PSLDX6

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

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSLDX6 PID I NIP I I I DN QS  
  QB HV DTMIN CID IP I      
  Vx Vy Vz THETA          

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PSOLID 77 7              
PSLDX6 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.
Default as defined by XSOLPRM (Integer)
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.
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.
  
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).
Default as defined by XSOLPRM (Integer)
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).
  
I Reduced pressure integration flag (I=14 and 24 only).
ON
OFF (Default)
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, and 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.

Default = 0.1 (0.0 ≤ Real ≤ 0.15)

  
DTMIN Minimum time step.

Default = 0.0 (Real)

  
CID Coordinate system identification number to define orthotropic directions.

(Integer ≥ 0)

  
IP Reference plane.
0 (Default)
Use CID (CID must be different from 0)
1
Plane (r,s) and angle THETA
2
Plane (s,t) and angle THETA
3
Plane (t,r) and angle THETA
11
Plane (r,s) and orthogonal projection of reference vector (Vx, Vy, and Vz) on plane (r,s)
12
Plane (s,t) and orthogonal projection of reference vector (Vx, Vy, and Vz) on plane (s,t)
13
Plane (t,r) and orthogonal projection of reference vector (Vx, Vy, and Vz) on plane (t,r)

(Integer)

  
I Orthotropic system formulation flag.
0
The first axis of orthotropy is maintained at constant angle with respect to the orthonormal co-rotational element coordinate system.
1
The first orthotropy direction is constant with respect to a non-orthonormal isoparametric coordinates.

(Integer)

  
Vx X component for reference vector.

(Real)

  
Vy Y component for reference vector.

(Real)

  
Vz Z component for reference vector.

(Real)

  
THETA Orientation angle in degrees of orthotropic with first reference plane direction.

Default = 0.0 (Real)

  

Comments

  1. The property identification number must be that of an existing PSOLID Bulk Data Entry. Only one PSLDX6 property extension can be associated with a particular PSOLID.
  2. PSLDX6 is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS=EXPDYN. It is ignored for all other subcases.
  3. PSLDX6 is only compatible with 8-node linear solid elements. Quadratic 20-node brick and 6-node pentahedron elements are not compatible, these element types should only be used with PSOLIDX.
  4. The I flag is not used with CTETRA elements. For elements with 4 and 10 nodes, the number of integration points is fixed at 1 and 4, respectively.
  5. 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.
  6. With the small strain option (I), strain and stress is engineering strain and stress. Otherwise, it is true strain and stress.
  7. In time history and animation files, the stress tensor is written in the co-rotational frame.
  8. Fully-integrated elements (I=12) only use full geometric non-linearity (corresponds to I=4). Time step limit has no effect.
  9. The time step control XSTEP, TYPEi=SOLID, TSCi=CST only works on elements with I=2.
  10. 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.
  11. For 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).
  12. For 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.
  13. The hourglass formulation is viscous for I=0, 1, and 2.
  14. Hourglass viscosity coefficient, HV is not active with 8 point integration.
  15. This card is represented as an extension to a PSOLID property in HyperMesh.