Basic principles (BS 5950)
Tekla Structural Designer calculates both relative and absolute deflections. Relative deflections measure the internal displacement occurring within the length of the member and take no account of the support settlements or rotations, whereas absolute deflections are concerned with deflection of the structure as a whole. The absolute deflections are the ones displayed in the structure deflection graphics. The difference between relative and absolute deflections is illustrated in the cantilever beam example below.
Relative deflections are given in the member analysis results graphics and are the ones used in the member design.