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GEOMETRY_PIPE

Geometries

*GEOMETRY_PIPE
"Optional title"
gid, csysid
$x_1$, $y_1$, $z_1$, $x_2$, $y_2$, $z_2$, $R_1$, $R_2$
$R_3$, $R_4$, $v_x$, $v_y$, $v_z$, $\alpha$

Parameter definition

Variable
Description
gid
Geometry identification number
csysid
Local coordinate system ID
default: global coordinate system is used
$x_1$, $y_1$, $z_1$
Face center coordinate 1
$x_2$, $y_2$, $z_2$
Face center coordinate 2
$R_1$
First radius at face 1
$R_2$
Second radius at face 1
$R_3$
First radius at face 2
default: $R_3 = R_1$
$R_4$
Second radius at face 2
default: $R_4 = R_2$
$v_x$, $v_y$, $v_z$
Radial vector at zero tangential angle
default: not used
$\alpha$
Pipe sector angle
default: $360^\circ$

Description

This command is used to define a straight pipe or cylinder in space, with its face center coordinates at ($x_1$, $y_1$, $z_1$) and ($x_2$, $y_2$, $z_2$). Note that the smaller of $R_1$ and $R_2$ is automatically taken as the inner radius.

pipe
pipe

Example

Different variants of pipe geometries

Example that highlights the various geometries that can be created by using the different parameters in the command.

*UNIT_SYSTEM SI *PARAMETER x1 = 0 y1 = 0 z1 = 0 x2 = 0 y2 = 0.3 z2 = 0 dx = 0.4 R1 = 0.15 R2 = 0.1 *GEOMETRY_PIPE "Cylinder - only specify R1 (R2 is set to 0)" 1 [%x1], [%y1], [%z1], [%x2], [%y2], [%z2], [%R1] *GEOMETRY_PIPE "Pipe - specify both R1 and R2" 2 [%x1+%dx], [%y1], [%z1], [%x2+%dx], [%y2], [%z2], [%R1], [%R2] *GEOMETRY_PIPE "Cone, specify R1 and R3" 3 [%x1+2*%dx], [%y1], [%z1], [%x2+2*%dx], [%y2], [%z2], [%R1] 0.05 *GEOMETRY_PIPE "Pipe with coned interior, specify all R1-R4" 4 [%x1+3*%dx], [%y1], [%z1], [%x2+3*%dx], [%y2], [%z2], [%R1], [%R2] [%R1], 0.05 *GEOMETRY_PIPE "A sector of a pipe. Specify vx, vy, vx and angle" 5 [%x1+4*%dx], [%y1], [%z1], [%x2+4*%dx], [%y2], [%z2], [%R1], [%R2] [%R1], 0.05, 1, 0, 0, 130 *GEOMETRY_PIPE "Sector of a cylinder, drawn from a different radial vector" 6 [%x1+5*%dx], [%y1], [%z1], [%x2+5*%dx], [%y2], [%z2], [%R1] [%R1], 0, 0, 0, 1, 90 *END
Pipe with internal pressure

Example of a pipe with an internal pressure. GEOMETRY_PIPE is used to apply a fixed boundary condition for the outer surface of the pipe.

*UNIT_SYSTEM SI *PARAMETER %tend = 0.01 *TIME [%tend] *OUTPUT [%tend/5] *COMPONENT_PIPE "Pipe with outer radius 0.5 and inner radius 0.4" 1, 1, 6, 10, 1 -2.0, 0.0, 0.0, 2.0, 0.0, 0.0, 0.5, 0.4 *PART 1, 1, , , 45 *MAT_ELASTIC 1, 7800.0, 210.0e9, 0.3 *CHANGE_P-ORDER P, 1, 3 *GEOMETRY_SEED_COORDINATE "Geometry used to apply internal pressure" 2 0.0, 0.0, 0.0, , 1 *LOAD_PRESSURE 2 G, 2, 123 *FUNCTION 123 1e11*(t/%tend) *GEOMETRY_PIPE "Geometry selecting the outer nodes of the pipe" 1 -2.01, 0.0, 0.0, 2.0, 0.0, 0.0, 0.52, 0.48 *BC_MOTION 1 G, 1, XYZ *END