PSOLID

Bulk Data Entry

PSOLID – Solid Element Property

Description

Defines the properties of solid elements, referenced by CHEXA, CPENTA, CPYRA and CTETRA bulk data entries.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
PSOLID	PID	MID	CORDM			ISOP	FCTN	DS

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
PSOLID	2	100						1

Field	Contents
PID	Unique solid element property identification number. No default (Integer > 0)
MID	Identification number of a MAT1, MAT4, MAT5, MAT9, MAT10, MATHE or MATPE1 bulk data entry. No default (Integer > 0)
CORDM	MID of material coordinate system. The default is 0, which is the basic coordinate system. Default = 0 (Integer > -1)
ISOP	Special integration schemes for elasto-plastic small displacement nonlinear analysis. The values available are: FULL – full integration, using the same integration schemes as for linear applications. MODPLAST – (default) uses special handling of pressure approximation, designed to circumvent the volumetric locking due to incompressibility of plastic flow. The specific details differ depending on the type and order of the element. REDPLAST – besides special handling for pressure approximation, uses reduced integration for second-order hexa and penta, and for 8-noded hexa elements (reduced integration is not practically viable in other element types, since it would create extensive spurious modes). See comments 1 and 2. (Character: FULL, MODPLAST, REDPLAST or blank)
FCTN	Fluid element flag. SMECH indicates a structural element. PFLUID indicates a fluid element. The MID must reference a MAT10 entry. PORO indicates poro-elastic material. The MID must reference a poro-elastic material entry. Default = SMECH (SMECH, PFLUID or PORO)
DS	Design switch. If non-zero, the elements associated with this PSOLID data are included in the topology design volume or space. Not valid for fluid elements. Default = blank (Integer or blank)

Comments

1.	Special integration flags MODPAST and REDPLAST affect only elasto-plastic materials (as identified by presence of MATS1) in nonlinear quasi-static subcases. They do not affect element behavior in linear analysis.

The FULL option in the ISOP field provides stable and convergent results, although it may appear “stiff” and converge rather slowly in cases of significant plastic deformation. MODPLAST uses special handling for volumetric pressure term, in effect providing good resolution of plastic flow while avoiding excessive flexibility that would lead to spurious modes. REDPLAST adds further release of locking tendencies and usually the “softest” behavior. It may, theoretically, exhibit spurious deformation modes in single unattached elements, although in practice these modes should vanish in fields of many elements.

Stresses are calculated in the material coordinate system. The material coordinate system may be defined as the basic coordinate system (CORDM = 0), a defined system (CORDM = Integer > 0), or the element coordinate system (CORDM = -1). Refer to the CHEXA, CPENTA, CPYRA and CTETRA pages of the Reference Guide for details on how the material coordinate system is defined for each element.

4.	If the material referenced by MID is a MAT9 material definition, then CORDM defines the material coordinate system for Gij on the MAT9 entry.

5.	If MID references a MATHE Bulk Data Entry, then only the PID and MID fields are utilized. The remaining fields are not used.

6.	This card is represented as a property in HyperMesh.