The following enhancements are made in this area in Tekla Structural Designer 2020 following customer feedback.
Seismic Wizard and Seismic Combinations - the engineer can now directly specify the use of orthogonal seismic combinations, in which the seismic load cases for both directions are included. Formerly the creation of these was automated only for certain specific types of Structural Irregularity. The new setting to directly activate these combinations is on the Structural Irregularities page of the Seismic Wizard as shown in the picture below.
Seismic Torsion Assessment of Columns & Walls - in previous releases, every column/wall in the model was considered when calculating the effects of Seismic Amplified Accidental Torsion. However, there may be situations in structures where columns/ walls are remote from the core structure and would be ignored for seismic torsion. The inclusions of columns/ walls in this calculation can now be controlled via the checkbox “Drift/Seismic drift checks and consider for seismic torsion”. This can be set both in the Properties Window for all and individual stacks/ panels in the Properties Window and the member edit dialog. When unchecked, the member is not considered for; the assessment of Accidental Torsion; the assessment of Amplified Accidental Torsion.