/SPHBCS

Block Format Keyword

/SPHBCS - SPH Symmetry Conditions

Description

Describes the SPH symmetry conditions.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/SPHBCS/type/sphbcs_ID
sphbcs_title
Dir	frame_ID	grnd_ID		Ilev

Field	Contents
type	Symmetry condition type: Slide: material is perfectly sliding along the plane Tied: material cannot slide along the symmetry plane
sphbcs_ID	Symmetry condition identifier (Integer, maximum 10 digits)
sphbcs_title	Symmetry condition title (Character, maximum 100 characters)
Dir	Direction: X, Y or Z (Comment 2) (Text)
frame_ID	Reference frame identifier. Must be fixed. (Integer)
grnd_ID	Nodes group identifier for kinematic boundary condition reinforcement (Integer)
Ilev	Formulation level (Integer) = 0: (Real) particles crossing symmetry plane will progressively not be taken into account anymore in the computation. = 1: (Real) particles will rebound on the symmetry plane, following the elastic shock equations (SPH Symmetry Conditions).

1.	The SPH symmetry conditions are insured through the automatic creation of ghost particles, symmetric to the real particles with respect to the symmetry plane.

2.	Dir = "X", "Y" or "Z"

Condition is a symmetry condition with respect to the plane going through the origin of the frame and normal to the local direction "Dir" of the frame.

Particles should lie into the positive semi-space:

where, 0 means the origin of the frame and is the local direction "Dir" of the frame (see the figure below).

3.	For mass consistency, it is recommended for the symmetry plane to be coincident to a plane of the initial net (particles to lie on the symmetry plane at the time t =0).

The nodes group identifier for kinematic boundary condition reinforcement is useful when modelizing axi-symmetry or spherical symmetry conditions through the use of several SPH symmetry conditions. For a description of how to use SPH symmetry conditions to model axi-symmetry or spherical symmetry conditions, refer to SPH Symmetry Conditions.

Symmetry plane for the SPH symmetry condition