# RR 22.02.00-4.3 Results Along a Cut Line

Stresses that are continuous across element boundaries and forces which are equilibrium can now be obtained any arbitrary cut line for elements in the Post Processing workflow.

Given a finite element, ABCD, which is subject to a set of stresses, it is possible using mechanics theory to cut that element along an arbitrary line, EF, and resolve the forces at the cut surface.

However, the forces of adjacent finite elements obtained this way are not balanced (i.e., not in equilibrium) and the stress values are discontinuous across element boundaries.

STAAD.Pro has stress result options for cut lines which employ a method of mathematically processing the FEA stress results which are then in equilibrium against the cross-section forces and are continuous across element boundaries. The cut line coordinate system, STR, is used (i.e., a local coordinate system with S as the axis along the cut line, T in the plane of the elements, and R normal to those elements).

The following nomenclature is used for the cut line-oriented results available in STAAD.Pro:

- St
- Normal stress perpendicular to the cut line,
σ
_{t}. - Sts
- Shear stress along the cut line, τ
_{t}. - Mt
- Bending moment along the cut line, M
_{t}. - Mts
- Bending Moment about the T axis. This is in the plane of the plate and perpendicular to the cut line (i.e. the S axis).
- Qt
- Out-of-plane shear, Q
_{t}

Forces listed in the table when these results are selected are given in the in a coordinate system relative to the cut line (i.e., "FS" is along the cut line, "FT" is in the plane of the element, and "FR" is normal to the element). This is indicated by the "-Line" suffix of the results.

- Fs
- Resultant force along the cutline
- Ms
- Resultant moment about the cutline
- Ft
- Resultant force perpindicular to the culine in the plane of the plate
- Mt
- Resultant moment about the line perpindicular to the cutline in the plane of the plate
- Fr
- Resultant force perpindicular to the cutline out of the plane of the plate
- Mr
- Resultant moment about the line perpindicular to the cutline out of the plane of the plate