A bridge structure is modeled as a single-degree-of-freedom system with an
equivalent mass of 5×105 kg and an equivalent stiffness of 25×106 N/m. During a
free-vibration test, the ratio of successive amplitudes was found to be 1.04. Estimate
the structural damping constant and the approximate free-vibration response of the
bridge if initial displacement and initial velocity are given to the bridge at the start of
free vibration.