Element Offsets

Another type of constraint that can be applied is in the form of element offsets. These are used where the ends of the element are effectively rigid and it is required to offset the flexible part of the element. The actual element can then be thought of as shorter than the node to node length of the element with the gaps filled in with “rigid links”. Element offsets are most useful where the span of a beam is less that the column to column centre-line distance or where the effect of eccentricity on the element is important.

• Longitudinal offsets can be applied to 1D elements that refer to section properties (beam, bar, rod, strut and tie). A positive offset is taken as the 'inwards' direction at both ends of the element, shortening the flexible part of the element.
• Transverse offsets can be applied to 1D beam elements (local y and z axis offsets) and 2D elements (local z offset)
• Taper offsets are used for 1D tapered elements to indicate which portion of the section taper applies to that element