How can the deformation of a structure be asked for?
As example, we take a look at a simple steel hall with a concrete slab added on the first floor. A uniform service load is applied to the slab and the beams that form the roof.
The displacements of the 1D and 2D member in the structure can be asked for seperately, as well as the deformation of the structure as a whole. You will find here an overview of the different types of results.
1) Absolute deformation of the 1D members wih regard to their LCS
Results > Beams > Deformations on beam, value uz:
Remark that the local z axis (= the blue axis) of each beam is oriented differently. This means that e.g. for the columns the deformation uz represents a horizontal deformation, while for the transverse beams it represents a vertical deformation.
The small characters for the values (ux, uy, uz, …) indicate that they are calculated with regard to the local co-ordinate system.
2) Absolute deformation of the 2D members with regard to the GCS
Results > 2D members > Displacement of nodes, value Uz:
The capitals for the values (Ux, Uy, Uz, …) indicate that they are calculated with regard to the global co-ordinate system. The value Uz thus shows the deformation in the vertical direction, with regard to the global Z axis.
3) Combination of the two above results
Results > Deformed Structure, value Uz/uz:
Remark that the option ‘Structure’ has been put to ‘Mesh’, so that the isoband results are displayed on the deformed slab and coincide with the deformation of the adjoining 1D members.
Don’t forget that for the slab it concerns global deformations (Uz), while for the beams it concerns local deformations (uz).
4) Global deformation of the 1D members
Results > Beams > Deformations on beam, value Deformed structure:
The grey line represents the global deformation of the 1D members, namely the combination of ux, uy, uz, phix, phiy and phiz. Only the relative form is displayed, without mention of absolute values.
Most of the time it is of course ideal to have the option to ask for the global deformation of the total structure (1D and 2D members together). This is discussed in the next paragraph.
5) Global deformation of the total structure
Results > Deformed structure, value Deformed structure:
This result gives insight in how each member deforms with regard to the other members. It is also a quick visual check if all members are correctly connected.
Attention: This result can only be displayed for load cases and simple (‘linear’) combinations!
6) Absolute displacement of the nodes with regard to the GCS
Results > Displacement of nodes, values Ux Uy Uz:
The capitals for the values (Ux, Uy, Uz, …) indicate that they are calculated with regard to the global co-ordinate system.