Storey displacements and forces

This dialog is accessible from the Tools > Storey displacements and forces and View > New chart view > Storey displacements and forces menu commands. When accessed from the Tools menu tabular output of storey displacements, drifts or forces is produced; when accessed from the View menu, storey output is displayed on charts. Output is in global axis directions.

Definition

Storey displacements

This option calculates the displacements of the each storey and reports in-plane displacements and rotation about the global z axis.

Storey drifts

This option calculates the relative displacements of the each storey and reports in-plane displacements and rotation about the global z axis.

Storey forces

The storey forces are calculated at mid-storey height. The structure is cut at this level and the force summed on the cutting plane.

Force calculation

To provide more control over the force calculation the elements to be considered can be specified (for example to select a single core in a building). By default the force/moment calculations are about the global origin, but this can be offset if this is convenient. Where the model contains 2D elements there is an option to use averaged 2D stresses to calculate storey forces, otherwise unaveraged stresses are used.

Result case

This allows any analysis or combination case (provided it has a single permutation) to be selected for which the displacements of forces will be calculated.

Storey drift and displacement calculations are calculated from the average of all the selected nodes on that storey. Rotations are about the centre of mass of the storey.

If the selected case is a response spectrum cases, the displacement/drift will be calculated for each mode individually and these results combined using the appropriate combination method for that case.