27 - Modal Damping and Rayleigh Damping Models - ETABS Demonstration on Damping in Dynamic Analysis

[@kumarshantveerayya5114]

Thank you for the excellent explanation, sir. Could you please share the data for time history analysis for the different seismic occurrences?

[@kebzkebz6437]

Hi sir! In specifying Damping by period, Are we going to select the period with Modes in the Orthogonal Directions? Also, I am confused with the Direct Specification. Aren't we supposed to mention Constants? why we have units in sec?

[@andreitudor1813]

The first two modes means from the same direction, most cases 1 with 4.

[@elvisroberto8137]

Good presentation, I wanted to ask about, from which pair of modes is recommended to take the angular frequency, to find the rayleigh damping factors (mass and stiffness)? I have seen documentation where it is usually used between modes 1 and 4 and others that consider between modes 1 and 5. I also wanted to ask why in the example a damping percentage of 0.001 is being considered. Finally, I would like to ask you what you think about the fact that in the USA a maximum damping of 2% is considered for reinforced concrete buildings. thank you in advance

[@janlhesternavasca3160]

Hi, did you find the why 0.001 damping percentage is being considered?