NEHRP Clearinghouse

Free Vibration Tests of Structural Concrete Walls and Analysis of Free Vibration Tests of Structural Walls.
Oesterle, R. G.; Fiorato, A. E.; Aristizabal-Ochoa, J. D.
National Science Foundation, Washington, DC. Engineering and Applied Science., February 1980, 42 p.
This report describes experimental free vibration tests and results conducted during lateral load tests to determine frequency and damping characteristics of isolated wall specimens. This study is part of an experimental and analytical investigation of structural walls for earthquake-resistant buildings in which large isolated reinforced concrete wall specimens are tested under reversing in-plane lateral loads. Initial tests were conducted on specimens before applying lateral loads, whereas final tests were performed on specimens that had been cycled through large inelastic deformations. The report details test specimens, the test procedure, and test results. Small amplitude free vibration tests of isolated structural walls indicate that frequency and damping characteristics are sensitive to the development of structural cracks in the walls. With increasing damage levels, frequency decreases and damping increases. These observations need to be considered in analyzing the dynamic response of reinforced concrete wall systems.
Dynamic response; Earthquake engineering; Earthquake resistant structures; Lateral pressure; Vibration; Reinforced concrete; Walls; Concrete construction; Resonant frequency; Dynamic structural analysis