Name

b2print_rayleigh_damping_coefficients — Print Rayleigh damping coefficients alpha and beta

Synopsis

b2print_rayleigh_damping_coefficients [options] DBNAME

Description

The b2print_rayleigh_damping_coefficients utility program computes the Rayleigh damping coefficients from the first two free-vibration modes in DBNAME. These coefficients can be used for a dynamic analysis or a static analysis with artificial damping (refer to Section 4 and to Undamped Free Vibration Solver). The program is launched from a shell.

If no free-vibration modes are found in the database, an error message is printed.

Arguments

DBNAME

The B2000++ database (required); it must contain at least two free-vibration modes.

Options

--case=case

Restrict output to free-vibration modes of analysis case case.

--zeta1=value

Critical damping ratio for the first free-vibration mode. Default is 0.001.

--zeta2=value

Critical damping ratio for the second free-vibration mode. Default is 0.001.

Examples

Print the coefficients with the default values for the critical damping:

$ b2print_rayleigh_damping_coefficients cylinder.b2m

case            4
rayleigh_alpha +1.61772e+00
rayleigh_beta  +6.18883e-07

Print the coefficients with higher values for the critical damping:

$ b2print_rayleigh_damping_coefficients --zeta1=0.002 --zeta2=0.002 cylinder.b2m

case            4
rayleigh_alpha +3.23544e+00
rayleigh_beta  +1.23777e-06