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Lab Room | Theory Map | Vibrational Parameters | LSQVIB

LSQVIB

LSQVIB is a program written in BASIC for ME 107A that provides estimates of the system parameters of a simple lumped-parameter spring-mass-diamper oscillator through a least squares fit of the steady state solution under harmonic excitation to measurements of forced response. LSQVIB returns undamped natural frequency, the damping ratio, and static signal amplitude.

LSQVIB takes input data pairs of, period and amplitude, Ai

where:

It then returns natural frequency, damping ratio, the static signal amplitude, a plot of the input data and curve fit, and a data file.

Tip: Take as many data points as you can around =1.

Tip: The frequency estimate has units equivalent to the inverse of the input period (e.g., Hz if seconds are input).

Tip: It is possible for the least squares procedure to return a value of less than zero. In this case, the damping coefficient is set equal to zero for future calculations and it is suggested that the data be examined for consistency.


Last Updated: January 16, 2000, beam@bits.me.berkeley.edu
Copyright © 1993-1995, 2000, Pamela A. Eibeck and Brandon Muramatsu
Original WWW Conversion by Winston Wang, 1994
WWW ReConversion by Brandon Muramtasu, 2000