PSOLIDX

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

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSOLIDX PID I NIP I I I DN QS  
  QB HV DTMIN LAMBDAV MUV I      

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSOLID 77 7              
PSOLIDX 77 24              

Definitions

Field Contents SI Unit Example
PID Property identification number of the associated PSOLID. 1

No default (Integer > 0)

  
I Solid elements formulation flag.
1
Standard 8-node solid element, 1 integration point. Viscous hourglass formulation with orthogonal and rigid deformation modes compensation (Belytschko).
2
Standard 8-node solid element, 1 integration point. Viscous hourglass formulation without orthogonality (Hallquist).
12
Standard 8-node solid, full integration (no hourglass).
14
HA8 locking-free 8-node solid element, co-rotational, full integration, variable number of Gauss points.
16
Quadratic 20-node solid, full integration, variable number of Gauss points.
17
H8C compatible solid full integration formulation.
24
HEPH 8-node solid element. Co-rotational, under-integrated (1 Gauss point) with physical stabilization. This element uses an hourglass formulation similar to QEPH shell elements.

Default as defined by XSOLPRM (Integer)

  
NIP Number of integration points (I=14 and 16 only).

Default as defined by XSOLPRM (Integer = ijk)

2 ≤ i, j, k ≤ 9 for I =14

2 ≤ i, k ≤ 3, 2 ≤ j ≤ 9 for I =16

Where,
i
Number of integration points in local x direction.
j
Number of integration points in local y direction.
k
Number of integration points in local z direction.
  
I Small strain formulation flag (I=1, 2, 14, and 24 only).
1
Small strain from time = 0.
2
Full geometric non-linearity with small strain formulation activation by time step.
3
Simplified small strain formulation from time=0 (non-objective formulation).
4
Full geometric non-linearity. Time step limit has no effect.
10
Lagrange type total strain. Only compatible with materials using total strain formulation (MATX42).

Default as defined by XSOLPRM (Integer)

  
I Reduced pressure integration flag (VAR=14, 17, and 24 only).

Default = OFF for I=14, 24, ON for I=17 (ON, OFF, or VAR)

VAR - Variable state between I=ON and I=OFF in function of plasticity state. Only available for elasto-plastic material law.

  
I Element coordinate system formulation flag (I=1, 2, 12, 17 only).

Default as defined by XSOLPRM (ON or OFF)

  
DN Numerical damping for stabilization (I=24 only).

Default = 0.1 (Real)

  
QS Quadratic bulk viscosity.

Default = 1.1 (Real)

  
QB Linear bulk viscosity.

Default = 0.05 (Real)

  
HV Hourglass viscosity coefficient. Is not active with 8 point integration.

Default = 0.1 (0.0 ≤ Real ≤ 0.15)

  
DTMIN Minimum time step.

Default = 0.0 (Real)

  
LAMBDAV Numerical Navier Stokes viscosity λ

No default (Real)

  
MUV Numerical Navier Stokes viscosity μ

No default (Real)

  
I Hourglass tangent modulus flag (I=24 only)
1 (Default)
Elastic modulus or numerical tangent modulus estimation.
2
Advanced tangent modulus estimation.
  

Comments

  1. The property identification number must be that of an existing PSOLID Bulk Data Entry. Only one PSOLIDX property extension can be associated with a particular PSOLID.
  2. PSOLIDX is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS=EXPDYN. It is ignored for all other subcases.
  3. The I flag is not used with CTETRA elements. For these elements with four and ten nodes, the number of integration points is fixed at one and four, respectively.
  4. For fully integrated solids (I=12), the deviatoric behavior is computed using 8 Gauss points; bulk behavior is under-integrated to avoid element locking. It is currently compatible with material MAT1, MATS1, MATX33, and MATX36.
  5. With the small strain option (I), strain and stress is engineering strain and stress. Otherwise, it is true strain and stress.
  6. In time history and animation files, the stress tensor is written in the co-rotational frame.
  7. Fully integrated elements (I=12) only uses full geometric non-linearity (corresponds to I=4). Time step limit has no effect.
  8. The time step control XSTEP, TYPEi=SOLID, TSCi=CST only works on elements with I=2.
  9. Co-rotational formulation: For I=1, 2, 12 and I=ON, the stress tensor is computed in a co-rotational coordinate system. This formulation is more accurate if large rotations are involved. It comes at the expense of higher computation cost. It is recommended in case of elastic or visco-elastic problems with important shear deformations. The co-rotational formulation is compatible with 8 node solids.
  10. HA8 (I=14) elements: this element uses a locking-free general solid formulation, co-rotational. The number of Gauss points is defined by NIP flag: for example, combined with NIP=222 gives an 8 Gauss integration point element, similar to I=12. The HA8 formulation is compatible with all material laws. Under-integration for pressure should be used (I=ON in case of elastic or visco-elastic material; I=VAR in case of elasto-plastic material).
  11. H8C (I=17) elements: Their brick deviatoric behavior is the same as I=12, but the bulk behavior can be chosen with I, and is compatible with all solid type material laws. I=VAR is the default value and I=OFF will not reduce pressure integration.
  12. The hourglass formulation is viscous for I=0, 1, and 2.
  13. It is recommended to use I=2 (I=24) and Lagrange type total strain, I=10 for foam or rubber materials, like MATX42 and MATX82. For elasto-plastic type material, I=2 will have a tighter yield stress criterion for an hourglass stress computation.
  14. This card is represented as an extension to a PSOLID property in HyperMesh.