP, 2 should be used.

If RADPRM, SMDISP is present, SH4NRP is always set as 0 internally.