4.2.3.11. Elastic Pipe Element

A 3D pipe element can be used for piping network. This element can consider internal pressure, thermal effects, shear deformation, and should be used with Pipe Material and Pipe Section.

The temperature is set through setNodeTemperature command.

element('Pipe', eleTag, *eleNodes, pipeMatTag, pipeSecTag, <'-T0', T0>, <'-p', p>, <'-noThermalLoad'>, <'-noPressureLoad'>)

eleTag (int)	unique element object tag
eleNodes (list (int))	a list of two element nodes
pipeMatTag (int)	identifier for previously-defined Pipe Material
pipeSecTag (int)	identifier for previously-defined Pipe Section
T0 (float)	the stress-free temperature, which must follow the option '-T0' and will be added to the average temperature for the element. Default is 0.
p (float)	the internal pressure, which must follow the option '-p'. The internal pressure will affect the axial deformation for the straight pipe element. Default is 0.
'-noThermalLoad' (str)	Do not include the load due to thermal effects. Default is to include.
'-noPressureLoad' (str)	Do not include the load due to internal pressure effects. Default is to include.

Note

Only the uniform load is accepted by the pipe elements for applying the gravity load. Different to regular eleLoad, the load values are interpreted in the global coordinate system as it’s convenient for the curved pipe elements. For example,

ops.eleLoad('-ele', *eleTags, '-type', '-beamUniform', wy, wz, wx)

where wy, wz, and wx are the member load per length in the global axes.

Note

The element responses can be obtained by

res = ops.eleResponse(ele, 'sectionI')
res = ops.eleResponse(ele, 'sectionC')
res = ops.eleResponse(ele, 'sectionJ')
res = ops.eleResponse(ele, 'sectionX', perc)

where the commands above return the section forces at node I, center, node J, or any section X.

• perc = -1: section I, i.e. \(\theta = -\theta_0\)

• perc = 0: center section, i.e. \(\theta = 0\)

• perc = 1: section I, i.e. \(\theta = \theta_0\)

• other perc: section at \(\theta = perc \times\theta_0\)