1. But

Create a list of modal depreciations calculated according to the RCC -G rule. The calculation is carried out by post-processing the modal calculation of a building-type structure whose base rests on a ground modelled by springs.

The principle of the calculation is to weight by the potential energy rates (in relation to the total energy) reduced dampenings affected by groups of cells constituting the structure (in fact input parameters of the potential energy table created by POST_ELEM) and dampenings radiated in the ground, by degree of freedom, by degree of freedom, functions of frequency [bib1] [bib2] [R4.05.01].

There is also the alternative possibility of directly creating a list of modal dampenings by calculated frequency of a mode_meca concept. This list depends both on the values of the frequencies of the mode and on the coefficients involved in the expression of Rayleigh damping.

A mode for automatically correcting calculated depreciations is also available.

The list created can then be used in the command DYNA_TRAN_MODAL [U4.53.21] behind the keyword LIST_AMOR.

Produces a listr8 concept.