PSLDX6

Bulk Data Entry

PSLDX6 – Optional SOLID Property Extension for Geometric Nonlinear Analysis

Description

Defines additional orthotropic SOLID properties for geometric nonlinear analysis.

Format

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

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
PSOLID	77	7
PSLDX6	77	24

Field	Contents
PID	Property identification number of the associated PSOLID. See comment 1. No default (Integer > 0)
ISOLID	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 (ISOLID = 14 and 16 only). Default as defined by XSOLPRM (Integer = ijk) 2 < i, j, k < 9 for ISOLID =14 2 ≤ i, k < 3, 2 < j < 9 for ISOLID =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.
ISMSTR	Small strain formulation flag (ISOLID = 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).
ICPRE	Reduced pressure integration flag (ISOLID = 14 and 24 only). Default = OFF (ON, OFF, or VAR) VAR - Variable state between ICPRE = ON and ICPRE = OFF in function of plasticity state. Only available for elasto-plastic material law.
IFRAME	Element coordinate system formulation flag (ISOLID = 1, 2, 12, and 17 only). Default as defined by XSOLPRM (ON or OFF)
DN	Numerical damping for stabilization (ISOLID =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. Default = 0 (Integer) 0 - 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)
IORTH	Orthotropic system formulation flag. (Integer = 0 or 1) 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.
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 ISOLID 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 (SOLID =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 (ISMSTR), 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 (ISOLID =12) only use full geometric non-linearity (corresponds to ISMSTR = 4). Time step limit has no effect.

9.	The time step control XSTEP, TYPEi = SOLID, TSCi = CST only works on elements with ISMSTR =2.

10.

Co-rotational formulation: For ISOLID = 1, 2, 12 and IFRAME = 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 (ISOLID = 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 ISOLID = 12. The HA8 formulation is compatible with all material laws. Under-integration for pressure should be used (ICPRE = ON in case of elastic or visco-elastic material; ICPRE = VAR in case of elasto-plastic material).

12.	For H8C (SOLID = 17) elements: Their brick deviatoric behavior is the same as ISOLID = 12, but the bulk behavior can be chosen with ICPRE, and is compatible with all solid type material laws. ICPRE = VAR is the default value and ICPRE = OFF will not reduce pressure integration.

13.	The hourglass formulation is viscous for ISOLID = 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.