08-10-2014, 04:00 PM
This study proposes a wavelet-based approach for the estimation of the response of linear and non-linear structural systems which are subjected to an earthquake ground motion process modelled by its wavelet coefficients. An orthogonal wavelet basis function has been proposed for this purpose. The proposed formulation considers a more realistic modelling of the ground motion, and is thus more generalized as compared to the earlier methods based on the use of frequency-independent modulating functions. The linear structures have been idealized by single-degree-of-freedom (SDOF) and classically damped multidegree- of-freedom (MDOF) systems for the purpose of formulation. Expressions have been derived for i) the representation of the input excitation through wavelets, ii) relationship between the wavelet coefficients of the excitation and response processes, and iii) instantaneous mean- square value and power spectral density function (PSDF) of the response. The moments of the PSDF of response are used to predict the response statistics of interest. Non-linear systems with