Summary Of The Dissertation Submitted In Partial Satisfaction Of The Requirements For The Degree Of Doctor Of Philosophy

Summary of the Dissertation[s] Submitted in Partial Satisfaction of the Requirements for the Degree of Doctor of Philosophy

The Analysis of Nonlinear Feedback Sampled-data Systems

Various techniques are available for the analysis of nonlinear sampled-data systems. Most of these methods use either the phase plane approach or the describing function technique. Since the performance of such a system is described, at sampling instants, by means of a difference equation, an approach based on the difference equation would seem to be both natural and direct. The principle of complex convolution for a transform is explained and its geometrical interpretation is given. It is shown how the application of the convolution transform is both direct and simple with respect to solving nonlinear difference equations when the equation is given in scalar form. Dependence of the convergence of the solution on the initial value and the degree of nonlinearity is pointed out. It is concluded that for difference equations of second order and higher, this method involves too much laborious computation to justify its use. A simple method is presented for examining free oscillations in a sampled-data system containing either relay or a saturating amplifier. In addition, a certain analytical technique, analogous to that for differential equations, is developed to investigate the stability of forced oscillations for certain types of nonlinear difference equations. (Author).

Seismic Behaviour of Ground and Geotechnical Structures: Special Volume of TC 4

Containing papers from the Special Technical Session on Earthquake Geotechnical Engineering, this volume includes coverage of: zonation maps; liquefaction; side effects; ground motions; slope instability; seismic behaviour of slopes; dikes and dams; and warning systems.