PSHELLX

Bulk Data Entry Defines additional SHELL properties for geometric nonlinear analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSHELLX PID ISHELL ISH3N ISMSTR NIP HM HF HR  
  DM DN ITHICK IPLAS          

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSHELL 73 7 1.0 7   7      
PSHELLX 73 24     5        

Definitions

Field Contents SI Unit Example
PID Property ID of the associated PSHELL. 1

No default (Integer > 0)

  
ISHELL CQUAD4 element formulation flag.
Default as defined by XSHLPRM (Integer)
=1
Q4, visco-elastic hourglass modes orthogonal to deformation and rigid modes (Belytschko).
=2
Q4, visco-elastic hourglass without orthogonality (Hallquist). Is incompatible with NIP=1.
=3
Q4, elastic-plastic hourglass with orthogonality.
=4
Q4 with improved type 1 formulation (orthogonalization for warped elements).
=12
QBAT or DKT18 shell formulation.
=24
QEPH shell formulation.
  
ISH3N CTRIA3 element formulation flag.
Default as defined by XSHLPRM (Integer)
=1
Standard triangle (C0).
=2
Standard triangle (C0) with modification for large rotation.
=30
DKT18.
=31
DKT_S3.
  
ISMSTR Shell small strain formulation flag.

Default as defined by XSHLPRM (Integer)

1
Small strain from time = 0.
2
Full geometric non-linearity with optional small strain formulation activation by time step XSTEP, TYPEi=SHELL, TSCi =CST.
3
Alternative small strain formulation from time = 0 (ISHELL=2 only).
4
Full geometric non-linearity (Time step limit has no effect).
  
NIP Number of integration points through the thickness.
0
Defines global integration is only compatible with MAT1, MATS1, MATX02, and MATX36.
1
Membrane only behavior happens for MAT1; otherwise, NIP is ignored and NIP=0 is used.

Default as defined by XSHLPRM (0 ≤ Integer ≤ 10)

  
HM Shell membrane hourglass coefficient (ISHELL=123, and 4 only).

Default = 0.01 (Real, 0.0 ≤ HM ≤ 0.05)

Except ISHELL=3: Default = 0.1 (Real)

  
HF Shell out of plane hourglass coefficient (ISHELL=1, 2, 3, and 4 only).

Default = 0.01 (0.0 ≤ Real ≤ 0.05)

  
HR Shell rotation hourglass coefficient (ISHELL=1, 2, 3, and 4 only).

Default = 0.01 (0.0 ≤ Real ≤ 0.05)

Except ISHELL=3: Default = 0.1 (Real)

  
DM Shell membrane damping (with MATX27 and MATX36 only).

Default: 7(Real)

  
DN Shell numerical damping (ISHELL=12, 24, ISH3N=30 only).

Default: See Comment 8 (Real)

  
ITHICK Shell resultant stresses calculation flag.
Default as defined by XSHLPRM (CONST or VAR)
CONST
Thickness is constant.
VAR
Thickness change is taken into account. The small strain option is automatically deactivated. It is recommended to use IPLAS=NEWT.
  
IPLAS Shell plane stress plasticity flag (with MATX2, MATX27, and MATX36 only).
Default as defined by XSHLPRM (RAD or NEWT)
RAD
Radial return.
NEWT
Iterative projection with 3 Newton iterations. The small strain option is automatically deactivated.
  

Comments

  1. The property identification number must be that of an existing PSHELL Bulk Data Entry. Only one PSHELLX property extension can be associated with a particular PSHELL.
  2. PSHELLX is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS=EXPDYN. It is ignored for all other subcases.
  3. Q4: Original 4 node OptiStruct shell with hourglass perturbation stabilization.

    QEPH: Formulation with physical hourglass stabilization for general use.

    QBAT: Modified BATOZ Q4g 24 shell with 4 Gauss integration points and reduced integration for in-plane shear. No hourglass control is needed for this shell.

    DKT18: BATOZ DKT18thin shell with 3 Hammer integration points.

  4. If the small strain option (ISMSTR) is set to 1 or 3, engineering strain and stress are used; otherwise they are true strain and stress.
  5. For MATX2, the default value for IPLAS and global integration (NIP=0) is IPLAS=RAD.
  6. For MATS1, MATX36 the default value for IPLAS and global integration (NIP=0) is IPLAS=NEWT.
  7. Defaults for DM:
    Material Element Type ISHELL/ISH3N Default
    MATX27 except QEPH, QBAT except 12, 24 5%
    QEPH 24 1.5%
    QBAT 12 0%
    MATX36 except QEPH except 24 0%
    QEPH 24 1.5%
  8. Defaults for DN:
    Element Type ISHELL/ISH3N Default Usage
    QBAT 12 0.1% All stress terms, except transverse shear.
    QEPH 24 1.5% Hourglass stress.
    DKT18 12/30 0.01% Membrane stress only.
  9. This card is represented as an extension to a PSHELL property in HyperMesh.