XSOLPRM

Bulk Data Entry

XSOLPRM – Default SOLID Properties for Geometric Nonlinear Analysis

Description

Defines default SOLID properties for geometric nonlinear analysis.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
XSOLPRM	ISOLID	ISMSTR	IFRAME	NIP

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
XSOLPRM	24			222

Field	Contents
ISOLID	Solid elements formulation flag. Default = 1 for explicit analysis and 14 for implicit analysis (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. 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. This element uses an hourglass formulation similar to QEPH shell elements. (1 Gauss point) with physical stabilization.
ISMSTR	Small strain formulation flag (ISOLID = 1, 2, 14, and 24 only). Default = 4 (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).
IFRAME	Co-rotational element formulation flag (ISOLID = 1, 2, 12, and 17 only). Default = OFF (ON or OFF)
NIP	Number of integration points (ISOLID = 14, 16 only). Default = 222 (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.

Comments

1.	XSOLPRM defines default settings for solid properties that can be overwritten by PSOLIDX.

2.	XSOLPRM is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS = EXPDYN. It is ignored for all other subcases.

3.	The ISOLID 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 (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.

5.	With the small strain option (ISMSTR), 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 (ISOLID =12) only uses full geometric non-linearity (corresponds to ISMSTR = 4). Time step limit has no effect.

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

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.

10.

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.

11.	The hourglass formulation is viscous for ISOLID = 0, 1, and 2.

12.	This card is represented as a control card in HyperMesh.