Guest
2.4.3.4.4 The DAMPING Command for the Input of Modal Damping
Ratios and Damping Proportionality Constants
General form:
Elements:
v1, v2, ..., vn = modaldampingratio (or percents of critical damping). These values
are used as RI in Eq. 2.4.3.4-1. These values must be decimal
numbers.
i1, i2, ..., in = integersindicatingthe numberofmodes in ascending order for which
vi is to be used. The default value is 1. These values must be integer
numbers.
f1, f2 = mass and stiffness damping proportionality constants used in Eq.
4-16, Section2.4.2.4.2 and Eq. 2.4.3.4-6. f1 and f2 mustbe decimal
numbers.
Explanation:
The DAMPING command is used to specify the input modal DAMPING
RATIOS (or PERCENTS ofcriticaldamping) that appear as RI incombinationwithother
stiffnessand mass dampingratios inaccordance withEq. 2.4.3.4-1, or it is used to specify
the mass and stiffness damping factors or proportionality constants that appear in Eq.
2.4.3.4-4 through Eq. 2.4.3.4-6.
Modal DAMPING RATIOS or PERCENTS canbe specified for anynumber of
modes. If more modes are used in a mode superposition solution than the number of