Effect Of Prestress On The Damping Of Concrete PDF Download

Under steady state conditions, internal damping in prestressed concrete members may be less than 1% of critical if the initial prestress is sufficient to prevent tension cracks from developing. If tension cracks are allowed to develop, but on a miscroscopic scale, damping can be expected of the order of 2% of critical. If larger (visible) cracks are permitted to develop, higher damping would result. Under transient conditions, the amount of internal damping present in prestressed concrete members depends to a great extent on the past history of loading and on the amplitude of displacements produced. For those cases where members have been dynamically loaded only a few times to a given stress level which produces considerable cracking, damping can be expected anywhere in the range of 3 to 6% of critical. Magnitude and type of prestress in concrete members have an indirect influence on internal damping only because these parameters control the amount of cracking which can take place. (Author).