The Earthquake Engineering Online Archive

Earthquake simulator study of a steel frame structure, Vol. II: Analytical results

Tang, David T.

UCB/EERC-75/36, Earthquake Engineering Research Center, University of California, Berkeley, 1975-10, 214 pages (550.3/C58/1975/v.2)

This study presents mainly the development of mathematical models and the verification of response predictions for a three-story single-bay moment-resistant frame structure, using the experimental results observed for the structure tested on the 20 ft x 20 ft shaking table at the Earthquake Engineering Research Center at the Univ. of California, Berkeley. The overall background and the test design for the research program which consisted of two series of experiments are described. In the first series, or Phase I study, the panel zones of the structure were overdesigned. In the Phase II study, the panel zones were reinforced to make the girders and columns the weak elements of the structure. Test results ranging from the small-amplitude vibration properties to the global and local nonlinear responses of the structure, which were used in the analytical studies, are summarized and discussed. Three mathematical models, called Model A, B and C respectively, were developed. However, the model, Model C, which takes into account the interaction between the shaking table and the test structure was considered a rational one from which the pitching motion of the shaking table could adequately be described. By means of Model C, with the damping and the element yield criteria being treated as the main parameters to be prescribed in each computer analysis, the predicted global and local time history responses for both linear and nonlinear tests of the structure subjected to simulated El Centro earthquake motions were compared with those observed during the two phases of tests. The nonlinear response prediction based on a linear analysis procedure was demonstrated for the structure, using an increased viscous damping for the model. The ability of the model in predicting the floor displacement responses of the structure excited by table motions other than the simulated El Centro earthquakes was investigated. Data correlation for the small-amplitude vibration test results was also made. Finally, conclusions are drawn regarding the performance of the test structure, the data correlation and the effect of the parameters of the mathematical models on the response prediction of the structure.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-75-36.pdf (12 MB)