Section recorders - eesd-epfl/OpenSees GitHub Wiki
Any section output can be asked with usual syntax (forceAndDeformation, force, deformation, fiber outputs, others). An example of a fibre output that can be asked to any uniaxial material is provided in the following
recorder Element -file "fName1" -ele $eTag section $sNum fiber $y $z $mTag stress
recorder Element -file "fName2" -ele $eTag section $sNum fiber $y $z $mTag strain
recorder Element -file "fName3" -ele $eTag section $sNum fiber $y $z $mTag tangent
Parameters:
| fName | string defining the output name, usually, but not necessarily, in format “.out” |
| eTag | element to output. Also ranges or multiple elements can be passed to the same recorder |
| sNum | section number. The ordering, starting from 1, is base-element-end section. If omitted, the required output is returned for all sections |
| y, z | local coordinates of the requested fibre |
| mTag | tag of the requested material (in composite sections more than one material can be found at the same location) |
If the section type is “NoTension3d” (i.e. also in every case in which no section model is directly passed to the element), additionally, the section can record the current value of the state variables controlling the crushing behaviour. The output is requested indifferently as “crushing”, “state”, or “muZeta”. The returned parameters are μ, or the ductility demand, and ζ representing the ratio between the crushed portion and the length of the section, for both section corners, relative to the i-th slice. In symbols:
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If the user is interested to a particular “slice” i in which the section is divided, this can be specified in the recorder; if no slice is specified, as a default option, the central slice is returned. In the first example the state parameters of all three sections, for the central slice, are returned. In the second example, the state parameters of the third section (ordering: sectionI, sectionE, sectionJ), for the fifth slice are returned (slice numbering starts from 1, at the negative side along local axis z)
# only for NoTensionSection3d
recorder Element -file "fName1" -ele $eTag section crushing
recorder Element -file "fName2" -ele $eTag section 3 crushing 5