Model modifiers for modal and seismic calculation
As indicated in paragraph 4.3.1 of EC 1998-1 the elastic flexural and shear stiffness properties of concrete and masonry elements should be reduced to half to take into account effect of cracking of the load baring elements during seismic calculation. In the past this was task not easy to do.
Watch this webinar to see a new option in SCIA Engineer 21 that allows you to use model modifiers for seismic load cases and modal calculations. As a result, you may easily verify the impact of stiffness reduction on the eigen frequencies of the structure.