Title: Damping Characteristics of Prestressed Concrete
Author(s): Joseph Penzien
Publication: Journal Proceedings
Appears on pages(s): 1125-1148
Reports on an investigation to determine the basic damp ing characteristics of prestressed concrete beams under dynamic loading. The basic structural parameters varied in the experiment were: type of prestress, intensity of prestress, and ultimate strength of concrete. The dynamic conditions imposed on each specimen were steady state forced vibration and free vibration about the static unloaded equilibrium position. Internal damping was observed to depend a great deal on loading history and on amplitude of displacement. was also observed that cracking of concrete is an important parameter. Therefore, magnitude and type of prestress have an indirect influence on damping since they control cracking to a considerable extent. Most of the equivalent viscous damping factors measured ranged, from 0.5 to 7.0 percent of critical values depending on the degree of cracking permitted in each test.