GEOMETRY_SEED_COORDINATE

Geometries

*GEOMETRY_SEED_COORDINATE
"Optional title"
gid
$x$, $y$, $z$, $\alpha_c$, pid

Parameter definition

Variable
Description
gid
Geometry identification number
$x$
x-coordinate
$y$
y-coordinate
$z$
z-coordinate
$\alpha_c$
Cut-off angle
default: $45^\circ$
pid
Optional part ID
default: not used

Description

This command is used to define a surface from a seed coordinate. The surface propagates from the external element face nearest the given seed coordinate. $\alpha_c$ is the angle between two faces that defines the boundary of the surface (default $\alpha_c = 45^\circ$).

Example

Pipe with varying diameter

Example of a pipe with reduction in diameter. One might want to apply a lower pressure at the section with reduced diameter.

GEOMETRY_SEED_COORDINATE is used to select the inner surfaces of the different sections of the pipe. The Cut-off angle, $\alpha_c$ is used to define the boundaries of the sections and is set to 10, 15 and 10 for the seed coordinates respectively.

*UNIT_SYSTEM SI *PARAMETER R1 = 0.05, "narrow section radius" R2 = 0.10, "wider section radius" t = 0.003, "wall thickness" h1 = 0.10, "height section 1" h2 = 0.15, "height section 2" h3 = 0.25, "height section 3" N = 4, "mesh density parameter" ang = 90, "Pipe angle in circumferential direction" tend = 0.001, "Termination time" *TIME [%tend], , 1.0e-6 *OUTPUT [%tend/5] # # --- MESH --- # *COMPONENT_PIPE 1, 1, 70, [4*%N], 1, , [%ang] 0, 0, [%t], 0, 0, [%h3], [%R1], [%R1+%t] *TRANSFORM_MESH_CYLINDRICAL 1, P, 1, 1, 111, 111 *COORDINATE_SYSTEM_CYLINDRICAL 1, 0, 0, 0 0, 0, 1, 1, 0, 0 *FUNCTION 111 0.5 * H(z-%h1) * (cos(180*min(1,(z-%h1)/(%h2-%h1))) - 1) * (%R1 - %R2) *CHANGE_P-ORDER ALL, 0, 3 *SMOOTH_MESH ALL, 0, 45.0 *MAT_METAL 1, 7800.0, 210.0e9, 0.3 1 *FUNCTION 1 5.0e8 + 5.0e8*epsp^0.3 *PART 1, 1 # # --- GEOMETRY SEED COORDINATES --- # *GEOMETRY_SEED_COORDINATE 1 0, 0, 0.05, 10 *GEOMETRY_SEED_COORDINATE 2 0.025, 0.025, 0.125, 15 *GEOMETRY_SEED_COORDINATE 3 0.05, 0.05, 0.20, 10 # # --- APPLIED PRESSURE --- # *LOAD_PRESSURE 1 G, 1, 1000, 5.0 *LOAD_PRESSURE 2 G, 2, 1000, 7.5 *LOAD_PRESSURE 3 G, 3, 1000, 10.0 *FUNCTION 1000 1e6 *END