A unified formulation of the piecewise exact method for inelastic seismic demand analysis including the P-delta effect
info:
The non-linear analysis of single-degree-of-freedom (SDOF) systems provides the essential background
information for both strength-based design and displacement-based evaluation=design methodologies
through the development of the inelastic response spectra. The recursive solution procedure called the
piecewise exact method, which is effciently used for the response analysis of linear SDOF systems,
is re-formulated in this paper in a uniffed format to analyse the non-linear SDOF systems with multilinear
hysteresis models. The uniffed formulation is also capable of handling the P-delta effect, which
generally involves the negative post-yield stiffness of the hysteresis loops. The attractiveness of the
method lies in the fact that it provides the exact solution when the loading time history is composed
of piecewise linear segments, a condition that is perfectly satisffed for the earthquake excitation. Based
on simple recursive relationships given for positive, negative and zero effective stiffnesses, the uniffed
form of the piecewise exact method proves to be an extremely powerful and probably the best tool for
the SDOF inelastic time-history and response spectrum analysis including the P-delta effect..
non-linear analysis; seismic demand;inelastic response spectra