The Earthquake Engineering Online Archive

Modeling and identification in nonlinear structural dynamics - I. One degree of freedom models

Distefano, J. Nestor; Rath, Amitav

UCB/EERC-74/15, Earthquake Engineering Research Center, University of California, Berkeley, 1974-12, 104 pages (555.3/D55/1974)

The present research deals with the development of reliable and efficient identification methods for the optimal determination of the model parameters associated with nonlinear characteristics of structural systems undergoing seismic effects. In Part I of the report, we introduce the central ideas of the proposed methodology and give a brief account of the difficulties to be expected in the solution of the problem. In addition, a review of related and previous work is presented. In Part II we introduce the fundamental methodology in the framework of control theory. No previous knowledge of this theory on the part of the reader is assumed in the presentation. Two main methods are introduced here: A filtering approach, which affords a sequential estimation of the state and the parameters, and a successive approximation Gauss-Newton procedure. In Part III we present extensive numerical experimentation involving (a) Nonlinear viscous damping models in terms of both Volterra integral equations and nonlinear differential equations and (b) Nonlinear damping in terms of bilinear hysteretic models.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-74-15.pdf (6 MB)